OpenGLRenderer.h revision f607bdc167f66b3e7003acaa4736ae46d78c1492 
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
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// Renderer
48///////////////////////////////////////////////////////////////////////////////
49
50/**
51 * OpenGL renderer used to draw accelerated 2D graphics. The API is a
52 * simplified version of Skia's Canvas API.
53 */
54class OpenGLRenderer {
55public:
56    OpenGLRenderer();
57    ~OpenGLRenderer();
58
59    void setViewport(int width, int height);
60    void prepare();
61    void acquireContext();
62    void releaseContext();
63
64    int getSaveCount() const;
65    int save(int flags);
66    void restore();
67    void restoreToCount(int saveCount);
68
69    int saveLayer(float left, float top, float right, float bottom, const SkPaint* p, int flags);
70    int saveLayerAlpha(float left, float top, float right, float bottom, int alpha, int flags);
71
72    void translate(float dx, float dy);
73    void rotate(float degrees);
74    void scale(float sx, float sy);
75
76    void setMatrix(SkMatrix* matrix);
77    void getMatrix(SkMatrix* matrix);
78    void concatMatrix(SkMatrix* matrix);
79
80    const Rect& getClipBounds();
81    bool quickReject(float left, float top, float right, float bottom);
82    bool clipRect(float left, float top, float right, float bottom, SkRegion::Op op);
83
84    void drawBitmap(SkBitmap* bitmap, float left, float top, const SkPaint* paint);
85    void drawBitmap(SkBitmap* bitmap, const SkMatrix* matrix, const SkPaint* paint);
86    void drawBitmap(SkBitmap* bitmap, float srcLeft, float srcTop, float srcRight, float srcBottom,
87            float dstLeft, float dstTop, float dstRight, float dstBottom, const SkPaint* paint);
88    void drawPatch(SkBitmap* bitmap, Res_png_9patch* patch, float left, float top,
89            float right, float bottom, const SkPaint* paint);
90    void drawColor(int color, SkXfermode::Mode mode);
91    void drawRect(float left, float top, float right, float bottom, const SkPaint* paint);
92    void drawPath(SkPath* path, SkPaint* paint);
93
94    void resetShader();
95    void setupShader(SkiaShader* shader);
96
97    void resetColorFilter();
98    void setupColorFilter(SkiaColorFilter* filter);
99
100    void resetShadow();
101    void setupShadow(float radius, float dx, float dy, int color);
102
103    void drawText(const char* text, int bytesCount, int count, float x, float y, SkPaint* paint);
104
105private:
106    /**
107     * Saves the current state of the renderer as a new snapshot.
108     * The new snapshot is saved in mSnapshot and the previous snapshot
109     * is linked from mSnapshot->previous.
110     *
111     * @param flags The save flags; see SkCanvas for more information
112     *
113     * @return The new save count. This value can be passed to #restoreToCount()
114     */
115    int saveSnapshot(int flags);
116
117    /**
118     * Restores the current snapshot; mSnapshot becomes mSnapshot->previous.
119     *
120     * @return True if the clip was modified.
121     */
122    bool restoreSnapshot();
123
124    /**
125     * Sets the clipping rectangle using glScissor. The clip is defined by
126     * the current snapshot's clipRect member.
127     */
128    void setScissorFromClip();
129
130    /**
131     * Compose the layer defined in the current snapshot with the layer
132     * defined by the previous snapshot.
133     *
134     * The current snapshot *must* be a layer (flag kFlagIsLayer set.)
135     *
136     * @param curent The current snapshot containing the layer to compose
137     * @param previous The previous snapshot to compose the current layer with
138     */
139    void composeLayer(sp<Snapshot> current, sp<Snapshot> previous);
140
141    /**
142     * Creates a new layer stored in the specified snapshot.
143     *
144     * @param snapshot The snapshot associated with the new layer
145     * @param left The left coordinate of the layer
146     * @param top The top coordinate of the layer
147     * @param right The right coordinate of the layer
148     * @param bottom The bottom coordinate of the layer
149     * @param alpha The translucency of the layer
150     * @param mode The blending mode of the layer
151     * @param flags The layer save flags
152     *
153     * @return True if the layer was successfully created, false otherwise
154     */
155    bool createLayer(sp<Snapshot> snapshot, float left, float top, float right, float bottom,
156            int alpha, SkXfermode::Mode mode, int flags);
157
158    /**
159     * Draws a colored rectangle with the specified color. The specified coordinates
160     * are transformed by the current snapshot's transform matrix.
