4 * Copyright © 2004 Keith Packard
6 * Permission to use, copy, modify, distribute, and sell this software and its
7 * documentation for any purpose is hereby granted without fee, provided that
8 * the above copyright notice appear in all copies and that both that
9 * copyright notice and this permission notice appear in supporting
10 * documentation, and that the name of Keith Packard not be used in
11 * advertising or publicity pertaining to distribution of the software without
12 * specific, written prior permission. Keith Packard makes no
13 * representations about the suitability of this software for any purpose. It
14 * is provided "as is" without express or implied warranty.
16 * KEITH PACKARD DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
17 * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
18 * EVENT SHALL KEITH PACKARD BE LIABLE FOR ANY SPECIAL, INDIRECT OR
19 * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
20 * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
21 * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
22 * PERFORMANCE OF THIS SOFTWARE.
29 rasterizeEdges (pixman_image_t *image,
37 uint32_t *buf = (image)->bits.bits;
38 uint32_t stride = (image)->bits.rowstride;
39 uint32_t width = (image)->bits.width;
41 line = buf + pixman_fixed_to_int (y) * stride;
55 if (pixman_fixed_to_int (rx) >= width)
56 rx = pixman_int_to_fixed (width);
58 /* Skip empty (or backwards) sections */
62 /* Find pixel bounds for span */
63 lxi = pixman_fixed_to_int (lx);
64 rxi = pixman_fixed_to_int (rx);
72 int width = rxi - lxi;
78 FbMaskBits (x, width, startmask, nmiddle, endmask);
80 WRITE(a, READ(a) | startmask);
84 WRITE(a++, FB_ALLONES);
86 WRITE(a, READ(a) | endmask);
90 DefineAlpha(line,lxi);
94 /* Sample coverage for edge pixels */
95 lxs = RenderSamplesX (lx, N_BITS);
96 rxs = RenderSamplesX (rx, N_BITS);
98 /* Add coverage across row */
101 AddAlpha (rxs - lxs);
107 AddAlpha (N_X_FRAC(N_BITS) - lxs);
109 for (xi = lxi + 1; xi < rxi; xi++)
111 AddAlpha (N_X_FRAC(N_BITS));
114 /* Do not add in a 0 alpha here. This check is necessary
115 * to avoid a buffer overrun when rx is exactly on a pixel
129 if (pixman_fixed_frac (y) != Y_FRAC_LAST(N_BITS))
131 RenderEdgeStepSmall (l);
132 RenderEdgeStepSmall (r);
133 y += STEP_Y_SMALL(N_BITS);
138 RenderEdgeStepBig (l);
139 RenderEdgeStepBig (r);
140 y += STEP_Y_BIG(N_BITS);