OpenGLRenderer.h revision 51769a68a5cb34e9564740c6a854fcb93018789d 
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 "TextureCache.h"
39#include "LayerCache.h"
40#include "GradientCache.h"
41#include "PatchCache.h"
42#include "Vertex.h"
43#include "FontRenderer.h"
44
45namespace android {
46namespace uirenderer {
47
48///////////////////////////////////////////////////////////////////////////////
49// Support
50///////////////////////////////////////////////////////////////////////////////
51
52/**
53 * Structure mapping Skia xfermodes to OpenGL blending factors.
54 */
55struct Blender {
56    SkXfermode::Mode mode;
57    GLenum src;
58    GLenum dst;
59}; // struct Blender
60
61///////////////////////////////////////////////////////////////////////////////
62// Renderer
63///////////////////////////////////////////////////////////////////////////////
64
65/**
66 * OpenGL renderer used to draw accelerated 2D graphics. The API is a
67 * simplified version of Skia's Canvas API.
68 */
69class OpenGLRenderer {
70public:
71    OpenGLRenderer();
72    ~OpenGLRenderer();
73
74    void setViewport(int width, int height);
75    void prepare();
76
77    int getSaveCount() const;
78    int save(int flags);
79    void restore();
80    void restoreToCount(int saveCount);
81
82    int saveLayer(float left, float top, float right, float bottom, const SkPaint* p, int flags);
83    int saveLayerAlpha(float left, float top, float right, float bottom, int alpha, int flags);
84
85    void translate(float dx, float dy);
86    void rotate(float degrees);
87    void scale(float sx, float sy);
88
89    void setMatrix(SkMatrix* matrix);
90    void getMatrix(SkMatrix* matrix);
91    void concatMatrix(SkMatrix* matrix);
92
93    const Rect& getClipBounds();
94    bool quickReject(float left, float top, float right, float bottom);
95    bool clipRect(float left, float top, float right, float bottom, SkRegion::Op op);
96
97    void drawBitmap(SkBitmap* bitmap, float left, float top, const SkPaint* paint);
98    void drawBitmap(SkBitmap* bitmap, const SkMatrix* matrix, const SkPaint* paint);
99    void drawBitmap(SkBitmap* bitmap, float srcLeft, float srcTop, float srcRight, float srcBottom,
100            float dstLeft, float dstTop, float dstRight, float dstBottom, const SkPaint* paint);
101    void drawPatch(SkBitmap* bitmap, Res_png_9patch* patch, float left, float top,
102            float right, float bottom, const SkPaint* paint);
103    void drawColor(int color, SkXfermode::Mode mode);
104    void drawRect(float left, float top, float right, float bottom, const SkPaint* paint);
105
106    void resetShader();
107    void setupBitmapShader(SkBitmap* bitmap, SkShader::TileMode tileX, SkShader::TileMode tileY,
108            SkMatrix* matrix, bool hasAlpha);
109    void setupLinearGradientShader(SkShader* shader, float* bounds, uint32_t* colors,
110            float* positions, int count, SkShader::TileMode tileMode,
111            SkMatrix* matrix, bool hasAlpha);
112
113    void drawText(const char* text, int count, float x, float y, SkPaint* paint);
114
115private:
116    /**
117     * Type of Skia shader in use.
118     */
119    enum ShaderType {
120        kShaderNone,
121        kShaderBitmap,
122        kShaderLinearGradient,
123        kShaderCircularGradient,
124        kShaderSweepGradient
125    };
126
127    /**
128     * Saves the current state of the renderer as a new snapshot.
129     * The new snapshot is saved in mSnapshot and the previous snapshot
130     * is linked from mSnapshot->previous.
131     *
132     * @return The new save count. This value can be passed to #restoreToCount()
133     */
134    int saveSnapshot();
135
136    /**
137     * Restores the current snapshot; mSnapshot becomes mSnapshot->previous.
138     *
139     * @return True if the clip should be also reapplied by calling
140     *         #setScissorFromClip().
141     */
142    bool restoreSnapshot();
143
144    /**
145     * Sets the clipping rectangle using glScissor. The clip is defined by
146     * the current snapshot's clipRect member.
147     */
148    void setScissorFromClip();
149
150    /**
151     * Compose the layer defined in the current snapshot with the layer
152     * defined by the previous snapshot.
