Apply gamma correction to font rendering. (b45c0c97) · Commits · e / os / android_frameworks_base

libs/hwui/Android.mk

+1 −0

Original line number	Diff line number	Diff line
		@@ -6,6 +6,7 @@ include $(CLEAR_VARS)
		ifeq ($(USE_OPENGL_RENDERER),true)
		LOCAL_SRC_FILES:= \
		FontRenderer.cpp \
		GammaFontRenderer.cpp \
		GradientCache.cpp \
		LayerCache.cpp \
		Matrix.cpp \

libs/hwui/Caches.h

+2 −3

Original line number	Diff line number	Diff line
		@@ -25,7 +25,7 @@
		#include "LayerCache.h"
		#include "GradientCache.h"
		#include "PatchCache.h"
		#include "FontRenderer.h"
		#include "GammaFontRenderer.h"
		#include "ProgramCache.h"
		#include "PathCache.h"
		#include "TextDropShadowCache.h"
		@@ -42,7 +42,6 @@ struct CacheLogger {
		class Caches: public Singleton<Caches> {
		Caches(): Singleton<Caches>(), blend(false), lastSrcMode(GL_ZERO),
		lastDstMode(GL_ZERO), currentProgram(NULL) {
		dropShadowCache.setFontRenderer(fontRenderer);
		}

		friend class Singleton<Caches>;
		@@ -62,7 +61,7 @@ public:
		PathCache pathCache;
		PatchCache patchCache;
		TextDropShadowCache dropShadowCache;
		FontRenderer fontRenderer;
		GammaFontRenderer fontRenderer;
		}; // class Caches

		}; // namespace uirenderer

libs/hwui/FontRenderer.cpp

+5 −4

Original line number	Diff line number	Diff line
		@@ -286,6 +286,7 @@ Font* Font::create(FontRenderer* state, uint32_t fontId, float fontSize) {
		FontRenderer::FontRenderer() {
		LOGD("Creating FontRenderer");

		mGammaTable = NULL;
		mInitialized = false;
		mMaxNumberOfQuads = 1024;
		mCurrentQuadIndex = 0;
		@@ -405,7 +406,7 @@ bool FontRenderer::cacheBitmap(const SkGlyph& glyph, uint32_t* retOriginX, uint3
		for (cacheX = startX, bX = 0; cacheX < endX; cacheX++, bX++) {
		for (cacheY = startY, bY = 0; cacheY < endY; cacheY++, bY++) {
		uint8_t tempCol = bitmapBuffer[bY * stride + bX];
		cacheBuffer[cacheY * cacheWidth + cacheX] = tempCol;
		cacheBuffer[cacheY * cacheWidth + cacheX] = mGammaTable[tempCol];
		}
		}

libs/hwui/FontRenderer.h

+6 −0

Original line number	Diff line number	Diff line
		@@ -124,6 +124,10 @@ public:
		void init();
		void deinit();

		void setGammaTable(const uint8_t* gammaTable) {
		mGammaTable = gammaTable;
		}

		void setFont(SkPaint* paint, uint32_t fontId, float fontSize);
		void renderText(SkPaint* paint, const Rect* clip, const char *text, uint32_t startIndex,
		uint32_t len, int numGlyphs, int x, int y);
		@@ -157,6 +161,8 @@ public:
		protected:
		friend class Font;

		const uint8_t* mGammaTable;

		struct CacheTextureLine {
		uint16_t mMaxHeight;
		uint16_t mMaxWidth;

libs/hwui/GammaFontRenderer.cpp

0 → 100644

+103 −0

Original line number	Diff line number	Diff line
		/*
		* Copyright (C) 2010 The Android Open Source Project
		*
		* Licensed under the Apache License, Version 2.0 (the "License");
		* you may not use this file except in compliance with the License.
		* You may obtain a copy of the License at
		*
		* http://www.apache.org/licenses/LICENSE-2.0
		*
		* Unless required by applicable law or agreed to in writing, software
		* distributed under the License is distributed on an "AS IS" BASIS,
		* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
		* See the License for the specific language governing permissions and
		* limitations under the License.
		*/

		#define LOG_TAG "OpenGLRenderer"

		#include "GammaFontRenderer.h"
		#include "Properties.h"

		namespace android {
		namespace uirenderer {

		///////////////////////////////////////////////////////////////////////////////
		// Constructors/destructor
		///////////////////////////////////////////////////////////////////////////////

		GammaFontRenderer::GammaFontRenderer() {
		LOGD("Creating gamma font renderer");

		// Get the renderer properties
		char property[PROPERTY_VALUE_MAX];

		// Get the gamma
		float gamma = DEFAULT_TEXT_GAMMA;
		if (property_get(PROPERTY_TEXT_GAMMA, property, NULL) > 0) {
		LOGD(" Setting text gamma to %s", property);
		gamma = atof(property);
		} else {
		LOGD(" Using default text gamma of %.2f", DEFAULT_TEXT_GAMMA);
		}

		// Get the black gamma threshold
		mBlackThreshold = DEFAULT_TEXT_BLACK_GAMMA_THRESHOLD;
		if (property_get(PROPERTY_TEXT_BLACK_GAMMA_THRESHOLD, property, NULL) > 0) {
		LOGD(" Setting text black gamma threshold to %s", property);
		mBlackThreshold = atoi(property);
		} else {
		LOGD(" Using default text black gamma threshold of %d",
		DEFAULT_TEXT_BLACK_GAMMA_THRESHOLD);
		}

		// Get the white gamma threshold
		mWhiteThreshold = DEFAULT_TEXT_WHITE_GAMMA_THRESHOLD;
		if (property_get(PROPERTY_TEXT_WHITE_GAMMA_THRESHOLD, property, NULL) > 0) {
		LOGD(" Setting text white gamma threshold to %s", property);
		mWhiteThreshold = atoi(property);
		} else {
		LOGD(" Using default white black gamma threshold of %d",
		DEFAULT_TEXT_WHITE_GAMMA_THRESHOLD);
		}

		// Compute the gamma tables
		const float blackGamma = gamma;
		const float whiteGamma = 1.0f / gamma;

		for (uint32_t i = 0; i <= 255; i++) {
		mDefault[i] = i;

		const float v = i / 255.0f;
		const float black = pow(v, blackGamma);
		const float white = pow(v, whiteGamma);

		mBlackGamma[i] = uint8_t((float)::floor(black * 255.0f + 0.5f));
		mWhiteGamma[i] = uint8_t((float)::floor(white * 255.0f + 0.5f));
		}

		// Configure the font renderers
		mDefaultRenderer.setGammaTable(&mDefault[0]);
		mBlackGammaRenderer.setGammaTable(&mBlackGamma[0]);
		mWhiteGammaRenderer.setGammaTable(&mWhiteGamma[0]);
		}

		FontRenderer& GammaFontRenderer::getFontRenderer(const SkPaint* paint) {
		if (paint->getShader() == NULL) {
		uint32_t c = paint->getColor();
		const int r = (c >> 16) & 0xFF;
		const int g = (c >> 8) & 0xFF;
		const int b = (c ) & 0xFF;
		const int luminance = (r * 2 + g * 5 + b) >> 3;

		if (luminance <= mBlackThreshold) {
		return mBlackGammaRenderer;
		} else if (luminance >= mWhiteThreshold) {
		return mWhiteGammaRenderer;
		}
		}
		return mDefaultRenderer;
		}

		}; // namespace uirenderer
		}; // namespace android