OpenGLRenderer.h revision a5aed0d58962a24c44728ffc46dc9e1ba2f9fda5 
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     */
170    void drawColorRect(float left, float top, float right, float bottom,
171    		int color, SkXfermode::Mode mode, bool ignoreTransform = false);
172
173    /**
174     * Draws a textured rectangle with the specified texture. The specified coordinates
175     * are transformed by the current snapshot's transform matrix.
176     *
177     * @param left The left coordinate of the rectangle
178     * @param top The top coordinate of the rectangle
179     * @param right The right coordinate of the rectangle
180     * @param bottom The bottom coordinate of the rectangle
181     * @param texture The texture name to map onto the rectangle
182     * @param alpha An additional translucency parameter, between 0.0f and 1.0f
183     * @param mode The blending mode
184     * @param blend True if the texture contains an alpha channel
185     */
186    void drawTextureRect(float left, float top, float right, float bottom, GLuint texture,
187            float alpha, SkXfermode::Mode mode, bool blend);
188
189    /**
190     * Draws a textured rectangle with the specified texture. The specified coordinates
191     * are transformed by the current snapshot's transform matrix.
192     *
193     * @param left The left coordinate of the rectangle
194     * @param top The top coordinate of the rectangle
195     * @param right The right coordinate of the rectangle
196     * @param bottom The bottom coordinate of the rectangle
197     * @param texture The texture to use
198     * @param paint The paint containing the alpha, blending mode, etc.
199     */
200    void drawTextureRect(float left, float top, float right, float bottom,
201            const Texture* texture, const SkPaint* paint);
202
203    /**
204     * Draws a textured mesh with the specified texture. If the indices are omitted, the
205     * mesh is drawn as a simple quad.
206     *
207     * @param left The left coordinate of the rectangle
208     * @param top The top coordinate of the rectangle
209     * @param right The right coordinate of the rectangle
210     * @param bottom The bottom coordinate of the rectangle
211     * @param texture The texture name to map onto the rectangle
212     * @param alpha An additional translucency parameter, between 0.0f and 1.0f
213     * @param mode The blending mode
214     * @param blend True if the texture contains an alpha channel
215     * @param vertices The vertices that define the mesh
216     * @param texCoords The texture coordinates of each vertex
217     * @param indices The indices of the vertices, can be NULL
218     * @param elementsCount The number of elements in the mesh, required by indices
219     */
220    void drawTextureMesh(float left, float top, float right, float bottom, GLuint texture,
221            float alpha, SkXfermode::Mode mode, bool blend,
222            GLvoid* vertices, GLvoid* texCoords, GLvoid* indices, GLsizei elementsCount = 0);
223
224    /**
225     * Prepares the renderer to draw the specified shadow.
226     *
227     * @param texture The shadow texture
228     * @param x The x coordinate of the shadow
229     * @param y The y coordinate of the shadow
230     * @param mode The blending mode
231     * @param alpha The alpha value
232     */
233    void setupShadow(const ShadowTexture* texture, float x, float y, SkXfermode::Mode mode,
234            float alpha);
235
236    /**
237     * Prepares the renderer to draw the specified Alpha8 texture as a rectangle.
238     *
239     * @param texture The texture to render with
240     * @param textureUnit The texture unit to use, may be modified
241     * @param x The x coordinate of the rectangle to draw
242     * @param y The y coordinate of the rectangle to draw
243     * @param r The red component of the color
244     * @param g The green component of the color
245     * @param b The blue component of the color
246     * @param a The alpha component of the color
247     * @param mode The blending mode
248     * @param transforms True if the matrix passed to the shader should be multiplied
249     *        by the model-view matrix
250     * @param applyFilters Whether or not to take color filters and
251     *        shaders into account
252     */
253    void setupTextureAlpha8(const Texture* texture, GLuint& textureUnit, float x, float y,
254            float r, float g, float b, float a, SkXfermode::Mode mode, bool transforms,
255            bool applyFilters);
256
257    /**
258     * Prepares the renderer to draw the specified Alpha8 texture as a rectangle.
