OpenGLRenderer.h revision 759ea80dca64ad652110a129e0d8bf93fea79f61 
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#include "Line.h"
44
45namespace android {
46namespace uirenderer {
47
48///////////////////////////////////////////////////////////////////////////////
49// Defines
50///////////////////////////////////////////////////////////////////////////////
51
52// Debug
53#define DEBUG_OPENGL 1
54
55///////////////////////////////////////////////////////////////////////////////
56// Renderer
57///////////////////////////////////////////////////////////////////////////////
58
59/**
60 * OpenGL renderer used to draw accelerated 2D graphics. The API is a
61 * simplified version of Skia's Canvas API.
62 */
63class OpenGLRenderer {
64public:
65    OpenGLRenderer();
66    ~OpenGLRenderer();
67
68    void setViewport(int width, int height);
69    void prepare();
70    void finish();
71    void acquireContext();
72    void releaseContext();
73
74    int getSaveCount() const;
75    int save(int flags);
76    void restore();
77    void restoreToCount(int saveCount);
78
79    int saveLayer(float left, float top, float right, float bottom, const SkPaint* p, int flags);
80    int saveLayerAlpha(float left, float top, float right, float bottom, int alpha, int flags);
81
82    void translate(float dx, float dy);
83    void rotate(float degrees);
84    void scale(float sx, float sy);
85
86    void setMatrix(SkMatrix* matrix);
87    void getMatrix(SkMatrix* matrix);
88    void concatMatrix(SkMatrix* matrix);
89
90    const Rect& getClipBounds();
91    bool quickReject(float left, float top, float right, float bottom);
92    bool clipRect(float left, float top, float right, float bottom, SkRegion::Op op);
93
94    void drawBitmap(SkBitmap* bitmap, float left, float top, const SkPaint* paint);
95    void drawBitmap(SkBitmap* bitmap, const SkMatrix* matrix, const SkPaint* paint);
96    void drawBitmap(SkBitmap* bitmap, float srcLeft, float srcTop, float srcRight, float srcBottom,
97            float dstLeft, float dstTop, float dstRight, float dstBottom, const SkPaint* paint);
98    void drawPatch(SkBitmap* bitmap, Res_png_9patch* patch, float left, float top,
99            float right, float bottom, const SkPaint* paint);
100    void drawColor(int color, SkXfermode::Mode mode);
101    void drawRect(float left, float top, float right, float bottom, const SkPaint* paint);
102    void drawPath(SkPath* path, SkPaint* paint);
103    void drawLines(float* points, int count, const SkPaint* paint);
104
105    void resetShader();
106    void setupShader(SkiaShader* shader);
107
108    void resetColorFilter();
109    void setupColorFilter(SkiaColorFilter* filter);
110
111    void resetShadow();
112    void setupShadow(float radius, float dx, float dy, int color);
113
114    void drawText(const char* text, int bytesCount, int count, float x, float y, SkPaint* paint);
115
116private:
117    /**
118     * Saves the current state of the renderer as a new snapshot.
119     * The new snapshot is saved in mSnapshot and the previous snapshot
120     * is linked from mSnapshot->previous.
121     *
122     * @param flags The save flags; see SkCanvas for more information
123     *
124     * @return The new save count. This value can be passed to #restoreToCount()
125     */
126    int saveSnapshot(int flags);
127
128    /**
129     * Restores the current snapshot; mSnapshot becomes mSnapshot->previous.
130     *
131     * @return True if the clip was modified.
132     */
133    bool restoreSnapshot();
134
135    /**
136     * Sets the clipping rectangle using glScissor. The clip is defined by
137     * the current snapshot's clipRect member.
138     */
139    void setScissorFromClip();
140
141    /**
142     * Compose the layer defined in the current snapshot with the layer
143     * defined by the previous snapshot.
144     *
145     * The current snapshot *must* be a layer (flag kFlagIsLayer set.)
146     *
147     * @param curent The current snapshot containing the layer to compose
148     * @param previous The previous snapshot to compose the current layer with
149     */
150    void composeLayer(sp<Snapshot> current, sp<Snapshot> previous);
151
152    /**
153     * Creates a new layer stored in the specified snapshot.
154     *
155     * @param snapshot The snapshot associated with the new layer
156     * @param left The left coordinate of the layer
157     * @param top The top coordinate of the layer
158     * @param right The right coordinate of the layer
159     * @param bottom The bottom coordinate of the layer
160     * @param alpha The translucency of the layer
161     * @param mode The blending mode of the layer
162     * @param flags The layer save flags
163     *
164     * @return True if the layer was successfully created, false otherwise
165     */
166    bool createLayer(sp<Snapshot> snapshot, float left, float top, float right, float bottom,
167            int alpha, SkXfermode::Mode mode, int flags);
168
169    /**
170     * Clears all the regions corresponding to the current list of layers.
171     * This method MUST be invoked before any drawing operation.
172     */
173    void clearLayerRegions();
174
175    /**
176     * Draws a colored rectangle with the specified color. The specified coordinates
177     * are transformed by the current snapshot's transform matrix.
