Specify COLRv1 gradient interpolation
Stage this behind a new SK_IGNORE_COLRV1_GRADIENT_COLORSPACE_FIX flag so
that users can be updated in an orderly fashion.
Bug: skia:40045100
Change-Id: I12b0b58f83476635b31b31deaa29e015bdf5010b
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/747671
Reviewed-by: Brian Osman <brianosman@google.com>
Commit-Queue: Ben Wagner <bungeman@google.com>
diff --git a/src/ports/SkFontHost_FreeType_common.cpp b/src/ports/SkFontHost_FreeType_common.cpp
index 70af197..885db58 100644
--- a/src/ports/SkFontHost_FreeType_common.cpp
+++ b/src/ports/SkFontHost_FreeType_common.cpp
@@ -434,6 +434,7 @@
// truncating and drawing color lines. When drawing into N32 surfaces, this is expected to be true.
// If that changes, or if we support other color spaces in CPAL tables at some point, this needs to
// be looked at.
+#ifdef SK_IGNORE_COLRV1_GRADIENT_COLORSPACE_FIX
SkColor lerpSkColor(SkColor c0, SkColor c1, float t) {
// Due to the floating point calculation in the caller, when interpolating between very narrow
// stops, we may get values outside the interpolation range, guard against these.
@@ -448,6 +449,26 @@
return Sk4f_toL32(c_4f);
}
+#else
+SkColor4f lerpSkColor(SkColor4f c0, SkColor4f c1, float t) {
+ // Due to the floating point calculation in the caller, when interpolating between very narrow
+ // stops, we may get values outside the interpolation range, guard against these.
+ if (t < 0) {
+ return c0;
+ }
+ if (t > 1) {
+ return c1;
+ }
+
+ const auto c0_4f = skvx::float4::Load(c0.vec());
+ const auto c1_4f = skvx::float4::Load(c1.vec());
+ const auto c_4f = c0_4f + (c1_4f - c0_4f) * t;
+
+ SkColor4f l;
+ c_4f.store(l.vec());
+ return l;
+}
+#endif
enum TruncateStops {
TruncateStart,
@@ -457,7 +478,11 @@
// Truncate a vector of color stops at a previously computed stop position and insert at that
// position the color interpolated between the surrounding stops.
void truncateToStopInterpolating(SkScalar zeroRadiusStop,
+#ifdef SK_IGNORE_COLRV1_GRADIENT_COLORSPACE_FIX
std::vector<SkColor>& colors,
+#else
+ std::vector<SkColor4f>& colors,
+#endif
std::vector<SkScalar>& stops,
TruncateStops truncateStops) {
if (stops.size() <= 1u ||
@@ -472,7 +497,11 @@
const float t = (zeroRadiusStop - stops[afterIndex - 1]) /
(stops[afterIndex] - stops[afterIndex - 1]);
+#ifdef SK_IGNORE_COLRV1_GRADIENT_COLORSPACE_FIX
SkColor lerpColor = lerpSkColor(colors[afterIndex - 1], colors[afterIndex], t);
+#else
+ SkColor4f lerpColor = lerpSkColor(colors[afterIndex - 1], colors[afterIndex], t);
+#endif
if (truncateStops == TruncateStart) {
stops.erase(stops.begin(), stops.begin() + afterIndex);
@@ -602,7 +631,11 @@
auto fetchColorStops = [&face, &palette, &foregroundColor](
const FT_ColorStopIterator& colorStopIterator,
std::vector<SkScalar>& stops,
+#ifdef SK_IGNORE_COLRV1_GRADIENT_COLORSPACE_FIX
std::vector<SkColor>& colors) -> bool {
+#else
+ std::vector<SkColor4f>& colors) -> bool {
+#endif
const FT_UInt colorStopCount = colorStopIterator.num_color_stops;
if (colorStopCount == 0) {
return false;
@@ -612,29 +645,52 @@
// "Applications shall apply the colorStops in increasing stopOffset order."
