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/*
* $Id: fbedgeimp.h,v 1.1 2006/11/26 18:15:35 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.
*/
#ifdef HAVE_DIX_CONFIG_H
#include <dix-config.h>
#endif
#ifndef rasterizeSpan
#endif
static void
rasterizeEdges (FbBits *buf,
int width,
int stride,
RenderEdge *l,
RenderEdge *r,
xFixed t,
xFixed b)
{
xFixed y = t;
FbBits *line;
line = buf + xFixedToInt (y) * stride;
for (;;)
{
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)
{
/* Find pixel bounds for span */
lxi = xFixedToInt (lx);
rxi = xFixedToInt (rx);
#if N_BITS == 1
{
FbBits *a = line;
FbBits startmask, endmask;
int nmiddle;
int width = rxi - lxi;
int x = lxi;
a += x >> FB_SHIFT;
x &= FB_MASK;
FbMaskBits (x, width, startmask, nmiddle, endmask);
if (startmask)
*a++ |= startmask;
while (nmiddle--)
*a++ = FB_ALLONES;
if (endmask)
*a |= endmask;
}
#else
{
DefineAlpha(line,lxi);
int lxs, rxs;
/* Sample coverage for edge pixels */
lxs = RenderSamplesX (lx, N_BITS);
rxs = RenderSamplesX (rx, N_BITS);
/* Add coverage across row */
if (lxi == rxi)
{
AddAlpha (rxs - lxs);
}
else
{
int xi;
AddAlpha (N_X_FRAC(N_BITS) - lxs);
StepAlpha;
for (xi = lxi + 1; xi < rxi; xi++)
{
AddAlpha (N_X_FRAC(N_BITS));
StepAlpha;
}
/* 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 != 0)
AddAlpha (rxs);
}
}
#endif
}
if (y == b)
break;
#if N_BITS > 1
if (xFixedFrac (y) != Y_FRAC_LAST(N_BITS))
{
RenderEdgeStepSmall (l);
RenderEdgeStepSmall (r);
y += STEP_Y_SMALL(N_BITS);
}
else
#endif
{
RenderEdgeStepBig (l);
RenderEdgeStepBig (r);
y += STEP_Y_BIG(N_BITS);
line += stride;
}
}
}
#undef rasterizeSpan
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