OpenGLRenderer.h revision 1e79386ba34f0db38c1b35b22cdf122632534354 
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 "Matrix.h"
34#include "Program.h"
35#include "Rect.h"
36#include "Snapshot.h"
37#include "TextureCache.h"
38#include "LayerCache.h"
39#include "PatchCache.h"
40#include "Vertex.h"
41
42namespace android {
43namespace uirenderer {
44
45///////////////////////////////////////////////////////////////////////////////
46// Support
47///////////////////////////////////////////////////////////////////////////////
48
49/**
50 * Structure mapping Skia xfermodes to OpenGL blending factors.
51 */
52struct Blender {
53    SkXfermode::Mode mode;
54    GLenum src;
55    GLenum dst;
56}; // struct Blender
57
58///////////////////////////////////////////////////////////////////////////////
59// Renderer
60///////////////////////////////////////////////////////////////////////////////
61
62/**
63 * OpenGL renderer used to draw accelerated 2D graphics. The API is a
64 * simplified version of Skia's Canvas API.
65 */
66class OpenGLRenderer {
67public:
68    OpenGLRenderer();
69    ~OpenGLRenderer();
70
71    void setViewport(int width, int height);
72    void prepare();
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
103    void resetShader();
104    void setupBitmapShader(SkBitmap* bitmap, SkShader::TileMode tileX, SkShader::TileMode tileY,
105            SkMatrix* matrix, bool hasAlpha);
106
107private:
108    /**
109     * Type of Skia shader in use.
110     */
111    enum ShaderType {
112        kShaderNone,
113        kShaderBitmap,
114        kShaderLinearGradient,
115        kShaderCircularGradient,
116        kShaderSweepGradient
117    };
118
119    /**
120     * Saves the current state of the renderer as a new snapshot.
121     * The new snapshot is saved in mSnapshot and the previous snapshot
122     * is linked from mSnapshot->previous.
123     *
124     * @return The new save count. This value can be passed to #restoreToCount()
125     */
126    int saveSnapshot();
127
128    /**
129     * Restores the current snapshot; mSnapshot becomes mSnapshot->previous.
130     *
131     * @return True if the clip should be also reapplied by calling
132     *         #setScissorFromClip().
133     */
134    bool restoreSnapshot();
135
136    /**
137     * Sets the clipping rectangle using glScissor. The clip is defined by
138     * the current snapshot's clipRect member.
139     */
140    void setScissorFromClip();
141
142    /**
143     * Compose the layer defined in the current snapshot with the layer
144     * defined by the previous snapshot.
145     *
146     * The current snapshot *must* be a layer (flag kFlagIsLayer set.)
147     *
148     * @param curent The current snapshot containing the layer to compose
149     * @param previous The previous snapshot to compose the current layer with
150     */
151    void composeLayer(sp<Snapshot> current, sp<Snapshot> previous);
152
153    /**
154     * Creates a new layer stored in the specified snapshot.
155     *
156     * @param snapshot The snapshot associated with the new layer
157     * @param left The left coordinate of the layer
158     * @param top The top coordinate of the layer
159     * @param right The right coordinate of the layer
160     * @param bottom The bottom coordinate of the layer
161     * @param alpha The translucency of the layer
162     * @param mode The blending mode of the layer
163     * @param flags The layer save flags
164     *
165     * @return True if the layer was successfully created, false otherwise
166     */
167    bool createLayer(sp<Snapshot> snapshot, float left, float top, float right, float bottom,
168            int alpha, SkXfermode::Mode mode, int flags);
169
170    /**
171     * Draws a colored rectangle with the specified color. The specified coordinates
172     * are transformed by the current snapshot's transform matrix.
173     *
174     * @param left The left coordinate of the rectangle
175     * @param top The top coordinate of the rectangle
176     * @param right The right coordinate of the rectangle
177     * @param bottom The bottom coordinate of the rectangle
178     * @param color The rectangle's ARGB color, defined as a packed 32 bits word
179     * @param mode The Skia xfermode to use
180     * @param ignoreTransform True if the current transform should be ignored
181     */
182    void drawColorRect(float left, float top, float right, float bottom,
183    		int color, SkXfermode::Mode mode, bool ignoreTransform = false);
184
185    /**
186     * Draws a textured rectangle with the specified texture. The specified coordinates
187     * are transformed by the current snapshot's transform matrix.
188     *
189     * @param left The left coordinate of the rectangle
190     * @param top The top coordinate of the rectangle
191     * @param right The right coordinate of the rectangle
192     * @param bottom The bottom coordinate of the rectangle
193     * @param texture The texture name to map onto the rectangle
194     * @param alpha An additional translucency parameter, between 0.0f and 1.0f
195     * @param mode The blending mode
196     * @param blend True if the texture contains an alpha channel
197     */
198    void drawTextureRect(float left, float top, float right, float bottom, GLuint texture,
199            float alpha, SkXfermode::Mode mode, bool blend);
200
201    /**
202     * Draws a textured rectangle with the specified texture. The specified coordinates
203     * are transformed by the current snapshot's transform matrix.