struct ColorStop {
SkScalar pos;
+#ifdef SK_IGNORE_COLRV1_GRADIENT_COLORSPACE_FIX
SkColor color;
+#else
+ SkColor4f color;
+#endif
};
std::vector<ColorStop> colorStopsSorted;
colorStopsSorted.resize(colorStopCount);
- FT_ColorStop color_stop;
+#ifdef SK_IGNORE_COLRV1_GRADIENT_COLORSPACE_FIX
+ FT_ColorStop color_stop;
+ FT_ColorStopIterator mutable_color_stop_iterator = colorStopIterator;
+ while (FT_Get_Colorline_Stops(face, &color_stop, &mutable_color_stop_iterator)) {
+ FT_UInt index = mutable_color_stop_iterator.current_color_stop - 1;
+ colorStopsSorted[index].pos = color_stop.stop_offset / kColorStopShift;
+ FT_UInt16& palette_index = color_stop.color.palette_index;
+ if (palette_index == kForegroundColorPaletteIndex) {
+ U8CPU newAlpha = SkColorGetA(foregroundColor) *
+ SkColrV1AlphaToFloat(color_stop.color.alpha);
+ colorStopsSorted[index].color = SkColorSetA(foregroundColor, newAlpha);
+ } else if (palette_index >= palette.size()) {
+ return false;
+ } else {
+ U8CPU newAlpha = SkColorGetA(palette[palette_index]) *
+ SkColrV1AlphaToFloat(color_stop.color.alpha);
+ colorStopsSorted[index].color = SkColorSetA(palette[palette_index], newAlpha);
+ }
+ }
+#else
+ FT_ColorStop ftStop;
FT_ColorStopIterator mutable_color_stop_iterator = colorStopIterator;
- while (FT_Get_Colorline_Stops(face, &color_stop, &mutable_color_stop_iterator)) {
+ while (FT_Get_Colorline_Stops(face, &ftStop, &mutable_color_stop_iterator)) {
FT_UInt index = mutable_color_stop_iterator.current_color_stop - 1;
- colorStopsSorted[index].pos = color_stop.stop_offset / kColorStopShift;
- FT_UInt16& palette_index = color_stop.color.palette_index;
+ ColorStop& skStop = colorStopsSorted[index];
+ skStop.pos = ftStop.stop_offset / kColorStopShift;
+ FT_UInt16& palette_index = ftStop.color.palette_index;
if (palette_index == kForegroundColorPaletteIndex) {
- U8CPU newAlpha = SkColorGetA(foregroundColor) *
- SkColrV1AlphaToFloat(color_stop.color.alpha);
- colorStopsSorted[index].color = SkColorSetA(foregroundColor, newAlpha);
+ skStop.color = SkColor4f::FromColor(foregroundColor);
} else if (palette_index >= palette.size()) {
return false;
} else {
- U8CPU newAlpha = SkColorGetA(palette[palette_index]) *
- SkColrV1AlphaToFloat(color_stop.color.alpha);
- colorStopsSorted[index].color = SkColorSetA(palette[palette_index], newAlpha);
+ skStop.color = SkColor4f::FromColor(palette[palette_index]);
}
+ skStop.color.fA *= SkColrV1AlphaToFloat(ftStop.color.alpha);
}
+#endif
std::stable_sort(colorStopsSorted.begin(), colorStopsSorted.end(),
[](const ColorStop& a, const ColorStop& b) { return a.pos < b.pos; });
@@ -653,6 +709,7 @@
FT_PaintSolid solid = colrPaint.u.solid;
// Dont' draw anything with this color if the palette index is out of bounds.
