1 /* Libart_LGPL - library of basic graphic primitives
2 * Copyright (C) 1998 Raph Levien
4 * This library is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU Library General Public
6 * License as published by the Free Software Foundation; either
7 * version 2 of the License, or (at your option) any later version.
9 * This library is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 * Library General Public License for more details.
14 * You should have received a copy of the GNU Library General Public
15 * License along with this library; if not, write to the
16 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
17 * Boston, MA 02111-1307, USA.
20 /* Render a sorted vector path into a graymap. */
22 #include <string.h> /* for memset */
26 #include "art_svp_render_aa.h"
27 #include "art_gray_svp.h"
29 typedef struct _ArtGraySVPData ArtGraySVPData;
31 struct _ArtGraySVPData {
38 art_gray_svp_callback (void *callback_data, int y,
39 int start, ArtSVPRenderAAStep *steps, int n_steps)
41 ArtGraySVPData *data = (ArtGraySVPData *)callback_data;
44 int running_sum = start;
49 printf ("start = %d", start);
51 for (k = 0; k < n_steps; k++)
53 running_sum += steps[k].delta;
54 printf (" %d:%d", steps[k].x, running_sum >> 16);
67 memset (linebuf, running_sum >> 16, run_x1 - x0);
69 for (k = 0; k < n_steps - 1; k++)
71 running_sum += steps[k].delta;
73 run_x1 = steps[k + 1].x;
75 memset (linebuf + run_x0 - x0, running_sum >> 16, run_x1 - run_x0);
77 running_sum += steps[k].delta;
79 memset (linebuf + run_x1 - x0, running_sum >> 16, x1 - run_x1);
83 memset (linebuf, running_sum >> 16, x1 - x0);
86 data->buf += data->rowstride;
90 * art_gray_svp_aa: Render the vector path into the bytemap.
91 * @svp: The SVP to render.
92 * @x0: The view window's left coord.
93 * @y0: The view window's top coord.
94 * @x1: The view window's right coord.
95 * @y1: The view window's bottom coord.
96 * @buf: The buffer where the bytemap is stored.
97 * @rowstride: the rowstride for @buf.
99 * Each pixel gets a value proportional to the area within the pixel
100 * overlapping the (filled) SVP. Pixel (x, y) is stored at:
102 * @buf[(y - * @y0) * @rowstride + (x - @x0)]
104 * All pixels @x0 <= x < @x1, @y0 <= y < @y1 are generated. A
105 * stored value of zero is no coverage, and a value of 255 is full
106 * coverage. The area within the pixel (x, y) is the region covered
107 * by [x..x+1] and [y..y+1].
110 art_gray_svp_aa (const ArtSVP *svp,
111 int x0, int y0, int x1, int y1,
112 art_u8 *buf, int rowstride)
117 data.rowstride = rowstride;
120 art_svp_render_aa (svp, x0, y0, x1, y1, art_gray_svp_callback, &data);