OpenGLRenderer.h revision 1c740bce8a762f02b5283045a0e2de7c8fb41277 
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#include <utils/Vector.h>
33
34#include "Extensions.h"
35#include "Matrix.h"
36#include "Program.h"
37#include "Rect.h"
38#include "Snapshot.h"
39#include "Vertex.h"
40#include "SkiaShader.h"
41#include "SkiaColorFilter.h"
42#include "Caches.h"
43
44namespace android {
45namespace uirenderer {
46
47///////////////////////////////////////////////////////////////////////////////
48// Renderer
49///////////////////////////////////////////////////////////////////////////////
50
51/**
52 * OpenGL renderer used to draw accelerated 2D graphics. The API is a
53 * simplified version of Skia's Canvas API.
54 */
55class OpenGLRenderer {
56public:
57    OpenGLRenderer();
58    ~OpenGLRenderer();
59
60    void setViewport(int width, int height);
61    void prepare();
62    void acquireContext();
63    void releaseContext();
64
65    int getSaveCount() const;
66    int save(int flags);
67    void restore();
68    void restoreToCount(int saveCount);
69
70    int saveLayer(float left, float top, float right, float bottom, const SkPaint* p, int flags);
71    int saveLayerAlpha(float left, float top, float right, float bottom, int alpha, int flags);
72
73    void translate(float dx, float dy);
74    void rotate(float degrees);
75    void scale(float sx, float sy);
76
77    void setMatrix(SkMatrix* matrix);
78    void getMatrix(SkMatrix* matrix);
79    void concatMatrix(SkMatrix* matrix);
80
81    const Rect& getClipBounds();
82    bool quickReject(float left, float top, float right, float bottom);
83    bool clipRect(float left, float top, float right, float bottom, SkRegion::Op op);
84
85    void drawBitmap(SkBitmap* bitmap, float left, float top, const SkPaint* paint);
86    void drawBitmap(SkBitmap* bitmap, const SkMatrix* matrix, const SkPaint* paint);
87    void drawBitmap(SkBitmap* bitmap, float srcLeft, float srcTop, float srcRight, float srcBottom,
88            float dstLeft, float dstTop, float dstRight, float dstBottom, const SkPaint* paint);
89    void drawPatch(SkBitmap* bitmap, Res_png_9patch* patch, float left, float top,
90            float right, float bottom, const SkPaint* paint);
91    void drawColor(int color, SkXfermode::Mode mode);
92    void drawRect(float left, float top, float right, float bottom, const SkPaint* paint);
93    void drawPath(SkPath* path, SkPaint* paint);
94
95    void resetShader();
96    void setupShader(SkiaShader* shader);
97
98    void resetColorFilter();
99    void setupColorFilter(SkiaColorFilter* filter);
100
101    void resetShadow();
102    void setupShadow(float radius, float dx, float dy, int color);
103
104    void drawText(const char* text, int bytesCount, int count, float x, float y, SkPaint* paint);
105
106private:
107    /**
108     * Saves the current state of the renderer as a new snapshot.
109     * The new snapshot is saved in mSnapshot and the previous snapshot
110     * is linked from mSnapshot->previous.
111     *
112     * @param flags The save flags; see SkCanvas for more information
113     *
114     * @return The new save count. This value can be passed to #restoreToCount()
115     */
116    int saveSnapshot(int flags);
117
118    /**
119     * Restores the current snapshot; mSnapshot becomes mSnapshot->previous.
120     *
121     * @return True if the clip was modified.
122     */
123    bool restoreSnapshot();
124
125    /**
126     * Sets the clipping rectangle using glScissor. The clip is defined by
127     * the current snapshot's clipRect member.
128     */
129    void setScissorFromClip();
130
131    /**
132     * Compose the layer defined in the current snapshot with the layer
133     * defined by the previous snapshot.
134     *
135     * The current snapshot *must* be a layer (flag kFlagIsLayer set.)
136     *
137     * @param curent The current snapshot containing the layer to compose
138     * @param previous The previous snapshot to compose the current layer with
139     */
140    void composeLayer(sp<Snapshot> current, sp<Snapshot> previous);
141
142    /**
143     * Creates a new layer stored in the specified snapshot.
144     *
145     * @param snapshot The snapshot associated with the new layer
146     * @param left The left coordinate of the layer
147     * @param top The top coordinate of the layer
148     * @param right The right coordinate of the layer
149     * @param bottom The bottom coordinate of the layer
150     * @param alpha The translucency of the layer
151     * @param mode The blending mode of the layer
152     * @param flags The layer save flags
153     *
154     * @return True if the layer was successfully created, false otherwise
155     */
156    bool createLayer(sp<Snapshot> snapshot, float left, float top, float right, float bottom,
157            int alpha, SkXfermode::Mode mode, int flags);
158
159    /**
160     * Clears all the regions corresponding to the current list of layers.
