OpenGLRenderer.h revision 29d8997bd43b7c4ad37fc3d6f91eaafa74913c88 
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/ResourceTypes.h>
32#include <utils/Vector.h>
33
34#include "Extensions.h"
35#include "Matrix.h"
36#include "Program.h"
37#include "Rect.h"
38#include "Snapshot.h"
39#include "Vertex.h"
40#include "SkiaShader.h"
41#include "SkiaColorFilter.h"
42#include "Caches.h"
43
44namespace android {
45namespace uirenderer {
46
47///////////////////////////////////////////////////////////////////////////////
48// Defines
49///////////////////////////////////////////////////////////////////////////////
50
51// Debug
52#define DEBUG_OPENGL 1
53
54///////////////////////////////////////////////////////////////////////////////
55// Renderer
56///////////////////////////////////////////////////////////////////////////////
57
58/**
59 * OpenGL renderer used to draw accelerated 2D graphics. The API is a
60 * simplified version of Skia's Canvas API.
61 */
62class OpenGLRenderer {
63public:
64    OpenGLRenderer();
65    ~OpenGLRenderer();
66
67    void setViewport(int width, int height);
68    void prepare();
69    void finish();
70    void acquireContext();
71    void releaseContext();
72
73    int getSaveCount() const;
74    int save(int flags);
75    void restore();
76    void restoreToCount(int saveCount);
77
78    int saveLayer(float left, float top, float right, float bottom, const SkPaint* p, int flags);
79    int saveLayerAlpha(float left, float top, float right, float bottom, int alpha, int flags);
80
81    void translate(float dx, float dy);
82    void rotate(float degrees);
83    void scale(float sx, float sy);
84
85    void setMatrix(SkMatrix* matrix);
86    void getMatrix(SkMatrix* matrix);
87    void concatMatrix(SkMatrix* matrix);
88
89    const Rect& getClipBounds();
90    bool quickReject(float left, float top, float right, float bottom);
91    bool clipRect(float left, float top, float right, float bottom, SkRegion::Op op);
92
93    void drawBitmap(SkBitmap* bitmap, float left, float top, const SkPaint* paint);
94    void drawBitmap(SkBitmap* bitmap, const SkMatrix* matrix, const SkPaint* paint);
95    void drawBitmap(SkBitmap* bitmap, float srcLeft, float srcTop, float srcRight, float srcBottom,
96            float dstLeft, float dstTop, float dstRight, float dstBottom, const SkPaint* paint);
97    void drawPatch(SkBitmap* bitmap, Res_png_9patch* patch, float left, float top,
98            float right, float bottom, const SkPaint* paint);
99    void drawColor(int color, SkXfermode::Mode mode);
100    void drawRect(float left, float top, float right, float bottom, const SkPaint* paint);
101    void drawPath(SkPath* path, SkPaint* paint);
102    void drawLines(float* points, int count, const SkPaint* paint);
103
104    void resetShader();
105    void setupShader(SkiaShader* shader);
106
107    void resetColorFilter();
108    void setupColorFilter(SkiaColorFilter* filter);
109
110    void resetShadow();
111    void setupShadow(float radius, float dx, float dy, int color);
112
113    void drawText(const char* text, int bytesCount, int count, float x, float y, SkPaint* paint);
114
115private:
116    /**
117     * Saves the current state of the renderer as a new snapshot.
118     * The new snapshot is saved in mSnapshot and the previous snapshot
119     * is linked from mSnapshot->previous.
120     *
121     * @param flags The save flags; see SkCanvas for more information
122     *
123     * @return The new save count. This value can be passed to #restoreToCount()
124     */
125    int saveSnapshot(int flags);
126
127    /**
128     * Restores the current snapshot; mSnapshot becomes mSnapshot->previous.
129     *
130     * @return True if the clip was modified.
