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Yajbir Singh f1b860b25c
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updated
2025-12-11 19:03:17 +05:30

3485 lines
92 KiB
C

/**
* libpsd - Photoshop file formats (*.psd) decode library
* Copyright (C) 2004-2007 Graphest Software.
*
* libpsd is the legal property of its developers, whose names are too numerous
* to list here. Please refer to the COPYRIGHT file distributed with this
* source distribution.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU Library General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU Library General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
* $Id: boundary.c, created by Patrick in 2006.07.19, libpsd@graphest.com Exp $
*
* Notice: we use some codes form the libart to implement the boundary and stroke,
* but we found there is a bug that causes the segment when it's rendering the boundary,
* and we don't know how to fix it.
*/
#include <stdlib.h>
#include <string.h>
#include <math.h>
#include "libpsd.h"
#include "psd_system.h"
#include "psd_bitmap.h"
#include "psd_color.h"
#include "psd_math.h"
#define PSD_BOUNDARY_THRESHOLD 24
/* BoundSeg array growth parameter */
#define PSD_BOUNDARY_MAX_SEGS_INC 2048
#define PSD_EPSILON 1e-6
#define PSD_EPSILON_2 1e-12
#define PSD_EPSILON_A 1e-5 /* Threshold for breaking lines at point insertions */
#define PSD_M_SQRT2 1.41421356237309504880 /* sqrt(2) */
/* Note: BNEG is 1 for \ lines, and 0 for /. Thus,
x[(flags & BNEG) ^ 1] <= x[flags & BNEG] */
#define PSD_ART_ACTIVE_FLAGS_BNEG 1
/* This flag is set if the segment has been inserted into the active
list. */
#define PSD_ART_ACTIVE_FLAGS_IN_ACTIVE 2
/* This flag is set when the segment is to be deleted in the
horiz commit process. */
#define PSD_ART_ACTIVE_FLAGS_DEL 4
/* This flag is set if the seg_id is a valid output segment. */
#define PSD_ART_ACTIVE_FLAGS_OUT 8
/* This flag is set if the segment is in the horiz list. */
#define PSD_ART_ACTIVE_FLAGS_IN_HORIZ 16
typedef struct _psd_gimp_bound_seg
{
psd_int x1;
psd_int y1;
psd_int x2;
psd_int y2;
psd_bool open;
psd_bool visited;
} psd_gimp_bound_seg;
typedef struct _psd_gimp_boundary
{
/* The array of segments */
psd_gimp_bound_seg * segs;
psd_int num_segs;
psd_int max_segs;
/* The array of vertical segments */
psd_int * vert_segs;
/* The empty segment arrays */
psd_int * empty_segs_n;
psd_int * empty_segs_c;
psd_int * empty_segs_l;
psd_int max_empty_segs;
} psd_gimp_boundary;
typedef struct _psd_vector2
{
psd_double x, y;
} psd_gimp_vector2;
typedef struct _psd_art_point {
/*< public >*/
psd_double x, y;
} psd_art_point;
typedef struct _psd_art_drect {
/*< public >*/
psd_double x0, y0, x1, y1;
} psd_art_drect;
typedef enum {
PSD_ART_MOVETO,
PSD_ART_MOVETO_OPEN,
PSD_ART_CURVETO,
PSD_ART_LINETO,
PSD_ART_END
} psd_art_pathcode;
typedef enum {
PSD_ART_WIND_RULE_NONZERO,
PSD_ART_WIND_RULE_INTERSECT,
PSD_ART_WIND_RULE_ODDEVEN,
PSD_ART_WIND_RULE_POSITIVE
} psd_art_wind_rule;
typedef enum {
PSD_ART_BREAK_LEFT = 1,
PSD_ART_BREAK_RIGHT = 2
} psd_art_break_flags;
/* CURVETO is not allowed! */
typedef struct _psd_art_vpath {
psd_art_pathcode code;
psd_double x;
psd_double y;
} psd_art_vpath;
typedef struct _psd_art_svp_seg {
psd_int n_points;
psd_int dir; /* == 0 for "up", 1 for "down" */
psd_art_drect bbox;
psd_art_point *points;
} psd_art_svp_seg;
typedef struct _psd_art_svp {
psd_int n_segs;
psd_art_svp_seg segs[1];
} psd_art_svp;
typedef struct _psd_gimp_scan_convert
{
psd_double ratio_xy;
psd_bool clip;
psd_int clip_x;
psd_int clip_y;
psd_int clip_w;
psd_int clip_h;
/* stuff necessary for the _add_polygons API... :-/ */
psd_bool got_first;
psd_bool need_closing;
psd_gimp_vector2 first;
psd_gimp_vector2 prev;
psd_bool have_open;
psd_int num_nodes;
psd_art_vpath *vpath;
psd_art_svp *svp; /* Sorted vector path
(extension no longer possible) */
/* stuff necessary for the rendering callback */
psd_bitmap * dst_bmp;
psd_int x0;
psd_int x1;
} psd_gimp_scan_convert;
typedef struct _psd_art_svp_writer psd_art_svp_writer;
struct _psd_art_svp_writer {
psd_int (*add_segment)(psd_art_svp_writer *self, psd_int wind_left, psd_int delta_wind,
psd_double x, psd_double y);
void (*add_point)(psd_art_svp_writer *self, psd_int seg_id, psd_double x, psd_double y);
void (*close_segment)(psd_art_svp_writer *self, psd_int seg_id);
};
typedef struct _psd_art_svp_writer_rewind {
psd_art_svp_writer super;
psd_art_wind_rule rule;
psd_art_svp *svp;
psd_int n_segs_max;
psd_int *n_points_max;
} psd_art_svp_writer_rewind;
typedef struct _psd_art_pri_point {
psd_double x;
psd_double y;
void *user_data;
} psd_art_pri_point;
typedef struct _psd_art_pri_q {
psd_int n_items;
psd_int n_items_max;
psd_art_pri_point **items;
} psd_art_pri_q;
typedef struct _psd_art_active_seg psd_art_active_seg;
struct _psd_art_active_seg {
psd_int flags;
psd_int wind_left, delta_wind;
psd_art_active_seg *left, *right; /* doubly linked list structure */
const psd_art_svp_seg *in_seg;
psd_int in_curs;
psd_double x[2];
psd_double y0, y1;
psd_double a, b, c; /* line equation; ax+by+c = 0 for the line, a^2 + b^2 = 1,
and a>0 */
/* bottom point and intersection point stack */
psd_int n_stack;
psd_int n_stack_max;
psd_art_point *stack;
/* horiz commit list */
psd_art_active_seg *horiz_left, *horiz_right;
psd_double horiz_x;
psd_int horiz_delta_wind;
psd_int seg_id;
};
typedef struct _psd_art_intersect_ctx {
const psd_art_svp *in;
psd_art_svp_writer *out;
psd_art_pri_q *pq;
psd_art_active_seg *active_head;
psd_double y;
psd_art_active_seg *horiz_first;
psd_art_active_seg *horiz_last;
/* segment index of next input segment to be added to pri q */
psd_int in_curs;
} psd_art_intersect_ctx;
typedef struct _psd_art_svp_render_aa_step {
psd_int x;
psd_int delta; /* stored with 16 fractional bits */
} psd_art_svp_render_aa_step;
typedef struct _psd_art_svp_render_aa_iter {
const psd_art_svp *svp;
psd_int x0, x1;
psd_int y;
psd_int seg_ix;
psd_int *active_segs;
psd_int n_active_segs;
psd_int *cursor;
psd_double *seg_x;
psd_double *seg_dx;
psd_art_svp_render_aa_step *steps;
} psd_art_svp_render_aa_iter;
extern psd_float psd_carm_sqrt(psd_float x);
psd_static psd_bool psd_get_bounds(psd_bitmap * src_bmp, psd_int *x1, psd_int *y1, psd_int *x2, psd_int *y2)
{
psd_int tx1, tx2, ty1, ty2;
psd_int i, j, width, height;
psd_argb_color * image_data;
/* go through and calculate the bounds */
tx1 = src_bmp->width;
ty1 = src_bmp->height;
tx2 = 0;
ty2 = 0;
width = src_bmp->width;
height = src_bmp->height;
for(i = 0; i < height; i ++)
{
if(tx1 > 0)
{
image_data = src_bmp->image_data + i * width;
for(j = 0; j < tx1; j ++)
{
if(*image_data > 0x00FFFFFF)
{
tx1 = j;
break;
}
image_data ++;
}
}
if(tx2 < width)
{
image_data = src_bmp->image_data + i * width + width - 1;
for(j = width - 1; j >= tx2; j --)
{
if(*image_data > 0x00FFFFFF)
{
tx2 = j;
break;
}
image_data --;
}
}
else if(tx1 == 0 && tx2 == width)
{
break;
}
}
if(tx1 > tx2)
return psd_false;
for(i = tx1; i < tx2; i ++)
{
if(ty1 > 0)
{
image_data = src_bmp->image_data + i;
for(j = 0; j < ty1; j ++)
{
if(*image_data > 0x00FFFFFF)
{
ty1 = j;
break;
}
image_data += width;
}
}
if(ty2 < height)
{
image_data = src_bmp->image_data + (height - 1) * width + i;
for(j = height - 1; j >= ty2; j --)
{
if(*image_data > 0x00FFFFFF)
{
ty2 = j;
break;
}
image_data -= width;
}
}
else if(ty1 == 0 && ty2 == height)
{
break;
}
}
if(ty1 > ty2)
return psd_false;
*x1 = tx1;
*y1 = ty1;
*x2 = tx2;
*y2 = ty2;
return psd_true;
}
psd_static psd_gimp_bound_seg * psd_boundary_free(psd_gimp_boundary *boundary, psd_bool free_segs)
{
psd_gimp_bound_seg *segs = NULL;
if(free_segs)
psd_free(boundary->segs);
else
segs = boundary->segs;
psd_free(boundary->vert_segs);
psd_free(boundary->empty_segs_n);
psd_free(boundary->empty_segs_c);
psd_free(boundary->empty_segs_l);
psd_free(boundary);
return segs;
}
/* private functions */
psd_static psd_gimp_boundary * psd_boundary_new(psd_bitmap * src_bmp, psd_int x1, psd_int y1,
psd_int x2, psd_int y2)
{
psd_int i;
psd_gimp_boundary *boundary = (psd_gimp_boundary *)psd_malloc(sizeof(psd_gimp_boundary));
memset(boundary, 0, sizeof(psd_gimp_boundary));
/* array for determining the vertical line segments
* which must be drawn
*/
boundary->vert_segs = (psd_int *)psd_malloc((x2 + 1) * 4);
memset(boundary->vert_segs, 0, (x2 + 1) * 4);
for(i = 0; i <= x2; i++)
boundary->vert_segs[i] = -1;
/* find the maximum possible number of empty segments
* given the current mask
*/
boundary->max_empty_segs = (x2 - x1) + 3;
boundary->empty_segs_n = (psd_int *)psd_malloc(boundary->max_empty_segs * 4);
memset(boundary->empty_segs_n, 0, boundary->max_empty_segs * 4);
boundary->empty_segs_c = (psd_int *)psd_malloc(boundary->max_empty_segs * 4);
memset(boundary->empty_segs_c, 0, boundary->max_empty_segs * 4);
boundary->empty_segs_l = (psd_int *)psd_malloc(boundary->max_empty_segs * 4);
memset(boundary->empty_segs_l, 0, boundary->max_empty_segs * 4);
return boundary;
}
psd_static void psd_find_empty_segs(psd_bitmap * src_bmp, psd_int scanline, psd_int empty_segs[],
psd_int max_empty, psd_int *num_empty, psd_int x1, psd_int y1, psd_int x2, psd_int y2)
{
psd_argb_color * data;
psd_int x;
psd_int val, last;
psd_int l_num_empty;
data = NULL;
*num_empty = 0;
if(scanline < y1 || scanline >= y2)
{
empty_segs[(*num_empty)++] = 0;
empty_segs[(*num_empty)++] = 0x7FFFFFFF;
return;
}
empty_segs[(*num_empty)++] = 0;
last = -1;
l_num_empty = *num_empty;
data = src_bmp->image_data + scanline * src_bmp->width + x1;
for(x = x1; x < x2; x ++, data ++)
{
if(PSD_GET_ALPHA_COMPONENT(*data) > PSD_BOUNDARY_THRESHOLD)
val = 1;
else
val = -1;
if(last != val)
empty_segs[l_num_empty++] = x;
last = val;
}
*num_empty = l_num_empty;
if(last > 0)
empty_segs[(*num_empty)++] = x;
empty_segs[(*num_empty)++] = 0x7FFFFFFF;
}
psd_static void psd_boundary_add_seg(psd_gimp_boundary *boundary, psd_int x1, psd_int y1, psd_int x2, psd_int y2,
psd_bool open)
{
if(boundary->num_segs >= boundary->max_segs)
{
boundary->max_segs += PSD_BOUNDARY_MAX_SEGS_INC;
boundary->segs = (psd_gimp_bound_seg *)psd_realloc(boundary->segs, sizeof(psd_gimp_bound_seg) * boundary->max_segs);
}
boundary->segs[boundary->num_segs].x1 = x1;
boundary->segs[boundary->num_segs].y1 = y1;
boundary->segs[boundary->num_segs].x2 = x2;
boundary->segs[boundary->num_segs].y2 = y2;
boundary->segs[boundary->num_segs].open = open;
boundary->num_segs ++;
}
psd_static void psd_process_horiz_seg(psd_gimp_boundary *boundary, psd_int x1, psd_int y1, psd_int x2, psd_int y2,
psd_bool open)
{
/* This procedure accounts for any vertical segments that must be
drawn to close in the horizontal segments. */
if(boundary->vert_segs[x1] >= 0)
{
psd_boundary_add_seg(boundary, x1, boundary->vert_segs[x1], x1, y1, (unsigned char)(!open));
boundary->vert_segs[x1] = -1;
}
else
boundary->vert_segs[x1] = y1;
if(boundary->vert_segs[x2] >= 0)
{
psd_boundary_add_seg(boundary, x2, boundary->vert_segs[x2], x2, y2, open);
boundary->vert_segs[x2] = -1;
}
else
boundary->vert_segs[x2] = y2;
