OpenGLRenderer.h revision 694b519ac647fe998fd396fe0784cc8e179aadc4 
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 "GradientCache.h"
40#include "PatchCache.h"
41#include "Vertex.h"
42#include "FontRenderer.h"
43
44namespace android {
45namespace uirenderer {
46
47///////////////////////////////////////////////////////////////////////////////
48// Support
49///////////////////////////////////////////////////////////////////////////////
50
51/**
52 * Structure mapping Skia xfermodes to OpenGL blending factors.
53 */
54struct Blender {
55    SkXfermode::Mode mode;
56    GLenum src;
57    GLenum dst;
58}; // struct Blender
59
60///////////////////////////////////////////////////////////////////////////////
61// Renderer
62///////////////////////////////////////////////////////////////////////////////
63
64/**
65 * OpenGL renderer used to draw accelerated 2D graphics. The API is a
66 * simplified version of Skia's Canvas API.
67 */
68class OpenGLRenderer {
69public:
70    OpenGLRenderer();
71    ~OpenGLRenderer();
72
73    void setViewport(int width, int height);
74    void prepare();
75
76    int getSaveCount() const;
77    int save(int flags);
78    void restore();
79    void restoreToCount(int saveCount);
80
81    int saveLayer(float left, float top, float right, float bottom, const SkPaint* p, int flags);
82    int saveLayerAlpha(float left, float top, float right, float bottom, int alpha, int flags);
83
84    void translate(float dx, float dy);
85    void rotate(float degrees);
86    void scale(float sx, float sy);
87
88    void setMatrix(SkMatrix* matrix);
89    void getMatrix(SkMatrix* matrix);
90    void concatMatrix(SkMatrix* matrix);
91
92    const Rect& getClipBounds();
93    bool quickReject(float left, float top, float right, float bottom);
94    bool clipRect(float left, float top, float right, float bottom, SkRegion::Op op);
95
96    void drawBitmap(SkBitmap* bitmap, float left, float top, const SkPaint* paint);
97    void drawBitmap(SkBitmap* bitmap, const SkMatrix* matrix, const SkPaint* paint);
98    void drawBitmap(SkBitmap* bitmap, float srcLeft, float srcTop, float srcRight, float srcBottom,
99            float dstLeft, float dstTop, float dstRight, float dstBottom, const SkPaint* paint);
100    void drawPatch(SkBitmap* bitmap, Res_png_9patch* patch, float left, float top,
101            float right, float bottom, const SkPaint* paint);
102    void drawColor(int color, SkXfermode::Mode mode);
103    void drawRect(float left, float top, float right, float bottom, const SkPaint* paint);
104
105    void resetShader();
106    void setupBitmapShader(SkBitmap* bitmap, SkShader::TileMode tileX, SkShader::TileMode tileY,
107            SkMatrix* matrix, bool hasAlpha);
108    void setupLinearGradientShader(SkShader* shader, float* bounds, uint32_t* colors,
109            float* positions, int count, SkShader::TileMode tileMode,
110            SkMatrix* matrix, bool hasAlpha);
111
112    void drawText(const char* text, int count, float x, float y, SkPaint* paint);
113
114private:
115    /**
116     * Type of Skia shader in use.
117     */
118    enum ShaderType {
119        kShaderNone,
120        kShaderBitmap,
121        kShaderLinearGradient,
122        kShaderCircularGradient,
123        kShaderSweepGradient
124    };
125
126    /**
127     * Saves the current state of the renderer as a new snapshot.
128     * The new snapshot is saved in mSnapshot and the previous snapshot
129     * is linked from mSnapshot->previous.
130     *
131     * @return The new save count. This value can be passed to #restoreToCount()
132     */
133    int saveSnapshot();
134
135    /**
136     * Restores the current snapshot; mSnapshot becomes mSnapshot->previous.
137     *
138     * @return True if the clip should be also reapplied by calling
139     *         #setScissorFromClip().
140     */
141    bool restoreSnapshot();
142
143    /**
144     * Sets the clipping rectangle using glScissor. The clip is defined by
145     * the current snapshot's clipRect member.
146     */
147    void setScissorFromClip();
148
149    /**
150     * Compose the layer defined in the current snapshot with the layer
151     * defined by the previous snapshot.
152     *
153     * The current snapshot *must* be a layer (flag kFlagIsLayer set.)
