OpenGLRenderer.h revision 889f8d1403761d5668115ced6cbb3f767cfe966d 
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#include "ProgramCache.h"
45
46namespace android {
47namespace uirenderer {
48
49///////////////////////////////////////////////////////////////////////////////
50// Renderer
51///////////////////////////////////////////////////////////////////////////////
52
53#define REQUIRED_TEXTURE_UNITS_COUNT 3
54
55/**
56 * OpenGL renderer used to draw accelerated 2D graphics. The API is a
57 * simplified version of Skia's Canvas API.
58 */
59class OpenGLRenderer {
60public:
61    OpenGLRenderer();
62    ~OpenGLRenderer();
63
64    void setViewport(int width, int height);
65    void prepare();
66
67    int getSaveCount() const;
68    int save(int flags);
69    void restore();
70    void restoreToCount(int saveCount);
71
72    int saveLayer(float left, float top, float right, float bottom, const SkPaint* p, int flags);
73    int saveLayerAlpha(float left, float top, float right, float bottom, int alpha, int flags);
74
75    void translate(float dx, float dy);
76    void rotate(float degrees);
77    void scale(float sx, float sy);
78
79    void setMatrix(SkMatrix* matrix);
80    void getMatrix(SkMatrix* matrix);
81    void concatMatrix(SkMatrix* matrix);
82
83    const Rect& getClipBounds();
84    bool quickReject(float left, float top, float right, float bottom);
85    bool clipRect(float left, float top, float right, float bottom, SkRegion::Op op);
86
87    void drawBitmap(SkBitmap* bitmap, float left, float top, const SkPaint* paint);
88    void drawBitmap(SkBitmap* bitmap, const SkMatrix* matrix, const SkPaint* paint);
89    void drawBitmap(SkBitmap* bitmap, float srcLeft, float srcTop, float srcRight, float srcBottom,
90            float dstLeft, float dstTop, float dstRight, float dstBottom, const SkPaint* paint);
91    void drawPatch(SkBitmap* bitmap, Res_png_9patch* patch, float left, float top,
92            float right, float bottom, const SkPaint* paint);
93    void drawColor(int color, SkXfermode::Mode mode);
94    void drawRect(float left, float top, float right, float bottom, const SkPaint* paint);
95
96    void resetShader();
97    void setupBitmapShader(SkBitmap* bitmap, SkShader::TileMode tileX, SkShader::TileMode tileY,
98            SkMatrix* matrix, bool hasAlpha);
99    void setupLinearGradientShader(SkShader* shader, float* bounds, uint32_t* colors,
100            float* positions, int count, SkShader::TileMode tileMode,
101            SkMatrix* matrix, bool hasAlpha);
102
103    void drawText(const char* text, int bytesCount, int count, float x, float y, SkPaint* paint);
104
105private:
106    /**
107     * Type of Skia shader in use.
108     */
109    enum ShaderType {
110        kShaderNone,
111        kShaderBitmap,
112        kShaderLinearGradient,
113        kShaderCircularGradient,
114        kShaderSweepGradient
115    };
116
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     * @return The new save count. This value can be passed to #restoreToCount()
123     */
124    int saveSnapshot();
125
126    /**
127     * Restores the current snapshot; mSnapshot becomes mSnapshot->previous.
128     *
129     * @return True if the clip should be also reapplied by calling
130     *         #setScissorFromClip().
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     * Draws a colored rectangle with the specified color. The specified coordinates
170     * are transformed by the current snapshot's transform matrix.
171     *
172     * @param left The left coordinate of the rectangle
173     * @param top The top coordinate of the rectangle
174     * @param right The right coordinate of the rectangle
175     * @param bottom The bottom coordinate of the rectangle
176     * @param color The rectangle's ARGB color, defined as a packed 32 bits word
177     * @param mode The Skia xfermode to use
178     * @param ignoreTransform True if the current transform should be ignored
179     */
180    void drawColorRect(float left, float top, float right, float bottom,
181    		int color, SkXfermode::Mode mode, bool ignoreTransform = false);
182
183    /**
184     * Draws a textured rectangle with the specified texture. The specified coordinates
185     * are transformed by the current snapshot's transform matrix.
186     *
187     * @param left The left coordinate of the rectangle
188     * @param top The top coordinate of the rectangle
189     * @param right The right coordinate of the rectangle
190     * @param bottom The bottom coordinate of the rectangle
191     * @param texture The texture name to map onto the rectangle
192     * @param alpha An additional translucency parameter, between 0.0f and 1.0f
193     * @param mode The blending mode
194     * @param blend True if the texture contains an alpha channel
195     */
196    void drawTextureRect(float left, float top, float right, float bottom, GLuint texture,
197            float alpha, SkXfermode::Mode mode, bool blend);
198
199    /**
200     * Draws a textured rectangle with the specified texture. The specified coordinates
201     * are transformed by the current snapshot's transform matrix.
202     *
203     * @param left The left coordinate of the rectangle
204     * @param top The top coordinate of the rectangle
205     * @param right The right coordinate of the rectangle
206     * @param bottom The bottom coordinate of the rectangle
207     * @param texture The texture to use
208     * @param paint The paint containing the alpha, blending mode, etc.
209     */
210    void drawTextureRect(float left, float top, float right, float bottom,
211            const Texture* texture, const SkPaint* paint);
212
213    /**
214     * Draws a textured mesh with the specified texture. If the indices are omitted, the
215     * mesh is drawn as a simple quad.