psd_boundary_add_seg(boundary, x1, y1, x2, y2, open);
}
psd_static void psd_make_horiz_segs(psd_gimp_boundary *boundary, psd_int start, psd_int end, psd_int scanline,
psd_int empty[], psd_int num_empty, psd_bool open)
{
psd_int empty_index;
psd_int e_s, e_e; /* empty segment start and end values */
for(empty_index = 0; empty_index < num_empty; empty_index += 2)
{
e_s = *empty++;
e_e = *empty++;
if(e_s <= start && e_e >= end)
psd_process_horiz_seg(boundary,
start, scanline, end, scanline, open);
else if((e_s > start && e_s < end) ||
(e_e < end && e_e > start))
psd_process_horiz_seg(boundary,
PSD_MAX(e_s, start), scanline,
PSD_MIN(e_e, end), scanline, open);
}
}
psd_static psd_gimp_boundary * psd_generate_boundary(psd_bitmap * src_bmp, psd_int x1, psd_int y1,
psd_int x2, psd_int y2)
{
psd_gimp_boundary *boundary;
psd_int scanline;
psd_int i;
psd_int start, end;
psd_int *tmp_segs;
psd_int num_empty_n = 0;
psd_int num_empty_c = 0;
psd_int num_empty_l = 0;
boundary = psd_boundary_new(src_bmp, x1, y1, x2, y2);
start = y1;
end = y2;
/* Find the empty segments for the previous and current scanlines */
psd_find_empty_segs(src_bmp, start - 1, boundary->empty_segs_l,
boundary->max_empty_segs, &num_empty_l,
x1, y1, x2, y2);
psd_find_empty_segs(src_bmp, start, boundary->empty_segs_c,
boundary->max_empty_segs, &num_empty_c,
x1, y1, x2, y2);
for(scanline = start; scanline < end; scanline++)
{
/* find the empty segment list for the next scanline */
psd_find_empty_segs(src_bmp, scanline + 1, boundary->empty_segs_n,
boundary->max_empty_segs, &num_empty_n,
x1, y1, x2, y2);
/* process the segments on the current scanline */
for(i = 1; i < num_empty_c - 1; i += 2)
{
psd_make_horiz_segs(boundary,
boundary->empty_segs_c [i],
boundary->empty_segs_c [i+1],
scanline, boundary->empty_segs_l, num_empty_l, psd_true);
psd_make_horiz_segs(boundary,
boundary->empty_segs_c [i],
boundary->empty_segs_c [i+1],
scanline + 1, boundary->empty_segs_n, num_empty_n, psd_false);
}
/* get the next scanline of empty segments, swap others */
tmp_segs = boundary->empty_segs_l;
boundary->empty_segs_l = boundary->empty_segs_c;
num_empty_l = num_empty_c;
boundary->empty_segs_c = boundary->empty_segs_n;
num_empty_c = num_empty_n;
boundary->empty_segs_n = tmp_segs;
}
return boundary;
}
psd_static psd_gimp_bound_seg * psd_boundary_find(psd_bitmap * src_bmp, psd_int x1, psd_int y1,
psd_int x2, psd_int y2, psd_int *num_segs)
{
psd_gimp_boundary *boundary;
boundary = psd_generate_boundary(src_bmp, x1, y1, x2, y2);
*num_segs = boundary->num_segs;
return psd_boundary_free(boundary, psd_false);
}
psd_static psd_bool psd_get_boundary(psd_bitmap * src_bmp, psd_gimp_bound_seg **segs, psd_int * num_segs,
psd_int *x1, psd_int *y1, psd_int *x2, psd_int *y2)
{
if(psd_get_bounds(src_bmp, x1, y1, x2, y2) == psd_true)
*segs = psd_boundary_find(src_bmp, *x1, *y1, *x2, *y2, num_segs);
else
return psd_false;
if(*segs == NULL)
return psd_false;
return psd_true;
}
/* sorting utility functions */
psd_static psd_int psd_find_segment(psd_gimp_bound_seg *segs, psd_int num_segs, psd_int x, psd_int y)
{
psd_int index;
for(index = 0; index < num_segs; index++)
{
if(((segs[index].x1 == x && segs[index].y1 == y) ||
(segs[index].x2 == x && segs[index].y2 == y)) &&
segs[index].visited == psd_false)
return index;
}
return -1;
}
/**
* boundary_sort:
* @segs: unsorted input segs.
* @num_segs: number of input segs
* @num_groups: number of groups in the sorted segs
*
* This function takes an array of #BoundSeg's as returned by
* boundary_find() and sorts it by contiguous groups. The returned
* array contains markers consisting of -1 coordinates and is
* @num_groups elements longer than @segs.
*
* Return value: the sorted segs
**/
psd_static psd_gimp_bound_seg * psd_boundary_sort(psd_gimp_bound_seg *segs, psd_int num_segs, psd_int *num_groups)
{
psd_gimp_boundary * boundary;
psd_int i;
psd_int index;
psd_int x, y;
psd_int startx, starty;
psd_bool empty;
psd_gimp_bound_seg * new_segs;
*num_groups = 0;
for(i = 0; i < num_segs; i++)
segs[i].visited = psd_false;
boundary = (psd_gimp_boundary *)psd_malloc(sizeof(psd_gimp_boundary));
memset(boundary, 0, sizeof(psd_gimp_boundary));
index = 0;
new_segs = NULL;
empty = psd_false;
while(empty == psd_false)
{
empty = psd_true;
/* find the index of a non-visited segment to start a group */
for(i = 0; i < num_segs; i++)
{
if(segs[i].visited == psd_false)
{
index = i;
empty = psd_false;
i = num_segs;
}
}
if(empty == psd_false)
{
psd_boundary_add_seg(boundary,
segs[index].x1, segs[index].y1,
segs[index].x2, segs[index].y2,
segs[index].open);
segs[index].visited = psd_true;
startx = segs[index].x1;
starty = segs[index].y1;
x = segs[index].x2;
y = segs[index].y2;
while((index = psd_find_segment(segs, num_segs, x, y)) != -1)
{
/* make sure ordering is correct */
if(x == segs[index].x1 && y == segs[index].y1)
{
psd_boundary_add_seg(boundary,
segs[index].x1, segs[index].y1,
segs[index].x2, segs[index].y2,
segs[index].open);
x = segs[index].x2;
y = segs[index].y2;
}
else
{
psd_boundary_add_seg(boundary,
segs[index].x2, segs[index].y2,
segs[index].x1, segs[index].y1,
segs[index].open);
x = segs[index].x1;
y = segs[index].y1;
}
segs[index].visited = psd_true;
}
/* Mark the end of a group */
*num_groups = *num_groups + 1;
psd_boundary_add_seg(boundary, -1, -1, -1, -1, psd_false);
}
}
return psd_boundary_free(boundary, psd_false);
}
psd_static void psd_scan_convert_close_add_points(psd_gimp_scan_convert *sc)
{
if(sc->need_closing &&
(sc->prev.x != sc->first.x || sc->prev.y != sc->first.y))
{
sc->vpath = (psd_art_vpath *)psd_realloc(sc->vpath, sizeof(psd_art_vpath) * (sc->num_nodes + 2));
sc->vpath[sc->num_nodes].code = PSD_ART_LINETO;
sc->vpath[sc->num_nodes].x = sc->first.x;
sc->vpath[sc->num_nodes].y = sc->first.y;
sc->num_nodes++;
sc->vpath[sc->num_nodes].code = PSD_ART_END;
sc->vpath[sc->num_nodes].x = 0.0;
sc->vpath[sc->num_nodes].y = 0.0;
sc->num_nodes++;
}
sc->need_closing = psd_false;
}
/**
* gimp_scan_convert_add_polyline:
* @sc: a #GimpScanConvert context
* @n_points: number of points to add
* @points: array of points to add
* @closed: whether to close the polyline and make it a polygon
*
* Add a polyline with @n_points @points that may be open or closed.
* It is not recommended to mix gimp_scan_convert_add_polyline() with
* gimp_scan_convert_add_points().
*
* Please note that you should use gimp_scan_convert_stroke() if you
* specify open polygons.
*/
psd_static void psd_scan_convert_add_polyline(psd_gimp_scan_convert *sc,
psd_int n_points, psd_gimp_vector2 *points, psd_bool closed)
{
psd_gimp_vector2 prev = { 0.0, 0.0, };
psd_int i;
if(n_points <= 0)
return;
if(sc->need_closing)
psd_scan_convert_close_add_points(sc);
if(closed == psd_false)
sc->have_open = psd_true;
/* make sure that we have enough space for the nodes */
sc->vpath = (psd_art_vpath *)psd_realloc(sc->vpath, sizeof(psd_art_vpath) * (sc->num_nodes + n_points + 2));
for(i = 0; i < n_points; i++)
{
/* compress multiple identical coordinates */
if(i == 0 ||
prev.x != points[i].x ||
prev.y != points[i].y)
{
sc->vpath[sc->num_nodes].code = (i == 0 ? (closed ?
PSD_ART_MOVETO :
PSD_ART_MOVETO_OPEN) :
PSD_ART_LINETO);
sc->vpath[sc->num_nodes].x = points[i].x;
sc->vpath[sc->num_nodes].y = points[i].y;
sc->num_nodes++;
prev = points[i];
}
}
/* close the polyline when needed */
if(closed && (prev.x != points[0].x ||
prev.y != points[0].y))
{
sc->vpath[sc->num_nodes].x = points[0].x;
sc->vpath[sc->num_nodes].y = points[0].y;
sc->vpath[sc->num_nodes].code = PSD_ART_LINETO;
sc->num_nodes++;
}
sc->vpath[sc->num_nodes].code = PSD_ART_END;
sc->vpath[sc->num_nodes].x = 0.0;
sc->vpath[sc->num_nodes].y = 0.0;
/* If someone wants to mix this function with _add_points ()
* try to do something reasonable...
*/
sc->got_first = psd_false;
}
/**
* art_svp_free: Free an #ArtSVP structure.
* @svp: #ArtSVP to free.
*
* Frees an #ArtSVP structure and all the segments in it.
**/
psd_static void psd_art_svp_free(psd_art_svp *svp)
{
psd_int n_segs = svp->n_segs;
psd_int i;
for(i = 0; i < n_segs; i++)
psd_free(svp->segs[i].points);
psd_free(svp);
}
/**
* gimp_scan_convert_free:
* @sc: a #GimpScanConvert context
*
* Frees the resources allocated for @sc.
*/
psd_static void psd_scan_convert_free(psd_gimp_scan_convert *sc)
{
if(sc == NULL)
return;
if(sc->vpath)
psd_free(sc->vpath);
if(sc->svp)
psd_art_svp_free(sc->svp);
psd_free(sc);
}
/**
* art_vpath_add_point: Add point to vpath.
* @p_vpath: Where the pointer to the #ArtVpath structure is stored.
* @pn_points: Pointer to the number of points in *@p_vpath.
* @pn_points_max: Pointer to the number of points allocated.
* @code: The pathcode for the new point.
* @x: The X coordinate of the new point.
* @y: The Y coordinate of the new point.
*
* Adds a new point to *@p_vpath, reallocating and updating *@p_vpath
* and *@pn_points_max as necessary. *@pn_points is incremented.
*
* This routine always adds the point after all points already in the
* vpath. Thus, it should be called in the order the points are
* desired.
**/
psd_static void psd_art_vpath_add_point(psd_art_vpath **p_vpath, psd_int *pn_points, psd_int *pn_points_max,
psd_art_pathcode code, psd_double x, psd_double y)
{
psd_int i;
i = (*pn_points)++;
if(i == *pn_points_max)
{
if(i > 0)
{
*pn_points_max *= 2;
*p_vpath = (psd_art_vpath *)psd_realloc(*p_vpath, sizeof(psd_art_vpath) * *pn_points_max);
}
else
{
*pn_points_max = 1;
*p_vpath = (psd_art_vpath *)psd_malloc(sizeof(psd_art_vpath));
}
}
(*p_vpath)[i].code = code;
(*p_vpath)[i].x = x;
(*p_vpath)[i].y = y;
}
/* Render an arc segment starting at (xc + x0, yc + y0) to (xc + x1,
yc + y1), centered at (xc, yc), and with given radius. Both x0^2 +
y0^2 and x1^2 + y1^2 should be equal to radius^2.
A positive value of radius means curve to the left, negative means
curve to the right.
*/
psd_static void psd_art_svp_vpath_stroke_arc(psd_art_vpath **p_vpath, psd_int *pn, psd_int *pn_max,
psd_double xc, psd_double yc,
psd_double x0, psd_double y0,
psd_double x1, psd_double y1,
psd_double radius,
psd_double flatness)
{
psd_double theta;
psd_double th_0, th_1;
psd_int n_pts;
psd_int i;
psd_double aradius;
aradius = PSD_ABS(radius);
theta = 2 * PSD_M_SQRT2 * (psd_double)psd_carm_sqrt((psd_float)(flatness / aradius));
th_0 = atan2(y0, x0);
th_1 = atan2(y1, x1);
if(radius > 0)
{
/* curve to the left */
if(th_0 < th_1) th_0 += PSD_PI * 2;
n_pts = (psd_int)ceil ((th_0 - th_1) / theta);
}
else
{
/* curve to the right */
if(th_1 < th_0) th_1 += PSD_PI * 2;
n_pts = (psd_int)ceil((th_1 - th_0) / theta);
}
psd_art_vpath_add_point(p_vpath, pn, pn_max,
PSD_ART_LINETO, xc + x0, yc + y0);
for(i = 1; i < n_pts; i++)
{
theta = th_0 + (th_1 - th_0) * i / n_pts;
psd_art_vpath_add_point(p_vpath, pn, pn_max,
PSD_ART_LINETO, xc + cos(theta) * aradius,
yc + sin(theta) * aradius);
}
psd_art_vpath_add_point(p_vpath, pn, pn_max,
PSD_ART_LINETO, xc + x1, yc + y1);
}
/* Assume that forw and rev are at point i0. Bring them to i1,
joining with the vector i1 - i2.
