libs/hwui/OpenGLRenderer.h - platform/frameworks/base - Gitiles

 /*
  * 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.
  */

 #ifndef ANDROID_HWUI_OPENGL_RENDERER_H
 #define ANDROID_HWUI_OPENGL_RENDERER_H

 #include <GLES2/gl2.h>
 #include <GLES2/gl2ext.h>

 #include <SkBitmap.h>
 #include <SkMatrix.h>
 #include <SkPaint.h>
 #include <SkRegion.h>
 #include <SkShader.h>
 #include <SkXfermode.h>

 #include <utils/Functor.h>
 #include <utils/RefBase.h>
 #include <utils/Vector.h>

 #include "Debug.h"
 #include "Extensions.h"
 #include "Matrix.h"
 #include "Program.h"
 #include "Rect.h"
 #include "Snapshot.h"
 #include "Vertex.h"
 #include "SkiaShader.h"
 #include "SkiaColorFilter.h"
 #include "Caches.h"

 namespace android {
 namespace uirenderer {

 ///////////////////////////////////////////////////////////////////////////////
 // Renderer
 ///////////////////////////////////////////////////////////////////////////////

 class DisplayList;

 /**
  * OpenGL renderer used to draw accelerated 2D graphics. The API is a
  * simplified version of Skia's Canvas API.
  */
 class OpenGLRenderer {
 public:
     OpenGLRenderer();
     virtual ~OpenGLRenderer();

     virtual void setViewport(int width, int height);

     void prepare(bool opaque);
     virtual void prepareDirty(float left, float top, float right, float bottom, bool opaque);
     virtual void finish();

     // These two calls must not be recorded in display lists
     virtual void interrupt();
     virtual void resume();

     virtual bool callDrawGLFunction(Functor *functor, Rect& dirty);

     int getSaveCount() const;
     virtual int save(int flags);
     virtual void restore();
     virtual void restoreToCount(int saveCount);

     virtual int saveLayer(float left, float top, float right, float bottom,
             SkPaint* p, int flags);
     virtual int saveLayerAlpha(float left, float top, float right, float bottom,
             int alpha, int flags);

     virtual void translate(float dx, float dy);
     virtual void rotate(float degrees);
     virtual void scale(float sx, float sy);
     virtual void skew(float sx, float sy);

     const float* getMatrix() const;
     void getMatrix(SkMatrix* matrix);
     virtual void setMatrix(SkMatrix* matrix);
     virtual void concatMatrix(SkMatrix* matrix);

     const Rect& getClipBounds();
     bool quickReject(float left, float top, float right, float bottom);
     virtual bool clipRect(float left, float top, float right, float bottom, SkRegion::Op op);

     virtual bool drawDisplayList(DisplayList* displayList, uint32_t width, uint32_t height,
             Rect& dirty, uint32_t level = 0);
     virtual void outputDisplayList(DisplayList* displayList, uint32_t level = 0);
     virtual void drawLayer(Layer* layer, float x, float y, SkPaint* paint);
     virtual void drawBitmap(SkBitmap* bitmap, float left, float top, SkPaint* paint);
     virtual void drawBitmap(SkBitmap* bitmap, SkMatrix* matrix, SkPaint* paint);
     virtual void drawBitmap(SkBitmap* bitmap, float srcLeft, float srcTop,
             float srcRight, float srcBottom, float dstLeft, float dstTop,
             float dstRight, float dstBottom, SkPaint* paint);
     virtual void drawBitmapMesh(SkBitmap* bitmap, int meshWidth, int meshHeight,
             float* vertices, int* colors, SkPaint* paint);
     virtual void drawPatch(SkBitmap* bitmap, const int32_t* xDivs, const int32_t* yDivs,
             const uint32_t* colors, uint32_t width, uint32_t height, int8_t numColors,
             float left, float top, float right, float bottom, SkPaint* paint);
     virtual void drawColor(int color, SkXfermode::Mode mode);
     virtual void drawRect(float left, float top, float right, float bottom, SkPaint* paint);
     virtual void drawRoundRect(float left, float top, float right, float bottom,
             float rx, float ry, SkPaint* paint);
     virtual void drawCircle(float x, float y, float radius, SkPaint* paint);
     virtual void drawOval(float left, float top, float right, float bottom, SkPaint* paint);
     virtual void drawArc(float left, float top, float right, float bottom,
             float startAngle, float sweepAngle, bool useCenter, SkPaint* paint);
     virtual void drawPath(SkPath* path, SkPaint* paint);
     virtual void drawLines(float* points, int count, SkPaint* paint);
     virtual void drawPoints(float* points, int count, SkPaint* paint);
     virtual void drawText(const char* text, int bytesCount, int count, float x, float y,
             SkPaint* paint);

     virtual void resetShader();
     virtual void setupShader(SkiaShader* shader);

     virtual void resetColorFilter();
     virtual void setupColorFilter(SkiaColorFilter* filter);

     virtual void resetShadow();
     virtual void setupShadow(float radius, float dx, float dy, int color);

 protected:
     /**
      * Compose the layer defined in the current snapshot with the layer
      * defined by the previous snapshot.
      *
      * The current snapshot *must* be a layer (flag kFlagIsLayer set.)
      *
      * @param curent The current snapshot containing the layer to compose
      * @param previous The previous snapshot to compose the current layer with
      */
     virtual void composeLayer(sp<Snapshot> current, sp<Snapshot> previous);