216     *
217     * @param left The left coordinate of the rectangle
218     * @param top The top coordinate of the rectangle
219     * @param right The right coordinate of the rectangle
220     * @param bottom The bottom coordinate of the rectangle
221     * @param texture The texture name to map onto the rectangle
222     * @param alpha An additional translucency parameter, between 0.0f and 1.0f
223     * @param mode The blending mode
224     * @param blend True if the texture contains an alpha channel
225     * @param vertices The vertices that define the mesh
226     * @param texCoords The texture coordinates of each vertex
227     * @param indices The indices of the vertices, can be NULL
228     * @param elementsCount The number of elements in the mesh, required by indices
229     */
230    void drawTextureMesh(float left, float top, float right, float bottom, GLuint texture,
231            float alpha, SkXfermode::Mode mode, bool blend,
232            GLvoid* vertices, GLvoid* texCoords, GLvoid* indices, GLsizei elementsCount = 0);
233
234    /**
235     * Fills the specified rectangle with the currently set bitmap shader.
236     *
237     * @param left The left coordinate of the rectangle
238     * @param top The top coordinate of the rectangle
239     * @param right The right coordinate of the rectangle
240     * @param bottom The bottom coordinate of the rectangle
241     * @param alpha An additional translucency parameter, between 0.0f and 1.0f
242     * @param mode The blending mode
243     */
244    void drawBitmapShader(float left, float top, float right, float bottom, float alpha,
245            SkXfermode::Mode mode);
246
247    /**
248     * Fills the specified rectangle with the currently set linear gradient shader.
249     *
250     * @param left The left coordinate of the rectangle
251     * @param top The top coordinate of the rectangle
252     * @param right The right coordinate of the rectangle
253     * @param bottom The bottom coordinate of the rectangle
254     * @param alpha An additional translucency parameter, between 0.0f and 1.0f
255     * @param mode The blending mode
256     */
257    void drawLinearGradientShader(float left, float top, float right, float bottom, float alpha,
258            SkXfermode::Mode mode);
259
260    /**
261     * Resets the texture coordinates stored in mMeshVertices. Setting the values
262     * back to default is achieved by calling:
263     *
264     * resetDrawTextureTexCoords(0.0f, 0.0f, 1.0f, 1.0f);
265     *
266     * @param u1 The left coordinate of the texture
267     * @param v1 The bottom coordinate of the texture
268     * @param u2 The right coordinate of the texture
269     * @param v2 The top coordinate of the texture
270     */
271    void resetDrawTextureTexCoords(float u1, float v1, float u2, float v2);
272
273    /**
274     * Gets the alpha and xfermode out of a paint object. If the paint is null
275     * alpha will be 255 and the xfermode will be SRC_OVER.
276     *
277     * @param paint The paint to extract values from
278     * @param alpha Where to store the resulting alpha
279     * @param mode Where to store the resulting xfermode
280     */
281    inline void getAlphaAndMode(const SkPaint* paint, int* alpha, SkXfermode::Mode* mode);
282
283    /**
284     * Binds the specified texture with the specified wrap modes.
285     */
286    inline void bindTexture(GLuint texture, GLenum wrapS, GLenum wrapT, GLuint textureUnit = 0);
287
288    /**
289     * Enable or disable blending as necessary. This function sets the appropriate
290     * blend function based on the specified xfermode.
291     */
292    inline void chooseBlending(bool blend, SkXfermode::Mode mode, bool isPremultiplied = true);
293
294    /**
295     * Use the specified program with the current GL context. If the program is already
296     * in use, it will not be bound again. If it is not in use, the current program is
297     * marked unused and the specified program becomes used and becomes the new
298     * current program.
299     *
300     * @param program The program to use
301     *
302     * @return true If the specified program was already in use, false otherwise.
303     */
304    inline bool useProgram(Program* program);
305
306    // Dimensions of the drawing surface
307    int mWidth, mHeight;
308
309    // Matrix used for ortho projection in shaders
310    mat4 mOrthoMatrix;
311
312    // Model-view matrix used to position/size objects
313    mat4 mModelView;
314
315    // Number of saved states
316    int mSaveCount;
317    // Base state
318    Snapshot mFirstSnapshot;
319    // Current state
320    sp<Snapshot> mSnapshot;
321
322    // Shaders
323    Program* mCurrentProgram;
324
325    // Used to draw textured quads
326    TextureVertex mMeshVertices[4];
327
328    // Current texture state
329    GLuint mLastTexture[REQUIRED_TEXTURE_UNITS_COUNT];
330    GLint mMaxTextureUnits;
331
332    // Last known blend state
333    bool mBlend;
334    GLenum mLastSrcMode;
335    GLenum mLastDstMode;
336
337    // Skia shaders
338    ShaderType mShader;
339    SkShader* mShaderKey;
340    bool mShaderBlend;
341    GLenum mShaderTileX;
342    GLenum mShaderTileY;
343    SkMatrix* mShaderMatrix;
344    // Bitmaps
345    SkBitmap* mShaderBitmap;
346    // Gradients
347    float* mShaderBounds;
348    uint32_t* mShaderColors;
349    float* mShaderPositions;
350    int mShaderCount;
351
352    // GL extensions
353    Extensions mExtensions;
354
355    // Font renderer
356    FontRenderer mFontRenderer;
357
358    // Various caches
359    TextureCache mTextureCache;
360    LayerCache mLayerCache;
361    GradientCache mGradientCache;
362    ProgramCache mProgramCache;
363    PatchCache mPatchCache;
364}; // class OpenGLRenderer
365
366}; // namespace uirenderer
367}; // namespace android
368
369#endif // ANDROID_UI_OPENGL_RENDERER_H
370