void
fbRasterizeTrapezoid (PicturePtr pPicture,
xTrapezoid *trap,
int x_off,
int y_off)
{
FbBits *buf;
int bpp;
int width;
int stride;
int height;
int pxoff, pyoff;
xFixed x_off_fixed;
xFixed y_off_fixed;
RenderEdge l, r;
xFixed t, b;
if (!xTrapezoidValid (trap))
return;
fbGetDrawable (pPicture->pDrawable, buf, stride, bpp, pxoff, pyoff);
width = pPicture->pDrawable->width;
height = pPicture->pDrawable->height;
x_off += pxoff;
y_off += pyoff;
x_off_fixed = IntToxFixed(x_off);
y_off_fixed = IntToxFixed(y_off);
t = trap->top + y_off_fixed;
if (t < 0)
t = 0;
t = RenderSampleCeilY (t, bpp);
b = trap->bottom + y_off_fixed;
if (xFixedToInt (b) >= height)
b = IntToxFixed (height) - 1;
b = RenderSampleFloorY (b, bpp);
if (b >= t)
{
/* initialize edge walkers */
RenderLineFixedEdgeInit (&l, bpp, t, &trap->left, x_off, y_off);
RenderLineFixedEdgeInit (&r, bpp, t, &trap->right, x_off, y_off);
fbRasterizeEdges (buf, bpp, width, stride, &l, &r, t, b);
}
}
void
fbAddTraps (PicturePtr pPicture,
INT16 x_off,
INT16 y_off,
int ntrap,
xTrap *traps)
{
FbBits *buf;
int bpp;
int width;
int stride;
int height;
int pxoff, pyoff;
xFixed x_off_fixed;
xFixed y_off_fixed;
RenderEdge l, r;
xFixed t, b;
fbGetDrawable (pPicture->pDrawable, buf, stride, bpp, pxoff, pyoff);
width = pPicture->pDrawable->width;
height = pPicture->pDrawable->height;
x_off += pxoff;
y_off += pyoff;
x_off_fixed = IntToxFixed(y_off);
y_off_fixed = IntToxFixed(y_off);
while (ntrap--)
{
t = traps->top.y + y_off_fixed;
if (t < 0)
t = 0;
t = RenderSampleCeilY (t, bpp);
b = traps->bot.y + y_off_fixed;
if (xFixedToInt (b) >= height)
b = IntToxFixed (height) - 1;
b = RenderSampleFloorY (b, bpp);
if (b >= t)
{
/* initialize edge walkers */
RenderEdgeInit (&l, bpp, t,
traps->top.l + x_off_fixed,
traps->top.y + y_off_fixed,
traps->bot.l + x_off_fixed,
traps->bot.y + y_off_fixed);
RenderEdgeInit (&r, bpp, t,
traps->top.r + x_off_fixed,
traps->top.y + y_off_fixed,
traps->bot.r + x_off_fixed,
traps->bot.y + y_off_fixed);
fbRasterizeEdges (buf, bpp, width, stride, &l, &r, t, b);
}
traps++;
}
}