     /**
      * Marks the specified region as dirty at the specified bounds.
      */
     void dirtyLayerUnchecked(Rect& bounds, Region* region);

     /**
      * Returns the current snapshot.
      */
     sp<Snapshot> getSnapshot() {
         return mSnapshot;
     }

     /**
      * Returns the region of the current layer.
      */
     virtual Region* getRegion() {
         return mSnapshot->region;
     }

     /**
      * Indicates whether rendering is currently targeted at a layer.
      */
     virtual bool hasLayer() {
         return (mSnapshot->flags & Snapshot::kFlagFboTarget) && mSnapshot->region;
     }

     /**
      * Returns the name of the FBO this renderer is rendering into.
      */
     virtual GLint getTargetFbo() {
         return 0;
     }

 private:
     /**
      * Saves the current state of the renderer as a new snapshot.
      * The new snapshot is saved in mSnapshot and the previous snapshot
      * is linked from mSnapshot->previous.
      *
      * @param flags The save flags; see SkCanvas for more information
      *
      * @return The new save count. This value can be passed to #restoreToCount()
      */
     int saveSnapshot(int flags);

     /**
      * Restores the current snapshot; mSnapshot becomes mSnapshot->previous.
      *
      * @return True if the clip was modified.
      */
     bool restoreSnapshot();

     /**
      * Sets the clipping rectangle using glScissor. The clip is defined by
      * the current snapshot's clipRect member.
      */
     void setScissorFromClip();

     /**
      * Creates a new layer stored in the specified snapshot.
      *
      * @param snapshot The snapshot associated with the new layer
      * @param left The left coordinate of the layer
      * @param top The top coordinate of the layer
      * @param right The right coordinate of the layer
      * @param bottom The bottom coordinate of the layer
      * @param alpha The translucency of the layer
      * @param mode The blending mode of the layer
      * @param flags The layer save flags
      * @param previousFbo The name of the current framebuffer
      *
      * @return True if the layer was successfully created, false otherwise
      */
     bool createLayer(sp<Snapshot> snapshot, float left, float top, float right, float bottom,
             int alpha, SkXfermode::Mode mode, int flags, GLuint previousFbo);

     /**
      * Creates a new layer stored in the specified snapshot as an FBO.
      *
      * @param layer The layer to store as an FBO
      * @param snapshot The snapshot associated with the new layer
      * @param bounds The bounds of the layer
      * @param previousFbo The name of the current framebuffer
      */
     bool createFboLayer(Layer* layer, Rect& bounds, sp<Snapshot> snapshot,
             GLuint previousFbo);

     /**
      * Compose the specified layer as a region.
      *
      * @param layer The layer to compose
      * @param rect The layer's bounds
      */
     void composeLayerRegion(Layer* layer, const Rect& rect);

     /**
      * Compose the specified layer as a simple rectangle.
      *
      * @param layer The layer to compose
      * @param rect The layer's bounds
      * @param swap If true, the source and destination are swapped
      */
     void composeLayerRect(Layer* layer, const Rect& rect, bool swap = false);

     void drawTextureLayer(Layer* layer, const Rect& rect);

     /**
      * Mark the layer as dirty at the specified coordinates. The coordinates
      * are transformed with the supplied matrix.
      */
     void dirtyLayer(const float left, const float top,
             const float right, const float bottom, const mat4 transform);

     /**
      * Mark the layer as dirty at the specified coordinates.
      */
     void dirtyLayer(const float left, const float top,
             const float right, const float bottom);

     /**
      * Draws a colored rectangle with the specified color. The specified coordinates
      * are transformed by the current snapshot's transform matrix.
      *
      * @param left The left coordinate of the rectangle
      * @param top The top coordinate of the rectangle
      * @param right The right coordinate of the rectangle
      * @param bottom The bottom coordinate of the rectangle
      * @param color The rectangle's ARGB color, defined as a packed 32 bits word
      * @param mode The Skia xfermode to use
      * @param ignoreTransform True if the current transform should be ignored
      * @param ignoreBlending True if the blending is set by the caller
      */
     void drawColorRect(float left, float top, float right, float bottom,
             int color, SkXfermode::Mode mode, bool ignoreTransform = false);

     void drawShape(float left, float top, const PathTexture* texture, SkPaint* paint);
     void drawRectAsShape(float left, float top, float right, float bottom, SkPaint* p);

     void drawAlphaBitmap(Texture* texture, float left, float top, SkPaint* paint);