This used to be psd_true, but isn't now that the stroke_raw code is
filtering out (near)zero length vectors: {It so happens that all
invocations of this function maintain the precondition i1 = i0 + 1,
so we could decrease the number of arguments by one. We haven't
done that here, though.}
forw is to the line's right and rev is to its left.
Precondition: no zero-length vectors, otherwise a divide by
zero will happen. */
psd_static void psd_render_seg(psd_art_vpath **p_forw, psd_int *pn_forw, psd_int *pn_forw_max,
psd_art_vpath **p_rev, psd_int *pn_rev, psd_int *pn_rev_max,
psd_art_vpath *vpath, psd_int i0, psd_int i1, psd_int i2,
psd_double line_width, psd_double flatness)
{
psd_double dx0, dy0;
psd_double dx1, dy1;
psd_double dlx0, dly0;
psd_double dlx1, dly1;
psd_double dmx, dmy;
psd_double dmr2;
psd_double scale;
psd_double cross;
/* The vectors of the lines from i0 to i1 and i1 to i2. */
dx0 = vpath[i1].x - vpath[i0].x;
dy0 = vpath[i1].y - vpath[i0].y;
dx1 = vpath[i2].x - vpath[i1].x;
dy1 = vpath[i2].y - vpath[i1].y;
/* Set dl[xy]0 to the vector from i0 to i1, rotated counterclockwise
90 degrees, and scaled to the length of line_width. */
scale = line_width / (psd_double)psd_carm_sqrt((psd_float)(dx0 * dx0 + dy0 * dy0));
dlx0 = dy0 * scale;
dly0 = -dx0 * scale;
/* Set dl[xy]1 to the vector from i1 to i2, rotated counterclockwise
90 degrees, and scaled to the length of line_width. */
scale = line_width / (psd_double)psd_carm_sqrt((psd_float)(dx1 * dx1 + dy1 * dy1));
dlx1 = dy1 * scale;
dly1 = -dx1 * scale;
/* now, forw's last point is expected to be colinear along d[xy]0
to point i0 - dl[xy]0, and rev with i0 + dl[xy]0. */
/* positive for positive area (i.e. left turn) */
cross = dx1 * dy0 - dx0 * dy1;
dmx = (dlx0 + dlx1) * 0.5;
dmy = (dly0 + dly1) * 0.5;
dmr2 = dmx * dmx + dmy * dmy;
/* the case when dmr2 is zero or very small bothers me
(i.e. near a 180 degree angle)
ALEX: So, we avoid the optimization when dmr2 is very small. This should
be safe since dmx/y is only used in optimization and in MITER case, and MITER
should be converted to BEVEL when dmr2 is very small. */
if(dmr2 > PSD_EPSILON_2)
{
scale = line_width * line_width / dmr2;
dmx *= scale;
dmy *= scale;
}
if(cross * cross < PSD_EPSILON_2 && dx0 * dx1 + dy0 * dy1 >= 0)
{
/* going straight */
psd_art_vpath_add_point(p_forw, pn_forw, pn_forw_max,
PSD_ART_LINETO, vpath[i1].x - dlx0, vpath[i1].y - dly0);
psd_art_vpath_add_point(p_rev, pn_rev, pn_rev_max,
PSD_ART_LINETO, vpath[i1].x + dlx0, vpath[i1].y + dly0);
}
else if(cross > 0)
{
/* left turn, forw is outside and rev is inside */
if((dmr2 > PSD_EPSILON_2) &&
/* check that i1 + dm[xy] is inside i0-i1 rectangle */
(dx0 + dmx) * dx0 + (dy0 + dmy) * dy0 > 0 &&
/* and that i1 + dm[xy] is inside i1-i2 rectangle */
((dx1 - dmx) * dx1 + (dy1 - dmy) * dy1 > 0))
{
/* can safely add single intersection point */
psd_art_vpath_add_point(p_rev, pn_rev, pn_rev_max,
PSD_ART_LINETO, vpath[i1].x + dmx, vpath[i1].y + dmy);
}
else
{
/* need to loop-de-loop the inside */
psd_art_vpath_add_point(p_rev, pn_rev, pn_rev_max,
PSD_ART_LINETO, vpath[i1].x + dlx0, vpath[i1].y + dly0);
psd_art_vpath_add_point(p_rev, pn_rev, pn_rev_max,
PSD_ART_LINETO, vpath[i1].x, vpath[i1].y);
psd_art_vpath_add_point(p_rev, pn_rev, pn_rev_max,
PSD_ART_LINETO, vpath[i1].x + dlx1, vpath[i1].y + dly1);
}
psd_art_svp_vpath_stroke_arc(p_forw, pn_forw, pn_forw_max,
vpath[i1].x, vpath[i1].y,
-dlx0, -dly0,
-dlx1, -dly1,
line_width,
flatness);
}
else
{
/* right turn, rev is outside and forw is inside */
if((dmr2 > PSD_EPSILON_2) &&
/* check that i1 - dm[xy] is inside i0-i1 rectangle */
(dx0 - dmx) * dx0 + (dy0 - dmy) * dy0 > 0 &&
/* and that i1 - dm[xy] is inside i1-i2 rectangle */
((dx1 + dmx) * dx1 + (dy1 + dmy) * dy1 > 0))
{
/* can safely add single intersection point */
psd_art_vpath_add_point(p_forw, pn_forw, pn_forw_max,
PSD_ART_LINETO, vpath[i1].x - dmx, vpath[i1].y - dmy);
}
else
{
/* need to loop-de-loop the inside */
psd_art_vpath_add_point(p_forw, pn_forw, pn_forw_max,
PSD_ART_LINETO, vpath[i1].x - dlx0, vpath[i1].y - dly0);
psd_art_vpath_add_point(p_forw, pn_forw, pn_forw_max,
PSD_ART_LINETO, vpath[i1].x, vpath[i1].y);
psd_art_vpath_add_point(p_forw, pn_forw, pn_forw_max,
PSD_ART_LINETO, vpath[i1].x - dlx1, vpath[i1].y - dly1);
}
psd_art_svp_vpath_stroke_arc(p_rev, pn_rev, pn_rev_max,
vpath[i1].x, vpath[i1].y,
dlx0, dly0,
dlx1, dly1,
-line_width,
flatness);
}
}
/* caps i1, under the assumption of a vector from i0 */
psd_static void psd_render_cap(psd_art_vpath **p_result, psd_int *pn_result, psd_int *pn_result_max,
psd_art_vpath *vpath, psd_int i0, psd_int i1,
psd_double line_width, psd_double flatness)
{
psd_double dx0, dy0;
psd_double dlx0, dly0;
psd_double scale;
psd_int n_pts;
psd_int i;
dx0 = vpath[i1].x - vpath[i0].x;
dy0 = vpath[i1].y - vpath[i0].y;
/* Set dl[xy]0 to the vector from i0 to i1, rotated counterclockwise
90 degrees, and scaled to the length of line_width. */
scale = line_width / (psd_double)psd_carm_sqrt((psd_float)(dx0 * dx0 + dy0 * dy0));
dlx0 = dy0 * scale;
dly0 = -dx0 * scale;
n_pts = (psd_int)ceil(PSD_PI / (2.0 * PSD_M_SQRT2 * (psd_double)psd_carm_sqrt((psd_float)(flatness / line_width))));
psd_art_vpath_add_point(p_result, pn_result, pn_result_max,
PSD_ART_LINETO, vpath[i1].x - dlx0, vpath[i1].y - dly0);
for(i = 1; i < n_pts; i++)
{
psd_double theta, c_th, s_th;
theta = PSD_PI * i / n_pts;
c_th = cos(theta);
s_th = sin(theta);
psd_art_vpath_add_point(p_result, pn_result, pn_result_max,
PSD_ART_LINETO,
vpath[i1].x - dlx0 * c_th - dly0 * s_th,
vpath[i1].y - dly0 * c_th + dlx0 * s_th);
}
psd_art_vpath_add_point(p_result, pn_result, pn_result_max,
PSD_ART_LINETO, vpath[i1].x + dlx0, vpath[i1].y + dly0);
}
/**
* art_svp_from_vpath_raw: Stroke a vector path, raw version
* @vpath: #ArtVPath to stroke.
* @join: Join style.
* @cap: Cap style.
* @line_width: Width of stroke.
* @miter_limit: Miter limit.
* @flatness: Flatness.
*
* Exactly the same as art_svp_vpath_stroke(), except that the resulting
* stroke outline may self-intersect and have regions of winding number
* greater than 1.
*
* Return value: Resulting raw stroked outline in svp format.
**/
psd_static psd_art_vpath * psd_art_svp_vpath_stroke_raw(psd_art_vpath *vpath,
psd_double line_width, psd_double flatness)
{
psd_int begin_idx, end_idx;
psd_int i;
psd_art_vpath *forw, *rev;
psd_int n_forw, n_rev;
psd_int n_forw_max, n_rev_max;
psd_art_vpath *result;
psd_int n_result, n_result_max;
psd_double half_lw = 0.5 * line_width;
psd_int closed;
psd_int last, this, next, second;
psd_double dx, dy;
n_forw_max = 16;
forw = (psd_art_vpath *)psd_malloc(sizeof(psd_art_vpath) * n_forw_max);
n_rev_max = 16;
rev = (psd_art_vpath *)psd_malloc(sizeof(psd_art_vpath) * n_rev_max);
n_result = 0;
n_result_max = 16;
result = (psd_art_vpath *)psd_malloc(sizeof(psd_art_vpath) * n_result_max);
for(begin_idx = 0; vpath[begin_idx].code != PSD_ART_END; begin_idx = end_idx)
{
n_forw = 0;
n_rev = 0;
closed = (vpath[begin_idx].code == PSD_ART_MOVETO);
/* we don't know what the first point joins with until we get to the
last point and see if it's closed. So we start with the second
line in the path.
Note: this is not strictly psd_true (we now know it's closed from
the opening pathcode), but why fix code that isn't broken?
*/
this = begin_idx;
/* skip over identical points at the beginning of the subpath */
for(i = this + 1; vpath[i].code == PSD_ART_LINETO; i++)
{
dx = vpath[i].x - vpath[this].x;
dy = vpath[i].y - vpath[this].y;
if(dx * dx + dy * dy > PSD_EPSILON_2)
break;
}
next = i;
second = next;
/* invariant: this doesn't coincide with next */
while(vpath[next].code == PSD_ART_LINETO)
{
last = this;
this = next;
/* skip over identical points after the beginning of the subpath */
for(i = this + 1; vpath[i].code == PSD_ART_LINETO; i++)
{
dx = vpath[i].x - vpath[this].x;
dy = vpath[i].y - vpath[this].y;
if(dx * dx + dy * dy > PSD_EPSILON_2)
break;
}
next = i;
if(vpath[next].code != PSD_ART_LINETO)
{
/* reached end of path */
/* make "closed" detection conform to PostScript
semantics (i.e. explicit closepath code rather than
just the fact that end of the path is the beginning) */
if(closed &&
vpath[this].x == vpath[begin_idx].x &&
vpath[this].y == vpath[begin_idx].y)
{
psd_int j;
/* path is closed, render join to beginning */
psd_render_seg(&forw, &n_forw, &n_forw_max,
&rev, &n_rev, &n_rev_max,
vpath, last, this, second,
half_lw, flatness);
/* do forward path */
psd_art_vpath_add_point(&result, &n_result, &n_result_max,
PSD_ART_MOVETO, forw[n_forw - 1].x,
forw[n_forw - 1].y);
for(j = 0; j < n_forw; j++)
psd_art_vpath_add_point(&result, &n_result, &n_result_max,
PSD_ART_LINETO, forw[j].x,
forw[j].y);
/* do reverse path, reversed */
psd_art_vpath_add_point(&result, &n_result, &n_result_max,
PSD_ART_MOVETO, rev[0].x,
rev[0].y);
for(j = n_rev - 1; j >= 0; j--)
psd_art_vpath_add_point(&result, &n_result, &n_result_max,
PSD_ART_LINETO, rev[j].x,
rev[j].y);
}
else
{
/* path is open */
psd_int j;
/* add to forw rather than result to ensure that
forw has at least one point. */
psd_render_cap(&forw, &n_forw, &n_forw_max,
vpath, last, this,
half_lw, flatness);
psd_art_vpath_add_point(&result, &n_result, &n_result_max,
PSD_ART_MOVETO, forw[0].x,
forw[0].y);
for(j = 1; j < n_forw; j++)
psd_art_vpath_add_point(&result, &n_result, &n_result_max,
PSD_ART_LINETO, forw[j].x,
forw[j].y);
for(j = n_rev - 1; j >= 0; j--)
psd_art_vpath_add_point(&result, &n_result, &n_result_max,
PSD_ART_LINETO, rev[j].x,
rev[j].y);
psd_render_cap(&result, &n_result, &n_result_max,
vpath, second, begin_idx,
half_lw, flatness);
psd_art_vpath_add_point(&result, &n_result, &n_result_max,
PSD_ART_LINETO, forw[0].x,
forw[0].y);
}
}
else
{
psd_render_seg(&forw, &n_forw, &n_forw_max,
&rev, &n_rev, &n_rev_max,
vpath, last, this, next,
half_lw, flatness);
}
}
end_idx = next;
}
psd_free(forw);
psd_free(rev);
psd_art_vpath_add_point(&result, &n_result, &n_result_max, PSD_ART_END, 0, 0);
return result;
}
/* reverse a list of points in place */
psd_static void psd_reverse_points(psd_art_point *points, psd_int n_points)
{
psd_int i;
psd_art_point tmp_p;
for(i = 0; i < (n_points >> 1); i++)
{
tmp_p = points[i];
points[i] = points[n_points - (i + 1)];
points[n_points - (i + 1)] = tmp_p;
}
}
/**
* art_svp_seg_compare: Compare two segments of an svp.
