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IABSD.fr/xenocara/xserver/fb/fbedge.c
matthieu
- xserver/fb/fbedge.c
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/* * $Id: fbedge.c,v 1.1.1.1 2006/11/26 18:15:37 matthieu Exp $ * * Copyright © 2004 Keith Packard * * Permission to use, copy, modify, distribute, and sell this software and its * documentation for any purpose is hereby granted without fee, provided that * the above copyright notice appear in all copies and that both that * copyright notice and this permission notice appear in supporting * documentation, and that the name of Keith Packard not be used in * advertising or publicity pertaining to distribution of the software without * specific, written prior permission. Keith Packard makes no * representations about the suitability of this software for any purpose. It * is provided "as is" without express or implied warranty. * * KEITH PACKARD DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO * EVENT SHALL KEITH PACKARD BE LIABLE FOR ANY SPECIAL, INDIRECT OR * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR * PERFORMANCE OF THIS SOFTWARE. */ #include <string.h> #ifdef HAVE_DIX_CONFIG_H #include <dix-config.h> #endif #include "fb.h" #ifdef RENDER #include "picturestr.h" #include "mipict.h" #include "renderedge.h" #include "fbpict.h" /* * 4 bit alpha */ #define N_BITS 4 #define rasterizeEdges fbRasterizeEdges4 #if BITMAP_BIT_ORDER == LSBFirst #define Shift4(o) ((o) << 2) #else #define Shift4(o) ((1-(o)) << 2) #endif #define Get4(x,o) (((x) >> Shift4(o)) & 0xf) #define Put4(x,o,v) (((x) & ~(0xf << Shift4(o))) | (((v) & 0xf) << Shift4(o))) #define DefineAlpha(line,x) \ CARD8 *__ap = (CARD8 *) line + ((x) >> 1); \ int __ao = (x) & 1 #define StepAlpha ((__ap += __ao), (__ao ^= 1)) #define AddAlpha(a) { \ CARD8 __o = *__ap; \ CARD8 __a = (a) + Get4(__o, __ao); \ *__ap = Put4 (__o, __ao, __a | (0 - ((__a) >> 4))); \ } #include "fbedgeimp.h" #undef AddAlpha #undef StepAlpha #undef DefineAlpha #undef rasterizeEdges #undef N_BITS /* * 1 bit alpha */ #define N_BITS 1 #define rasterizeEdges fbRasterizeEdges1 #include "fbedgeimp.h" #undef rasterizeEdges #undef N_BITS /* * 8 bit alpha */ static INLINE CARD8 clip255 (int x) { if (x > 255) return 255; return x; } static INLINE void add_saturate_8 (CARD8 *buf, int value, int length) { while (length--) { *buf = clip255 (*buf + value); buf++; } } /* * We want to detect the case where we add the same value to a long * span of pixels. The triangles on the end are filled in while we * count how many sub-pixel scanlines contribute to the middle section. * * +--------------------------+ * fill_height =| \ / * +------------------+ * |================| * fill_start fill_end */ static void fbRasterizeEdges8 (FbBits *buf, int width, int stride, RenderEdge *l, RenderEdge *r, xFixed t, xFixed b) { xFixed y = t; FbBits *line; int fill_start = -1, fill_end = -1; int fill_size = 0; line = buf + xFixedToInt (y) * stride; for (;;) { CARD8 *ap = (CARD8 *) line; xFixed lx, rx; int lxi, rxi; /* clip X */ lx = l->x; if (lx < 0) lx = 0; rx = r->x; if (xFixedToInt (rx) >= width) rx = IntToxFixed (width); /* Skip empty (or backwards) sections */ if (rx > lx) { int lxs, rxs; /* Find pixel bounds for span. */ lxi = xFixedToInt (lx); rxi = xFixedToInt (rx); /* Sample coverage for edge pixels */ lxs = RenderSamplesX (lx, 8); rxs = RenderSamplesX (rx, 8); /* Add coverage across row */ if (lxi == rxi) { ap[lxi] = clip255 (ap[lxi] + rxs - lxs); } else { ap[lxi] = clip255 (ap[lxi] + N_X_FRAC(8) - lxs); /* Move forward so that lxi/rxi is the pixel span */ lxi++; /* Don't bother trying to optimize the fill unless * the span is longer than 4 pixels. */ if (rxi - lxi > 4) { if (fill_start < 0) { fill_start = lxi; fill_end = rxi; fill_size++; } else { if (lxi >= fill_end || rxi < fill_start) { /* We're beyond what we saved, just fill it */ add_saturate_8 (ap + fill_start, fill_size * N_X_FRAC(8), fill_end - fill_start); fill_start = lxi; fill_end = rxi; fill_size = 1; } else { /* Update fill_start */ if (lxi > fill_start) { add_saturate_8 (ap + fill_start, fill_size * N_X_FRAC(8), lxi - fill_start); fill_start = lxi; } else if (lxi < fill_start) { add_saturate_8 (ap + lxi, N_X_FRAC(8), fill_start - lxi); } /* Update fill_end */ if (rxi < fill_end) { add_saturate_8 (ap + rxi, fill_size * N_X_FRAC(8), fill_end - rxi); fill_end = rxi; } else if (fill_end < rxi) { add_saturate_8 (ap + fill_end, N_X_FRAC(8), rxi - fill_end); } fill_size++; } } } else { add_saturate_8 (ap + lxi, N_X_FRAC(8), rxi - lxi); } /* Do not add in a 0 alpha here. This check is * necessary to avoid a buffer overrun, (when rx * is exactly on a pixel boundary). */ if (rxs) ap[rxi] = clip255 (ap[rxi] + rxs); } } if (y == b) { /* We're done, make sure we clean up any remaining fill. */ if (fill_start != fill_end) { if (fill_size == N_Y_FRAC(8)) { memset (ap + fill_start, 0xff, fill_end - fill_start); } else { add_saturate_8 (ap + fill_start, fill_size * N_X_FRAC(8), fill_end - fill_start); } } break; } if (xFixedFrac (y) != Y_FRAC_LAST(8)) { RenderEdgeStepSmall (l); RenderEdgeStepSmall (r); y += STEP_Y_SMALL(8); } else { RenderEdgeStepBig (l); RenderEdgeStepBig (r); y += STEP_Y_BIG(8); if (fill_start != fill_end) { if (fill_size == N_Y_FRAC(8)) { memset (ap + fill_start, 0xff, fill_end - fill_start); } else { add_saturate_8 (ap + fill_start, fill_size * N_X_FRAC(8), fill_end - fill_start); } fill_start = fill_end = -1; fill_size = 0; } line += stride; } } } void fbRasterizeEdges (FbBits *buf, int bpp, int width, int stride, RenderEdge *l, RenderEdge *r, xFixed t, xFixed b) { switch (bpp) { case 1: fbRasterizeEdges1 (buf, width, stride, l, r, t, b); break; case 4: fbRasterizeEdges4 (buf, width, stride, l, r, t, b); break; case 8: fbRasterizeEdges8 (buf, width, stride, l, r, t, b); break; } } #endif /* RENDER */