     /**
      * Draws a textured rectangle with the specified texture. The specified coordinates
      * are transformed by the current snapshot's transform matrix.
      *
      * @param left The left coordinate of the rectangle
      * @param top The top coordinate of the rectangle
      * @param right The right coordinate of the rectangle
      * @param bottom The bottom coordinate of the rectangle
      * @param texture The texture name to map onto the rectangle
      * @param alpha An additional translucency parameter, between 0.0f and 1.0f
      * @param mode The blending mode
      * @param blend True if the texture contains an alpha channel
      */
     void drawTextureRect(float left, float top, float right, float bottom, GLuint texture,
             float alpha, SkXfermode::Mode mode, bool blend);

     /**
      * Draws a textured rectangle with the specified texture. The specified coordinates
      * are transformed by the current snapshot's transform matrix.
      *
      * @param left The left coordinate of the rectangle
      * @param top The top coordinate of the rectangle
      * @param right The right coordinate of the rectangle
      * @param bottom The bottom coordinate of the rectangle
      * @param texture The texture to use
      * @param paint The paint containing the alpha, blending mode, etc.
      */
     void drawTextureRect(float left, float top, float right, float bottom,
             Texture* texture, SkPaint* paint);

     /**
      * Draws a textured mesh with the specified texture. If the indices are omitted,
      * the mesh is drawn as a simple quad. The mesh pointers become offsets when a
      * VBO is bound.
      *
      * @param left The left coordinate of the rectangle
      * @param top The top coordinate of the rectangle
      * @param right The right coordinate of the rectangle
      * @param bottom The bottom coordinate of the rectangle
      * @param texture The texture name to map onto the rectangle
      * @param alpha An additional translucency parameter, between 0.0f and 1.0f
      * @param mode The blending mode
      * @param blend True if the texture contains an alpha channel
      * @param vertices The vertices that define the mesh
      * @param texCoords The texture coordinates of each vertex
      * @param elementsCount The number of elements in the mesh, required by indices
      * @param swapSrcDst Whether or not the src and dst blending operations should be swapped
      * @param ignoreTransform True if the current transform should be ignored
      * @param vbo The VBO used to draw the mesh
      * @param ignoreScale True if the model view matrix should not be scaled
      * @param dirty True if calling this method should dirty the current layer
      */
     void drawTextureMesh(float left, float top, float right, float bottom, GLuint texture,
             float alpha, SkXfermode::Mode mode, bool blend,
             GLvoid* vertices, GLvoid* texCoords, GLenum drawMode, GLsizei elementsCount,
             bool swapSrcDst = false, bool ignoreTransform = false, GLuint vbo = 0,
             bool ignoreScale = false, bool dirty = true);

     /**
      * Draws text underline and strike-through if needed.
      *
      * @param text The text to decor
      * @param bytesCount The number of bytes in the text
      * @param length The length in pixels of the text, can be <= 0.0f to force a measurement
      * @param x The x coordinate where the text will be drawn
      * @param y The y coordinate where the text will be drawn
      * @param paint The paint to draw the text with
      */
     void drawTextDecorations(const char* text, int bytesCount, float length,
             float x, float y, SkPaint* paint);

     void drawPathTexture(const PathTexture* texture, float x, float y, SkPaint* paint);

     /**
      * Resets the texture coordinates stored in mMeshVertices. Setting the values
      * back to default is achieved by calling:
      *
      * resetDrawTextureTexCoords(0.0f, 0.0f, 1.0f, 1.0f);
      *
      * @param u1 The left coordinate of the texture
      * @param v1 The bottom coordinate of the texture
      * @param u2 The right coordinate of the texture
      * @param v2 The top coordinate of the texture
      */
     void resetDrawTextureTexCoords(float u1, float v1, float u2, float v2);

     /**
      * Gets the alpha and xfermode out of a paint object. If the paint is null
      * alpha will be 255 and the xfermode will be SRC_OVER.
      *
      * @param paint The paint to extract values from
      * @param alpha Where to store the resulting alpha
      * @param mode Where to store the resulting xfermode
      */
     inline void getAlphaAndMode(SkPaint* paint, int* alpha, SkXfermode::Mode* mode);

     /**
      * Binds the specified texture. The texture unit must have been selected
      * prior to calling this method.
      */
     inline void bindTexture(GLuint texture) {
         glBindTexture(GL_TEXTURE_2D, texture);
     }

     /**
      * Binds the specified EGLImage texture. The texture unit must have been selected
      * prior to calling this method.
      */
     inline void bindExternalTexture(GLuint texture) {
         glBindTexture(GL_TEXTURE_EXTERNAL_OES, texture);
     }

     /**
      * Sets the wrap modes for the specified texture. The wrap modes are modified
      * only when needed.
      */
     inline void setTextureWrapModes(Texture* texture, GLenum wrapS, GLenum wrapT);