* @seg1: First segment to compare.
* @seg2: Second segment to compare.
*
* Compares two segments of an svp. Return 1 if @seg2 is below or to the
* right of @seg1, -1 otherwise.
**/
psd_static psd_int psd_art_svp_seg_compare(const void *s1, const void *s2)
{
const psd_art_svp_seg *seg1 = s1;
const psd_art_svp_seg *seg2 = s2;
if(seg1->points[0].y > seg2->points[0].y)
return 1;
else if(seg1->points[0].y < seg2->points[0].y)
return -1;
else if(seg1->points[0].x > seg2->points[0].x)
return 1;
else if(seg1->points[0].x < seg2->points[0].x)
return -1;
else if((seg1->points[1].x - seg1->points[0].x) *
(seg2->points[1].y - seg2->points[0].y) -
(seg1->points[1].y - seg1->points[0].y) *
(seg2->points[1].x - seg2->points[0].x) > 0)
return 1;
return -1;
}
/**
* art_svp_from_vpath: Convert a vpath to a sorted vector path.
* @vpath: #ArtVPath to convert.
*
* Converts a vector path into sorted vector path form. The svp form is
* more efficient for rendering and other vector operations.
*
* Basically, the implementation is to traverse the vector path,
* generating a new segment for each "run" of points in the vector
* path with monotonically increasing Y values. All the resulting
* values are then sorted.
*
* Note: I'm not sure that the sorting rule is correct with respect
* to numerical stability issues.
*
* Return value: Resulting sorted vector path.
**/
psd_static psd_art_svp * psd_art_svp_from_vpath(psd_art_vpath *vpath)
{
psd_int n_segs, n_segs_max;
psd_art_svp *svp;
psd_int dir;
psd_int new_dir;
psd_int i;
psd_art_point *points;
psd_int n_points, n_points_max;
psd_double x, y;
psd_double x_min, x_max;
n_segs = 0;
n_segs_max = 16;
svp = (psd_art_svp *)psd_malloc(sizeof(psd_art_svp) +
(n_segs_max - 1) * sizeof(psd_art_svp_seg));
dir = 0;
n_points = 0;
n_points_max = 0;
points = NULL;
i = 0;
x = y = 0; /* unnecessary, given "first code must not be LINETO" invariant,
but it makes gcc -Wall -ansi -pedantic happier */
x_min = x_max = 0; /* same */
while(vpath[i].code != PSD_ART_END)
{
if(vpath[i].code == PSD_ART_MOVETO || vpath[i].code == PSD_ART_MOVETO_OPEN)
{
if(points != NULL && n_points >= 2)
{
if(n_segs == n_segs_max)
{
n_segs_max <<= 1;
svp = (psd_art_svp *)psd_realloc(svp, sizeof(psd_art_svp) +
(n_segs_max - 1) * sizeof(psd_art_svp_seg));
}
svp->segs[n_segs].n_points = n_points;
svp->segs[n_segs].dir = (dir > 0);
if(dir < 0)
psd_reverse_points(points, n_points);
svp->segs[n_segs].points = points;
svp->segs[n_segs].bbox.x0 = x_min;
svp->segs[n_segs].bbox.x1 = x_max;
svp->segs[n_segs].bbox.y0 = points[0].y;
svp->segs[n_segs].bbox.y1 = points[n_points - 1].y;
n_segs++;
points = NULL;
}
if(points == NULL)
{
n_points_max = 4;
points = (psd_art_point *)psd_malloc(sizeof(psd_art_point) * n_points_max);
}
n_points = 1;
points[0].x = x = vpath[i].x;
points[0].y = y = vpath[i].y;
x_min = x;
x_max = x;
dir = 0;
}
else /* must be LINETO */
{
new_dir = (vpath[i].y > y ||
(vpath[i].y == y && vpath[i].x > x)) ? 1 : -1;
if(dir && dir != new_dir)
{
/* new segment */
x = points[n_points - 1].x;
y = points[n_points - 1].y;
if(n_segs == n_segs_max)
{
n_segs_max <<= 1;
svp = (psd_art_svp *)psd_realloc(svp, sizeof(psd_art_svp) +
(n_segs_max - 1) * sizeof(psd_art_svp_seg));
}
svp->segs[n_segs].n_points = n_points;
svp->segs[n_segs].dir = (dir > 0);
if(dir < 0)
psd_reverse_points(points, n_points);
svp->segs[n_segs].points = points;
svp->segs[n_segs].bbox.x0 = x_min;
svp->segs[n_segs].bbox.x1 = x_max;
svp->segs[n_segs].bbox.y0 = points[0].y;
svp->segs[n_segs].bbox.y1 = points[n_points - 1].y;
n_segs++;
n_points = 1;
n_points_max = 4;
points = (psd_art_point *)psd_malloc(sizeof(psd_art_point) * n_points_max);
points[0].x = x;
points[0].y = y;
x_min = x;
x_max = x;
}
if(points != NULL)
{
if(n_points == n_points_max)
{
if(n_points > 0)
{
n_points_max *= 2;
points = (psd_art_point *)psd_realloc(points, sizeof(psd_art_point) * n_points_max);
}
else
{
n_points_max = 1;
points = (psd_art_point *)psd_malloc(sizeof(psd_art_point));
}
}
points[n_points].x = x = vpath[i].x;
points[n_points].y = y = vpath[i].y;
if(x < x_min)
x_min = x;
else if(x > x_max)
x_max = x;
n_points++;
}
dir = new_dir;
}
i++;
}
if(points != NULL)
{
if(n_points >= 2)
{
if(n_segs == n_segs_max)
{
n_segs_max *= 2;
svp = (psd_art_svp *)psd_realloc(svp, sizeof(psd_art_svp) +
(n_segs_max - 1) * sizeof(psd_art_svp_seg));
}
svp->segs[n_segs].n_points = n_points;
svp->segs[n_segs].dir = (dir > 0);
if(dir < 0)
psd_reverse_points(points, n_points);
svp->segs[n_segs].points = points;
svp->segs[n_segs].bbox.x0 = x_min;
svp->segs[n_segs].bbox.x1 = x_max;
svp->segs[n_segs].bbox.y0 = points[0].y;
svp->segs[n_segs].bbox.y1 = points[n_points - 1].y;
n_segs++;
}
else
{
psd_free(points);
}
}
svp->n_segs = n_segs;
qsort(&svp->segs, n_segs, sizeof(psd_art_svp_seg), psd_art_svp_seg_compare);
return svp;
}
psd_static psd_int psd_art_svp_writer_rewind_add_segment(psd_art_svp_writer *self, psd_int wind_left,
psd_int delta_wind, psd_double x, psd_double y)
{
psd_art_svp_writer_rewind *swr = (psd_art_svp_writer_rewind *)self;
psd_art_svp *svp;
psd_art_svp_seg *seg;
psd_bool left_filled, right_filled;
psd_int wind_right = wind_left + delta_wind;
psd_int seg_num;
const psd_int init_n_points_max = 4;
switch(swr->rule)
{
case PSD_ART_WIND_RULE_NONZERO:
left_filled = (wind_left != 0);
right_filled = (wind_right != 0);
break;
case PSD_ART_WIND_RULE_INTERSECT:
left_filled = (wind_left > 1);
right_filled = (wind_right > 1);
break;
case PSD_ART_WIND_RULE_ODDEVEN:
left_filled = (wind_left & 1);
right_filled = (wind_right & 1);
break;
case PSD_ART_WIND_RULE_POSITIVE:
left_filled = (wind_left > 0);
right_filled = (wind_right > 0);
break;
default:
//art_die ("Unknown wind rule %d\n", swr->rule);
psd_assert(0);
break;
}
if(left_filled == right_filled)
{
/* discard segment now */
return -1;
}
svp = swr->svp;
seg_num = svp->n_segs++;
if(swr->n_segs_max == seg_num)
{
swr->n_segs_max <<= 1;
svp = (psd_art_svp *)psd_realloc(svp, sizeof(psd_art_svp) +
(swr->n_segs_max - 1) * sizeof(psd_art_svp_seg));
swr->svp = svp;
swr->n_points_max = (psd_int *)psd_realloc(swr->n_points_max, swr->n_segs_max * 4);
}
seg = &svp->segs[seg_num];
seg->n_points = 1;
seg->dir = right_filled;
swr->n_points_max[seg_num] = init_n_points_max;
seg->bbox.x0 = x;
seg->bbox.y0 = y;
seg->bbox.x1 = x;
seg->bbox.y1 = y;
seg->points = (psd_art_point *)psd_malloc(sizeof(psd_art_point) * init_n_points_max);
seg->points[0].x = x;
seg->points[0].y = y;
return seg_num;
}
psd_static void psd_art_svp_writer_rewind_add_point(psd_art_svp_writer *self, psd_int seg_id,
psd_double x, psd_double y)
{
psd_art_svp_writer_rewind *swr = (psd_art_svp_writer_rewind *)self;
psd_art_svp_seg *seg;
psd_int n_points;
if(seg_id < 0)
/* omitted segment */
return;
seg = &swr->svp->segs[seg_id];
n_points = seg->n_points++;
if(swr->n_points_max[seg_id] == n_points)
{
if(n_points > 0)
{
swr->n_points_max[seg_id] *= 2;
seg->points = (psd_art_point *)psd_realloc(seg->points,
sizeof(psd_art_point) * swr->n_points_max[seg_id]);
}
else
{
swr->n_points_max[seg_id] = 1;
seg->points = (psd_art_point *)psd_malloc(sizeof(psd_art_point));
}
}
seg->points[n_points].x = x;
seg->points[n_points].y = y;
if(x < seg->bbox.x0)
seg->bbox.x0 = x;
if(x > seg->bbox.x1)
seg->bbox.x1 = x;
seg->bbox.y1 = y;
}
psd_static void psd_art_svp_writer_rewind_close_segment(psd_art_svp_writer *self, psd_int seg_id)
{
//do nothing
}
psd_static psd_art_svp_writer * psd_art_svp_writer_rewind_new(psd_art_wind_rule rule)
{
psd_art_svp_writer_rewind *result = (psd_art_svp_writer_rewind *)psd_malloc(sizeof(psd_art_svp_writer_rewind));
result->super.add_segment = psd_art_svp_writer_rewind_add_segment;
result->super.add_point = psd_art_svp_writer_rewind_add_point;
result->super.close_segment = psd_art_svp_writer_rewind_close_segment;
result->rule = rule;
result->n_segs_max = 16;
result->svp = (psd_art_svp *)psd_malloc(sizeof(psd_art_svp) +
(result->n_segs_max - 1) * sizeof(psd_art_svp_seg));
result->svp->n_segs = 0;
result->n_points_max = (psd_int *)psd_malloc(result->n_segs_max * 4);
return &result->super;
}
psd_static psd_art_pri_q * psd_art_pri_new(void)
{
psd_art_pri_q *result = (psd_art_pri_q *)psd_malloc(sizeof(psd_art_pri_q));
result->n_items = 0;
result->n_items_max = 16;
result->items = (psd_art_pri_point **)psd_malloc(sizeof(psd_art_pri_point *) * result->n_items_max);
return result;
}
psd_static void psd_art_pri_insert(psd_art_pri_q *pq, psd_art_pri_point *point)
{
if(pq->n_items == pq->n_items_max)
{
if(pq->n_items > 0)
{
pq->n_items_max *= 2;
pq->items = (psd_art_pri_point **)psd_realloc(pq->items, sizeof(psd_art_pri_point *) * pq->n_items_max);
}
else
{
pq->n_items_max = 1;
pq->items = (psd_art_pri_point **)psd_malloc(sizeof(psd_art_pri_point *));
}
}
pq->items[pq->n_items++] = point;
}
psd_static psd_bool psd_art_pri_empty(psd_art_pri_q *pq)
{
return pq->n_items == 0;
}
/* Choose least point in queue */
psd_static psd_art_pri_point * psd_art_pri_choose(psd_art_pri_q *pq)
{
psd_int i;
psd_int best = 0;
psd_double best_x, best_y;
psd_double y;
psd_art_pri_point *result;
if(pq->n_items == 0)
return NULL;
best_x = pq->items[best]->x;
best_y = pq->items[best]->y;
for(i = 1; i < pq->n_items; i++)
{
y = pq->items[i]->y;
if(y < best_y || (y == best_y && pq->items[i]->x < best_x))
{
best = i;
best_x = pq->items[best]->x;
best_y = y;
}
}
result = pq->items[best];
pq->items[best] = pq->items[--pq->n_items];
return result;
}
/**
* art_svp_intersect_active_free: Free an active segment.
* @seg: Segment to delete.
*
* Frees @seg.
**/
psd_static /* todo inline */ void psd_art_svp_intersect_active_free(psd_art_active_seg *seg)
{
psd_free(seg->stack);
psd_free(seg);
}
/**
* art_svp_intersect_horiz_commit: Commit points in horiz list to output.
* @ctx: Intersection context.
*
* The main function of the horizontal commit is to output new
* points to the output writer.
*
* This "commit" pass is also where winding numbers are assigned,
* because doing it here provides much greater tolerance for inputs
* which are not in strict SVP order.
*
* Each cluster in the horiz_list contains both segments that are in
* the active list (ART_ACTIVE_FLAGS_DEL is psd_false) and that are not,
* and are scheduled to be deleted (ART_ACTIVE_FLAGS_DEL is psd_true). We
* need to deal with both.