204     *
205     * @param left The left coordinate of the rectangle
206     * @param top The top coordinate of the rectangle
207     * @param right The right coordinate of the rectangle
208     * @param bottom The bottom coordinate of the rectangle
209     * @param texture The texture to use
210     * @param paint The paint containing the alpha, blending mode, etc.
211     */
212    void drawTextureRect(float left, float top, float right, float bottom,
213            const Texture* texture, const SkPaint* paint);
214
215    /**
216     * Draws a textured mesh with the specified texture. If the indices are omitted, the
217     * mesh is drawn as a simple quad.
218     *
219     * @param left The left coordinate of the rectangle
220     * @param top The top coordinate of the rectangle
221     * @param right The right coordinate of the rectangle
222     * @param bottom The bottom coordinate of the rectangle
223     * @param texture The texture name to map onto the rectangle
224     * @param alpha An additional translucency parameter, between 0.0f and 1.0f
225     * @param mode The blending mode
226     * @param blend True if the texture contains an alpha channel
227     * @param vertices The vertices that define the mesh
228     * @param texCoords The texture coordinates of each vertex
229     * @param indices The indices of the vertices, can be NULL
230     * @param elementsCount The number of elements in the mesh, required by indices
231     */
232    void drawTextureMesh(float left, float top, float right, float bottom, GLuint texture,
233            float alpha, SkXfermode::Mode mode, bool blend,
234            GLvoid* vertices, GLvoid* texCoords, GLvoid* indices, GLsizei elementsCount = 0);
235
236    /**
237     * Fills the specified rectangle with the currently set bitmap shader.
238     *
239     * @param left The left coordinate of the rectangle
240     * @param top The top coordinate of the rectangle
241     * @param right The right coordinate of the rectangle
242     * @param bottom The bottom coordinate of the rectangle
243     * @param alpha An additional translucency parameter, between 0.0f and 1.0f
244     * @param mode The blending mode
245     */
246    void drawBitmapShader(float left, float top, float right, float bottom, float alpha,
247            SkXfermode::Mode mode);
248
249    /**
250     * Resets the texture coordinates stored in mDrawTextureVertices. Setting the values
251     * back to default is achieved by calling:
252     *
253     * resetDrawTextureTexCoords(0.0f, 0.0f, 1.0f, 1.0f);
254     *
255     * @param u1 The left coordinate of the texture
256     * @param v1 The bottom coordinate of the texture
257     * @param u2 The right coordinate of the texture
258     * @param v2 The top coordinate of the texture
259     */
260    void resetDrawTextureTexCoords(float u1, float v1, float u2, float v2);
261
262    /**
263     * Gets the alpha and xfermode out of a paint object. If the paint is null
264     * alpha will be 255 and the xfermode will be SRC_OVER.
265     *
266     * @param paint The paint to extract values from
267     * @param alpha Where to store the resulting alpha
268     * @param mode Where to store the resulting xfermode
269     */
270    inline void getAlphaAndMode(const SkPaint* paint, int* alpha, SkXfermode::Mode* mode);
271
272    /**
273     * Enable or disable blending as necessary. This function sets the appropriate
274     * blend function based on the specified xfermode.
275     */
276    inline void chooseBlending(bool blend, SkXfermode::Mode mode, bool isPremultiplied = true);
277
278    /**
279     * Use the specified program with the current GL context. If the program is already
280     * in use, it will not be bound again. If it is not in use, the current program is
281     * marked unused and the specified program becomes used and becomes the new
282     * current program.
283     *
284     * @param program The program to use
285     *
286     * @return true If the specified program was already in use, false otherwise.
287     */
288    inline bool useProgram(const sp<Program>& program);
289
290    // Dimensions of the drawing surface
291    int mWidth, mHeight;
292
293    // Matrix used for ortho projection in shaders
294    mat4 mOrthoMatrix;
295
296    // Model-view matrix used to position/size objects
297    mat4 mModelView;
298
299    // Number of saved states
300    int mSaveCount;
301    // Base state
302    Snapshot mFirstSnapshot;
303    // Current state
304    sp<Snapshot> mSnapshot;
305
306    // Shaders
307    sp<Program> mCurrentProgram;
308    sp<DrawColorProgram> mDrawColorProgram;
309    sp<DrawTextureProgram> mDrawTextureProgram;
310
311    // Used to draw textured quads
312    TextureVertex mDrawTextureVertices[4];
313
314    // Current texture state
315    GLuint mLastTexture;
316
317    // Last known blend state
318    bool mBlend;
319    GLenum mLastSrcMode;
320    GLenum mLastDstMode;
321
322    // Skia shader
323    ShaderType mShader;
324    bool mShaderBlend;
325    SkBitmap* mShaderBitmap;
326    SkShader::TileMode mShaderTileX;
327    SkShader::TileMode mShaderTileY;
328    SkMatrix* mShaderMatrix;
329
330    // Various caches
331    TextureCache mTextureCache;
332    LayerCache mLayerCache;
333    PatchCache mPatchCache;
334}; // class OpenGLRenderer
335
336}; // namespace uirenderer
337}; // namespace android
338
339#endif // ANDROID_UI_OPENGL_RENDERER_H
340