     /**
      * Enable or disable blending as necessary. This function sets the appropriate
      * blend function based on the specified xfermode.
      */
     inline void chooseBlending(bool blend, SkXfermode::Mode mode, ProgramDescription& description,
             bool swapSrcDst = false);

     /**
      * Safely retrieves the mode from the specified xfermode. If the specified
      * xfermode is null, the mode is assumed to be SkXfermode::kSrcOver_Mode.
      */
     inline SkXfermode::Mode getXfermode(SkXfermode* mode);

     /**
      * Use the specified program with the current GL context. If the program is already
      * in use, it will not be bound again. If it is not in use, the current program is
      * marked unused and the specified program becomes used and becomes the new
      * current program.
      *
      * @param program The program to use
      *
      * @return true If the specified program was already in use, false otherwise.
      */
     inline bool useProgram(Program* program);

     /**
      * Invoked before any drawing operation. This sets required state.
      */
     void setupDraw();
     /**
      * Various methods to setup OpenGL rendering.
      */
     void setupDrawWithTexture(bool isAlpha8 = false);
     void setupDrawWithExternalTexture();
     void setupDrawAALine();
     void setupDrawPoint(float pointSize);
     void setupDrawColor(int color);
     void setupDrawColor(int color, int alpha);
     void setupDrawColor(float r, float g, float b, float a);
     void setupDrawAlpha8Color(int color, int alpha);
     void setupDrawAlpha8Color(float r, float g, float b, float a);
     void setupDrawShader();
     void setupDrawColorFilter();
     void setupDrawBlending(SkXfermode::Mode mode = SkXfermode::kSrcOver_Mode,
             bool swapSrcDst = false);
     void setupDrawBlending(bool blend = true, SkXfermode::Mode mode = SkXfermode::kSrcOver_Mode,
             bool swapSrcDst = false);
     void setupDrawProgram();
     void setupDrawDirtyRegionsDisabled();
     void setupDrawModelViewIdentity(bool offset = false);
     void setupDrawModelView(float left, float top, float right, float bottom,
             bool ignoreTransform = false, bool ignoreModelView = false);
     void setupDrawModelViewTranslate(float left, float top, float right, float bottom,
             bool ignoreTransform = false);
     void setupDrawPointUniforms();
     void setupDrawColorUniforms();
     void setupDrawPureColorUniforms();
     void setupDrawShaderIdentityUniforms();
     void setupDrawShaderUniforms(bool ignoreTransform = false);
     void setupDrawColorFilterUniforms();
     void setupDrawSimpleMesh();
     void setupDrawTexture(GLuint texture);
     void setupDrawExternalTexture(GLuint texture);
     void setupDrawTextureTransform();
     void setupDrawTextureTransformUniforms(mat4& transform);
     void setupDrawMesh(GLvoid* vertices, GLvoid* texCoords = NULL, GLuint vbo = 0);
     void setupDrawVertices(GLvoid* vertices);
     void setupDrawAALine(GLvoid* vertices, GLvoid* distanceCoords, GLvoid* lengthCoords,
             float strokeWidth);
     void finishDrawTexture();

     void drawRegionRects(const Region& region);

     /**
      * Should be invoked every time the glScissor is modified.
      */
     inline void dirtyClip() {
         mDirtyClip = true;
     }

     // Dimensions of the drawing surface
     int mWidth, mHeight;

     // Matrix used for ortho projection in shaders
     mat4 mOrthoMatrix;

     // Model-view matrix used to position/size objects
     mat4 mModelView;

     // Number of saved states
     int mSaveCount;
     // Base state
     sp<Snapshot> mFirstSnapshot;
     // Current state
     sp<Snapshot> mSnapshot;

     // Shaders
     SkiaShader* mShader;

     // Color filters
     SkiaColorFilter* mColorFilter;

     // Used to draw textured quads
     TextureVertex mMeshVertices[4];

     // Drop shadow
     bool mHasShadow;
     float mShadowRadius;
     float mShadowDx;
     float mShadowDy;
     int mShadowColor;

     // Various caches
     Caches& mCaches;

     // Indentity matrix
     const mat4 mIdentity;

     // Indicates whether the clip must be restored
     bool mDirtyClip;

     // The following fields are used to setup drawing
     // Used to describe the shaders to generate
     ProgramDescription mDescription;
     // Color description
     bool mColorSet;
     float mColorA, mColorR, mColorG, mColorB;
     // Indicates that the shader should get a color
     bool mSetShaderColor;
     // Current texture unit
     GLuint mTextureUnit;
     // Track dirty regions, true by default
     bool mTrackDirtyRegions;
     // Texture coordinates slot
     int mTexCoordsSlot;

     friend class DisplayListRenderer;

 }; // class OpenGLRenderer

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

 #endif // ANDROID_HWUI_OPENGL_RENDERER_H
	/*
	* 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.
	*/