**/
psd_static void psd_art_svp_intersect_horiz_commit(psd_art_intersect_ctx *ctx)
{
psd_art_active_seg *seg;
psd_int winding_number = 0; /* initialization just to avoid warning */
psd_int horiz_wind = 0;
psd_double last_x = 0; /* initialization just to avoid warning */
/* Output points to svp writer. */
for(seg = ctx->horiz_first; seg != NULL;)
{
/* Find a cluster with common horiz_x, */
psd_art_active_seg *curs;
psd_double x = seg->horiz_x;
/* Generate any horizontal segments. */
if(horiz_wind != 0)
{
psd_art_svp_writer *swr = ctx->out;
psd_int seg_id;
seg_id = swr->add_segment(swr, winding_number, horiz_wind,
last_x, ctx->y);
swr->add_point(swr, seg_id, x, ctx->y);
swr->close_segment(swr, seg_id);
}
/* Find first active segment in cluster. */
for(curs = seg; curs != NULL && curs->horiz_x == x;
curs = curs->horiz_right)
if(!(curs->flags & PSD_ART_ACTIVE_FLAGS_DEL))
break;
if(curs != NULL && curs->horiz_x == x)
{
/* There exists at least one active segment in this cluster. */
/* Find beginning of cluster. */
for(; curs->left != NULL; curs = curs->left)
if(curs->left->horiz_x != x)
break;
if(curs->left != NULL)
winding_number = curs->left->wind_left + curs->left->delta_wind;
else
winding_number = 0;
do
{
if(!(curs->flags & PSD_ART_ACTIVE_FLAGS_OUT) ||
curs->wind_left != winding_number)
{
psd_art_svp_writer *swr = ctx->out;
if(curs->flags & PSD_ART_ACTIVE_FLAGS_OUT)
{
swr->add_point(swr, curs->seg_id,
curs->horiz_x, ctx->y);
swr->close_segment(swr, curs->seg_id);
}
curs->seg_id = swr->add_segment(swr, winding_number,
curs->delta_wind,
x, ctx->y);
curs->flags |= PSD_ART_ACTIVE_FLAGS_OUT;
}
curs->wind_left = winding_number;
winding_number += curs->delta_wind;
curs = curs->right;
}
while(curs != NULL && curs->horiz_x == x);
}
/* Skip past cluster. */
do
{
psd_art_active_seg *next = seg->horiz_right;
seg->flags &= ~PSD_ART_ACTIVE_FLAGS_IN_HORIZ;
horiz_wind += seg->horiz_delta_wind;
seg->horiz_delta_wind = 0;
if(seg->flags & PSD_ART_ACTIVE_FLAGS_DEL)
{
if(seg->flags & PSD_ART_ACTIVE_FLAGS_OUT)
{
psd_art_svp_writer *swr = ctx->out;
swr->close_segment(swr, seg->seg_id);
}
psd_art_svp_intersect_active_free(seg);
}
seg = next;
}
while(seg != NULL && seg->horiz_x == x);
last_x = x;
}
ctx->horiz_first = NULL;
ctx->horiz_last = NULL;
}
/**
* art_svp_intersect_setup_seg: Set up an active segment from input segment.
* @seg: Active segment.
* @pri_pt: Priority queue point to initialize.
*
* Sets the x[], a, b, c, flags, and stack fields according to the
* line from the current cursor value. Sets the priority queue point
* to the bottom point of this line. Also advances the input segment
* cursor.
**/
psd_static void psd_art_svp_intersect_setup_seg(psd_art_active_seg *seg, psd_art_pri_point *pri_pt)
{
const psd_art_svp_seg *in_seg = seg->in_seg;
psd_int in_curs = seg->in_curs++;
psd_double x0, y0, x1, y1;
psd_double dx, dy, s;
psd_double a, b, r2;
x0 = in_seg->points[in_curs].x;
y0 = in_seg->points[in_curs].y;
x1 = in_seg->points[in_curs + 1].x;
y1 = in_seg->points[in_curs + 1].y;
pri_pt->x = x1;
pri_pt->y = y1;
dx = x1 - x0;
dy = y1 - y0;
r2 = dx * dx + dy * dy;
s = r2 == 0 ? 1 : 1 / (psd_double)psd_carm_sqrt((psd_float)r2);
seg->a = a = dy * s;
seg->b = b = -dx * s;
seg->c = -(a * x0 + b * y0);
seg->flags = (seg->flags & ~PSD_ART_ACTIVE_FLAGS_BNEG) | (dx > 0);
seg->x[0] = x0;
seg->x[1] = x1;
seg->y0 = y0;
seg->y1 = y1;
seg->n_stack = 1;
seg->stack[0].x = x1;
seg->stack[0].y = y1;
}
psd_static void psd_art_svp_intersect_push_pt(psd_art_intersect_ctx *ctx, psd_art_active_seg *seg,
psd_double x, psd_double y)
{
psd_art_pri_point *pri_pt;
psd_int n_stack = seg->n_stack;
if(n_stack == seg->n_stack_max)
{
if(n_stack > 0)
{
seg->n_stack_max *= 2;
seg->stack = (psd_art_point *)psd_realloc(seg->stack, sizeof(psd_art_point) * seg->n_stack_max);
}
else
{
seg->n_stack_max = 1;
seg->stack = (psd_art_point *)psd_malloc(sizeof(psd_art_point));
}
}
seg->stack[n_stack].x = x;
seg->stack[n_stack].y = y;
seg->n_stack++;
seg->x[1] = x;
seg->y1 = y;
pri_pt = (psd_art_pri_point *)psd_malloc(sizeof(psd_art_pri_point));
pri_pt->x = x;
pri_pt->y = y;
pri_pt->user_data = seg;
psd_art_pri_insert(ctx->pq, pri_pt);
}
/**
* art_svp_intersect_add_horiz: Add point to horizontal list.
* @ctx: Intersector context.
* @seg: Segment with point to insert into horizontal list.
*
* Inserts @seg into horizontal list, keeping it in ascending horiz_x
* order.
*
* Note: the horiz_commit routine processes "clusters" of segs in the
* horiz list, all sharing the same horiz_x value. The cluster is
* processed in active list order, rather than horiz list order. Thus,
* the order of segs in the horiz list sharing the same horiz_x
* _should_ be irrelevant. Even so, we use b as a secondary sorting key,
* as a "belt and suspenders" defensive coding tactic.
**/
psd_static void psd_art_svp_intersect_add_horiz(psd_art_intersect_ctx *ctx, psd_art_active_seg *seg)
{
psd_art_active_seg **pp = &ctx->horiz_last;
psd_art_active_seg *place;
psd_art_active_seg *place_right = NULL;
if(seg->flags & PSD_ART_ACTIVE_FLAGS_IN_HORIZ)
return;
seg->flags |= PSD_ART_ACTIVE_FLAGS_IN_HORIZ;
for(place = *pp; place != NULL && (place->horiz_x > seg->horiz_x ||
(place->horiz_x == seg->horiz_x &&
place->b < seg->b));
place = *pp)
{
place_right = place;
pp = &place->horiz_left;
}
*pp = seg;
seg->horiz_left = place;
seg->horiz_right = place_right;
if (place == NULL)
ctx->horiz_first = seg;
else
place->horiz_right = seg;
}
/**
* art_svp_intersect_break: Break an active segment.
*
* Note: y must be greater than the top point's y, and less than
* the bottom's.
*
* Return value: x coordinate of break point.
*/
psd_static psd_double psd_art_svp_intersect_break(psd_art_intersect_ctx *ctx, psd_art_active_seg *seg,
psd_double x_ref, psd_double y, psd_art_break_flags break_flags)
{
psd_double x0, y0, x1, y1;
const psd_art_svp_seg *in_seg = seg->in_seg;
psd_int in_curs = seg->in_curs;
psd_double x;
x0 = in_seg->points[in_curs - 1].x;
y0 = in_seg->points[in_curs - 1].y;
x1 = in_seg->points[in_curs].x;
y1 = in_seg->points[in_curs].y;
x = x0 + (x1 - x0) * ((y - y0) / (y1 - y0));
/* I think we can count on min(x0, x1) <= x <= max(x0, x1) with sane
arithmetic, but it might be worthwhile to check just in case. */
if(y > ctx->y)
psd_art_svp_intersect_push_pt(ctx, seg, x, y);
else
{
seg->x[0] = x;
seg->y0 = y;
seg->horiz_x = x;
psd_art_svp_intersect_add_horiz(ctx, seg);
}
return x;
}
/**
* art_svp_intersect_add_point: Add a point, breaking nearby neighbors.
* @ctx: Intersector context.
* @x: X coordinate of point to add.
* @y: Y coordinate of point to add.
* @seg: "nearby" segment, or NULL if leftmost.
*
* Return value: Segment immediately to the left of the new point, or
* NULL if the new point is leftmost.
**/
psd_static psd_art_active_seg * psd_art_svp_intersect_add_point(psd_art_intersect_ctx *ctx, psd_double x, psd_double y,
psd_art_active_seg *seg, psd_art_break_flags break_flags)
{
psd_art_active_seg *left, *right;
psd_double x_min = x, x_max = x;
psd_bool left_live, right_live;
psd_double d;
psd_double new_x;
psd_art_active_seg *test, *result = NULL;
psd_double x_test;
left = seg;
if(left == NULL)
right = ctx->active_head;
else
right = left->right;
left_live = (break_flags & PSD_ART_BREAK_LEFT) && (left != NULL);
right_live = (break_flags & PSD_ART_BREAK_RIGHT) && (right != NULL);
while(left_live || right_live)
{
if(left_live)
{
if(x <= left->x[left->flags & PSD_ART_ACTIVE_FLAGS_BNEG] &&
/* It may be that one of these conjuncts turns out to be always
psd_true. We test both anyway, to be defensive. */
y != left->y0 && y < left->y1)
{
d = x_min * left->a + y * left->b + left->c;
if(d < PSD_EPSILON_A)
{
new_x = psd_art_svp_intersect_break(ctx, left, x_min, y,
PSD_ART_BREAK_LEFT);
if(new_x > x_max)
{
x_max = new_x;
right_live = (right != NULL);
}
else if(new_x < x_min)
x_min = new_x;
left = left->left;
left_live = (left != NULL);
}
else
left_live = psd_false;
}
else
left_live = psd_false;
}
else if(right_live)
{
if(x >= right->x[(right->flags & PSD_ART_ACTIVE_FLAGS_BNEG) ^ 1] &&
/* It may be that one of these conjuncts turns out to be always
psd_true. We test both anyway, to be defensive. */
y != right->y0 && y < right->y1)
{
d = x_max * right->a + y * right->b + right->c;
if(d > -PSD_EPSILON_A)
{
new_x = psd_art_svp_intersect_break(ctx, right, x_max, y,
PSD_ART_BREAK_RIGHT);
if(new_x < x_min)
{
x_min = new_x;
left_live = (left != NULL);
}
else if(new_x >= x_max)
x_max = new_x;
right = right->right;
right_live = (right != NULL);
}
else
right_live = psd_false;
}
else
right_live = psd_false;
}
}
/* Ascending order is guaranteed by break_flags. Thus, we don't need
to actually fix up non-ascending pairs. */
/* Now, (left, right) defines an interval of segments broken. Sort
into ascending x order. */
test = left == NULL ? ctx->active_head : left->right;
result = left;
if(test != NULL && test != right)
{
if(y == test->y0)
x_test = test->x[0];
else /* assert y == test->y1, I think */
x_test = test->x[1];
for(;;)
{
if(x_test <= x)
result = test;
test = test->right;
if(test == right)
break;
new_x = x_test;
x_test = new_x;
}
}
return result;
}
psd_static void psd_art_svp_intersect_swap_active(psd_art_intersect_ctx *ctx,
psd_art_active_seg *left_seg, psd_art_active_seg *right_seg)
{
right_seg->left = left_seg->left;
if(right_seg->left != NULL)
right_seg->left->right = right_seg;
else
ctx->active_head = right_seg;
left_seg->right = right_seg->right;
if(left_seg->right != NULL)
left_seg->right->left = left_seg;
left_seg->left = right_seg;
right_seg->right = left_seg;
}
/**
* art_svp_intersect_test_cross: Test crossing of a pair of active segments.
* @ctx: Intersector context.
* @left_seg: Left segment of the pair.
* @right_seg: Right segment of the pair.
* @break_flags: Flags indicating whether to break neighbors.
*
* Tests crossing of @left_seg and @right_seg. If there is a crossing,
* inserts the intersection point into both segments.
*
* Return value: True if the intersection took place at the current
* scan line, indicating further iteration is needed.