161     * This method MUST be invoked before any drawing operation.
162     */
163    void clearLayerRegions();
164
165    /**
166     * Draws a colored rectangle with the specified color. The specified coordinates
167     * are transformed by the current snapshot's transform matrix.
168     *
169     * @param left The left coordinate of the rectangle
170     * @param top The top coordinate of the rectangle
171     * @param right The right coordinate of the rectangle
172     * @param bottom The bottom coordinate of the rectangle
173     * @param color The rectangle's ARGB color, defined as a packed 32 bits word
174     * @param mode The Skia xfermode to use
175     * @param ignoreTransform True if the current transform should be ignored
176     * @paran ignoreBlending True if the blending is set by the caller
177     */
178    void drawColorRect(float left, float top, float right, float bottom,
179            int color, SkXfermode::Mode mode, bool ignoreTransform = false);
180
181    /**
182     * Draws a textured rectangle with the specified texture. The specified coordinates
183     * are transformed by the current snapshot's transform matrix.
184     *
185     * @param left The left coordinate of the rectangle
186     * @param top The top coordinate of the rectangle
187     * @param right The right coordinate of the rectangle
188     * @param bottom The bottom coordinate of the rectangle
189     * @param texture The texture name to map onto the rectangle
190     * @param alpha An additional translucency parameter, between 0.0f and 1.0f
191     * @param mode The blending mode
192     * @param blend True if the texture contains an alpha channel
193     */
194    void drawTextureRect(float left, float top, float right, float bottom, GLuint texture,
195            float alpha, SkXfermode::Mode mode, bool blend);
196
197    /**
198     * Draws a textured rectangle with the specified texture. The specified coordinates
199     * are transformed by the current snapshot's transform matrix.
200     *
201     * @param left The left coordinate of the rectangle
202     * @param top The top coordinate of the rectangle
203     * @param right The right coordinate of the rectangle
204     * @param bottom The bottom coordinate of the rectangle
205     * @param texture The texture to use
206     * @param paint The paint containing the alpha, blending mode, etc.
207     */
208    void drawTextureRect(float left, float top, float right, float bottom,
209            const Texture* texture, const SkPaint* paint);
210
211    /**
212     * Draws a textured mesh with the specified texture. If the indices are omitted, the
213     * mesh is drawn as a simple quad.
214     *
215     * @param left The left coordinate of the rectangle
216     * @param top The top coordinate of the rectangle
217     * @param right The right coordinate of the rectangle
218     * @param bottom The bottom coordinate of the rectangle
219     * @param texture The texture name to map onto the rectangle
220     * @param alpha An additional translucency parameter, between 0.0f and 1.0f
221     * @param mode The blending mode
222     * @param blend True if the texture contains an alpha channel
223     * @param vertices The vertices that define the mesh
224     * @param texCoords The texture coordinates of each vertex
225     * @param indices The indices of the vertices, can be NULL
226     * @param elementsCount The number of elements in the mesh, required by indices
227     * @param swapSrcDst Whether or not the src and dst blending operations should be swapped
228     * @param ignoreTransform True if the current transform should be ignored
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            bool swapSrcDst = false, bool ignoreTransform = false);
234
235    /**
236     * Prepares the renderer to draw the specified shadow.
237     *
238     * @param texture The shadow texture
239     * @param x The x coordinate of the shadow
240     * @param y The y coordinate of the shadow
241     * @param mode The blending mode
242     * @param alpha The alpha value
243     */
244    void setupShadow(const ShadowTexture* texture, float x, float y, SkXfermode::Mode mode,
245            float alpha);
246
247    /**
248     * Prepares the renderer to draw the specified Alpha8 texture as a rectangle.
249     *
250     * @param texture The texture to render with
251     * @param textureUnit The texture unit to use, may be modified
252     * @param x The x coordinate of the rectangle to draw
253     * @param y The y coordinate of the rectangle to draw
254     * @param r The red component of the color
255     * @param g The green component of the color
256     * @param b The blue component of the color
257     * @param a The alpha component of the color
258     * @param mode The blending mode
259     * @param transforms True if the matrix passed to the shader should be multiplied
260     *        by the model-view matrix
261     * @param applyFilters Whether or not to take color filters and
262     *        shaders into account
263     */
264    void setupTextureAlpha8(const Texture* texture, GLuint& textureUnit, float x, float y,
265            float r, float g, float b, float a, SkXfermode::Mode mode, bool transforms,
266            bool applyFilters);
267
268    /**
269     * Prepares the renderer to draw the specified Alpha8 texture as a rectangle.