	#ifndef ANDROID_HWUI_OPENGL_RENDERER_H
	#define ANDROID_HWUI_OPENGL_RENDERER_H

	#include <GLES2/gl2.h>
	#include <GLES2/gl2ext.h>

	#include <SkBitmap.h>
	#include <SkMatrix.h>
	#include <SkPaint.h>
	#include <SkRegion.h>
	#include <SkShader.h>
	#include <SkXfermode.h>

	#include <utils/Functor.h>
	#include <utils/RefBase.h>
	#include <utils/Vector.h>

	#include "Debug.h"
	#include "Extensions.h"
	#include "Matrix.h"
	#include "Program.h"
	#include "Rect.h"
	#include "Snapshot.h"
	#include "Vertex.h"
	#include "SkiaShader.h"
	#include "SkiaColorFilter.h"
	#include "Caches.h"

	namespace android {
	namespace uirenderer {

	///////////////////////////////////////////////////////////////////////////////
	// Renderer
	///////////////////////////////////////////////////////////////////////////////

	class DisplayList;

	/**
	* OpenGL renderer used to draw accelerated 2D graphics. The API is a
	* simplified version of Skia's Canvas API.
	*/
	class OpenGLRenderer {
	public:
	OpenGLRenderer();
	virtual ~OpenGLRenderer();

	virtual void setViewport(int width, int height);

	void prepare(bool opaque);
	virtual void prepareDirty(float left, float top, float right, float bottom, bool opaque);
	virtual void finish();

	// These two calls must not be recorded in display lists
	virtual void interrupt();
	virtual void resume();

	virtual bool callDrawGLFunction(Functor *functor, Rect& dirty);

	int getSaveCount() const;
	virtual int save(int flags);
	virtual void restore();
	virtual void restoreToCount(int saveCount);

	virtual int saveLayer(float left, float top, float right, float bottom,
	SkPaint* p, int flags);
	virtual int saveLayerAlpha(float left, float top, float right, float bottom,
	int alpha, int flags);

	virtual void translate(float dx, float dy);
	virtual void rotate(float degrees);
	virtual void scale(float sx, float sy);
	virtual void skew(float sx, float sy);

	const float* getMatrix() const;
	void getMatrix(SkMatrix* matrix);
	virtual void setMatrix(SkMatrix* matrix);
	virtual void concatMatrix(SkMatrix* matrix);

	const Rect& getClipBounds();
	bool quickReject(float left, float top, float right, float bottom);
	virtual bool clipRect(float left, float top, float right, float bottom, SkRegion::Op op);

	virtual bool drawDisplayList(DisplayList* displayList, uint32_t width, uint32_t height,
	Rect& dirty, uint32_t level = 0);
	virtual void outputDisplayList(DisplayList* displayList, uint32_t level = 0);
	virtual void drawLayer(Layer* layer, float x, float y, SkPaint* paint);
	virtual void drawBitmap(SkBitmap* bitmap, float left, float top, SkPaint* paint);
	virtual void drawBitmap(SkBitmap* bitmap, SkMatrix* matrix, SkPaint* paint);
	virtual void drawBitmap(SkBitmap* bitmap, float srcLeft, float srcTop,
	float srcRight, float srcBottom, float dstLeft, float dstTop,
	float dstRight, float dstBottom, SkPaint* paint);
	virtual void drawBitmapMesh(SkBitmap* bitmap, int meshWidth, int meshHeight,
	float* vertices, int* colors, SkPaint* paint);
	virtual void drawPatch(SkBitmap* bitmap, const int32_t* xDivs, const int32_t* yDivs,
	const uint32_t* colors, uint32_t width, uint32_t height, int8_t numColors,
	float left, float top, float right, float bottom, SkPaint* paint);
	virtual void drawColor(int color, SkXfermode::Mode mode);
	virtual void drawRect(float left, float top, float right, float bottom, SkPaint* paint);
	virtual void drawRoundRect(float left, float top, float right, float bottom,
	float rx, float ry, SkPaint* paint);
	virtual void drawCircle(float x, float y, float radius, SkPaint* paint);
	virtual void drawOval(float left, float top, float right, float bottom, SkPaint* paint);
	virtual void drawArc(float left, float top, float right, float bottom,
	float startAngle, float sweepAngle, bool useCenter, SkPaint* paint);
	virtual void drawPath(SkPath* path, SkPaint* paint);
	virtual void drawLines(float* points, int count, SkPaint* paint);
	virtual void drawPoints(float* points, int count, SkPaint* paint);
	virtual void drawText(const char* text, int bytesCount, int count, float x, float y,
	SkPaint* paint);

	virtual void resetShader();
	virtual void setupShader(SkiaShader* shader);

	virtual void resetColorFilter();
	virtual void setupColorFilter(SkiaColorFilter* filter);

	virtual void resetShadow();
	virtual void setupShadow(float radius, float dx, float dy, int color);

	protected:
	/**
	* Compose the layer defined in the current snapshot with the layer
	* defined by the previous snapshot.
	*
	* The current snapshot must be a layer (flag kFlagIsLayer set.)
	*
	* @param curent The current snapshot containing the layer to compose
	* @param previous The previous snapshot to compose the current layer with
	*/
	virtual void composeLayer(sp<Snapshot> current, sp<Snapshot> previous);