178     *
179     * @param left The left coordinate of the rectangle
180     * @param top The top coordinate of the rectangle
181     * @param right The right coordinate of the rectangle
182     * @param bottom The bottom coordinate of the rectangle
183     * @param color The rectangle's ARGB color, defined as a packed 32 bits word
184     * @param mode The Skia xfermode to use
185     * @param ignoreTransform True if the current transform should be ignored
186     * @paran ignoreBlending True if the blending is set by the caller
187     */
188    void drawColorRect(float left, float top, float right, float bottom,
189            int color, SkXfermode::Mode mode, bool ignoreTransform = false);
190
191    /**
192     * Draws a textured rectangle with the specified texture. The specified coordinates
193     * are transformed by the current snapshot's transform matrix.
194     *
195     * @param left The left coordinate of the rectangle
196     * @param top The top coordinate of the rectangle
197     * @param right The right coordinate of the rectangle
198     * @param bottom The bottom coordinate of the rectangle
199     * @param texture The texture name to map onto the rectangle
200     * @param alpha An additional translucency parameter, between 0.0f and 1.0f
201     * @param mode The blending mode
202     * @param blend True if the texture contains an alpha channel
203     */
204    void drawTextureRect(float left, float top, float right, float bottom, GLuint texture,
205            float alpha, SkXfermode::Mode mode, bool blend);
206
207    /**
208     * Draws a textured rectangle with the specified texture. The specified coordinates
209     * are transformed by the current snapshot's transform matrix.
210     *
211     * @param left The left coordinate of the rectangle
212     * @param top The top coordinate of the rectangle
213     * @param right The right coordinate of the rectangle
214     * @param bottom The bottom coordinate of the rectangle
215     * @param texture The texture to use
216     * @param paint The paint containing the alpha, blending mode, etc.
217     */
218    void drawTextureRect(float left, float top, float right, float bottom,
219            const Texture* texture, const SkPaint* paint);
220
221    /**
222     * Draws a textured mesh with the specified texture. If the indices are omitted, the
223     * mesh is drawn as a simple quad.
224     *
225     * @param left The left coordinate of the rectangle
226     * @param top The top coordinate of the rectangle
227     * @param right The right coordinate of the rectangle
228     * @param bottom The bottom coordinate of the rectangle
229     * @param texture The texture name to map onto the rectangle
230     * @param alpha An additional translucency parameter, between 0.0f and 1.0f
231     * @param mode The blending mode
232     * @param blend True if the texture contains an alpha channel
233     * @param vertices The vertices that define the mesh
234     * @param texCoords The texture coordinates of each vertex
235     * @param indices The indices of the vertices, can be NULL
236     * @param elementsCount The number of elements in the mesh, required by indices
237     * @param swapSrcDst Whether or not the src and dst blending operations should be swapped
238     * @param ignoreTransform True if the current transform should be ignored
239     */
240    void drawTextureMesh(float left, float top, float right, float bottom, GLuint texture,
241            float alpha, SkXfermode::Mode mode, bool blend,
242            GLvoid* vertices, GLvoid* texCoords, GLenum drawMode, GLsizei elementsCount,
243            bool swapSrcDst = false, bool ignoreTransform = false);
244
245    /**
246     * Prepares the renderer to draw the specified shadow.
247     *
248     * @param texture The shadow texture
249     * @param x The x coordinate of the shadow
250     * @param y The y coordinate of the shadow
251     * @param mode The blending mode
252     * @param alpha The alpha value
253     */
254    void setupShadow(const ShadowTexture* texture, float x, float y, SkXfermode::Mode mode,
255            float alpha);
256
257    /**
258     * Prepares the renderer to draw the specified Alpha8 texture as a rectangle.
259     *
260     * @param texture The texture to render with
261     * @param textureUnit The texture unit to use, may be modified
262     * @param x The x coordinate of the rectangle to draw
263     * @param y The y coordinate of the rectangle to draw
264     * @param r The red component of the color
265     * @param g The green component of the color
266     * @param b The blue component of the color
267     * @param a The alpha component of the color
268     * @param mode The blending mode
269     * @param transforms True if the matrix passed to the shader should be multiplied
270     *        by the model-view matrix
271     * @param applyFilters Whether or not to take color filters and
272     *        shaders into account
273     */
274    void setupTextureAlpha8(const Texture* texture, GLuint& textureUnit, float x, float y,
275            float r, float g, float b, float a, SkXfermode::Mode mode, bool transforms,
276            bool applyFilters);
277
278    /**
279     * Prepares the renderer to draw the specified Alpha8 texture as a rectangle.
