Merge "Bowing my head in shame, going back to gamma interpolated gradients" (f596ba93) · Commits · e / os / android_frameworks_base

libs/hwui/FloatColor.h

+7 −6

Original line number	Diff line number	Diff line
		@@ -38,13 +38,14 @@ struct FloatColor {
		}

		// "color" is a gamma-encoded sRGB color
		// After calling this method, the color is stored as a linear color. The color
		// is not pre-multiplied.
		void setUnPreMultipliedSRGB(uint32_t color) {
		// After calling this method, the color is stored as a un-premultiplied linear color
		// if linear blending is enabled. Otherwise, the color is stored as a un-premultiplied
		// gamma-encoded sRGB color
		void setUnPreMultiplied(uint32_t color) {
		a = ((color >> 24) & 0xff) / 255.0f;
		r = EOCF_sRGB(((color >> 16) & 0xff) / 255.0f);
		g = EOCF_sRGB(((color >> 8) & 0xff) / 255.0f);
		b = EOCF_sRGB(((color ) & 0xff) / 255.0f);
		r = EOCF(((color >> 16) & 0xff) / 255.0f);
		g = EOCF(((color >> 8) & 0xff) / 255.0f);
		b = EOCF(((color ) & 0xff) / 255.0f);
		}

		bool isNotBlack() {

libs/hwui/GradientCache.cpp

+10 −13

Original line number	Diff line number	Diff line
		@@ -189,9 +189,9 @@ void GradientCache::mixBytes(const FloatColor& start, const FloatColor& end,
		float amount, uint8_t*& dst) const {
		float oppAmount = 1.0f - amount;
		float a = start.a * oppAmount + end.a * amount;
		dst++ = uint8_t(a OECF_sRGB((start.r * oppAmount + end.r * amount)) * 255.0f);
		dst++ = uint8_t(a OECF_sRGB((start.g * oppAmount + end.g * amount)) * 255.0f);
		dst++ = uint8_t(a OECF_sRGB((start.b * oppAmount + end.b * amount)) * 255.0f);
		dst++ = uint8_t(a OECF(start.r * oppAmount + end.r * amount) * 255.0f);
		dst++ = uint8_t(a OECF(start.g * oppAmount + end.g * amount) * 255.0f);
		dst++ = uint8_t(a OECF(start.b * oppAmount + end.b * amount) * 255.0f);
		dst++ = uint8_t(a 255.0f);
		}

		@@ -201,17 +201,14 @@ void GradientCache::mixFloats(const FloatColor& start, const FloatColor& end,
		float a = start.a * oppAmount + end.a * amount;
		float* d = (float*) dst;
		#ifdef ANDROID_ENABLE_LINEAR_BLENDING
		// We want to stay linear
		d++ = a (start.r * oppAmount + end.r * amount);
		d++ = a (start.g * oppAmount + end.g * amount);
		d++ = a (start.b * oppAmount + end.b * amount);
		#else
		// What we're doing to the alpha channel here is technically incorrect
		// but reproduces Android's old behavior when the alpha was pre-multiplied
		// with gamma-encoded colors
		a = EOCF_sRGB(a);
		d++ = a OECF_sRGB(start.r * oppAmount + end.r * amount);
		d++ = a OECF_sRGB(start.g * oppAmount + end.g * amount);
		d++ = a OECF_sRGB(start.b * oppAmount + end.b * amount);
		d++ = a OECF(start.r * oppAmount + end.r * amount);
		d++ = a OECF(start.g * oppAmount + end.g * amount);
		d++ = a OECF(start.b * oppAmount + end.b * amount);
		#endif
		*d++ = a;
		dst += 4 * sizeof(float);
		@@ -232,10 +229,10 @@ void GradientCache::generateTexture(uint32_t* colors, float* positions,
		ChannelMixer mix = gMixers[mUseFloatTexture];

		FloatColor start;
		start.setUnPreMultipliedSRGB(colors[0]);
		start.setUnPreMultiplied(colors[0]);

