Refactor Skia shaders handling.
With this change, Skia shaders can easily be applied to any mesh. This change also
supports ComposeShader. For instance, this can be used to blend a gradient and a
bitmap togehter and paint a string of text with the result.
Change-Id: I701c2f9cf7f89b2ff58005e8a1d0d80ccf4a4aea
diff --git a/libs/hwui/SkiaShader.cpp b/libs/hwui/SkiaShader.cpp
new file mode 100644
index 0000000..fedb56c
--- /dev/null
+++ b/libs/hwui/SkiaShader.cpp
@@ -0,0 +1,220 @@
+/*
+ * 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 <utils/Log.h>
+
+#include <SkMatrix.h>
+
+#include "SkiaShader.h"
+#include "Texture.h"
+#include "Matrix.h"
+
+namespace android {
+namespace uirenderer {
+
+///////////////////////////////////////////////////////////////////////////////
+// Support
+///////////////////////////////////////////////////////////////////////////////
+
+static const GLenum gTextureUnitsMap[] = {
+ GL_TEXTURE0,
+ GL_TEXTURE1,
+ GL_TEXTURE2
+};
+
+static const GLint gTileModes[] = {
+ GL_CLAMP_TO_EDGE, // == SkShader::kClamp_TileMode
+ GL_REPEAT, // == SkShader::kRepeat_Mode
+ GL_MIRRORED_REPEAT // == SkShader::kMirror_TileMode
+};
+
+///////////////////////////////////////////////////////////////////////////////
+// Base shader
+///////////////////////////////////////////////////////////////////////////////
+
+SkiaShader::SkiaShader(Type type, SkShader* key, SkShader::TileMode tileX,
+ SkShader::TileMode tileY, SkMatrix* matrix, bool blend):
+ mType(type), mKey(key), mTileX(tileX), mTileY(tileY), mMatrix(matrix), mBlend(blend) {
+}
+
+SkiaShader::~SkiaShader() {
+}
+
+void SkiaShader::describe(ProgramDescription& description, const Extensions& extensions) {
+}
+
+void SkiaShader::setupProgram(Program* program, const mat4& modelView, const Snapshot& snapshot,
+ GLuint* textureUnit) {
+}
+
+void SkiaShader::bindTexture(GLuint texture, GLenum wrapS, GLenum wrapT, GLuint textureUnit) {
+ glActiveTexture(gTextureUnitsMap[textureUnit]);
+ glBindTexture(GL_TEXTURE_2D, texture);
+ glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, wrapS);
+ glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, wrapT);
+}
+
+///////////////////////////////////////////////////////////////////////////////
+// Bitmap shader
+///////////////////////////////////////////////////////////////////////////////
+
+SkiaBitmapShader::SkiaBitmapShader(SkBitmap* bitmap, SkShader* key, SkShader::TileMode tileX,
+ SkShader::TileMode tileY, SkMatrix* matrix, bool blend):
+ SkiaShader(kBitmap, key, tileX, tileY, matrix, blend), mBitmap(bitmap) {
+}
+
+SkiaBitmapShader::~SkiaBitmapShader() {
+}
+
+void SkiaBitmapShader::describe(ProgramDescription& description, const Extensions& extensions) {
+ const Texture* texture = mTextureCache->get(mBitmap);
+
+ const float width = texture->width;
+ const float height = texture->height;
+
+ description.hasBitmap = true;
+ // The driver does not support non-power of two mirrored/repeated
+ // textures, so do it ourselves
+ if (!extensions.hasNPot() && !isPowerOfTwo(width) && !isPowerOfTwo(height)) {
+ description.isBitmapNpot = true;
+ description.bitmapWrapS = gTileModes[mTileX];
+ description.bitmapWrapT = gTileModes[mTileY];
+ }
+}
+
+void SkiaBitmapShader::setupProgram(Program* program, const mat4& modelView,
+ const Snapshot& snapshot, GLuint* textureUnit) {
+ GLuint textureSlot = (*textureUnit)++;
+ glActiveTexture(gTextureUnitsMap[textureSlot]);
+ const Texture* texture = mTextureCache->get(mBitmap);
+
+ const float width = texture->width;
+ const float height = texture->height;
+
+ mat4 textureTransform;
+ if (mMatrix) {
+ SkMatrix inverse;
+ mMatrix->invert(&inverse);
+ textureTransform.load(inverse);
+ textureTransform.multiply(modelView);
+ } else {
+ textureTransform.load(modelView);
+ }
+
+ // Uniforms
