Aurelien
/
xf86-video-intel
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

sna/traps: Make the inline u8 arithmetic more robust 

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
This commit is contained in:
Chris Wilson 2012-03-16 09:28:24 +00:00
parent d55bbdf42c
commit cb04cf9f43
1 changed files with 29 additions and 4 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

33
src/sna/sna_trapezoids.c
View File

@ -3553,6 +3553,19 @@ struct inplace {
uint8_t opacity;
};
static inline uint8_t
mul_8_8(uint8_t a, uint8_t b)
{
uint16_t t = a * (uint16_t)b + 0x7f;
return ((t >> 8) + t) >> 8;
}
static uint8_t coverage_opacity(int coverage, uint8_t opacity)
{
coverage = coverage * 256 / FAST_SAMPLES_XY;
return mul_8_8(coverage - (coverage >> 8), opacity);
}
static void
tor_blt_src(struct sna *sna,
struct sna_composite_spans_op *op,
@ -3564,7 +3577,7 @@ tor_blt_src(struct sna *sna,
uint8_t *ptr = in->ptr;
int h, w;
coverage = coverage * in->opacity / FAST_SAMPLES_XY;
coverage = coverage_opacity(coverage, in->opacity);
ptr += box->y1 * in->stride + box->x1;
@ -3613,19 +3626,22 @@ tor_blt_in(struct sna *sna,
uint8_t *ptr = in->ptr;
int h, w, i;
coverage = coverage * in->opacity / FAST_SAMPLES_XY;
if (coverage == 0) {
tor_blt_src(sna, op, clip, box, 0);
return;
}
coverage = coverage_opacity(coverage, in->opacity);
if (coverage == 0xff)
return;
ptr += box->y1 * in->stride + box->x1;
h = box->y2 - box->y1;
w = box->x2 - box->x1;
do {
for (i = 0; i < w; i++)
ptr[i] = (ptr[i] * coverage) >> 8;
ptr[i] = mul_8_8(ptr[i], coverage);
ptr += in->stride;
} while (--h);
}
@ -3660,10 +3676,15 @@ tor_blt_add(struct sna *sna,
uint8_t *ptr = in->ptr;
int h, w, v, i;
coverage = coverage * in->opacity / FAST_SAMPLES_XY;
if (coverage == 0)
return;
coverage = coverage_opacity(coverage, in->opacity);
if (coverage == 0xff) {
tor_blt_src(sna, op, clip, box, 0xff);
return;
}
ptr += box->y1 * in->stride + box->x1;
h = box->y2 - box->y1;
@ -4057,10 +4078,14 @@ trapezoid_span_inplace(CARD8 op, PicturePtr src, PicturePtr dst,
case PictOpAdd:
if (priv->clear && priv->clear_color == 0)
op = PictOpSrc;
if ((color >> 24) == 0)
return true;
break;
case PictOpIn:
if (priv->clear && priv->clear_color == 0)
return true;
if ((color >> 24) == 0)
return true;
case PictOpSrc:
break;
default: