OpenGLRenderer.h revision 4aa90573bbf86db0d33a3a790c5dbd0d93b95cfe 
1/*
2 * Copyright (C) 2010 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17#ifndef ANDROID_UI_OPENGL_RENDERER_H
18#define ANDROID_UI_OPENGL_RENDERER_H
19
20#include <GLES2/gl2.h>
21#include <GLES2/gl2ext.h>
22
23#include <SkBitmap.h>
24#include <SkMatrix.h>
25#include <SkPaint.h>
26#include <SkRegion.h>
27#include <SkShader.h>
28#include <SkXfermode.h>
29
30#include <utils/RefBase.h>
31#include <utils/Vector.h>
32
33#include "Extensions.h"
34#include "Matrix.h"
35#include "Program.h"
36#include "Rect.h"
37#include "Snapshot.h"
38#include "Vertex.h"
39#include "SkiaShader.h"
40#include "SkiaColorFilter.h"
41#include "Caches.h"
42
43namespace android {
44namespace uirenderer {
45
46///////////////////////////////////////////////////////////////////////////////
47// Defines
48///////////////////////////////////////////////////////////////////////////////
49
50// Debug
51#define DEBUG_OPENGL 1
52
53///////////////////////////////////////////////////////////////////////////////
54// Renderer
55///////////////////////////////////////////////////////////////////////////////
56
57/**
58 * OpenGL renderer used to draw accelerated 2D graphics. The API is a
59 * simplified version of Skia's Canvas API.
60 */
61class OpenGLRenderer {
62public:
63    OpenGLRenderer();
64    virtual ~OpenGLRenderer();
65
66    void setViewport(int width, int height);
67
68    virtual void prepare();
69    virtual void finish();
70
71    virtual void acquireContext();
72    virtual void releaseContext();
73
74    int getSaveCount() const;
75    virtual int save(int flags);
76    virtual void restore();
77    virtual void restoreToCount(int saveCount);
78
79    virtual int saveLayer(float left, float top, float right, float bottom,
80            const SkPaint* p, int flags);
81    virtual int saveLayerAlpha(float left, float top, float right, float bottom,
82            int alpha, int flags);
83
84    virtual void translate(float dx, float dy);
85    virtual void rotate(float degrees);
86    virtual void scale(float sx, float sy);
87
88    void getMatrix(SkMatrix* matrix);
89    virtual void setMatrix(SkMatrix* matrix);
90    virtual void concatMatrix(SkMatrix* matrix);
91
92    const Rect& getClipBounds();
93    bool quickReject(float left, float top, float right, float bottom);
94    virtual bool clipRect(float left, float top, float right, float bottom, SkRegion::Op op);
95
96    virtual void drawBitmap(SkBitmap* bitmap, float left, float top, const SkPaint* paint);
97    virtual void drawBitmap(SkBitmap* bitmap, const SkMatrix* matrix, const SkPaint* paint);
98    virtual void drawBitmap(SkBitmap* bitmap, float srcLeft, float srcTop,
99            float srcRight, float srcBottom, float dstLeft, float dstTop,
100            float dstRight, float dstBottom, const SkPaint* paint);
101    virtual void drawPatch(SkBitmap* bitmap, const int32_t* xDivs, const int32_t* yDivs,
102            uint32_t width, uint32_t height, float left, float top, float right, float bottom,
103            const SkPaint* paint);
104    virtual void drawColor(int color, SkXfermode::Mode mode);
105    virtual void drawRect(float left, float top, float right, float bottom, const SkPaint* paint);
106    virtual void drawPath(SkPath* path, SkPaint* paint);
107    virtual void drawLines(float* points, int count, const SkPaint* paint);
108    virtual void drawText(const char* text, int bytesCount, int count, float x, float y,
109            SkPaint* paint);
110
111    virtual void resetShader();
112    virtual void setupShader(SkiaShader* shader);
113
114    virtual void resetColorFilter();
115    virtual void setupColorFilter(SkiaColorFilter* filter);
116
117    virtual void resetShadow();
118    virtual void setupShadow(float radius, float dx, float dy, int color);
119
120protected:
121    /**
122     * Compose the layer defined in the current snapshot with the layer
123     * defined by the previous snapshot.
124     *
125     * The current snapshot *must* be a layer (flag kFlagIsLayer set.)
126     *
127     * @param curent The current snapshot containing the layer to compose
128     * @param previous The previous snapshot to compose the current layer with
129     */
130    virtual void composeLayer(sp<Snapshot> current, sp<Snapshot> previous);
131
132private:
133    /**
134     * Saves the current state of the renderer as a new snapshot.
135     * The new snapshot is saved in mSnapshot and the previous snapshot
136     * is linked from mSnapshot->previous.
137     *
138     * @param flags The save flags; see SkCanvas for more information
139     *
140     * @return The new save count. This value can be passed to #restoreToCount()
141     */
142    int saveSnapshot(int flags);
143
144    /**
145     * Restores the current snapshot; mSnapshot becomes mSnapshot->previous.
146     *
147     * @return True if the clip was modified.
148     */
149    bool restoreSnapshot();
150
151    /**
152     * Sets the clipping rectangle using glScissor. The clip is defined by
153     * the current snapshot's clipRect member.
154     */
155    void setScissorFromClip();
156
157    /**
158     * Creates a new layer stored in the specified snapshot.
159     *
160     * @param snapshot The snapshot associated with the new layer
161     * @param left The left coordinate of the layer
162     * @param top The top coordinate of the layer
163     * @param right The right coordinate of the layer
164     * @param bottom The bottom coordinate of the layer
165     * @param alpha The translucency of the layer
166     * @param mode The blending mode of the layer
167     * @param flags The layer save flags
168     *
169     * @return True if the layer was successfully created, false otherwise
170     */
171    bool createLayer(sp<Snapshot> snapshot, float left, float top, float right, float bottom,
172            int alpha, SkXfermode::Mode mode, int flags);
173
174    /**
175     * Clears all the regions corresponding to the current list of layers.
176     * This method MUST be invoked before any drawing operation.
177     */
178    void clearLayerRegions();
179
180    /**
181     * Draws a colored rectangle with the specified color. The specified coordinates
182     * are transformed by the current snapshot's transform matrix.
183     *
184     * @param left The left coordinate of the rectangle
185     * @param top The top coordinate of the rectangle
186     * @param right The right coordinate of the rectangle
187     * @param bottom The bottom coordinate of the rectangle
188     * @param color The rectangle's ARGB color, defined as a packed 32 bits word
189     * @param mode The Skia xfermode to use
190     * @param ignoreTransform True if the current transform should be ignored
191     * @paran ignoreBlending True if the blending is set by the caller
192     */
193    void drawColorRect(float left, float top, float right, float bottom,
194            int color, SkXfermode::Mode mode, bool ignoreTransform = false);
195
196    /**
197     * Setups shaders to draw a colored rect.
198     */
199    void setupColorRect(float left, float top, float right, float bottom,
200            float r, float g, float b, float a, SkXfermode::Mode mode, bool ignoreTransform);
201
202    /**
203     * Draws a textured rectangle with the specified texture. The specified coordinates
204     * are transformed by the current snapshot's transform matrix.
205     *
206     * @param left The left coordinate of the rectangle
207     * @param top The top coordinate of the rectangle
208     * @param right The right coordinate of the rectangle
209     * @param bottom The bottom coordinate of the rectangle
210     * @param texture The texture name to map onto the rectangle
211     * @param alpha An additional translucency parameter, between 0.0f and 1.0f
212     * @param mode The blending mode
213     * @param blend True if the texture contains an alpha channel
214     */
215    void drawTextureRect(float left, float top, float right, float bottom, GLuint texture,
216            float alpha, SkXfermode::Mode mode, bool blend);
217
218    /**
219     * Draws a textured rectangle with the specified texture. The specified coordinates
220     * are transformed by the current snapshot's transform matrix.
221     *
222     * @param left The left coordinate of the rectangle
223     * @param top The top coordinate of the rectangle
224     * @param right The right coordinate of the rectangle
225     * @param bottom The bottom coordinate of the rectangle
226     * @param texture The texture to use
227     * @param paint The paint containing the alpha, blending mode, etc.
228     */
229    void drawTextureRect(float left, float top, float right, float bottom,
230            const Texture* texture, const SkPaint* paint);
231
232    /**
233     * Draws a textured mesh with the specified texture. If the indices are omitted, the
234     * mesh is drawn as a simple quad.
235     *
236     * @param left The left coordinate of the rectangle
237     * @param top The top coordinate of the rectangle
238     * @param right The right coordinate of the rectangle
239     * @param bottom The bottom coordinate of the rectangle
240     * @param texture The texture name to map onto the rectangle
241     * @param alpha An additional translucency parameter, between 0.0f and 1.0f
242     * @param mode The blending mode
243     * @param blend True if the texture contains an alpha channel
244     * @param vertices The vertices that define the mesh
245     * @param texCoords The texture coordinates of each vertex
246     * @param indices The indices of the vertices, can be NULL
247     * @param elementsCount The number of elements in the mesh, required by indices
248     * @param swapSrcDst Whether or not the src and dst blending operations should be swapped
249     * @param ignoreTransform True if the current transform should be ignored
250     */
251    void drawTextureMesh(float left, float top, float right, float bottom, GLuint texture,
252            float alpha, SkXfermode::Mode mode, bool blend,
253            GLvoid* vertices, GLvoid* texCoords, GLenum drawMode, GLsizei elementsCount,
254            bool swapSrcDst = false, bool ignoreTransform = false);
255
256    /**
257     * Prepares the renderer to draw the specified shadow.
258     *
259     * @param texture The shadow texture
260     * @param x The x coordinate of the shadow
261     * @param y The y coordinate of the shadow
262     * @param mode The blending mode
263     * @param alpha The alpha value
264     */
265    void setupShadow(const ShadowTexture* texture, float x, float y, SkXfermode::Mode mode,
266            float alpha);
267
268    /**
269     * Prepares the renderer to draw the specified Alpha8 texture as a rectangle.
270     *
271     * @param texture The texture to render with
272     * @param textureUnit The texture unit to use, may be modified
273     * @param x The x coordinate of the rectangle to draw
274     * @param y The y coordinate of the rectangle to draw
275     * @param r The red component of the color
276     * @param g The green component of the color
277     * @param b The blue component of the color
278     * @param a The alpha component of the color
279     * @param mode The blending mode
280     * @param transforms True if the matrix passed to the shader should be multiplied
281     *        by the model-view matrix
282     * @param applyFilters Whether or not to take color filters and
283     *        shaders into account
284     */
285    void setupTextureAlpha8(const Texture* texture, GLuint& textureUnit, float x, float y,
286            float r, float g, float b, float a, SkXfermode::Mode mode, bool transforms,
287            bool applyFilters);
288
289    /**
290     * Prepares the renderer to draw the specified Alpha8 texture as a rectangle.
291     *
292     * @param texture The texture to render with
293     * @param width The width of the texture
294     * @param height The height of the texture
295     * @param textureUnit The texture unit to use, may be modified
296     * @param x The x coordinate of the rectangle to draw
297     * @param y The y coordinate of the rectangle to draw
298     * @param r The red component of the color
299     * @param g The green component of the color
300     * @param b The blue component of the color
301     * @param a The alpha component of the color
302     * @param mode The blending mode
303     * @param transforms True if the matrix passed to the shader should be multiplied
304     *        by the model-view matrix
305     * @param applyFilters Whether or not to take color filters and
306     *        shaders into account
307     */
308    void setupTextureAlpha8(GLuint texture, uint32_t width, uint32_t height,
309            GLuint& textureUnit, float x, float y, float r, float g, float b, float a,
310            SkXfermode::Mode mode, bool transforms, bool applyFilters);
311
312    /**
313     * Same as above setupTextureAlpha8() but specifies the mesh's vertices
314     * and texCoords pointers.
315     */
316    void setupTextureAlpha8(GLuint texture, uint32_t width, uint32_t height,
317            GLuint& textureUnit, float x, float y, float r, float g, float b, float a,
318            SkXfermode::Mode mode, bool transforms, bool applyFilters,
319            GLvoid* vertices, GLvoid* texCoords);
320
321    /**
322     * Draws text underline and strike-through if needed.
323     *
324     * @param text The text to decor
325     * @param bytesCount The number of bytes in the text
326     * @param length The length in pixels of the text, can be <= 0.0f to force a measurement
327     * @param x The x coordinate where the text will be drawn
328     * @param y The y coordinate where the text will be drawn
329     * @param paint The paint to draw the text with
330     */
331    void drawTextDecorations(const char* text, int bytesCount, float length,
332            float x, float y, SkPaint* paint);
333
334    /**
335     * Resets the texture coordinates stored in mMeshVertices. Setting the values
336     * back to default is achieved by calling:
337     *
338     * resetDrawTextureTexCoords(0.0f, 0.0f, 1.0f, 1.0f);
339     *
340     * @param u1 The left coordinate of the texture
341     * @param v1 The bottom coordinate of the texture
342     * @param u2 The right coordinate of the texture
343     * @param v2 The top coordinate of the texture
344     */
345    void resetDrawTextureTexCoords(float u1, float v1, float u2, float v2);
346
347    /**
348     * Gets the alpha and xfermode out of a paint object. If the paint is null
349     * alpha will be 255 and the xfermode will be SRC_OVER.
350     *
351     * @param paint The paint to extract values from
352     * @param alpha Where to store the resulting alpha
353     * @param mode Where to store the resulting xfermode
354     */
355    inline void getAlphaAndMode(const SkPaint* paint, int* alpha, SkXfermode::Mode* mode);
356
357    /**
358     * Binds the specified texture with the specified wrap modes.
359     */
360    inline void bindTexture(GLuint texture, GLenum wrapS, GLenum wrapT, GLuint textureUnit = 0);
361
362    /**
363     * Enable or disable blending as necessary. This function sets the appropriate
364     * blend function based on the specified xfermode.
365     */
366    inline void chooseBlending(bool blend, SkXfermode::Mode mode, ProgramDescription& description,
367            bool swapSrcDst = false);
368
369    /**
370     * Safely retrieves the mode from the specified xfermode. If the specified
371     * xfermode is null, the mode is assumed to be SkXfermode::kSrcOver_Mode.
372     */
373    inline SkXfermode::Mode getXfermode(SkXfermode* mode);
374
375    /**
376     * Use the specified program with the current GL context. If the program is already
377     * in use, it will not be bound again. If it is not in use, the current program is
378     * marked unused and the specified program becomes used and becomes the new
379     * current program.
380     *
381     * @param program The program to use
382     *
383     * @return true If the specified program was already in use, false otherwise.
384     */
385    inline bool useProgram(Program* program);
386
387    // Dimensions of the drawing surface
388    int mWidth, mHeight;
389
390    // Matrix used for ortho projection in shaders
391    mat4 mOrthoMatrix;
392
393    // Model-view matrix used to position/size objects
394    mat4 mModelView;
395
396    // Number of saved states
397    int mSaveCount;
398    // Base state
399    sp<Snapshot> mFirstSnapshot;
400    // Current state
401    sp<Snapshot> mSnapshot;
402
403    // Shaders
404    SkiaShader* mShader;
405
406    // Color filters
407    SkiaColorFilter* mColorFilter;
408
409    // Used to draw textured quads
410    TextureVertex mMeshVertices[4];
411
412    // GL extensions
413    Extensions mExtensions;
414
415    // Drop shadow
416    bool mHasShadow;
417    float mShadowRadius;
418    float mShadowDx;
419    float mShadowDy;
420    int mShadowColor;
421
422    // Various caches
423    Caches& mCaches;
424
425    // List of rectangles to clear due to calls to saveLayer()
426    Vector<Rect*> mLayers;
427
428    // Misc
429    GLint mMaxTextureSize;
430
431}; // class OpenGLRenderer
432
433}; // namespace uirenderer
434}; // namespace android
435
436#endif // ANDROID_UI_OPENGL_RENDERER_H
437