131     */
132    bool restoreSnapshot();
133
134    /**
135     * Sets the clipping rectangle using glScissor. The clip is defined by
136     * the current snapshot's clipRect member.
137     */
138    void setScissorFromClip();
139
140    /**
141     * Compose the layer defined in the current snapshot with the layer
142     * defined by the previous snapshot.
143     *
144     * The current snapshot *must* be a layer (flag kFlagIsLayer set.)
145     *
146     * @param curent The current snapshot containing the layer to compose
147     * @param previous The previous snapshot to compose the current layer with
148     */
149    void composeLayer(sp<Snapshot> current, sp<Snapshot> previous);
150
151    /**
152     * Creates a new layer stored in the specified snapshot.
153     *
154     * @param snapshot The snapshot associated with the new layer
155     * @param left The left coordinate of the layer
156     * @param top The top coordinate of the layer
157     * @param right The right coordinate of the layer
158     * @param bottom The bottom coordinate of the layer
159     * @param alpha The translucency of the layer
160     * @param mode The blending mode of the layer
161     * @param flags The layer save flags
162     *
163     * @return True if the layer was successfully created, false otherwise
164     */
165    bool createLayer(sp<Snapshot> snapshot, float left, float top, float right, float bottom,
166            int alpha, SkXfermode::Mode mode, int flags);
167
168    /**
169     * Clears all the regions corresponding to the current list of layers.
170     * This method MUST be invoked before any drawing operation.
171     */
172    void clearLayerRegions();
173
174    /**
175     * Draws a colored rectangle with the specified color. The specified coordinates
176     * are transformed by the current snapshot's transform matrix.
177     *
178     * @param left The left coordinate of the rectangle
179     * @param top The top coordinate of the rectangle
180     * @param right The right coordinate of the rectangle
181     * @param bottom The bottom coordinate of the rectangle
182     * @param color The rectangle's ARGB color, defined as a packed 32 bits word
183     * @param mode The Skia xfermode to use
184     * @param ignoreTransform True if the current transform should be ignored
185     * @paran ignoreBlending True if the blending is set by the caller
186     */
187    void drawColorRect(float left, float top, float right, float bottom,
188            int color, SkXfermode::Mode mode, bool ignoreTransform = false);
189
190    /**
191     * Setups shaders to draw a colored rect.
192     */
193    void setupColorRect(float left, float top, float right, float bottom,
194            float r, float g, float b, float a, SkXfermode::Mode mode, bool ignoreTransform);
195
196    /**
197     * Draws a textured rectangle with the specified texture. The specified coordinates
198     * are transformed by the current snapshot's transform matrix.
199     *
200     * @param left The left coordinate of the rectangle
201     * @param top The top coordinate of the rectangle
202     * @param right The right coordinate of the rectangle
203     * @param bottom The bottom coordinate of the rectangle
204     * @param texture The texture name to map onto the rectangle
205     * @param alpha An additional translucency parameter, between 0.0f and 1.0f
206     * @param mode The blending mode
207     * @param blend True if the texture contains an alpha channel
208     */
209    void drawTextureRect(float left, float top, float right, float bottom, GLuint texture,
210            float alpha, SkXfermode::Mode mode, bool blend);
211
212    /**
213     * Draws a textured rectangle with the specified texture. The specified coordinates
214     * are transformed by the current snapshot's transform matrix.
215     *
216     * @param left The left coordinate of the rectangle
217     * @param top The top coordinate of the rectangle
218     * @param right The right coordinate of the rectangle
219     * @param bottom The bottom coordinate of the rectangle
220     * @param texture The texture to use
221     * @param paint The paint containing the alpha, blending mode, etc.
222     */
223    void drawTextureRect(float left, float top, float right, float bottom,
224            const Texture* texture, const SkPaint* paint);
225
226    /**
227     * Draws a textured mesh with the specified texture. If the indices are omitted, the
228     * mesh is drawn as a simple quad.
