/** We take the original colors, not our premultiplied PMColors, since we can
build a 16bit table as long as the original colors are opaque, even if the
paint specifies a non-opaque alpha.
*/
void SkGradientShaderBase::GradientShaderCache::Build16bitCache(
uint16_t cache[], SkColor c0, SkColor c1, int count, bool dither) {
SkASSERT(count > 1);
SkASSERT(SkColorGetA(c0) == 0xFF);
SkASSERT(SkColorGetA(c1) == 0xFF);
SkFixed r = SkColorGetR(c0);
SkFixed g = SkColorGetG(c0);
SkFixed b = SkColorGetB(c0);
SkFixed dr = SkIntToFixed(SkColorGetR(c1) - r) / (count - 1);
SkFixed dg = SkIntToFixed(SkColorGetG(c1) - g) / (count - 1);
SkFixed db = SkIntToFixed(SkColorGetB(c1) - b) / (count - 1);
r = SkIntToFixed(r) + 0x8000;
g = SkIntToFixed(g) + 0x8000;
b = SkIntToFixed(b) + 0x8000;
if (dither) {
do {
unsigned rr = r >> 16;
unsigned gg = g >> 16;
unsigned bb = b >> 16;
cache[0] = SkPackRGB16(SkR32ToR16(rr), SkG32ToG16(gg), SkB32ToB16(bb));
cache[kCache16Count] = SkDitherPack888ToRGB16(rr, gg, bb);
cache += 1;
r += dr;
g += dg;
b += db;
} while (--count != 0);
} else {
do {
static uint16_t lighten_modeproc16_255(SkPMColor src, uint16_t dst) {
SkASSERT(require_255(src));
unsigned r = SkMax32(SkPacked32ToR16(src), SkGetPackedR16(dst));
unsigned g = SkMax32(SkPacked32ToG16(src), SkGetPackedG16(dst));
unsigned b = SkMax32(SkPacked32ToB16(src), SkGetPackedB16(dst));
return SkPackRGB16(r, g, b);
}
static uint16_t srcatop_modeproc16(SkPMColor src, uint16_t dst) {
unsigned isa = 255 - SkGetPackedA32(src);
return SkPackRGB16(
SkPacked32ToR16(src) + SkAlphaMulAlpha(SkGetPackedR16(dst), isa),
SkPacked32ToG16(src) + SkAlphaMulAlpha(SkGetPackedG16(dst), isa),
SkPacked32ToB16(src) + SkAlphaMulAlpha(SkGetPackedB16(dst), isa));
}
static inline U16CPU SkBlend3216(SkPMColor src, U16CPU dst, unsigned scale) {
SkASSERT(scale <= 32);
scale <<= 3;
return SkPackRGB16(SkAlphaBlend(SkPacked32ToR16(src), SkGetPackedR16(dst), scale),
SkAlphaBlend(SkPacked32ToG16(src), SkGetPackedG16(dst), scale),
SkAlphaBlend(SkPacked32ToB16(src), SkGetPackedB16(dst), scale));
}
static inline void D16_S32A_Blend_Pixel_helper(uint16_t* dst, SkPMColor sc,
unsigned src_scale) {
uint16_t dc = *dst;
unsigned sa = SkGetPackedA32(sc);
unsigned dr, dg, db;
if (255 == sa) {
dr = SkAlphaBlend(SkPacked32ToR16(sc), SkGetPackedR16(dc), src_scale);
dg = SkAlphaBlend(SkPacked32ToG16(sc), SkGetPackedG16(dc), src_scale);
db = SkAlphaBlend(SkPacked32ToB16(sc), SkGetPackedB16(dc), src_scale);
} else {
unsigned dst_scale = 255 - SkAlphaMul(sa, src_scale);
dr = (SkPacked32ToR16(sc) * src_scale + SkGetPackedR16(dc) * dst_scale) >> 8;
dg = (SkPacked32ToG16(sc) * src_scale + SkGetPackedG16(dc) * dst_scale) >> 8;
db = (SkPacked32ToB16(sc) * src_scale + SkGetPackedB16(dc) * dst_scale) >> 8;
}
*dst = SkPackRGB16(dr, dg, db);
}
static inline void test_565blend() {
int total_failures = 0;
for (int global_alpha = 0; global_alpha <= 255; ++global_alpha) {
int failures = 0;
int total = 0;
for (int src_a = 0; src_a <= 255; ++src_a) {
for (int src_c = 0; src_c <= src_a; ++src_c) {
SkPMColor sc = SkPackARGB32(src_a, src_c, src_c, src_c);
for (int dst_r = 0; dst_r <= 31; ++dst_r) {
for (int dst_g = 0; dst_g <= 63; ++dst_g) {
uint16_t dc = SkPackRGB16(dst_r, dst_g, dst_r);
failures += !S32A_D565_Blend_0(sc, dc, global_alpha);
total += 1;
}
}
}
}
SkDebugf("global_alpha=%d failures=%d total=%d %g\n", global_alpha, failures, total, failures * 100.0 / total);
total_failures += failures;
}
SkDebugf("total failures %d\n", total_failures);
}
unsigned rr = r >> 16;
unsigned gg = g >> 16;
unsigned bb = b >> 16;
cache[0] = SkPackRGB16(SkR32ToR16(rr), SkG32ToG16(gg), SkB32ToB16(bb));
cache[kCache16Count] = SkDitherPack888ToRGB16(rr, gg, bb);
cache += 1;
r += dr;
g += dg;
b += db;
} while (--count != 0);
} else {
do {
unsigned rr = r >> 16;
unsigned gg = g >> 16;
unsigned bb = b >> 16;
cache[0] = SkPackRGB16(SkR32ToR16(rr), SkG32ToG16(gg), SkB32ToB16(bb));
cache[kCache16Count] = cache[0];
cache += 1;
r += dr;
g += dg;
b += db;
} while (--count != 0);
}
}
/*
* r,g,b used to be SkFixed, but on gcc (4.2.1 mac and 4.6.3 goobuntu) in
* release builds, we saw a compiler error where the 0xFF parameter in
* SkPackARGB32() was being totally ignored whenever it was called with
* a non-zero add (e.g. 0x8000).
*