**/
psd_static psd_bool psd_art_svp_intersect_test_cross(psd_art_intersect_ctx *ctx,
psd_art_active_seg *left_seg, psd_art_active_seg *right_seg,
psd_art_break_flags break_flags)
{
psd_double left_x0, left_y0, left_x1;
psd_double left_y1 = left_seg->y1;
psd_double right_y1 = right_seg->y1;
psd_double d;
const psd_art_svp_seg *in_seg;
psd_int in_curs;
psd_double d0, d1, t;
psd_double x, y; /* intersection point */
if(left_seg->y0 == right_seg->y0 && left_seg->x[0] == right_seg->x[0])
{
/* Top points of left and right segments coincide. This case
feels like a bit of duplication - we may want to merge it
with the cases below. However, this way, we're sure that this
logic makes only localized changes. */
if(left_y1 < right_y1)
{
/* Test left (x1, y1) against right segment */
psd_double left_x1 = left_seg->x[1];
if(left_x1 <
right_seg->x[(right_seg->flags & PSD_ART_ACTIVE_FLAGS_BNEG) ^ 1] ||
left_y1 == right_seg->y0)
return psd_false;
d = left_x1 * right_seg->a + left_y1 * right_seg->b + right_seg->c;
if(d < -PSD_EPSILON_A)
return psd_false;
else if(d < PSD_EPSILON_A)
{
/* I'm unsure about the break flags here. */
psd_double right_x1 = psd_art_svp_intersect_break(ctx, right_seg,
left_x1, left_y1,
PSD_ART_BREAK_RIGHT);
if(left_x1 <= right_x1)
return psd_false;
}
}
else if(left_y1 > right_y1)
{
/* Test right (x1, y1) against left segment */
psd_double right_x1 = right_seg->x[1];
if(right_x1 > left_seg->x[left_seg->flags & PSD_ART_ACTIVE_FLAGS_BNEG] ||
right_y1 == left_seg->y0)
return psd_false;
d = right_x1 * left_seg->a + right_y1 * left_seg->b + left_seg->c;
if(d > PSD_EPSILON_A)
return psd_false;
else if(d > -PSD_EPSILON_A)
{
/* See above regarding break flags. */
psd_double left_x1 = psd_art_svp_intersect_break(ctx, left_seg,
right_x1, right_y1,
PSD_ART_BREAK_LEFT);
if(left_x1 <= right_x1)
return psd_false;
}
}
else /* left_y1 == right_y1 */
{
psd_double left_x1 = left_seg->x[1];
psd_double right_x1 = right_seg->x[1];
if(left_x1 <= right_x1)
return psd_false;
}
psd_art_svp_intersect_swap_active(ctx, left_seg, right_seg);
return psd_true;
}
if(left_y1 < right_y1)
{
/* Test left (x1, y1) against right segment */
psd_double left_x1 = left_seg->x[1];
if(left_x1 <
right_seg->x[(right_seg->flags & PSD_ART_ACTIVE_FLAGS_BNEG) ^ 1] ||
left_y1 == right_seg->y0)
return psd_false;
d = left_x1 * right_seg->a + left_y1 * right_seg->b + right_seg->c;
if(d < -PSD_EPSILON_A)
return psd_false;
else if(d < PSD_EPSILON_A)
{
psd_double right_x1 = psd_art_svp_intersect_break(ctx, right_seg,
left_x1, left_y1,
PSD_ART_BREAK_RIGHT);
if(left_x1 <= right_x1)
return psd_false;
}
}
else if(left_y1 > right_y1)
{
/* Test right (x1, y1) against left segment */
psd_double right_x1 = right_seg->x[1];
if(right_x1 > left_seg->x[left_seg->flags & PSD_ART_ACTIVE_FLAGS_BNEG] ||
right_y1 == left_seg->y0)
return psd_false;
d = right_x1 * left_seg->a + right_y1 * left_seg->b + left_seg->c;
if(d > PSD_EPSILON_A)
return psd_false;
else if(d > -PSD_EPSILON_A)
{
psd_double left_x1 = psd_art_svp_intersect_break(ctx, left_seg,
right_x1, right_y1,
PSD_ART_BREAK_LEFT);
if(left_x1 <= right_x1)
return psd_false;
}
}
else /* left_y1 == right_y1 */
{
psd_double left_x1 = left_seg->x[1];
psd_double right_x1 = right_seg->x[1];
if(left_x1 <= right_x1)
return psd_false;
}
/* The segments cross. Find the intersection point. */
in_seg = left_seg->in_seg;
in_curs = left_seg->in_curs;
left_x0 = in_seg->points[in_curs - 1].x;
left_y0 = in_seg->points[in_curs - 1].y;
left_x1 = in_seg->points[in_curs].x;
left_y1 = in_seg->points[in_curs].y;
d0 = left_x0 * right_seg->a + left_y0 * right_seg->b + right_seg->c;
d1 = left_x1 * right_seg->a + left_y1 * right_seg->b + right_seg->c;
if(d0 == d1)
{
x = left_x0;
y = left_y0;
}
else
{
/* Is this division always safe? It could possibly overflow. */
t = d0 / (d0 - d1);
if(t <= 0)
{
x = left_x0;
y = left_y0;
}
else if(t >= 1)
{
x = left_x1;
y = left_y1;
}
else
{
x = left_x0 + t * (left_x1 - left_x0);
y = left_y0 + t * (left_y1 - left_y0);
}
}
/* Make sure intersection point is within bounds of right seg. */
if(y < right_seg->y0)
{
x = right_seg->x[0];
y = right_seg->y0;
}
else if(y > right_seg->y1)
{
x = right_seg->x[1];
y = right_seg->y1;
}
else if(x < right_seg->x[(right_seg->flags & PSD_ART_ACTIVE_FLAGS_BNEG) ^ 1])
x = right_seg->x[(right_seg->flags & PSD_ART_ACTIVE_FLAGS_BNEG) ^ 1];
else if(x > right_seg->x[right_seg->flags & PSD_ART_ACTIVE_FLAGS_BNEG])
x = right_seg->x[right_seg->flags & PSD_ART_ACTIVE_FLAGS_BNEG];
if(y == left_seg->y0)
{
if(y != right_seg->y0)
{
psd_art_svp_intersect_push_pt(ctx, right_seg, x, y);
if((break_flags & PSD_ART_BREAK_RIGHT) && right_seg->right != NULL)
psd_art_svp_intersect_add_point(ctx, x, y, right_seg->right,
break_flags);
}
else
{
/* Intersection takes place at current scan line; process
immediately rather than queueing intersection point into
priq. */
psd_art_active_seg *winner, *loser;
/* Choose "most vertical" segement */
if(left_seg->a > right_seg->a)
{
winner = left_seg;
loser = right_seg;
}
else
{
winner = right_seg;
loser = left_seg;
}
loser->x[0] = winner->x[0];
loser->horiz_x = loser->x[0];
loser->horiz_delta_wind += loser->delta_wind;
winner->horiz_delta_wind -= loser->delta_wind;
psd_art_svp_intersect_swap_active(ctx, left_seg, right_seg);
return psd_true;
}
}
else if(y == right_seg->y0)
{
psd_art_svp_intersect_push_pt(ctx, left_seg, x, y);
if((break_flags & PSD_ART_BREAK_LEFT) && left_seg->left != NULL)
psd_art_svp_intersect_add_point(ctx, x, y, left_seg->left,
break_flags);
}
else
{
/* Insert the intersection point into both segments. */
psd_art_svp_intersect_push_pt(ctx, left_seg, x, y);
psd_art_svp_intersect_push_pt(ctx, right_seg, x, y);
if((break_flags & PSD_ART_BREAK_LEFT) && left_seg->left != NULL)
psd_art_svp_intersect_add_point(ctx, x, y, left_seg->left, break_flags);
if((break_flags & PSD_ART_BREAK_RIGHT) && right_seg->right != NULL)
psd_art_svp_intersect_add_point(ctx, x, y, right_seg->right, break_flags);
}
return psd_false;
}
/**
* art_svp_intersect_horiz: Add horizontal line segment.
* @ctx: Intersector context.
* @seg: Segment on which to add horizontal line.
* @x0: Old x position.
* @x1: New x position.
*
* Adds a horizontal line from @x0 to @x1, and updates the current
* location of @seg to @x1.
**/
psd_static void psd_art_svp_intersect_horiz(psd_art_intersect_ctx *ctx, psd_art_active_seg *seg,
psd_double x0, psd_double x1)
{
psd_art_active_seg *hs;
if(x0 == x1)
return;
hs = (psd_art_active_seg *)psd_malloc(sizeof(psd_art_active_seg));
hs->flags = PSD_ART_ACTIVE_FLAGS_DEL | (seg->flags & PSD_ART_ACTIVE_FLAGS_OUT);
if(seg->flags & PSD_ART_ACTIVE_FLAGS_OUT)
{
psd_art_svp_writer *swr = ctx->out;
swr->add_point(swr, seg->seg_id, x0, ctx->y);
}
hs->seg_id = seg->seg_id;
hs->horiz_x = x0;
hs->horiz_delta_wind = seg->delta_wind;
hs->stack = NULL;
/* Ideally, the (a, b, c) values will never be read. However, there
are probably some tests remaining that don't check for _DEL
before evaluating the line equation. For those, these
initializations will at least prevent a UMR of the values, which
can crash on some platforms. */
hs->a = 0.0;
hs->b = 0.0;
hs->c = 0.0;
seg->horiz_delta_wind -= seg->delta_wind;
psd_art_svp_intersect_add_horiz(ctx, hs);
if(x0 > x1)
{
psd_art_active_seg *left;
psd_bool first = psd_true;
for(left = seg->left; left != NULL; left = seg->left)
{
psd_int left_bneg = left->flags & PSD_ART_ACTIVE_FLAGS_BNEG;
if(left->x[left_bneg] <= x1)
break;
if(left->x[left_bneg ^ 1] <= x1 &&
x1 * left->a + ctx->y * left->b + left->c >= 0)
break;
if(left->y0 != ctx->y && left->y1 != ctx->y)
{
psd_art_svp_intersect_break(ctx, left, x1, ctx->y,
PSD_ART_BREAK_LEFT);
}
psd_art_svp_intersect_swap_active(ctx, left, seg);
if(first && left->right != NULL)
{
psd_art_svp_intersect_test_cross(ctx, left, left->right,
PSD_ART_BREAK_RIGHT);
first = psd_false;
}
}
}
else
{
psd_art_active_seg *right;
psd_bool first = psd_true;
for(right = seg->right; right != NULL; right = seg->right)
{
psd_int right_bneg = right->flags & PSD_ART_ACTIVE_FLAGS_BNEG;
if(right->x[right_bneg ^ 1] >= x1)
break;
if(right->x[right_bneg] >= x1 &&
x1 * right->a + ctx->y * right->b + right->c <= 0)
break;
if(right->y0 != ctx->y && right->y1 != ctx->y)
{
psd_art_svp_intersect_break(ctx, right, x1, ctx->y,
PSD_ART_BREAK_LEFT);
}
psd_art_svp_intersect_swap_active(ctx, seg, right);
if(first && right->left != NULL)
{
psd_art_svp_intersect_test_cross(ctx, right->left, right,
PSD_ART_BREAK_RIGHT);
first = psd_false;
}
}
}
seg->x[0] = x1;
seg->x[1] = x1;
seg->horiz_x = x1;
seg->flags &= ~PSD_ART_ACTIVE_FLAGS_OUT;
}
/**
* art_svp_intersect_insert_cross: Test crossings of newly inserted line.
*
* Tests @seg against its left and right neighbors for intersections.
* Precondition: the line in @seg is not purely horizontal.
**/
psd_static void psd_art_svp_intersect_insert_cross(psd_art_intersect_ctx *ctx,
psd_art_active_seg *seg)
{
psd_art_active_seg *left = seg, *right = seg;
for(;;)
{
if(left != NULL)
{
psd_art_active_seg *leftc;
for(leftc = left->left; leftc != NULL; leftc = leftc->left)
if(!(leftc->flags & PSD_ART_ACTIVE_FLAGS_DEL))
break;
if(leftc != NULL &&
psd_art_svp_intersect_test_cross(ctx, leftc, left,
PSD_ART_BREAK_LEFT))
{
if(left == right || right == NULL)
right = left->right;
}
else
{
left = NULL;
}
}
else if(right != NULL && right->right != NULL)
{
psd_art_active_seg *rightc;
for(rightc = right->right; rightc != NULL; rightc = rightc->right)
if(!(rightc->flags & PSD_ART_ACTIVE_FLAGS_DEL))
break;
if(rightc != NULL &&
psd_art_svp_intersect_test_cross(ctx, right, rightc,
PSD_ART_BREAK_RIGHT))
{
if(left == right || left == NULL)
left = right->left;
}
else
{
right = NULL;
}
}
else
break;
}
}
/**
* art_svp_intersect_insert_line: Insert a line into the active list.
* @ctx: Intersector context.
* @seg: Segment containing line to insert.
*
* Inserts the line into the intersector context, taking care of any
* intersections, and adding the appropriate horizontal points to the
* active list.
**/
psd_static void psd_art_svp_intersect_insert_line(psd_art_intersect_ctx *ctx, psd_art_active_seg *seg)
{
if(seg->y1 == seg->y0)
{
psd_art_svp_intersect_horiz(ctx, seg, seg->x[0], seg->x[1]);
}
else
{
psd_art_svp_intersect_insert_cross(ctx, seg);
psd_art_svp_intersect_add_horiz(ctx, seg);
}
}
psd_static void psd_art_svp_intersect_add_seg(psd_art_intersect_ctx *ctx, const psd_art_svp_seg *in_seg)
{
psd_art_active_seg *seg = (psd_art_active_seg *)psd_malloc(sizeof(psd_art_active_seg));
psd_art_active_seg *test;
psd_double x0, y0;
psd_art_active_seg *beg_range;
psd_art_active_seg *last = NULL;
psd_art_active_seg *left, *right;
psd_art_pri_point *pri_pt = (psd_art_pri_point *)psd_malloc(sizeof(psd_art_pri_point));
seg->flags = 0;
seg->in_seg = in_seg;
seg->in_curs = 0;
seg->n_stack_max = 4;
seg->stack = (psd_art_point *)psd_malloc(sizeof(psd_art_point) * seg->n_stack_max);
seg->horiz_delta_wind = 0;
seg->wind_left = 0;
pri_pt->user_data = seg;
psd_art_svp_intersect_setup_seg(seg, pri_pt);
psd_art_pri_insert(ctx->pq, pri_pt);
/* Find insertion place for new segment */
/* This is currently a left-to-right scan, but should be replaced
with a binary search as soon as it's validated. */
x0 = in_seg->points[0].x;
y0 = in_seg->points[0].y;
beg_range = NULL;
for(test = ctx->active_head; test != NULL; test = test->right)
{
psd_double d;
psd_int test_bneg = test->flags & PSD_ART_ACTIVE_FLAGS_BNEG;
if(x0 < test->x[test_bneg])
{
if(x0 < test->x[test_bneg ^ 1])
break;
d = x0 * test->a + y0 * test->b + test->c;
if(d < 0)
break;
}
last = test;
}
left = psd_art_svp_intersect_add_point(ctx, x0, y0, last, PSD_ART_BREAK_LEFT | PSD_ART_BREAK_RIGHT);
seg->left = left;
if(left == NULL)
{
right = ctx->active_head;
ctx->active_head = seg;
}
else
{
right = left->right;
left->right = seg;
}
seg->right = right;
if(right != NULL)
right->left = seg;
seg->delta_wind = in_seg->dir ? 1 : -1;
seg->horiz_x = x0;
psd_art_svp_intersect_insert_line(ctx, seg);
}
psd_static void psd_art_svp_intersect_process_intersection(psd_art_intersect_ctx *ctx,
psd_art_active_seg *seg)
{
psd_int n_stack = --seg->n_stack;
seg->x[1] = seg->stack[n_stack - 1].x;
seg->y1 = seg->stack[n_stack - 1].y;
seg->x[0] = seg->stack[n_stack].x;
seg->y0 = seg->stack[n_stack].y;
seg->horiz_x = seg->x[0];
psd_art_svp_intersect_insert_line(ctx, seg);
}
/**
* art_svp_intersect_active_delete: Delete segment from active list.
* @ctx: Intersection context.
* @seg: Segment to delete.
*
* Deletes @seg from the active list.
**/
psd_static /* todo inline */ void psd_art_svp_intersect_active_delete(psd_art_intersect_ctx *ctx, psd_art_active_seg *seg)
{
psd_art_active_seg *left = seg->left, *right = seg->right;
if(left != NULL)
left->right = right;
else
ctx->active_head = right;
if(right != NULL)
right->left = left;
}
psd_static void psd_art_svp_intersect_advance_cursor(psd_art_intersect_ctx *ctx, psd_art_active_seg *seg,
psd_art_pri_point *pri_pt)
{
const psd_art_svp_seg *in_seg = seg->in_seg;
psd_int in_curs = seg->in_curs;
psd_art_svp_writer *swr = seg->flags & PSD_ART_ACTIVE_FLAGS_OUT ? ctx->out : NULL;
if(swr != NULL)
swr->add_point(swr, seg->seg_id, seg->x[1], seg->y1);
if(in_curs + 1 == in_seg->n_points)
{
psd_art_active_seg *left = seg->left, *right = seg->right;
seg->flags |= PSD_ART_ACTIVE_FLAGS_DEL;
psd_art_svp_intersect_add_horiz(ctx, seg);
psd_art_svp_intersect_active_delete(ctx, seg);
if(left != NULL && right != NULL)
psd_art_svp_intersect_test_cross(ctx, left, right,
PSD_ART_BREAK_LEFT | PSD_ART_BREAK_RIGHT);
psd_free(pri_pt);
}
else
{
seg->horiz_x = seg->x[1];
psd_art_svp_intersect_setup_seg(seg, pri_pt);
psd_art_pri_insert (ctx->pq, pri_pt);
psd_art_svp_intersect_insert_line(ctx, seg);
}
}
psd_static void psd_art_pri_free(psd_art_pri_q *pq)
{
psd_free(pq->items);
psd_free(pq);
}
psd_static void psd_art_svp_intersector(const psd_art_svp *in, psd_art_svp_writer *out)
{
psd_art_intersect_ctx *ctx;
psd_art_pri_q *pq;
psd_art_pri_point *first_point;
if(in->n_segs == 0)
return;
ctx = (psd_art_intersect_ctx *)psd_malloc(sizeof(psd_art_intersect_ctx));
ctx->in = in;
ctx->out = out;
pq = psd_art_pri_new();
ctx->pq = pq;
ctx->active_head = NULL;
ctx->horiz_first = NULL;
ctx->horiz_last = NULL;
ctx->in_curs = 0;
first_point = (psd_art_pri_point *)psd_malloc(sizeof(psd_art_pri_point));
first_point->x = in->segs[0].points[0].x;
first_point->y = in->segs[0].points[0].y;
first_point->user_data = NULL;
ctx->y = first_point->y;
psd_art_pri_insert(pq, first_point);
while(!psd_art_pri_empty(pq))
{
psd_art_pri_point *pri_point = psd_art_pri_choose(pq);
psd_art_active_seg *seg = (psd_art_active_seg *)pri_point->user_data;
if(ctx->y != pri_point->y)
{
psd_art_svp_intersect_horiz_commit(ctx);
ctx->y = pri_point->y;
}
if(seg == NULL)
{
/* Insert new segment from input */
const psd_art_svp_seg *in_seg = &in->segs[ctx->in_curs++];
psd_art_svp_intersect_add_seg(ctx, in_seg);
if(ctx->in_curs < in->n_segs)
{
const psd_art_svp_seg *next_seg = &in->segs[ctx->in_curs];
pri_point->x = next_seg->points[0].x;
pri_point->y = next_seg->points[0].y;
/* user_data is already NULL */
psd_art_pri_insert(pq, pri_point);
}
else
{
psd_free(pri_point);
}
}
else
{
psd_int n_stack = seg->n_stack;
if(n_stack > 1)
{
psd_art_svp_intersect_process_intersection(ctx, seg);
psd_free(pri_point);
}
else
{
psd_art_svp_intersect_advance_cursor(ctx, seg, pri_point);
}
}
}
psd_art_svp_intersect_horiz_commit(ctx);
psd_art_pri_free(pq);
psd_free(ctx);
}
psd_static psd_art_svp * psd_art_svp_writer_rewind_reap(psd_art_svp_writer *self)
{
psd_art_svp_writer_rewind *swr = (psd_art_svp_writer_rewind *)self;
psd_art_svp *result = swr->svp;
psd_free(swr->n_points_max);
psd_free(swr);
return result;
}
/* Render a vector path into a stroked outline.
Status of this routine:
Basic correctness: Only miter and bevel line joins are implemented,
and only butt line caps. Otherwise, seems to be fine.
Numerical stability: We cheat (adding random perturbation). Thus,
it seems very likely that no numerical stability problems will be
seen in practice.
Speed: Should be pretty good.
Precision: The perturbation fuzzes the coordinates slightly,
but not enough to be visible. */
/**
* art_svp_vpath_stroke: Stroke a vector path.
* @vpath: #ArtVPath to stroke.
* @join: Join style.
* @cap: Cap style.
* @line_width: Width of stroke.
* @miter_limit: Miter limit.
* @flatness: Flatness.
*
* Computes an svp representing the stroked outline of @vpath. The
* width of the stroked line is @line_width.
*
* Lines are joined according to the @join rule. Possible values are
* ART_PATH_STROKE_JOIN_MITER (for mitered joins),
* ART_PATH_STROKE_JOIN_ROUND (for round joins), and
* ART_PATH_STROKE_JOIN_BEVEL (for bevelled joins). The mitered join
* is converted to a bevelled join if the miter would extend to a
* distance of more than @miter_limit * @line_width from the actual
* join point.
*
* If there are open subpaths, the ends of these subpaths are capped
* according to the @cap rule. Possible values are
* ART_PATH_STROKE_CAP_BUTT (squared cap, extends exactly to end
* point), ART_PATH_STROKE_CAP_ROUND (rounded half-circle centered at
* the end point), and ART_PATH_STROKE_CAP_SQUARE (squared cap,
* extending half @line_width past the end point).
*
* The @flatness parameter controls the accuracy of the rendering. It
* is most important for determining the number of points to use to
* approximate circular arcs for round lines and joins. In general, the
* resulting vector path will be within @flatness pixels of the "ideal"
* path containing actual circular arcs. I reserve the right to use
* the @flatness parameter to convert bevelled joins to miters for very
* small turn angles, as this would reduce the number of points in the
* resulting outline path.
*
* The resulting path is "clean" with respect to self-intersections, i.e.
* the winding number is 0 or 1 at each point.
*
* Return value: Resulting stroked outline in svp format.
**/
psd_static psd_art_svp * psd_art_svp_vpath_stroke(psd_art_vpath *vpath,
psd_double line_width, psd_double flatness)
{
psd_art_vpath *vpath_stroke;
psd_art_svp *svp, *svp2;
psd_art_svp_writer *swr;
vpath_stroke = psd_art_svp_vpath_stroke_raw(vpath, line_width, flatness);
svp = psd_art_svp_from_vpath(vpath_stroke);
psd_free(vpath_stroke);
swr = psd_art_svp_writer_rewind_new(PSD_ART_WIND_RULE_NONZERO);
psd_art_svp_intersector(svp, swr);
svp2 = psd_art_svp_writer_rewind_reap(swr);
psd_art_svp_free(svp);
return svp2;
}
psd_static void psd_stroke_scan_convert(psd_gimp_scan_convert *sc, psd_int stroke_size)
{
psd_art_svp *stroke;
psd_int i;
if(sc->need_closing)
psd_scan_convert_close_add_points(sc);
if(sc->ratio_xy != 1.0)
{
for(i = 0; i < sc->num_nodes; i++)
sc->vpath[i].x *= sc->ratio_xy;
}
if(sc->vpath)
{
stroke = psd_art_svp_vpath_stroke(sc->vpath, stroke_size, 0.2);
if(sc->ratio_xy != 1.0)
{
psd_art_svp_seg *segment;
psd_art_point *point;
psd_int i, j;
for(i = 0; i < stroke->n_segs; i++)
{
segment = stroke->segs + i;
segment->bbox.x0 /= sc->ratio_xy;
segment->bbox.x1 /= sc->ratio_xy;
for(j = 0; j < segment->n_points; j++)
{
point = segment->points + j;
point->x /= sc->ratio_xy;
}
}
}
sc->svp = stroke;
}
}
/* private function to convert the vpath to a svp when not using
* gimp_scan_convert_stroke
*/
psd_static void psd_scan_convert_finish(psd_gimp_scan_convert *sc)
{
psd_art_svp *svp, *svp2;
psd_art_svp_writer *swr;
/* return gracefully on empty path */
if(!sc->vpath)
return;
if(sc->need_closing)
psd_scan_convert_close_add_points(sc);
if(sc->svp)
return; /* We already have a valid SVP */
/* Debug output of libart path */
/* {
* gint i;
* for (i = 0; i < sc->num_nodes + 1; i++)
* {
* g_printerr ("X: %f, Y: %f, Type: %d\n", sc->vpath[i].x,
* sc->vpath[i].y,
* sc->vpath[i].code );
* }
* }
*/
if(sc->have_open)
{
psd_int i;
for(i = 0; i < sc->num_nodes; i++)
if(sc->vpath[i].code == PSD_ART_MOVETO_OPEN)
sc->vpath[i].code = PSD_ART_MOVETO;
}
svp = psd_art_svp_from_vpath(sc->vpath);
swr = psd_art_svp_writer_rewind_new(PSD_ART_WIND_RULE_ODDEVEN);
psd_art_svp_intersector(svp, swr);
svp2 = psd_art_svp_writer_rewind_reap(swr); /* this also frees swr */
psd_art_svp_free(svp);
sc->svp = svp2;
}
/* Render the sorted vector path in the given rectangle, antialiased.
This interface uses a callback for the actual pixel rendering. The
callback is called y1 - y0 times (once for each scan line). The y
coordinate is given as an argument for convenience (it could be
stored in the callback's private data and incremented on each
call).
The rendered polygon is represented in a semi-runlength format: a
start value and a sequence of "steps". Each step has an x
coordinate and a value delta. The resulting value at position x is
equal to the sum of the start value and all step delta values for
which the step x coordinate is less than or equal to x. An
efficient algorithm will traverse the steps left to right, keeping
a running sum.
All x coordinates in the steps are guaranteed to be x0 <= x < x1.
(This guarantee is a change from the gfonted vpaar renderer, and is
designed to simplify the callback).
There is now a further guarantee that no two steps will have the
same x value. This may allow for further speedup and simplification
of renderers.
The value 0x8000 represents 0% coverage by the polygon, while
0xff8000 represents 100% coverage. This format is designed so that
>> 16 results in a standard 0x00..0xff value range, with nice
rounding.
Status of this routine:
Basic correctness: OK
Numerical stability: pretty good, although probably not
bulletproof.
Speed: Needs more aggressive culling of bounding boxes. Can
probably speed up the [x0,x1) clipping of step values. Can do more
of the step calculation in fixed point.
Precision: No known problems, although it should be tested
thoroughly, especially for symmetry.