153     *
154     * The current snapshot *must* be a layer (flag kFlagIsLayer set.)
155     *
156     * @param curent The current snapshot containing the layer to compose
157     * @param previous The previous snapshot to compose the current layer with
158     */
159    void composeLayer(sp<Snapshot> current, sp<Snapshot> previous);
160
161    /**
162     * Creates a new layer stored in the specified snapshot.
163     *
164     * @param snapshot The snapshot associated with the new layer
165     * @param left The left coordinate of the layer
166     * @param top The top coordinate of the layer
167     * @param right The right coordinate of the layer
168     * @param bottom The bottom coordinate of the layer
169     * @param alpha The translucency of the layer
170     * @param mode The blending mode of the layer
171     * @param flags The layer save flags
172     *
173     * @return True if the layer was successfully created, false otherwise
174     */
175    bool createLayer(sp<Snapshot> snapshot, float left, float top, float right, float bottom,
176            int alpha, SkXfermode::Mode mode, int flags);
177
178    /**
179     * Draws a colored rectangle with the specified color. The specified coordinates
180     * are transformed by the current snapshot's transform matrix.
181     *
182     * @param left The left coordinate of the rectangle
183     * @param top The top coordinate of the rectangle
184     * @param right The right coordinate of the rectangle
185     * @param bottom The bottom coordinate of the rectangle
186     * @param color The rectangle's ARGB color, defined as a packed 32 bits word
187     * @param mode The Skia xfermode to use
188     * @param ignoreTransform True if the current transform should be ignored
189     */
190    void drawColorRect(float left, float top, float right, float bottom,
191    		int color, SkXfermode::Mode mode, bool ignoreTransform = false);
192
193    /**
194     * Draws a textured rectangle with the specified texture. The specified coordinates
195     * are transformed by the current snapshot's transform matrix.
196     *
197     * @param left The left coordinate of the rectangle
198     * @param top The top coordinate of the rectangle
199     * @param right The right coordinate of the rectangle
200     * @param bottom The bottom coordinate of the rectangle
201     * @param texture The texture name to map onto the rectangle
202     * @param alpha An additional translucency parameter, between 0.0f and 1.0f
203     * @param mode The blending mode
204     * @param blend True if the texture contains an alpha channel
205     */
206    void drawTextureRect(float left, float top, float right, float bottom, GLuint texture,
207            float alpha, SkXfermode::Mode mode, bool blend);
208
209    /**
210     * Draws a textured rectangle with the specified texture. The specified coordinates
211     * are transformed by the current snapshot's transform matrix.
212     *
213     * @param left The left coordinate of the rectangle
214     * @param top The top coordinate of the rectangle
215     * @param right The right coordinate of the rectangle
216     * @param bottom The bottom coordinate of the rectangle
217     * @param texture The texture to use
218     * @param paint The paint containing the alpha, blending mode, etc.
219     */
220    void drawTextureRect(float left, float top, float right, float bottom,
221            const Texture* texture, const SkPaint* paint);
222
223    /**
224     * Draws a textured mesh with the specified texture. If the indices are omitted, the
225     * mesh is drawn as a simple quad.
226     *
227     * @param left The left coordinate of the rectangle
228     * @param top The top coordinate of the rectangle
229     * @param right The right coordinate of the rectangle
230     * @param bottom The bottom coordinate of the rectangle
231     * @param texture The texture name to map onto the rectangle
232     * @param alpha An additional translucency parameter, between 0.0f and 1.0f
233     * @param mode The blending mode
234     * @param blend True if the texture contains an alpha channel
235     * @param vertices The vertices that define the mesh
236     * @param texCoords The texture coordinates of each vertex
237     * @param indices The indices of the vertices, can be NULL
238     * @param elementsCount The number of elements in the mesh, required by indices
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, GLvoid* indices, GLsizei elementsCount = 0);
243
244    /**
245     * Fills the specified rectangle with the currently set bitmap shader.
246     *
247     * @param left The left coordinate of the rectangle
248     * @param top The top coordinate of the rectangle
249     * @param right The right coordinate of the rectangle
250     * @param bottom The bottom coordinate of the rectangle
251     * @param alpha An additional translucency parameter, between 0.0f and 1.0f
252     * @param mode The blending mode
253     */
254    void drawBitmapShader(float left, float top, float right, float bottom, float alpha,
255            SkXfermode::Mode mode);
256
257    /**
258     * Fills the specified rectangle with the currently set linear gradient shader.