229     *
230     * @param left The left coordinate of the rectangle
231     * @param top The top coordinate of the rectangle
232     * @param right The right coordinate of the rectangle
233     * @param bottom The bottom coordinate of the rectangle
234     * @param texture The texture name to map onto the rectangle
235     * @param alpha An additional translucency parameter, between 0.0f and 1.0f
236     * @param mode The blending mode
237     * @param blend True if the texture contains an alpha channel
238     * @param vertices The vertices that define the mesh
239     * @param texCoords The texture coordinates of each vertex
240     * @param indices The indices of the vertices, can be NULL
241     * @param elementsCount The number of elements in the mesh, required by indices
242     * @param swapSrcDst Whether or not the src and dst blending operations should be swapped
243     * @param ignoreTransform True if the current transform should be ignored
244     */
245    void drawTextureMesh(float left, float top, float right, float bottom, GLuint texture,
246            float alpha, SkXfermode::Mode mode, bool blend,
247            GLvoid* vertices, GLvoid* texCoords, GLenum drawMode, GLsizei elementsCount,
248            bool swapSrcDst = false, bool ignoreTransform = false);
249
250    /**
251     * Prepares the renderer to draw the specified shadow.
252     *
253     * @param texture The shadow texture
254     * @param x The x coordinate of the shadow
255     * @param y The y coordinate of the shadow
256     * @param mode The blending mode
257     * @param alpha The alpha value
258     */
259    void setupShadow(const ShadowTexture* texture, float x, float y, SkXfermode::Mode mode,
260            float alpha);
261
262    /**
263     * Prepares the renderer to draw the specified Alpha8 texture as a rectangle.
264     *
265     * @param texture The texture to render with
266     * @param textureUnit The texture unit to use, may be modified
267     * @param x The x coordinate of the rectangle to draw
268     * @param y The y coordinate of the rectangle to draw
269     * @param r The red component of the color
270     * @param g The green component of the color
271     * @param b The blue component of the color
272     * @param a The alpha component of the color
273     * @param mode The blending mode
274     * @param transforms True if the matrix passed to the shader should be multiplied
275     *        by the model-view matrix
276     * @param applyFilters Whether or not to take color filters and
277     *        shaders into account
278     */
279    void setupTextureAlpha8(const Texture* texture, GLuint& textureUnit, float x, float y,
280            float r, float g, float b, float a, SkXfermode::Mode mode, bool transforms,
281            bool applyFilters);
282
283    /**
284     * Prepares the renderer to draw the specified Alpha8 texture as a rectangle.
285     *
286     * @param texture The texture to render with
287     * @param width The width of the texture
288     * @param height The height of the texture
289     * @param textureUnit The texture unit to use, may be modified
290     * @param x The x coordinate of the rectangle to draw
291     * @param y The y coordinate of the rectangle to draw
292     * @param r The red component of the color
293     * @param g The green component of the color
294     * @param b The blue component of the color
295     * @param a The alpha component of the color
296     * @param mode The blending mode
297     * @param transforms True if the matrix passed to the shader should be multiplied
298     *        by the model-view matrix
299     * @param applyFilters Whether or not to take color filters and
300     *        shaders into account
301     */
302    void setupTextureAlpha8(GLuint texture, uint32_t width, uint32_t height,
303            GLuint& textureUnit, float x, float y, float r, float g, float b, float a,
304            SkXfermode::Mode mode, bool transforms, bool applyFilters);
305
306    /**
307     * Same as above setupTextureAlpha8() but specifies the mesh's vertices
308     * and texCoords pointers.
309     */
310    void setupTextureAlpha8(GLuint texture, uint32_t width, uint32_t height,
311            GLuint& textureUnit, float x, float y, float r, float g, float b, float a,
312            SkXfermode::Mode mode, bool transforms, bool applyFilters,
313            GLvoid* vertices, GLvoid* texCoords);
314
315    /**
316     * Draws text underline and strike-through if needed.