270     *
271     * @param texture The texture to render with
272     * @param width The width of the texture
273     * @param height The height of the texture
274     * @param textureUnit The texture unit to use, may be modified
275     * @param x The x coordinate of the rectangle to draw
276     * @param y The y coordinate of the rectangle to draw
277     * @param r The red component of the color
278     * @param g The green component of the color
279     * @param b The blue component of the color
280     * @param a The alpha component of the color
281     * @param mode The blending mode
282     * @param transforms True if the matrix passed to the shader should be multiplied
283     *        by the model-view matrix
284     * @param applyFilters Whether or not to take color filters and
285     *        shaders into account
286     */
287    void setupTextureAlpha8(GLuint texture, uint32_t width, uint32_t height,
288            GLuint& textureUnit, float x, float y, float r, float g, float b, float a,
289            SkXfermode::Mode mode, bool transforms, bool applyFilters);
290
291    /**
292     * Draws text underline and strike-through if needed.
293     *
294     * @param text The text to decor
295     * @param bytesCount The number of bytes in the text
296     * @param length The length in pixels of the text, can be <= 0.0f to force a measurement
297     * @param x The x coordinate where the text will be drawn
298     * @param y The y coordinate where the text will be drawn
299     * @param paint The paint to draw the text with
300     */
301    void drawTextDecorations(const char* text, int bytesCount, float length,
302            float x, float y, SkPaint* paint);
303
304    /**
305     * Resets the texture coordinates stored in mMeshVertices. Setting the values
306     * back to default is achieved by calling:
307     *
308     * resetDrawTextureTexCoords(0.0f, 0.0f, 1.0f, 1.0f);
309     *
310     * @param u1 The left coordinate of the texture
311     * @param v1 The bottom coordinate of the texture
312     * @param u2 The right coordinate of the texture
313     * @param v2 The top coordinate of the texture
314     */
315    void resetDrawTextureTexCoords(float u1, float v1, float u2, float v2);
316
317    /**
318     * Gets the alpha and xfermode out of a paint object. If the paint is null
319     * alpha will be 255 and the xfermode will be SRC_OVER.
320     *
321     * @param paint The paint to extract values from
322     * @param alpha Where to store the resulting alpha
323     * @param mode Where to store the resulting xfermode
324     */
325    inline void getAlphaAndMode(const SkPaint* paint, int* alpha, SkXfermode::Mode* mode);
326
327    /**
328     * Binds the specified texture with the specified wrap modes.
329     */
330    inline void bindTexture(GLuint texture, GLenum wrapS, GLenum wrapT, GLuint textureUnit = 0);
331
332    /**
333     * Enable or disable blending as necessary. This function sets the appropriate
334     * blend function based on the specified xfermode.
335     */
336    inline void chooseBlending(bool blend, SkXfermode::Mode mode, ProgramDescription& description,
337            bool swapSrcDst = false);
338
339    /**
340     * Safely retrieves the mode from the specified xfermode. If the specified
341     * xfermode is null, the mode is assumed to be SkXfermode::kSrcOver_Mode.
342     */
343    inline SkXfermode::Mode getXfermode(SkXfermode* mode);
344
345    /**
346     * Use the specified program with the current GL context. If the program is already
347     * in use, it will not be bound again. If it is not in use, the current program is
348     * marked unused and the specified program becomes used and becomes the new
349     * current program.
350     *
351     * @param program The program to use
352     *
353     * @return true If the specified program was already in use, false otherwise.
354     */
355    inline bool useProgram(Program* program);
356
357    // Dimensions of the drawing surface
358    int mWidth, mHeight;
359
360    // Matrix used for ortho projection in shaders
361    mat4 mOrthoMatrix;
362
363    // Model-view matrix used to position/size objects
364    mat4 mModelView;
365
366    // Number of saved states
367    int mSaveCount;
368    // Base state
369    sp<Snapshot> mFirstSnapshot;
370    // Current state
371    sp<Snapshot> mSnapshot;
372
373    // Shaders
374    SkiaShader* mShader;
375
376    // Color filters
377    SkiaColorFilter* mColorFilter;
378
379    // Used to draw textured quads
380    TextureVertex mMeshVertices[4];
381
382    // GL extensions
383    Extensions mExtensions;
384
385    // Drop shadow
386    bool mHasShadow;
387    float mShadowRadius;
388    float mShadowDx;
389    float mShadowDy;
390    int mShadowColor;
391
392    // Various caches
393    Caches& mCaches;
394
395    // List of rectangles to clear due to calls to saveLayer()
396    Vector<Rect*> mLayers;
397
398}; // class OpenGLRenderer
399
400}; // namespace uirenderer
401}; // namespace android
402
403#endif // ANDROID_UI_OPENGL_RENDERER_H
404