+ bindTexture(texture->id, gTileModes[mTileX], gTileModes[mTileY], textureSlot);
+ glUniform1i(program->getUniform("bitmapSampler"), textureSlot);
+ glUniformMatrix4fv(program->getUniform("textureTransform"), 1,
+ GL_FALSE, &textureTransform.data[0]);
+ glUniform2f(program->getUniform("textureDimension"), 1.0f / width, 1.0f / height);
+}
+
+///////////////////////////////////////////////////////////////////////////////
+// Linear gradient shader
+///////////////////////////////////////////////////////////////////////////////
+
+SkiaLinearGradientShader::SkiaLinearGradientShader(float* bounds, uint32_t* colors,
+ float* positions, int count, SkShader* key, SkShader::TileMode tileMode,
+ SkMatrix* matrix, bool blend):
+ SkiaShader(kLinearGradient, key, tileMode, tileMode, matrix, blend),
+ mBounds(bounds), mColors(colors), mPositions(positions), mCount(count) {
+}
+
+SkiaLinearGradientShader::~SkiaLinearGradientShader() {
+ delete mBounds;
+ delete mColors;
+ delete mPositions;
+}
+
+void SkiaLinearGradientShader::describe(ProgramDescription& description,
+ const Extensions& extensions) {
+ description.hasGradient = true;
+}
+
+void SkiaLinearGradientShader::setupProgram(Program* program, const mat4& modelView,
+ const Snapshot& snapshot, GLuint* textureUnit) {
+ GLuint textureSlot = (*textureUnit)++;
+ glActiveTexture(gTextureUnitsMap[textureSlot]);
+
+ Texture* texture = mGradientCache->get(mKey);
+ if (!texture) {
+ texture = mGradientCache->addLinearGradient(mKey, mBounds, mColors, mPositions,
+ mCount, mTileX);
+ }
+
+ Rect start(mBounds[0], mBounds[1], mBounds[2], mBounds[3]);
+ if (mMatrix) {
+ mat4 shaderMatrix(*mMatrix);
+ shaderMatrix.mapRect(start);
+ }
+ snapshot.transform.mapRect(start);
+
+ const float gradientX = start.right - start.left;
+ const float gradientY = start.bottom - start.top;
+
+ mat4 screenSpace(snapshot.transform);
+ screenSpace.multiply(modelView);
+
+ // Uniforms
+ bindTexture(texture->id, gTileModes[mTileX], gTileModes[mTileY], textureSlot);
+ glUniform1i(program->getUniform("gradientSampler"), textureSlot);
+ glUniform2f(program->getUniform("gradientStart"), start.left, start.top);
+ glUniform2f(program->getUniform("gradient"), gradientX, gradientY);
+ glUniform1f(program->getUniform("gradientLength"),
+ 1.0f / (gradientX * gradientX + gradientY * gradientY));
+ glUniformMatrix4fv(program->getUniform("screenSpace"), 1, GL_FALSE, &screenSpace.data[0]);
+}
+
+///////////////////////////////////////////////////////////////////////////////
+// Compose shader
+///////////////////////////////////////////////////////////////////////////////
+
+SkiaComposeShader::SkiaComposeShader(SkiaShader* first, SkiaShader* second,
+ SkXfermode::Mode mode, SkShader* key):
+ SkiaShader(kCompose, key, SkShader::kClamp_TileMode, SkShader::kClamp_TileMode,
+ NULL, first->blend() || second->blend()), mFirst(first), mSecond(second), mMode(mode) {
+}
+
+SkiaComposeShader::~SkiaComposeShader() {
+ delete mFirst;
+ delete mSecond;
+}
+
+void SkiaComposeShader::set(TextureCache* textureCache, GradientCache* gradientCache) {
+ SkiaShader::set(textureCache, gradientCache);
+ mFirst->set(textureCache, gradientCache);
+ mSecond->set(textureCache, gradientCache);
+}
+
+void SkiaComposeShader::describe(ProgramDescription& description, const Extensions& extensions) {
+ mFirst->describe(description, extensions);
+ mSecond->describe(description, extensions);
+ if (mFirst->type() == kBitmap) {
+ description.isBitmapFirst = true;
+ }
+ description.shadersMode = mMode;
+}
+
+void SkiaComposeShader::setupProgram(Program* program, const mat4& modelView,
+ const Snapshot& snapshot, GLuint* textureUnit) {
+ mFirst->setupProgram(program, modelView, snapshot, textureUnit);
+ mSecond->setupProgram(program, modelView, snapshot, textureUnit);
+}
+
+}; // namespace uirenderer
+}; // namespace android