+#ifdef SK_IGNORE_COLRV1_GRADIENT_COLORSPACE_FIX
SkColor color = SK_ColorTRANSPARENT;
if (solid.color.palette_index == kForegroundColorPaletteIndex) {
U8CPU newAlpha = SkColorGetA(foregroundColor) *
@@ -665,6 +722,17 @@
SkColrV1AlphaToFloat(solid.color.alpha);
color = SkColorSetA(palette[solid.color.palette_index], newAlpha);
}
+#else
+ SkColor4f color = SkColors::kTransparent;
+ if (solid.color.palette_index == kForegroundColorPaletteIndex) {
+ color = SkColor4f::FromColor(foregroundColor);
+ } else if (solid.color.palette_index >= palette.size()) {
+ return false;
+ } else {
+ color = SkColor4f::FromColor(palette[solid.color.palette_index]);
+ }
+ color.fA *= SkColrV1AlphaToFloat(solid.color.alpha);
+#endif
paint->setShader(nullptr);
paint->setColor(color);
return true;
@@ -672,7 +740,11 @@
case FT_COLR_PAINTFORMAT_LINEAR_GRADIENT: {
const FT_PaintLinearGradient& linearGradient = colrPaint.u.linear_gradient;
std::vector<SkScalar> stops;
+#ifdef SK_IGNORE_COLRV1_GRADIENT_COLORSPACE_FIX
std::vector<SkColor> colors;
+#else
+ std::vector<SkColor4f> colors;
+#endif
if (!fetchColorStops(linearGradient.colorline.color_stop_iterator, stops, colors)) {
return false;
@@ -761,10 +833,24 @@
}
}
+#ifdef SK_IGNORE_COLRV1_GRADIENT_COLORSPACE_FIX
sk_sp<SkShader> shader(SkGradientShader::MakeLinear(
linePositions,
colors.data(), stops.data(), stops.size(),
tileMode));
+#else
+ sk_sp<SkShader> shader(SkGradientShader::MakeLinear(
+ linePositions,
+ colors.data(), SkColorSpace::MakeSRGB(), stops.data(), stops.size(),
+ tileMode,
+ SkGradientShader::Interpolation{
+ SkGradientShader::Interpolation::InPremul::kNo,
+ SkGradientShader::Interpolation::ColorSpace::kSRGB,
+ SkGradientShader::Interpolation::HueMethod::kShorter
+ },
+ nullptr));
+#endif
+
SkASSERT(shader);
// An opaque color is needed to ensure the gradient is not modulated by alpha.
paint->setColor(SK_ColorBLACK);
@@ -782,7 +868,11 @@
std::vector<SkScalar> stops;
+#ifdef SK_IGNORE_COLRV1_GRADIENT_COLORSPACE_FIX
std::vector<SkColor> colors;
+#else
+ std::vector<SkColor4f> colors;
+#endif
if (!fetchColorStops(radialGradient.colorline.color_stop_iterator, stops, colors)) {
return false;
}
@@ -938,9 +1028,23 @@
// An opaque color is needed to ensure the gradient is not modulated by alpha.
paint->setColor(SK_ColorBLACK);
+#ifdef SK_IGNORE_COLRV1_GRADIENT_COLORSPACE_FIX
paint->setShader(SkGradientShader::MakeTwoPointConical(
start, startRadius, end, endRadius, colors.data(), stops.data(), stops.size(),
tileMode));
+#else
+ paint->setShader(SkGradientShader::MakeTwoPointConical(
+ start, startRadius, end, endRadius,
+ colors.data(), SkColorSpace::MakeSRGB(), stops.data(), stops.size(),
+ tileMode,
+ SkGradientShader::Interpolation{
+ SkGradientShader::Interpolation::InPremul::kNo,
+ SkGradientShader::Interpolation::ColorSpace::kSRGB,
+ SkGradientShader::Interpolation::HueMethod::kShorter
+ },
+ nullptr));
+#endif
+
return true;
}
case FT_COLR_PAINTFORMAT_SWEEP_GRADIENT: {
@@ -957,7 +1061,11 @@
endAngle += 180.0f;
std::vector<SkScalar> stops;
+#ifdef SK_IGNORE_COLRV1_GRADIENT_COLORSPACE_FIX
std::vector<SkColor> colors;
+#else
+ std::vector<SkColor4f> colors;
+#endif
if (!fetchColorStops(sweepGradient.colorline.color_stop_iterator, stops, colors)) {
return false;
}
@@ -1042,6 +1150,7 @@
}
}
+#ifdef SK_IGNORE_COLRV1_GRADIENT_COLORSPACE_FIX
paint->setShader(SkGradientShader::MakeSweep(center.x(), center.y(),
colors.data(),
stops.data(), stops.size(),
@@ -1049,6 +1158,20 @@
startAngleScaled,
endAngleScaled,
0, nullptr));