*/
psd_static psd_art_svp_render_aa_iter * psd_art_svp_render_aa_iter_new(const psd_art_svp *svp,
psd_int x0, psd_int y0, psd_int x1, psd_int y1)
{
psd_art_svp_render_aa_iter *iter = (psd_art_svp_render_aa_iter *)psd_malloc(sizeof(psd_art_svp_render_aa_iter));
iter->svp = svp;
iter->y = y0;
iter->x0 = x0;
iter->x1 = x1;
iter->seg_ix = 0;
iter->active_segs = (psd_int *)psd_malloc(svp->n_segs * sizeof(psd_int));
iter->cursor = (psd_int *)psd_malloc(svp->n_segs * sizeof(psd_int));
iter->seg_x = (psd_double *)psd_malloc(svp->n_segs * sizeof(psd_double));
iter->seg_dx = (psd_double *)psd_malloc(svp->n_segs * sizeof(psd_double));
iter->steps = (psd_art_svp_render_aa_step *)psd_malloc((x1 - x0) * sizeof(psd_art_svp_render_aa_step));
iter->n_active_segs = 0;
return iter;
}
psd_static void psd_art_svp_render_insert_active(psd_int i, psd_int *active_segs, psd_int n_active_segs,
psd_double *seg_x, psd_double *seg_dx)
{
psd_int j;
psd_double x;
psd_int tmp1, tmp2;
/* this is a cheap hack to get ^'s sorted correctly */
x = seg_x[i] + 0.001 * seg_dx[i];
for(j = 0; j < n_active_segs && seg_x[active_segs[j]] < x; j++);
tmp1 = i;
while(j < n_active_segs)
{
tmp2 = active_segs[j];
active_segs[j] = tmp1;
tmp1 = tmp2;
j++;
}
active_segs[j] = tmp1;
}
psd_static void psd_art_svp_render_delete_active(psd_int *active_segs, psd_int j, psd_int n_active_segs)
{
psd_int k;
for(k = j; k < n_active_segs; k++)
active_segs[k] = active_segs[k + 1];
}
#define PSD_ADD_STEP(xpos, xdelta) \
/* stereotype code fragment for adding a step */ \
if(n_steps == 0 || steps[n_steps - 1].x < xpos) \
{ \
sx = n_steps; \
steps[sx].x = xpos; \
steps[sx].delta = xdelta; \
n_steps++; \
} \
else \
{ \
for(sx = n_steps; sx > 0; sx--) \
{ \
if(steps[sx - 1].x == xpos) \
{ \
steps[sx - 1].delta += xdelta; \
sx = n_steps; \
break; \
} \
else if(steps[sx - 1].x < xpos) \
{ \
break; \
} \
} \
if(sx < n_steps) \
{ \
memmove(&steps[sx + 1], &steps[sx], \
(n_steps - sx) * sizeof(steps[0])); \
steps[sx].x = xpos; \
steps[sx].delta = xdelta; \
n_steps++; \
} \
}
psd_static void psd_art_svp_render_aa_iter_step(psd_art_svp_render_aa_iter *iter, psd_int *p_start,
psd_art_svp_render_aa_step **p_steps, psd_int *p_n_steps)
{
const psd_art_svp *svp = iter->svp;
psd_int *active_segs = iter->active_segs;
psd_int n_active_segs = iter->n_active_segs;
psd_int *cursor = iter->cursor;
psd_double *seg_x = iter->seg_x;
psd_double *seg_dx = iter->seg_dx;
psd_int i = iter->seg_ix;
psd_int j;
psd_int x0 = iter->x0;
psd_int x1 = iter->x1;
psd_int y = iter->y;
psd_int seg_index;
psd_int x;
psd_art_svp_render_aa_step *steps = iter->steps;
psd_int n_steps;
psd_double y_top, y_bot;
psd_double x_top, x_bot;
psd_double x_min, x_max;
psd_int ix_min, ix_max;
psd_double delta; /* delta should be psd_int too? */
psd_int last, this;
psd_int xdelta;
psd_double rslope, drslope;
psd_int start;
const psd_art_svp_seg *seg;
psd_int curs;
psd_double dy;
psd_int sx;
/* insert new active segments */
for(; i < svp->n_segs && svp->segs[i].bbox.y0 < y + 1; i++)
{
if(svp->segs[i].bbox.y1 > y &&
svp->segs[i].bbox.x0 < x1)
{
seg = &svp->segs[i];
/* move cursor to topmost vector which overlaps [y,y+1) */
for(curs = 0; seg->points[curs + 1].y < y; curs++);
cursor[i] = curs;
dy = seg->points[curs + 1].y - seg->points[curs].y;
if(PSD_ABS(dy) >= PSD_EPSILON)
seg_dx[i] = (seg->points[curs + 1].x - seg->points[curs].x) / dy;
else
seg_dx[i] = 1e12;
seg_x[i] = seg->points[curs].x +
(y - seg->points[curs].y) * seg_dx[i];
psd_art_svp_render_insert_active(i, active_segs, n_active_segs++,
seg_x, seg_dx);
}
}
n_steps = 0;
/* render the runlengths, advancing and deleting as we go */
start = 0x8000;
for(j = 0; j < n_active_segs; j++)
{
seg_index = active_segs[j];
seg = &svp->segs[seg_index];
curs = cursor[seg_index];
while(curs != seg->n_points - 1 &&
seg->points[curs].y < y + 1)
{
y_top = y;
if(y_top < seg->points[curs].y)
y_top = seg->points[curs].y;
y_bot = y + 1;
if(y_bot > seg->points[curs + 1].y)
y_bot = seg->points[curs + 1].y;
if(y_top != y_bot)
{
delta = (seg->dir ? 16711680.0 : -16711680.0) *
(y_bot - y_top);
x_top = seg_x[seg_index] + (y_top - y) * seg_dx[seg_index];
x_bot = seg_x[seg_index] + (y_bot - y) * seg_dx[seg_index];
if(x_top < x_bot)
{
x_min = x_top;
x_max = x_bot;
}
else
{
x_min = x_bot;
x_max = x_top;
}
ix_min = (psd_int)floor(x_min);
ix_max = (psd_int)floor(x_max);
if(ix_min >= x1)
{
/* skip; it starts to the right of the render region */
}
else if(ix_max < x0)
/* it ends to the left of the render region */
start += (psd_int)delta;
else if(ix_min == ix_max)
{
/* case 1, antialias a single pixel */
xdelta = (psd_int)((ix_min + 1 - (x_min + x_max) * 0.5) * delta);
PSD_ADD_STEP(ix_min, xdelta)
if(ix_min + 1 < x1)
{
xdelta = (psd_int)delta - xdelta;
PSD_ADD_STEP(ix_min + 1, xdelta)
}
}
else
{
/* case 2, antialias a run */
rslope = 1.0 / PSD_ABS(seg_dx[seg_index]);
drslope = delta * rslope;
last = (psd_int)(drslope * 0.5 *
(ix_min + 1 - x_min) * (ix_min + 1 - x_min));
xdelta = last;
if(ix_min >= x0)
{
PSD_ADD_STEP(ix_min, xdelta)
x = ix_min + 1;
}
else
{
start += last;
x = x0;
}
if(ix_max > x1)
ix_max = x1;
for(; x < ix_max; x++)
{
this = (psd_int)((seg->dir ? 16711680.0 : -16711680.0) * rslope *
(x + 0.5 - x_min));
xdelta = this - last;
last = this;
PSD_ADD_STEP(x, xdelta)
}
if(x < x1)
{
this = (psd_int)(delta * (1 - 0.5 *
(x_max - ix_max) * (x_max - ix_max) *
rslope));
xdelta = this - last;
last = this;
PSD_ADD_STEP(x, xdelta)
if(x + 1 < x1)
{
xdelta = (psd_int)delta - last;
PSD_ADD_STEP(x + 1, xdelta)
}
}
}
}
curs++;
if(curs != seg->n_points - 1 &&
seg->points[curs].y < y + 1)
{
dy = seg->points[curs + 1].y - seg->points[curs].y;
if (PSD_ABS(dy) >= PSD_EPSILON)
seg_dx[seg_index] = (seg->points[curs + 1].x -
seg->points[curs].x) / dy;
else
seg_dx[seg_index] = 1e12;
seg_x[seg_index] = seg->points[curs].x +
(y - seg->points[curs].y) * seg_dx[seg_index];
}
/* break here, instead of duplicating predicate in while? */
}
if(seg->points[curs].y >= y + 1)
{
curs--;
cursor[seg_index] = curs;
seg_x[seg_index] += seg_dx[seg_index];
}
else
{
psd_art_svp_render_delete_active(active_segs, j--,
--n_active_segs);
}
}
*p_start = start;
*p_steps = steps;
*p_n_steps = n_steps;
iter->seg_ix = i;
iter->n_active_segs = n_active_segs;
iter->y++;
}
psd_static void psd_art_svp_render_aa_iter_done(psd_art_svp_render_aa_iter *iter)
{
psd_free(iter->steps);
psd_free(iter->seg_dx);
psd_free(iter->seg_x);
psd_free(iter->cursor);
psd_free(iter->active_segs);
psd_free(iter);
}
/**
* art_svp_render_aa: Render SVP antialiased.
* @svp: The #ArtSVP to render.
* @x0: Left coordinate of destination rectangle.
* @y0: Top coordinate of destination rectangle.
* @x1: Right coordinate of destination rectangle.
* @y1: Bottom coordinate of destination rectangle.
* @callback: The callback which actually paints the pixels.
* @callback_data: Private data for @callback.
*
* Renders the sorted vector path in the given rectangle, antialiased.
*
* This interface uses a callback for the actual pixel rendering. The
* callback is called @y1 - @y0 times (once for each scan line). The y
* coordinate is given as an argument for convenience (it could be
* stored in the callback's private data and incremented on each
* call).
*
* The rendered polygon is represented in a semi-runlength format: a
* start value and a sequence of "steps". Each step has an x
* coordinate and a value delta. The resulting value at position x is
* equal to the sum of the start value and all step delta values for
* which the step x coordinate is less than or equal to x. An
* efficient algorithm will traverse the steps left to right, keeping
* a running sum.
*
* All x coordinates in the steps are guaranteed to be @x0 <= x < @x1.
* (This guarantee is a change from the gfonted vpaar renderer from
* which this routine is derived, and is designed to simplify the
* callback).
*
* The value 0x8000 represents 0% coverage by the polygon, while
* 0xff8000 represents 100% coverage. This format is designed so that
* >> 16 results in a standard 0x00..0xff value range, with nice
* rounding.
*
**/
psd_static void psd_art_svp_render_aa(const psd_art_svp *svp,
psd_int x0, psd_int y0, psd_int x1, psd_int y1,
void (*callback) (void *callback_data,
psd_int y,
psd_int start,
psd_art_svp_render_aa_step *steps, psd_int n_steps),
void *callback_data)
{
psd_art_svp_render_aa_iter *iter;
psd_int y;
psd_int start;
psd_art_svp_render_aa_step *steps;
psd_int n_steps;
iter = psd_art_svp_render_aa_iter_new(svp, x0, y0, x1, y1);
for(y = y0; y < y1; y++)
{
psd_art_svp_render_aa_iter_step(iter, &start, &steps, &n_steps);
(*callback)(callback_data, y, start, steps, n_steps);
}
psd_art_svp_render_aa_iter_done(iter);
}
psd_static void psd_scan_convert_render_callback(void * user_data,
psd_int y, psd_int start_value, psd_art_svp_render_aa_step *steps, psd_int n_steps)
{
psd_gimp_scan_convert *sc = (psd_gimp_scan_convert *)user_data;
psd_int cur_value = start_value;
psd_int k, run_x0, run_x1;
psd_argb_color * image_data = sc->dst_bmp->image_data + y * sc->dst_bmp->width;
#define VALUE_TO_PIXEL(x) ((x) >> 16)
if(n_steps > 0)
{
run_x1 = steps[0].x;
if(run_x1 > sc->x0)
{
psd_color_memset(image_data + sc->x0,
VALUE_TO_PIXEL(cur_value) << 24, run_x1 - sc->x0);
}
for(k = 0; k < n_steps - 1; k++)
{
cur_value += steps[k].delta;
cur_value = PSD_MAX(cur_value, 0);
run_x0 = run_x1;
run_x1 = steps[k + 1].x;
if(run_x1 > run_x0)
psd_color_memset(image_data + run_x0,
VALUE_TO_PIXEL(cur_value) << 24, run_x1 - run_x0);
}
if(sc->x1 > run_x1)
{
cur_value += steps[k].delta;
cur_value = PSD_MAX(cur_value, 0);
psd_color_memset(image_data + run_x1,
VALUE_TO_PIXEL(cur_value) << 24, sc->x1 - run_x1);
}
}
else
{
psd_color_memset(image_data + sc->x0,
VALUE_TO_PIXEL(cur_value) << 24, sc->x1 - sc->x0);
}
}
psd_static void psd_scan_convert_render_internal(psd_gimp_scan_convert *sc, psd_bitmap * dst_bmp,
psd_int x1, psd_int y1, psd_int x2, psd_int y2)
{
psd_scan_convert_finish(sc);
if(!sc->svp)
return;
sc->dst_bmp = dst_bmp;
sc->x0 = x1;
sc->x1 = x2;
psd_art_svp_render_aa(sc->svp,
x1, y1, x2, y2,
psd_scan_convert_render_callback, sc);
}
psd_static void psd_stroke_boundary(psd_bitmap * dst_bmp, psd_int stroke_size,
psd_gimp_bound_seg *segs, psd_int num_segs,
psd_int x1, psd_int y1, psd_int x2, psd_int y2)
{
psd_gimp_scan_convert *scan_convert;
psd_gimp_bound_seg *stroke_segs;
psd_int n_stroke_segs;
psd_gimp_vector2 *points;
psd_int n_points;
psd_int seg;
psd_int i;
stroke_segs = psd_boundary_sort(segs, num_segs, &n_stroke_segs);
if(n_stroke_segs == 0)
return;
scan_convert = (psd_gimp_scan_convert *)psd_malloc(sizeof(psd_gimp_scan_convert));
memset(scan_convert, 0, sizeof(psd_gimp_scan_convert));
scan_convert->ratio_xy = 1.0;
points = (psd_gimp_vector2 *)psd_malloc(sizeof(psd_gimp_vector2) * (num_segs + 4));
memset(points, 0, sizeof(psd_gimp_vector2) * (num_segs + 4));
seg = 0;
n_points = 0;
points[n_points].x = (psd_double)(stroke_segs[0].x1);
points[n_points].y = (psd_double)(stroke_segs[0].y1);
n_points++;
for(i = 0; i < n_stroke_segs; i++)
{
while(stroke_segs[seg].x1 != -1 ||
stroke_segs[seg].x2 != -1 ||
stroke_segs[seg].y1 != -1 ||
stroke_segs[seg].y2 != -1)
{
points[n_points].x = (psd_double)(stroke_segs[seg].x1);
points[n_points].y = (psd_double)(stroke_segs[seg].y1);
n_points++;
seg++;
}
/* Close the stroke points up */
points[n_points] = points[0];
n_points++;
psd_scan_convert_add_polyline(scan_convert, n_points, points, psd_true);
n_points = 0;
seg++;
points[n_points].x = (psd_double)(stroke_segs[seg].x1);
points[n_points].y = (psd_double)(stroke_segs[seg].y1);
n_points++;
}
psd_free(points);
psd_free(stroke_segs);
psd_stroke_scan_convert(scan_convert, stroke_size);
/* render the stroke into it */
psd_scan_convert_render_internal(scan_convert, dst_bmp,
PSD_MAX(0, x1 - stroke_size), PSD_MAX(0, y1 - stroke_size),
PSD_MIN(dst_bmp->width, x2 + stroke_size), PSD_MIN(dst_bmp->height, y2 + stroke_size));
psd_scan_convert_free(scan_convert);
}
psd_bool psd_draw_stroke(psd_bitmap * dst_bmp, psd_bitmap * src_bmp, psd_int stroke_size)
{
psd_gimp_bound_seg *segs;
psd_int num_segs;
psd_int x1, y1, x2, y2;
if(psd_get_boundary(src_bmp, &segs, &num_segs, &x1, &y1, &x2, &y2) == psd_false)
return psd_false;
psd_stroke_boundary(dst_bmp, stroke_size, segs, num_segs, x1, y1, x2, y2);
return psd_true;
}