135 lines
2.9 KiB
C
135 lines
2.9 KiB
C
/*
|
|
* $Id$
|
|
*
|
|
* 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.
|
|
*/
|
|
|
|
#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;
|
|
}
|
|
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
|