259     *
260     * @param left The left coordinate of the rectangle
261     * @param top The top coordinate of the rectangle
262     * @param right The right coordinate of the rectangle
263     * @param bottom The bottom coordinate of the rectangle
264     * @param alpha An additional translucency parameter, between 0.0f and 1.0f
265     * @param mode The blending mode
266     */
267    void drawLinearGradientShader(float left, float top, float right, float bottom, float alpha,
268            SkXfermode::Mode mode);
269
270    /**
271     * Resets the texture coordinates stored in mDrawTextureVertices. Setting the values
272     * back to default is achieved by calling:
273     *
274     * resetDrawTextureTexCoords(0.0f, 0.0f, 1.0f, 1.0f);
275     *
276     * @param u1 The left coordinate of the texture
277     * @param v1 The bottom coordinate of the texture
278     * @param u2 The right coordinate of the texture
279     * @param v2 The top coordinate of the texture
280     */
281    void resetDrawTextureTexCoords(float u1, float v1, float u2, float v2);
282
283    /**
284     * Gets the alpha and xfermode out of a paint object. If the paint is null
285     * alpha will be 255 and the xfermode will be SRC_OVER.
286     *
287     * @param paint The paint to extract values from
288     * @param alpha Where to store the resulting alpha
289     * @param mode Where to store the resulting xfermode
290     */
291    inline void getAlphaAndMode(const SkPaint* paint, int* alpha, SkXfermode::Mode* mode);
292
293    /**
294     * Binds the specified texture with the specified wrap modes.
295     */
296    inline void bindTexture(GLuint texture, GLenum wrapS, GLenum wrapT);
297
298    /**
299     * Enable or disable blending as necessary. This function sets the appropriate
300     * blend function based on the specified xfermode.
301     */
302    inline void chooseBlending(bool blend, SkXfermode::Mode mode, bool isPremultiplied = true);
303
304    /**
305     * Use the specified program with the current GL context. If the program is already
306     * in use, it will not be bound again. If it is not in use, the current program is
307     * marked unused and the specified program becomes used and becomes the new
308     * current program.
309     *
310     * @param program The program to use
311     *
312     * @return true If the specified program was already in use, false otherwise.
313     */
314    inline bool useProgram(const sp<Program>& program);
315
316    // Dimensions of the drawing surface
317    int mWidth, mHeight;
318
319    // Matrix used for ortho projection in shaders
320    mat4 mOrthoMatrix;
321
322    // Model-view matrix used to position/size objects
323    mat4 mModelView;
324
325    // Number of saved states
326    int mSaveCount;
327    // Base state
328    Snapshot mFirstSnapshot;
329    // Current state
330    sp<Snapshot> mSnapshot;
331
332    // Shaders
333    sp<Program> mCurrentProgram;
334    sp<DrawColorProgram> mDrawColorProgram;
335    sp<DrawTextureProgram> mDrawTextureProgram;
336    sp<DrawTextProgram> mDrawTextProgram;
337    sp<DrawLinearGradientProgram> mDrawLinearGradientProgram;
338
339    // Used to draw textured quads
340    TextureVertex mDrawTextureVertices[4];
341
342    // Current texture state
343    GLuint mLastTexture;
344
345    // Last known blend state
346    bool mBlend;
347    GLenum mLastSrcMode;
348    GLenum mLastDstMode;
349
350    // Skia shaders
351    ShaderType mShader;
352    SkShader* mShaderKey;
353    bool mShaderBlend;
354    GLenum mShaderTileX;
355    GLenum mShaderTileY;
356    SkMatrix* mShaderMatrix;
357    // Bitmaps
358    SkBitmap* mShaderBitmap;
359    // Gradients
360    float* mShaderBounds;
361    uint32_t* mShaderColors;
362    float* mShaderPositions;
363    int mShaderCount;
364
365    // GL extensions
366    Extensions mExtensions;
367
368    // Font renderer
369    FontRenderer mFontRenderer;
370
371    // Various caches
372    TextureCache mTextureCache;
373    LayerCache mLayerCache;
374    GradientCache mGradientCache;
375    PatchCache mPatchCache;
376}; // class OpenGLRenderer
377
378}; // namespace uirenderer
379}; // namespace android
380
381#endif // ANDROID_UI_OPENGL_RENDERER_H
382