259     *
260     * @param texture The texture to render with
261     * @param width The width of the texture
262     * @param height The height of the texture
263     * @param textureUnit The texture unit to use, may be modified
264     * @param x The x coordinate of the rectangle to draw
265     * @param y The y coordinate of the rectangle to draw
266     * @param r The red component of the color
267     * @param g The green component of the color
268     * @param b The blue component of the color
269     * @param a The alpha component of the color
270     * @param mode The blending mode
271     * @param transforms True if the matrix passed to the shader should be multiplied
272     *        by the model-view matrix
273     * @param applyFilters Whether or not to take color filters and
274     *        shaders into account
275     */
276    void setupTextureAlpha8(GLuint texture, uint32_t width, uint32_t height,
277            GLuint& textureUnit, float x, float y, float r, float g, float b, float a,
278            SkXfermode::Mode mode, bool transforms, bool applyFilters);
279
280    /**
281     * Draws text underline and strike-through if needed.
282     *
283     * @param text The text to decor
284     * @param bytesCount The number of bytes in the text
285     * @param length The length in pixels of the text, can be <= 0.0f to force a measurement
286     * @param x The x coordinate where the text will be drawn
287     * @param y The y coordinate where the text will be drawn
288     * @param paint The paint to draw the text with
289     */
290    void drawTextDecorations(const char* text, int bytesCount, float length,
291            float x, float y, SkPaint* paint);
292
293    /**
294     * Resets the texture coordinates stored in mMeshVertices. Setting the values
295     * back to default is achieved by calling:
296     *
297     * resetDrawTextureTexCoords(0.0f, 0.0f, 1.0f, 1.0f);
298     *
299     * @param u1 The left coordinate of the texture
300     * @param v1 The bottom coordinate of the texture
301     * @param u2 The right coordinate of the texture
302     * @param v2 The top coordinate of the texture
303     */
304    void resetDrawTextureTexCoords(float u1, float v1, float u2, float v2);
305
306    /**
307     * Gets the alpha and xfermode out of a paint object. If the paint is null
308     * alpha will be 255 and the xfermode will be SRC_OVER.
309     *
310     * @param paint The paint to extract values from
311     * @param alpha Where to store the resulting alpha
312     * @param mode Where to store the resulting xfermode
313     */
314    inline void getAlphaAndMode(const SkPaint* paint, int* alpha, SkXfermode::Mode* mode);
315
316    /**
317     * Binds the specified texture with the specified wrap modes.
318     */
319    inline void bindTexture(GLuint texture, GLenum wrapS, GLenum wrapT, GLuint textureUnit = 0);
320
321    /**
322     * Enable or disable blending as necessary. This function sets the appropriate
323     * blend function based on the specified xfermode.
324     */
325    inline void chooseBlending(bool blend, SkXfermode::Mode mode, ProgramDescription& description);
326
327    inline SkXfermode::Mode getXfermode(SkXfermode* mode);
328
329    /**
330     * Use the specified program with the current GL context. If the program is already
331     * in use, it will not be bound again. If it is not in use, the current program is
332     * marked unused and the specified program becomes used and becomes the new
333     * current program.
334     *
335     * @param program The program to use
336     *
337     * @return true If the specified program was already in use, false otherwise.
338     */
339    inline bool useProgram(Program* program);
340
341    // Dimensions of the drawing surface
342    int mWidth, mHeight;
343
344    // Matrix used for ortho projection in shaders
345    mat4 mOrthoMatrix;
346
347    // Model-view matrix used to position/size objects
348    mat4 mModelView;
349
350    // Number of saved states
351    int mSaveCount;
352    // Base state
353    sp<Snapshot> mFirstSnapshot;
354    // Current state
355    sp<Snapshot> mSnapshot;
356
357    // Shaders
358    SkiaShader* mShader;
359
360    // Color filters
361    SkiaColorFilter* mColorFilter;
362
363    // Used to draw textured quads
364    TextureVertex mMeshVertices[4];
365
366    // GL extensions
367    Extensions mExtensions;
368
369    // Drop shadow
370    bool mHasShadow;
371    float mShadowRadius;
372    float mShadowDx;
373    float mShadowDy;
374    int mShadowColor;
375
376    // Various caches
377    Caches& mCaches;
378}; // class OpenGLRenderer
379
380}; // namespace uirenderer
381}; // namespace android
382
383#endif // ANDROID_UI_OPENGL_RENDERER_H
384