	/**
	* Marks the specified region as dirty at the specified bounds.
	*/
	void dirtyLayerUnchecked(Rect& bounds, Region* region);

	/**
	* Returns the current snapshot.
	*/
	sp<Snapshot> getSnapshot() {
	return mSnapshot;
	}

	/**
	* Returns the region of the current layer.
	*/
	virtual Region* getRegion() {
	return mSnapshot->region;
	}

	/**
	* Indicates whether rendering is currently targeted at a layer.
	*/
	virtual bool hasLayer() {
	return (mSnapshot->flags & Snapshot::kFlagFboTarget) && mSnapshot->region;
	}

	/**
	* Returns the name of the FBO this renderer is rendering into.
	*/
	virtual GLint getTargetFbo() {
	return 0;
	}

	private:
	/**
	* Saves the current state of the renderer as a new snapshot.
	* The new snapshot is saved in mSnapshot and the previous snapshot
	* is linked from mSnapshot->previous.
	*
	* @param flags The save flags; see SkCanvas for more information
	*
	* @return The new save count. This value can be passed to #restoreToCount()
	*/
	int saveSnapshot(int flags);

	/**
	* Restores the current snapshot; mSnapshot becomes mSnapshot->previous.
	*
	* @return True if the clip was modified.
	*/
	bool restoreSnapshot();

	/**
	* Sets the clipping rectangle using glScissor. The clip is defined by
	* the current snapshot's clipRect member.
	*/
	void setScissorFromClip();

	/**
	* Creates a new layer stored in the specified snapshot.
	*
	* @param snapshot The snapshot associated with the new layer
	* @param left The left coordinate of the layer
	* @param top The top coordinate of the layer
	* @param right The right coordinate of the layer
	* @param bottom The bottom coordinate of the layer
	* @param alpha The translucency of the layer
	* @param mode The blending mode of the layer
	* @param flags The layer save flags
	* @param previousFbo The name of the current framebuffer
	*
	* @return True if the layer was successfully created, false otherwise
	*/
	bool createLayer(sp<Snapshot> snapshot, float left, float top, float right, float bottom,
	int alpha, SkXfermode::Mode mode, int flags, GLuint previousFbo);

	/**
	* Creates a new layer stored in the specified snapshot as an FBO.
	*
	* @param layer The layer to store as an FBO
	* @param snapshot The snapshot associated with the new layer
	* @param bounds The bounds of the layer
	* @param previousFbo The name of the current framebuffer
	*/
	bool createFboLayer(Layer* layer, Rect& bounds, sp<Snapshot> snapshot,
	GLuint previousFbo);

	/**
	* Compose the specified layer as a region.
	*
	* @param layer The layer to compose
	* @param rect The layer's bounds
	*/
	void composeLayerRegion(Layer* layer, const Rect& rect);

	/**
	* Compose the specified layer as a simple rectangle.
	*
	* @param layer The layer to compose
	* @param rect The layer's bounds
	* @param swap If true, the source and destination are swapped
	*/
	void composeLayerRect(Layer* layer, const Rect& rect, bool swap = false);

	void drawTextureLayer(Layer* layer, const Rect& rect);

	/**
	* Mark the layer as dirty at the specified coordinates. The coordinates
	* are transformed with the supplied matrix.
	*/
	void dirtyLayer(const float left, const float top,
	const float right, const float bottom, const mat4 transform);

	/**
	* Mark the layer as dirty at the specified coordinates.
	*/
	void dirtyLayer(const float left, const float top,
	const float right, const float bottom);

	/**
	* Draws a colored rectangle with the specified color. The specified coordinates
	* are transformed by the current snapshot's transform matrix.
	*
	* @param left The left coordinate of the rectangle
	* @param top The top coordinate of the rectangle
	* @param right The right coordinate of the rectangle
	* @param bottom The bottom coordinate of the rectangle
	* @param color The rectangle's ARGB color, defined as a packed 32 bits word
	* @param mode The Skia xfermode to use
	* @param ignoreTransform True if the current transform should be ignored
	* @param ignoreBlending True if the blending is set by the caller
	*/
	void drawColorRect(float left, float top, float right, float bottom,
	int color, SkXfermode::Mode mode, bool ignoreTransform = false);

	void drawShape(float left, float top, const PathTexture* texture, SkPaint* paint);
	void drawRectAsShape(float left, float top, float right, float bottom, SkPaint* p);

	void drawAlphaBitmap(Texture* texture, float left, float top, SkPaint* paint);