+#else
+ paint->setShader(SkGradientShader::MakeSweep(
+ center.x(), center.y(),
+ colors.data(), SkColorSpace::MakeSRGB(), stops.data(), stops.size(),
+ tileMode,
+ startAngleScaled, endAngleScaled,
+ SkGradientShader::Interpolation{
+ SkGradientShader::Interpolation::InPremul::kNo,
+ SkGradientShader::Interpolation::ColorSpace::kSRGB,
+ SkGradientShader::Interpolation::HueMethod::kShorter
+ },
+ nullptr));
+#endif
+
return true;
}
default: {
diff --git a/src/ports/SkScalerContext_win_dw.cpp b/src/ports/SkScalerContext_win_dw.cpp
index 608374a..68b4744 100644
--- a/src/ports/SkScalerContext_win_dw.cpp
+++ b/src/ports/SkScalerContext_win_dw.cpp
@@ -781,16 +781,24 @@
}
}
- std::unique_ptr<SkColor[]> skColors(new SkColor[stops.size()]);
+ std::unique_ptr<SkColor4f[]> skColors(new SkColor4f[stops.size()]);
std::unique_ptr<SkScalar[]> skStops(new SkScalar[stops.size()]);
for (size_t i = 0; i < stops.size(); ++i) {
- skColors[i] = sk_color_from(stops[i].color).toSkColor();
+ skColors[i] = sk_color_from(stops[i].color);
skStops[i] = stops[i].position;
}
sk_sp<SkShader> shader(SkGradientShader::MakeLinear(
linePositions,
- skColors.get(), skStops.get(), stops.size(), tileMode));
+ skColors.get(), SkColorSpace::MakeSRGB(), skStops.get(), stops.size(),
+ tileMode,
+ SkGradientShader::Interpolation{
+ SkGradientShader::Interpolation::InPremul::kNo,
+ SkGradientShader::Interpolation::ColorSpace::kSRGB,
+ SkGradientShader::Interpolation::HueMethod::kShorter
+ },
+ nullptr));
+
SkASSERT(shader);
// An opaque color is needed to ensure the gradient is not modulated by alpha.
skPaint.setColor(SK_ColorBLACK);
@@ -964,10 +972,10 @@
}
}
- std::unique_ptr<SkColor[]> skColors(new SkColor[stops.size()]);
+ std::unique_ptr<SkColor4f[]> skColors(new SkColor4f[stops.size()]);
std::unique_ptr<SkScalar[]> skStops(new SkScalar[stops.size()]);
for (size_t i = 0; i < stops.size(); ++i) {
- skColors[i] = sk_color_from(stops[i].color).toSkColor();
+ skColors[i] = sk_color_from(stops[i].color);
skStops[i] = stops[i].position;
}
@@ -975,7 +983,14 @@
skPaint.setColor(SK_ColorBLACK);
skPaint.setShader(SkGradientShader::MakeTwoPointConical(
start, startRadius, end, endRadius,
- skColors.get(), skStops.get(), stops.size(), tileMode));
+ skColors.get(), SkColorSpace::MakeSRGB(), skStops.get(), stops.size(),
+ tileMode,
+ SkGradientShader::Interpolation{
+ SkGradientShader::Interpolation::InPremul::kNo,
+ SkGradientShader::Interpolation::ColorSpace::kSRGB,
+ SkGradientShader::Interpolation::HueMethod::kShorter
+ },
+ nullptr));
canvas.drawPaint(skPaint);
return true;
}
@@ -1082,18 +1097,24 @@
}
}
- std::unique_ptr<SkColor[]> skColors(new SkColor[stops.size()]);
+ std::unique_ptr<SkColor4f[]> skColors(new SkColor4f[stops.size()]);
std::unique_ptr<SkScalar[]> skStops(new SkScalar[stops.size()]);
for (size_t i = 0; i < stops.size(); ++i) {
- skColors[i] = sk_color_from(stops[i].color).toSkColor();
+ skColors[i] = sk_color_from(stops[i].color);
skStops[i] = stops[i].position;
}
skPaint.setShader(SkGradientShader::MakeSweep(
center.x(), center.y(),
- skColors.get(), skStops.get(), stops.size(), tileMode,
+ skColors.get(), SkColorSpace::MakeSRGB(), skStops.get(), stops.size(),
+ tileMode,
startAngleScaled, endAngleScaled,
- 0, nullptr));
+ SkGradientShader::Interpolation{
+ SkGradientShader::Interpolation::InPremul::kNo,
+ SkGradientShader::Interpolation::ColorSpace::kSRGB,
+ SkGradientShader::Interpolation::HueMethod::kShorter
+ },
+ nullptr));
canvas.drawPaint(skPaint);
return true;
}
