void SkComposeShader::ComposeShaderContext::shadeSpan(int x, int y, SkPMColor result[], int count) {
SkShader::Context* shaderContextA = fShaderContextA;
SkShader::Context* shaderContextB = fShaderContextB;
SkBlendMode mode = static_cast<const SkComposeShader&>(fShader).fMode;
unsigned scale = SkAlpha255To256(this->getPaintAlpha());
SkPMColor tmp[TMP_COLOR_COUNT];
SkXfermode* xfer = SkXfermode::Peek(mode);
if (nullptr == xfer) { // implied SRC_OVER
// TODO: when we have a good test-case, should use SkBlitRow::Proc32
// for these loops
do {
int n = count;
if (n > TMP_COLOR_COUNT) {
n = TMP_COLOR_COUNT;
}
shaderContextA->shadeSpan(x, y, result, n);
shaderContextB->shadeSpan(x, y, tmp, n);
if (256 == scale) {
for (int i = 0; i < n; i++) {
result[i] = SkPMSrcOver(tmp[i], result[i]);
}
} else {
for (int i = 0; i < n; i++) {
result[i] = SkAlphaMulQ(SkPMSrcOver(tmp[i], result[i]),
scale);
}
}
result += n;
x += n;
count -= n;
} while (count > 0);
} else { // use mode for the composition
do {
int n = count;
if (n > TMP_COLOR_COUNT) {
n = TMP_COLOR_COUNT;
}
shaderContextA->shadeSpan(x, y, result, n);
shaderContextB->shadeSpan(x, y, tmp, n);
xfer->xfer32(result, tmp, n, nullptr);
if (256 != scale) {
for (int i = 0; i < n; i++) {
result[i] = SkAlphaMulQ(result[i], scale);
}
}
result += n;
x += n;
count -= n;
} while (count > 0);
}
}
DEF_TEST(Color4f_shader, reporter) {
struct {
sk_sp<SkShader> (*fFact)();
bool fSupports4f;
float fTolerance;
} recs[] = {
{ make_color_sh, true, 1.0f/255 },
// PMColor 4f gradients are interpolated in 255-multiplied values, so we need a
// slightly relaxed tolerance to accommodate the cumulative precision deviation.
{ make_grad_sh, true, 1.001f/255 },
{ make_image_sh, false, 1.0f/255 },
{ make_cf_sh, true, 1.0f/255 },
};
SkPaint paint;
for (const auto& rec : recs) {
uint32_t storage[300];
paint.setShader(rec.fFact());
// Encourage 4f context selection. At some point we may need
// to instantiate two separate contexts for optimal 4b/4f selection.
const SkShader::ContextRec contextRec(paint, SkMatrix::I(), nullptr,
SkShader::ContextRec::kPM4f_DstType);
SkASSERT(paint.getShader()->contextSize(contextRec) <= sizeof(storage));
SkShader::Context* ctx = paint.getShader()->createContext(contextRec, storage);
if (rec.fSupports4f) {
const int N = 100;
SkPM4f buffer4f[N];
ctx->shadeSpan4f(0, 0, buffer4f, N);
SkPMColor buffer4b[N];
ctx->shadeSpan(0, 0, buffer4b, N);
REPORTER_ASSERT(reporter, compare_spans(buffer4f, buffer4b, N, rec.fTolerance));
}
ctx->~Context();
}
}
void onDraw(int loops, SkCanvas*) override {
int width = fSrcSize.fWidth;
int height = fSrcSize.fHeight;
SkAutoTMalloc<SkPMColor> buffer4b(width*height);
uint32_t storage[kSkBlitterContextSize];
const SkShader::ContextRec rec(fPaint, fM, nullptr,
SkShader::ContextRec::kPMColor_DstType);
SkASSERT(fPaint.getShader()->contextSize(rec) <= sizeof(storage));
SkShader::Context* ctx = fPaint.getShader()->createContext(rec, storage);
int count = 100;
for (int n = 0; n < 1000*loops; n++) {
ctx->shadeSpan(3, 6, buffer4b, count);
}
ctx->~Context();
}
void SkComposeShader::ComposeShaderContext::shadeSpan(int x, int y, SkPMColor result[], int count) {
SkShader::Context* shaderContextA = fShaderContextA;
SkShader::Context* shaderContextB = fShaderContextB;
SkXfermode* mode = static_cast<const SkComposeShader&>(fShader).fMode;
unsigned scale = SkAlpha255To256(this->getPaintAlpha());
#ifdef SK_BUILD_FOR_ANDROID
scale = 256; // ugh -- maintain old bug/behavior for now
#endif
SkPMColor tmp[TMP_COLOR_COUNT];
if (NULL == mode) { // implied SRC_OVER
// TODO: when we have a good test-case, should use SkBlitRow::Proc32
// for these loops
do {
int n = count;
if (n > TMP_COLOR_COUNT) {
n = TMP_COLOR_COUNT;
}
shaderContextA->shadeSpan(x, y, result, n);
shaderContextB->shadeSpan(x, y, tmp, n);
if (256 == scale) {
for (int i = 0; i < n; i++) {
result[i] = SkPMSrcOver(tmp[i], result[i]);
}
} else {
for (int i = 0; i < n; i++) {
result[i] = SkAlphaMulQ(SkPMSrcOver(tmp[i], result[i]),
scale);
}
}
result += n;
x += n;
count -= n;
} while (count > 0);
} else { // use mode for the composition
do {
int n = count;
if (n > TMP_COLOR_COUNT) {
n = TMP_COLOR_COUNT;
}
shaderContextA->shadeSpan(x, y, result, n);
shaderContextB->shadeSpan(x, y, tmp, n);
mode->xfer32(result, tmp, n, NULL);
if (256 != scale) {
for (int i = 0; i < n; i++) {
result[i] = SkAlphaMulQ(result[i], scale);
}
}
result += n;
x += n;
count -= n;
} while (count > 0);
}
}