	/**
	* Draws a textured rectangle with the specified texture. The specified coordinates
	* are transformed by the current snapshot's transform matrix.
	*
	* @param left The left coordinate of the rectangle
	* @param top The top coordinate of the rectangle
	* @param right The right coordinate of the rectangle
	* @param bottom The bottom coordinate of the rectangle
	* @param texture The texture name to map onto the rectangle
	* @param alpha An additional translucency parameter, between 0.0f and 1.0f
	* @param mode The blending mode
	* @param blend True if the texture contains an alpha channel
	*/
	void drawTextureRect(float left, float top, float right, float bottom, GLuint texture,
	float alpha, SkXfermode::Mode mode, bool blend);

	/**
	* Draws a textured rectangle with the specified texture. The specified coordinates
	* are transformed by the current snapshot's transform matrix.
	*
	* @param left The left coordinate of the rectangle
	* @param top The top coordinate of the rectangle
	* @param right The right coordinate of the rectangle
	* @param bottom The bottom coordinate of the rectangle
	* @param texture The texture to use
	* @param paint The paint containing the alpha, blending mode, etc.
	*/
	void drawTextureRect(float left, float top, float right, float bottom,
	Texture* texture, SkPaint* paint);

	/**
	* Draws a textured mesh with the specified texture. If the indices are omitted,
	* the mesh is drawn as a simple quad. The mesh pointers become offsets when a
	* VBO is bound.
	*
	* @param left The left coordinate of the rectangle
	* @param top The top coordinate of the rectangle
	* @param right The right coordinate of the rectangle
	* @param bottom The bottom coordinate of the rectangle
	* @param texture The texture name to map onto the rectangle
	* @param alpha An additional translucency parameter, between 0.0f and 1.0f
	* @param mode The blending mode
	* @param blend True if the texture contains an alpha channel
	* @param vertices The vertices that define the mesh
	* @param texCoords The texture coordinates of each vertex
	* @param elementsCount The number of elements in the mesh, required by indices
	* @param swapSrcDst Whether or not the src and dst blending operations should be swapped
	* @param ignoreTransform True if the current transform should be ignored
	* @param vbo The VBO used to draw the mesh
	* @param ignoreScale True if the model view matrix should not be scaled
	* @param dirty True if calling this method should dirty the current layer
	*/
	void drawTextureMesh(float left, float top, float right, float bottom, GLuint texture,
	float alpha, SkXfermode::Mode mode, bool blend,
	GLvoid* vertices, GLvoid* texCoords, GLenum drawMode, GLsizei elementsCount,
	bool swapSrcDst = false, bool ignoreTransform = false, GLuint vbo = 0,
	bool ignoreScale = false, bool dirty = true);

	/**
	* Draws text underline and strike-through if needed.
	*
	* @param text The text to decor
	* @param bytesCount The number of bytes in the text
	* @param length The length in pixels of the text, can be <= 0.0f to force a measurement
	* @param x The x coordinate where the text will be drawn
	* @param y The y coordinate where the text will be drawn
	* @param paint The paint to draw the text with
	*/
	void drawTextDecorations(const char* text, int bytesCount, float length,
	float x, float y, SkPaint* paint);

	void drawPathTexture(const PathTexture* texture, float x, float y, SkPaint* paint);

	/**
	* Resets the texture coordinates stored in mMeshVertices. Setting the values
	* back to default is achieved by calling:
	*
	* resetDrawTextureTexCoords(0.0f, 0.0f, 1.0f, 1.0f);
	*
	* @param u1 The left coordinate of the texture
	* @param v1 The bottom coordinate of the texture
	* @param u2 The right coordinate of the texture
	* @param v2 The top coordinate of the texture
	*/
	void resetDrawTextureTexCoords(float u1, float v1, float u2, float v2);

	/**
	* Gets the alpha and xfermode out of a paint object. If the paint is null
	* alpha will be 255 and the xfermode will be SRC_OVER.
	*
	* @param paint The paint to extract values from
	* @param alpha Where to store the resulting alpha
	* @param mode Where to store the resulting xfermode
	*/
	inline void getAlphaAndMode(SkPaint* paint, int* alpha, SkXfermode::Mode* mode);

	/**
	* Binds the specified texture. The texture unit must have been selected
	* prior to calling this method.
	*/
	inline void bindTexture(GLuint texture) {
	glBindTexture(GL_TEXTURE_2D, texture);
	}

	/**
	* Binds the specified EGLImage texture. The texture unit must have been selected
	* prior to calling this method.
	*/
	inline void bindExternalTexture(GLuint texture) {
	glBindTexture(GL_TEXTURE_EXTERNAL_OES, texture);
	}

	/**
	* Sets the wrap modes for the specified texture. The wrap modes are modified
	* only when needed.
	*/
	inline void setTextureWrapModes(Texture* texture, GLenum wrapS, GLenum wrapT);