154     *
155     * @param curent The current snapshot containing the layer to compose
156     * @param previous The previous snapshot to compose the current layer with
157     */
158    void composeLayer(sp<Snapshot> current, sp<Snapshot> previous);
159
160    /**
161     * Creates a new layer stored in the specified snapshot.
162     *
163     * @param snapshot The snapshot associated with the new layer
164     * @param left The left coordinate of the layer
165     * @param top The top coordinate of the layer
166     * @param right The right coordinate of the layer
167     * @param bottom The bottom coordinate of the layer
168     * @param alpha The translucency of the layer
169     * @param mode The blending mode of the layer
170     * @param flags The layer save flags
171     *
172     * @return True if the layer was successfully created, false otherwise
173     */
174    bool createLayer(sp<Snapshot> snapshot, float left, float top, float right, float bottom,
175            int alpha, SkXfermode::Mode mode, int flags);
176
177    /**
178     * Draws a colored rectangle with the specified color. The specified coordinates
179     * are transformed by the current snapshot's transform matrix.
180     *
181     * @param left The left coordinate of the rectangle
182     * @param top The top coordinate of the rectangle
183     * @param right The right coordinate of the rectangle
184     * @param bottom The bottom coordinate of the rectangle
185     * @param color The rectangle's ARGB color, defined as a packed 32 bits word
186     * @param mode The Skia xfermode to use
187     * @param ignoreTransform True if the current transform should be ignored
188     */
189    void drawColorRect(float left, float top, float right, float bottom,
190    		int color, SkXfermode::Mode mode, bool ignoreTransform = false);
191
192    /**
193     * Draws a textured rectangle with the specified texture. The specified coordinates
194     * are transformed by the current snapshot's transform matrix.
195     *
196     * @param left The left coordinate of the rectangle
197     * @param top The top coordinate of the rectangle
198     * @param right The right coordinate of the rectangle
199     * @param bottom The bottom coordinate of the rectangle
200     * @param texture The texture name to map onto the rectangle
201     * @param alpha An additional translucency parameter, between 0.0f and 1.0f
202     * @param mode The blending mode
203     * @param blend True if the texture contains an alpha channel
204     */
205    void drawTextureRect(float left, float top, float right, float bottom, GLuint texture,
206            float alpha, SkXfermode::Mode mode, bool blend);
207
208    /**
209     * Draws a textured rectangle with the specified texture. The specified coordinates
210     * are transformed by the current snapshot's transform matrix.
211     *
212     * @param left The left coordinate of the rectangle
213     * @param top The top coordinate of the rectangle
214     * @param right The right coordinate of the rectangle
215     * @param bottom The bottom coordinate of the rectangle
216     * @param texture The texture to use
217     * @param paint The paint containing the alpha, blending mode, etc.
218     */
219    void drawTextureRect(float left, float top, float right, float bottom,
220            const Texture* texture, const SkPaint* paint);
221
222    /**
223     * Draws a textured mesh with the specified texture. If the indices are omitted, the
224     * mesh is drawn as a simple quad.
225     *
226     * @param left The left coordinate of the rectangle
227     * @param top The top coordinate of the rectangle
228     * @param right The right coordinate of the rectangle
229     * @param bottom The bottom coordinate of the rectangle
230     * @param texture The texture name to map onto the rectangle
231     * @param alpha An additional translucency parameter, between 0.0f and 1.0f
232     * @param mode The blending mode
233     * @param blend True if the texture contains an alpha channel
234     * @param vertices The vertices that define the mesh
235     * @param texCoords The texture coordinates of each vertex
236     * @param indices The indices of the vertices, can be NULL
237     * @param elementsCount The number of elements in the mesh, required by indices
238     */
239    void drawTextureMesh(float left, float top, float right, float bottom, GLuint texture,
240            float alpha, SkXfermode::Mode mode, bool blend,
241            GLvoid* vertices, GLvoid* texCoords, GLvoid* indices, GLsizei elementsCount = 0);
242
243    /**
244     * Fills the specified rectangle with the currently set bitmap shader.
245     *
246     * @param left The left coordinate of the rectangle
247     * @param top The top coordinate of the rectangle
248     * @param right The right coordinate of the rectangle
249     * @param bottom The bottom coordinate of the rectangle
250     * @param alpha An additional translucency parameter, between 0.0f and 1.0f
251     * @param mode The blending mode
252     */
253    void drawBitmapShader(float left, float top, float right, float bottom, float alpha,
254            SkXfermode::Mode mode);
255
256    /**
257     * Fills the specified rectangle with the currently set linear gradient shader.