280     *
281     * @param texture The texture to render with
282     * @param width The width of the texture
283     * @param height The height of the texture
284     * @param textureUnit The texture unit to use, may be modified
285     * @param x The x coordinate of the rectangle to draw
286     * @param y The y coordinate of the rectangle to draw
287     * @param r The red component of the color
288     * @param g The green component of the color
289     * @param b The blue component of the color
290     * @param a The alpha component of the color
291     * @param mode The blending mode
292     * @param transforms True if the matrix passed to the shader should be multiplied
293     *        by the model-view matrix
294     * @param applyFilters Whether or not to take color filters and
295     *        shaders into account
296     */
297    void setupTextureAlpha8(GLuint texture, uint32_t width, uint32_t height,
298            GLuint& textureUnit, float x, float y, float r, float g, float b, float a,
299            SkXfermode::Mode mode, bool transforms, bool applyFilters);
300
301    /**
302     * Same as above setupTextureAlpha8() but specifies the mesh's vertices
303     * and texCoords pointers.
304     */
305    void setupTextureAlpha8(GLuint texture, uint32_t width, uint32_t height,
306            GLuint& textureUnit, float x, float y, float r, float g, float b, float a,
307            SkXfermode::Mode mode, bool transforms, bool applyFilters,
308            GLvoid* vertices, GLvoid* texCoords);
309
310    /**
311     * Draws text underline and strike-through if needed.
312     *
313     * @param text The text to decor
314     * @param bytesCount The number of bytes in the text
315     * @param length The length in pixels of the text, can be <= 0.0f to force a measurement
316     * @param x The x coordinate where the text will be drawn
317     * @param y The y coordinate where the text will be drawn
318     * @param paint The paint to draw the text with
319     */
320    void drawTextDecorations(const char* text, int bytesCount, float length,
321            float x, float y, SkPaint* paint);
322
323    /**
324     * Resets the texture coordinates stored in mMeshVertices. Setting the values
325     * back to default is achieved by calling:
326     *
327     * resetDrawTextureTexCoords(0.0f, 0.0f, 1.0f, 1.0f);
328     *
329     * @param u1 The left coordinate of the texture
330     * @param v1 The bottom coordinate of the texture
331     * @param u2 The right coordinate of the texture
332     * @param v2 The top coordinate of the texture
333     */
334    void resetDrawTextureTexCoords(float u1, float v1, float u2, float v2);
335
336    /**
337     * Gets the alpha and xfermode out of a paint object. If the paint is null
338     * alpha will be 255 and the xfermode will be SRC_OVER.
339     *
340     * @param paint The paint to extract values from
341     * @param alpha Where to store the resulting alpha
342     * @param mode Where to store the resulting xfermode
343     */
344    inline void getAlphaAndMode(const SkPaint* paint, int* alpha, SkXfermode::Mode* mode);
345
346    /**
347     * Binds the specified texture with the specified wrap modes.
348     */
349    inline void bindTexture(GLuint texture, GLenum wrapS, GLenum wrapT, GLuint textureUnit = 0);
350
351    /**
352     * Enable or disable blending as necessary. This function sets the appropriate
353     * blend function based on the specified xfermode.
354     */
355    inline void chooseBlending(bool blend, SkXfermode::Mode mode, ProgramDescription& description,
356            bool swapSrcDst = false);
357
358    /**
359     * Safely retrieves the mode from the specified xfermode. If the specified
360     * xfermode is null, the mode is assumed to be SkXfermode::kSrcOver_Mode.
361     */
362    inline SkXfermode::Mode getXfermode(SkXfermode* mode);
363
364    /**
365     * Use the specified program with the current GL context. If the program is already
366     * in use, it will not be bound again. If it is not in use, the current program is
367     * marked unused and the specified program becomes used and becomes the new
368     * current program.
369     *
370     * @param program The program to use
371     *
372     * @return true If the specified program was already in use, false otherwise.
373     */
374    inline bool useProgram(Program* program);
375
376    // Dimensions of the drawing surface
377    int mWidth, mHeight;
378
379    // Matrix used for ortho projection in shaders
380    mat4 mOrthoMatrix;
381
382    // Model-view matrix used to position/size objects
383    mat4 mModelView;
384
385    // Number of saved states
386    int mSaveCount;
387    // Base state
388    sp<Snapshot> mFirstSnapshot;
389    // Current state
390    sp<Snapshot> mSnapshot;
391
392    // Shaders
393    SkiaShader* mShader;
394
395    // Color filters
396    SkiaColorFilter* mColorFilter;
397
398    // Used to draw textured quads
399    TextureVertex mMeshVertices[4];
400
401    // GL extensions
402    Extensions mExtensions;
403
404    // Drop shadow
405    bool mHasShadow;
406    float mShadowRadius;
407    float mShadowDx;
408    float mShadowDy;
409    int mShadowColor;
410
411    // Various caches
412    Caches& mCaches;
413
414    // List of rectangles to clear due to calls to saveLayer()
415    Vector<Rect*> mLayers;
416
417    // Single object used to draw lines
418    Line mLine;
419
420    // Misc
421    GLint mMaxTextureSize;
422
423}; // class OpenGLRenderer
424
425}; // namespace uirenderer
426}; // namespace android
427
428#endif // ANDROID_UI_OPENGL_RENDERER_H
429