	/**
	* Enable or disable blending as necessary. This function sets the appropriate
	* blend function based on the specified xfermode.
	*/
	inline void chooseBlending(bool blend, SkXfermode::Mode mode, ProgramDescription& description,
	bool swapSrcDst = false);

	/**
	* Safely retrieves the mode from the specified xfermode. If the specified
	* xfermode is null, the mode is assumed to be SkXfermode::kSrcOver_Mode.
	*/
	inline SkXfermode::Mode getXfermode(SkXfermode* mode);

	/**
	* Use the specified program with the current GL context. If the program is already
	* in use, it will not be bound again. If it is not in use, the current program is
	* marked unused and the specified program becomes used and becomes the new
	* current program.
	*
	* @param program The program to use
	*
	* @return true If the specified program was already in use, false otherwise.
	*/
	inline bool useProgram(Program* program);

	/**
	* Invoked before any drawing operation. This sets required state.
	*/
	void setupDraw();
	/**
	* Various methods to setup OpenGL rendering.
	*/
	void setupDrawWithTexture(bool isAlpha8 = false);
	void setupDrawWithExternalTexture();
	void setupDrawAALine();
	void setupDrawPoint(float pointSize);
	void setupDrawColor(int color);
	void setupDrawColor(int color, int alpha);
	void setupDrawColor(float r, float g, float b, float a);
	void setupDrawAlpha8Color(int color, int alpha);
	void setupDrawAlpha8Color(float r, float g, float b, float a);
	void setupDrawShader();
	void setupDrawColorFilter();
	void setupDrawBlending(SkXfermode::Mode mode = SkXfermode::kSrcOver_Mode,
	bool swapSrcDst = false);
	void setupDrawBlending(bool blend = true, SkXfermode::Mode mode = SkXfermode::kSrcOver_Mode,
	bool swapSrcDst = false);
	void setupDrawProgram();
	void setupDrawDirtyRegionsDisabled();
	void setupDrawModelViewIdentity(bool offset = false);
	void setupDrawModelView(float left, float top, float right, float bottom,
	bool ignoreTransform = false, bool ignoreModelView = false);
	void setupDrawModelViewTranslate(float left, float top, float right, float bottom,
	bool ignoreTransform = false);
	void setupDrawPointUniforms();
	void setupDrawColorUniforms();
	void setupDrawPureColorUniforms();
	void setupDrawShaderIdentityUniforms();
	void setupDrawShaderUniforms(bool ignoreTransform = false);
	void setupDrawColorFilterUniforms();
	void setupDrawSimpleMesh();
	void setupDrawTexture(GLuint texture);
	void setupDrawExternalTexture(GLuint texture);
	void setupDrawTextureTransform();
	void setupDrawTextureTransformUniforms(mat4& transform);
	void setupDrawMesh(GLvoid* vertices, GLvoid* texCoords = NULL, GLuint vbo = 0);
	void setupDrawVertices(GLvoid* vertices);
	void setupDrawAALine(GLvoid* vertices, GLvoid* distanceCoords, GLvoid* lengthCoords,
	float strokeWidth);
	void finishDrawTexture();

	void drawRegionRects(const Region& region);

	/**
	* Should be invoked every time the glScissor is modified.
	*/
	inline void dirtyClip() {
	mDirtyClip = true;
	}

	// Dimensions of the drawing surface
	int mWidth, mHeight;

	// Matrix used for ortho projection in shaders
	mat4 mOrthoMatrix;

	// Model-view matrix used to position/size objects
	mat4 mModelView;

	// Number of saved states
	int mSaveCount;
	// Base state
	sp<Snapshot> mFirstSnapshot;
	// Current state
	sp<Snapshot> mSnapshot;

	// Shaders
	SkiaShader* mShader;

	// Color filters
	SkiaColorFilter* mColorFilter;

	// Used to draw textured quads
	TextureVertex mMeshVertices[4];

	// Drop shadow
	bool mHasShadow;
	float mShadowRadius;
	float mShadowDx;
	float mShadowDy;
	int mShadowColor;

	// Various caches
	Caches& mCaches;

	// Indentity matrix
	const mat4 mIdentity;

	// Indicates whether the clip must be restored
	bool mDirtyClip;

	// The following fields are used to setup drawing
	// Used to describe the shaders to generate
	ProgramDescription mDescription;
	// Color description
	bool mColorSet;
	float mColorA, mColorR, mColorG, mColorB;
	// Indicates that the shader should get a color
	bool mSetShaderColor;
	// Current texture unit
	GLuint mTextureUnit;
	// Track dirty regions, true by default
	bool mTrackDirtyRegions;
	// Texture coordinates slot
	int mTexCoordsSlot;

	friend class DisplayListRenderer;

	}; // class OpenGLRenderer

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

	#endif // ANDROID_HWUI_OPENGL_RENDERER_H