		FloatColor end;
		end.setUnPreMultipliedSRGB(colors[1]);
		end.setUnPreMultiplied(colors[1]);

		int currentPos = 1;
		float startPos = positions[0];
		@@ -250,7 +247,7 @@ void GradientCache::generateTexture(uint32_t* colors, float* positions,

		currentPos++;

		end.setUnPreMultipliedSRGB(colors[currentPos]);
		end.setUnPreMultiplied(colors[currentPos]);
		distance = positions[currentPos] - startPos;
		}

libs/hwui/ProgramCache.cpp

+22 −19

Original line number	Diff line number	Diff line
		@@ -202,23 +202,26 @@ const char* gFS_Gradient_Functions = R"__SHADER__(
		)__SHADER__";
		const char* gFS_Gradient_Preamble[2] = {
		// Linear framebuffer
		"\nvec4 dither(const vec4 color) {\n"
		" return color + (triangleNoise(gl_FragCoord.xy * screenSize.xy) / 255.0);\n"
		"}\n"
		"\nvec4 gammaMix(const vec4 a, const vec4 b, float v) {\n"
		" vec4 c = mix(a, b, v);\n"
		" c.a = EOTF_sRGB(c.a);\n" // This is technically incorrect but preserves compatibility
		" return vec4(OETF_sRGB(c.rgb) * c.a, c.a);\n"
		"}\n",
		R"__SHADER__(
		vec4 dither(const vec4 color) {
		return color + (triangleNoise(gl_FragCoord.xy * screenSize.xy) / 255.0);
		}
		vec4 gradientMix(const vec4 a, const vec4 b, float v) {
		vec4 c = mix(a, b, v);
		return vec4(c.rgb * c.a, c.a);
		}
		)__SHADER__",
		// sRGB framebuffer
		"\nvec4 dither(const vec4 color) {\n"
		" vec3 dithered = sqrt(color.rgb) + (triangleNoise(gl_FragCoord.xy * screenSize.xy) / 255.0);\n"
		" return vec4(dithered * dithered, color.a);\n"
		"}\n"
		"\nvec4 gammaMix(const vec4 a, const vec4 b, float v) {\n"
		" vec4 c = mix(a, b, v);\n"
		" return vec4(c.rgb * c.a, c.a);\n"
		"}\n"
		R"__SHADER__(
		vec4 dither(const vec4 color) {
		vec3 dithered = sqrt(color.rgb) + (triangleNoise(gl_FragCoord.xy * screenSize.xy) / 255.0);
		return vec4(dithered * dithered, color.a);
		}
		vec4 gradientMixMix(const vec4 a, const vec4 b, float v) {
		vec4 c = mix(a, b, v);
		return vec4(c.rgb * c.a, c.a);
		}
		)__SHADER__",
		};

		// Uses luminance coefficients from Rec.709 to choose the appropriate gamma
		@@ -272,19 +275,19 @@ const char* gFS_Main_FetchGradient[6] = {
		// Linear
		" vec4 gradientColor = texture2D(gradientSampler, linear);\n",

		" vec4 gradientColor = gammaMix(startColor, endColor, clamp(linear, 0.0, 1.0));\n",
		" vec4 gradientColor = gradientMix(startColor, endColor, clamp(linear, 0.0, 1.0));\n",

		// Circular
		" vec4 gradientColor = texture2D(gradientSampler, vec2(length(circular), 0.5));\n",

		" vec4 gradientColor = gammaMix(startColor, endColor, clamp(length(circular), 0.0, 1.0));\n",
		" vec4 gradientColor = gradientMix(startColor, endColor, clamp(length(circular), 0.0, 1.0));\n",

		// Sweep
		" highp float index = atan(sweep.y, sweep.x) * 0.15915494309; // inv(2 * PI)\n"
		" vec4 gradientColor = texture2D(gradientSampler, vec2(index - floor(index), 0.5));\n",

		" highp float index = atan(sweep.y, sweep.x) * 0.15915494309; // inv(2 * PI)\n"
		" vec4 gradientColor = gammaMix(startColor, endColor, clamp(index - floor(index), 0.0, 1.0));\n"
		" vec4 gradientColor = gradientMix(startColor, endColor, clamp(index - floor(index), 0.0, 1.0));\n"
		};
		const char* gFS_Main_FetchBitmap =
		" vec4 bitmapColor = OETF(texture2D(bitmapSampler, outBitmapTexCoords));\n";

libs/hwui/SkiaShader.cpp

+2 −2

Original line number	Diff line number	Diff line
		@@ -173,8 +173,8 @@ bool tryStoreGradient(Caches& caches, const SkShader& shader, const Matrix4 mode
		outData->gradientSampler = 0;
		outData->gradientTexture = nullptr;

		outData->startColor.setUnPreMultipliedSRGB(gradInfo.fColors[0]);
		outData->endColor.setUnPreMultipliedSRGB(gradInfo.fColors[1]);
		outData->startColor.setUnPreMultiplied(gradInfo.fColors[0]);
		outData->endColor.setUnPreMultiplied(gradInfo.fColors[1]);
		}

		return true;