161     *
162     * @param left The left coordinate of the rectangle
163     * @param top The top coordinate of the rectangle
164     * @param right The right coordinate of the rectangle
165     * @param bottom The bottom coordinate of the rectangle
166     * @param color The rectangle's ARGB color, defined as a packed 32 bits word
167     * @param mode The Skia xfermode to use
168     * @param ignoreTransform True if the current transform should be ignored
169     * @paran ignoreBlending True if the blending is set by the caller
170     */
171    void drawColorRect(float left, float top, float right, float bottom,
172    		int color, SkXfermode::Mode mode, bool ignoreTransform = false,
173    		bool ignoreBlending = false);
174
175    /**
176     * Draws a textured rectangle with the specified texture. 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 texture The texture name to map onto the rectangle
184     * @param alpha An additional translucency parameter, between 0.0f and 1.0f
185     * @param mode The blending mode
186     * @param blend True if the texture contains an alpha channel
187     */
188    void drawTextureRect(float left, float top, float right, float bottom, GLuint texture,
189            float alpha, SkXfermode::Mode mode, bool blend);
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 to use
200     * @param paint The paint containing the alpha, blending mode, etc.
201     */
202    void drawTextureRect(float left, float top, float right, float bottom,
203            const Texture* texture, const SkPaint* paint);
204
205    /**
206     * Draws a textured mesh with the specified texture. If the indices are omitted, the
207     * mesh is drawn as a simple quad.
208     *
209     * @param left The left coordinate of the rectangle
210     * @param top The top coordinate of the rectangle
211     * @param right The right coordinate of the rectangle
212     * @param bottom The bottom coordinate of the rectangle
213     * @param texture The texture name to map onto the rectangle
214     * @param alpha An additional translucency parameter, between 0.0f and 1.0f
215     * @param mode The blending mode
216     * @param blend True if the texture contains an alpha channel
217     * @param vertices The vertices that define the mesh
218     * @param texCoords The texture coordinates of each vertex
219     * @param indices The indices of the vertices, can be NULL
220     * @param elementsCount The number of elements in the mesh, required by indices
221     * @param swapSrcDst Whether or not the src and dst blending operations should be swapped
222     * @param ignoreTransform True if the current transform should be ignored
223     */
224    void drawTextureMesh(float left, float top, float right, float bottom, GLuint texture,
225            float alpha, SkXfermode::Mode mode, bool blend,
226            GLvoid* vertices, GLvoid* texCoords, GLvoid* indices, GLsizei elementsCount = 0,
227            bool swapSrcDst = false, bool ignoreTransform = false);
228
229    /**
230     * Prepares the renderer to draw the specified shadow.
231     *
232     * @param texture The shadow texture
233     * @param x The x coordinate of the shadow
234     * @param y The y coordinate of the shadow
235     * @param mode The blending mode
236     * @param alpha The alpha value
237     */
238    void setupShadow(const ShadowTexture* texture, float x, float y, SkXfermode::Mode mode,
239            float alpha);
240
241    /**
242     * Prepares the renderer to draw the specified Alpha8 texture as a rectangle.
243     *
244     * @param texture The texture to render with
245     * @param textureUnit The texture unit to use, may be modified
246     * @param x The x coordinate of the rectangle to draw
247     * @param y The y coordinate of the rectangle to draw
248     * @param r The red component of the color
249     * @param g The green component of the color
250     * @param b The blue component of the color
251     * @param a The alpha component of the color
252     * @param mode The blending mode
253     * @param transforms True if the matrix passed to the shader should be multiplied
254     *        by the model-view matrix
255     * @param applyFilters Whether or not to take color filters and
256     *        shaders into account
257     */
258    void setupTextureAlpha8(const Texture* texture, GLuint& textureUnit, float x, float y,
259            float r, float g, float b, float a, SkXfermode::Mode mode, bool transforms,
260            bool applyFilters);
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 width The width of the texture
267     * @param height The height of the texture
268     * @param textureUnit The texture unit to use, may be modified
269     * @param x The x coordinate of the rectangle to draw
270     * @param y The y coordinate of the rectangle to draw
271     * @param r The red component of the color
272     * @param g The green component of the color
273     * @param b The blue component of the color
274     * @param a The alpha component of the color
275     * @param mode The blending mode
276     * @param transforms True if the matrix passed to the shader should be multiplied
277     *        by the model-view matrix
278     * @param applyFilters Whether or not to take color filters and
279     *        shaders into account
280     */
281    void setupTextureAlpha8(GLuint texture, uint32_t width, uint32_t height,
282            GLuint& textureUnit, float x, float y, float r, float g, float b, float a,
283            SkXfermode::Mode mode, bool transforms, bool applyFilters);
284
285    /**
286     * Draws text underline and strike-through if needed.