258     *
259     * @param left The left coordinate of the rectangle
260     * @param top The top coordinate of the rectangle
261     * @param right The right coordinate of the rectangle
262     * @param bottom The bottom coordinate of the rectangle
263     * @param alpha An additional translucency parameter, between 0.0f and 1.0f
264     * @param mode The blending mode
265     */
266    void drawLinearGradientShader(float left, float top, float right, float bottom, float alpha,
267            SkXfermode::Mode mode);
268
269    /**
270     * Resets the texture coordinates stored in mDrawTextureVertices. Setting the values
271     * back to default is achieved by calling:
272     *
273     * resetDrawTextureTexCoords(0.0f, 0.0f, 1.0f, 1.0f);
274     *
275     * @param u1 The left coordinate of the texture
276     * @param v1 The bottom coordinate of the texture
277     * @param u2 The right coordinate of the texture
278     * @param v2 The top coordinate of the texture
279     */
280    void resetDrawTextureTexCoords(float u1, float v1, float u2, float v2);
281
282    /**
283     * Gets the alpha and xfermode out of a paint object. If the paint is null
284     * alpha will be 255 and the xfermode will be SRC_OVER.
285     *
286     * @param paint The paint to extract values from
287     * @param alpha Where to store the resulting alpha
288     * @param mode Where to store the resulting xfermode
289     */
290    inline void getAlphaAndMode(const SkPaint* paint, int* alpha, SkXfermode::Mode* mode);
291
292    /**
293     * Binds the specified texture with the specified wrap modes.
294     */
295    inline void bindTexture(GLuint texture, GLenum wrapS, GLenum wrapT);
296
297    /**
298     * Enable or disable blending as necessary. This function sets the appropriate
299     * blend function based on the specified xfermode.
300     */
301    inline void chooseBlending(bool blend, SkXfermode::Mode mode, bool isPremultiplied = true);
302
303    /**
304     * Use the specified program with the current GL context. If the program is already
305     * in use, it will not be bound again. If it is not in use, the current program is
306     * marked unused and the specified program becomes used and becomes the new
307     * current program.
308     *
309     * @param program The program to use
310     *
311     * @return true If the specified program was already in use, false otherwise.
312     */
313    inline bool useProgram(const sp<Program>& program);
314
315    // Dimensions of the drawing surface
316    int mWidth, mHeight;
317
318    // Matrix used for ortho projection in shaders
319    mat4 mOrthoMatrix;
320
321    // Model-view matrix used to position/size objects
322    mat4 mModelView;
323
324    // Number of saved states
325    int mSaveCount;
326    // Base state
327    Snapshot mFirstSnapshot;
328    // Current state
329    sp<Snapshot> mSnapshot;
330
331    // Shaders
332    sp<Program> mCurrentProgram;
333    sp<DrawColorProgram> mDrawColorProgram;
334    sp<DrawTextureProgram> mDrawTextureProgram;
335    sp<DrawTextProgram> mDrawTextProgram;
336    sp<DrawLinearGradientProgram> mDrawLinearGradientProgram;
337
338    // Used to draw textured quads
339    TextureVertex mDrawTextureVertices[4];
340
341    // Current texture state
342    GLuint mLastTexture;
343
344    // Last known blend state
345    bool mBlend;
346    GLenum mLastSrcMode;
347    GLenum mLastDstMode;
348
349    // Skia shaders
350    ShaderType mShader;
351    SkShader* mShaderKey;
352    bool mShaderBlend;
353    GLenum mShaderTileX;
354    GLenum mShaderTileY;
355    SkMatrix* mShaderMatrix;
356    // Bitmaps
357    SkBitmap* mShaderBitmap;
358    // Gradients
359    float* mShaderBounds;
360    uint32_t* mShaderColors;
361    float* mShaderPositions;
362    int mShaderCount;
363
364    // Font renderer
365    FontRenderer mFontRenderer;
366
367    // Various caches
368    TextureCache mTextureCache;
369    LayerCache mLayerCache;
370    GradientCache mGradientCache;
371    PatchCache mPatchCache;
372}; // class OpenGLRenderer
373
374}; // namespace uirenderer
375}; // namespace android
376
377#endif // ANDROID_UI_OPENGL_RENDERER_H
378