317     *
318     * @param text The text to decor
319     * @param bytesCount The number of bytes in the text
320     * @param length The length in pixels of the text, can be <= 0.0f to force a measurement
321     * @param x The x coordinate where the text will be drawn
322     * @param y The y coordinate where the text will be drawn
323     * @param paint The paint to draw the text with
324     */
325    void drawTextDecorations(const char* text, int bytesCount, float length,
326            float x, float y, SkPaint* paint);
327
328    /**
329     * Resets the texture coordinates stored in mMeshVertices. Setting the values
330     * back to default is achieved by calling:
331     *
332     * resetDrawTextureTexCoords(0.0f, 0.0f, 1.0f, 1.0f);
333     *
334     * @param u1 The left coordinate of the texture
335     * @param v1 The bottom coordinate of the texture
336     * @param u2 The right coordinate of the texture
337     * @param v2 The top coordinate of the texture
338     */
339    void resetDrawTextureTexCoords(float u1, float v1, float u2, float v2);
340
341    /**
342     * Gets the alpha and xfermode out of a paint object. If the paint is null
343     * alpha will be 255 and the xfermode will be SRC_OVER.
344     *
345     * @param paint The paint to extract values from
346     * @param alpha Where to store the resulting alpha
347     * @param mode Where to store the resulting xfermode
348     */
349    inline void getAlphaAndMode(const SkPaint* paint, int* alpha, SkXfermode::Mode* mode);
350
351    /**
352     * Binds the specified texture with the specified wrap modes.
353     */
354    inline void bindTexture(GLuint texture, GLenum wrapS, GLenum wrapT, GLuint textureUnit = 0);
355
356    /**
357     * Enable or disable blending as necessary. This function sets the appropriate
358     * blend function based on the specified xfermode.
359     */
360    inline void chooseBlending(bool blend, SkXfermode::Mode mode, ProgramDescription& description,
361            bool swapSrcDst = false);
362
363    /**
364     * Safely retrieves the mode from the specified xfermode. If the specified
365     * xfermode is null, the mode is assumed to be SkXfermode::kSrcOver_Mode.
366     */
367    inline SkXfermode::Mode getXfermode(SkXfermode* mode);
368
369    /**
370     * Use the specified program with the current GL context. If the program is already
371     * in use, it will not be bound again. If it is not in use, the current program is
372     * marked unused and the specified program becomes used and becomes the new
373     * current program.
374     *
375     * @param program The program to use
376     *
377     * @return true If the specified program was already in use, false otherwise.
378     */
379    inline bool useProgram(Program* program);
380
381    // Dimensions of the drawing surface
382    int mWidth, mHeight;
383
384    // Matrix used for ortho projection in shaders
385    mat4 mOrthoMatrix;
386
387    // Model-view matrix used to position/size objects
388    mat4 mModelView;
389
390    // Number of saved states
391    int mSaveCount;
392    // Base state
393    sp<Snapshot> mFirstSnapshot;
394    // Current state
395    sp<Snapshot> mSnapshot;
396
397    // Shaders
398    SkiaShader* mShader;
399
400    // Color filters
401    SkiaColorFilter* mColorFilter;
402
403    // Used to draw textured quads
404    TextureVertex mMeshVertices[4];
405
406    // GL extensions
407    Extensions mExtensions;
408
409    // Drop shadow
410    bool mHasShadow;
411    float mShadowRadius;
412    float mShadowDx;
413    float mShadowDy;
414    int mShadowColor;
415
416    // Various caches
417    Caches& mCaches;
418
419    // List of rectangles to clear due to calls to saveLayer()
420    Vector<Rect*> mLayers;
421
422    // Misc
423    GLint mMaxTextureSize;
424
425}; // class OpenGLRenderer
426
427}; // namespace uirenderer
428}; // namespace android
429
430#endif // ANDROID_UI_OPENGL_RENDERER_H
431