287     *
288     * @param text The text to decor
289     * @param bytesCount The number of bytes in the text
290     * @param length The length in pixels of the text, can be <= 0.0f to force a measurement
291     * @param x The x coordinate where the text will be drawn
292     * @param y The y coordinate where the text will be drawn
293     * @param paint The paint to draw the text with
294     */
295    void drawTextDecorations(const char* text, int bytesCount, float length,
296            float x, float y, SkPaint* paint);
297
298    /**
299     * Resets the texture coordinates stored in mMeshVertices. Setting the values
300     * back to default is achieved by calling:
301     *
302     * resetDrawTextureTexCoords(0.0f, 0.0f, 1.0f, 1.0f);
303     *
304     * @param u1 The left coordinate of the texture
305     * @param v1 The bottom coordinate of the texture
306     * @param u2 The right coordinate of the texture
307     * @param v2 The top coordinate of the texture
308     */
309    void resetDrawTextureTexCoords(float u1, float v1, float u2, float v2);
310
311    /**
312     * Gets the alpha and xfermode out of a paint object. If the paint is null
313     * alpha will be 255 and the xfermode will be SRC_OVER.
314     *
315     * @param paint The paint to extract values from
316     * @param alpha Where to store the resulting alpha
317     * @param mode Where to store the resulting xfermode
318     */
319    inline void getAlphaAndMode(const SkPaint* paint, int* alpha, SkXfermode::Mode* mode);
320
321    /**
322     * Binds the specified texture with the specified wrap modes.
323     */
324    inline void bindTexture(GLuint texture, GLenum wrapS, GLenum wrapT, GLuint textureUnit = 0);
325
326    /**
327     * Enable or disable blending as necessary. This function sets the appropriate
328     * blend function based on the specified xfermode.
329     */
330    inline void chooseBlending(bool blend, SkXfermode::Mode mode, ProgramDescription& description,
331            bool swapSrcDst = false);
332
333    /**
334     * Safely retrieves the mode from the specified xfermode. If the specified
335     * xfermode is null, the mode is assumed to be SkXfermode::kSrcOver_Mode.
336     */
337    inline SkXfermode::Mode getXfermode(SkXfermode* mode);
338
339    /**
340     * Use the specified program with the current GL context. If the program is already
341     * in use, it will not be bound again. If it is not in use, the current program is
342     * marked unused and the specified program becomes used and becomes the new
343     * current program.
344     *
345     * @param program The program to use
346     *
347     * @return true If the specified program was already in use, false otherwise.
348     */
349    inline bool useProgram(Program* program);
350
351    // Dimensions of the drawing surface
352    int mWidth, mHeight;
353
354    // Matrix used for ortho projection in shaders
355    mat4 mOrthoMatrix;
356
357    // Model-view matrix used to position/size objects
358    mat4 mModelView;
359
360    // Number of saved states
361    int mSaveCount;
362    // Base state
363    sp<Snapshot> mFirstSnapshot;
364    // Current state
365    sp<Snapshot> mSnapshot;
366
367    // Shaders
368    SkiaShader* mShader;
369
370    // Color filters
371    SkiaColorFilter* mColorFilter;
372
373    // Used to draw textured quads
374    TextureVertex mMeshVertices[4];
375
376    // GL extensions
377    Extensions mExtensions;
378
379    // Drop shadow
380    bool mHasShadow;
381    float mShadowRadius;
382    float mShadowDx;
383    float mShadowDy;
384    int mShadowColor;
385
386    // Various caches
387    Caches& mCaches;
388}; // class OpenGLRenderer
389
390}; // namespace uirenderer
391}; // namespace android
392
393#endif // ANDROID_UI_OPENGL_RENDERER_H
394