OpenGLRenderer.h revision 8694230ff25fa0a60e480d424843e56b718f0516 
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    		bool ignoreBlending = false);
181
182    /**
183     * Draws a textured rectangle with the specified texture. The specified coordinates
184     * are transformed by the current snapshot's transform matrix.
185     *
186     * @param left The left coordinate of the rectangle
187     * @param top The top coordinate of the rectangle
188     * @param right The right coordinate of the rectangle
189     * @param bottom The bottom coordinate of the rectangle
190     * @param texture The texture name to map onto the rectangle
191     * @param alpha An additional translucency parameter, between 0.0f and 1.0f
192     * @param mode The blending mode
193     * @param blend True if the texture contains an alpha channel
194     */
195    void drawTextureRect(float left, float top, float right, float bottom, GLuint texture,
196            float alpha, SkXfermode::Mode mode, bool blend);
197
198    /**
199     * Draws a textured rectangle with the specified texture. The specified coordinates
200     * are transformed by the current snapshot's transform matrix.
201     *
202     * @param left The left coordinate of the rectangle
203     * @param top The top coordinate of the rectangle
204     * @param right The right coordinate of the rectangle
205     * @param bottom The bottom coordinate of the rectangle
206     * @param texture The texture to use
207     * @param paint The paint containing the alpha, blending mode, etc.
208     */
209    void drawTextureRect(float left, float top, float right, float bottom,
210            const Texture* texture, const SkPaint* paint);
211
212    /**
213     * Draws a textured mesh with the specified texture. If the indices are omitted, the
214     * mesh is drawn as a simple quad.
215     *
216     * @param left The left coordinate of the rectangle
217     * @param top The top coordinate of the rectangle
218     * @param right The right coordinate of the rectangle
219     * @param bottom The bottom coordinate of the rectangle
220     * @param texture The texture name to map onto the rectangle
221     * @param alpha An additional translucency parameter, between 0.0f and 1.0f
222     * @param mode The blending mode
223     * @param blend True if the texture contains an alpha channel
224     * @param vertices The vertices that define the mesh
225     * @param texCoords The texture coordinates of each vertex
226     * @param indices The indices of the vertices, can be NULL
227     * @param elementsCount The number of elements in the mesh, required by indices
228     * @param swapSrcDst Whether or not the src and dst blending operations should be swapped
229     * @param ignoreTransform True if the current transform should be ignored
230     */
231    void drawTextureMesh(float left, float top, float right, float bottom, GLuint texture,
232            float alpha, SkXfermode::Mode mode, bool blend,
233            GLvoid* vertices, GLvoid* texCoords, GLvoid* indices, GLsizei elementsCount = 0,
234            bool swapSrcDst = false, bool ignoreTransform = false);
235
236    /**
237     * Prepares the renderer to draw the specified shadow.
238     *
239     * @param texture The shadow texture
240     * @param x The x coordinate of the shadow
241     * @param y The y coordinate of the shadow
242     * @param mode The blending mode
243     * @param alpha The alpha value
244     */
245    void setupShadow(const ShadowTexture* texture, float x, float y, SkXfermode::Mode mode,
246            float alpha);
247
248    /**
249     * Prepares the renderer to draw the specified Alpha8 texture as a rectangle.
250     *
251     * @param texture The texture to render with
252     * @param textureUnit The texture unit to use, may be modified
253     * @param x The x coordinate of the rectangle to draw
254     * @param y The y coordinate of the rectangle to draw
255     * @param r The red component of the color
256     * @param g The green component of the color
257     * @param b The blue component of the color
258     * @param a The alpha component of the color
259     * @param mode The blending mode
260     * @param transforms True if the matrix passed to the shader should be multiplied
261     *        by the model-view matrix
262     * @param applyFilters Whether or not to take color filters and
263     *        shaders into account
264     */
265    void setupTextureAlpha8(const Texture* texture, GLuint& textureUnit, float x, float y,
266            float r, float g, float b, float a, SkXfermode::Mode mode, bool transforms,
267            bool applyFilters);
268
269    /**
270     * Prepares the renderer to draw the specified Alpha8 texture as a rectangle.
271     *
272     * @param texture The texture to render with
273     * @param width The width of the texture
274     * @param height The height of the texture
275     * @param textureUnit The texture unit to use, may be modified
276     * @param x The x coordinate of the rectangle to draw
277     * @param y The y coordinate of the rectangle to draw
278     * @param r The red component of the color
279     * @param g The green component of the color
280     * @param b The blue component of the color
281     * @param a The alpha component of the color
282     * @param mode The blending mode
283     * @param transforms True if the matrix passed to the shader should be multiplied
284     *        by the model-view matrix
285     * @param applyFilters Whether or not to take color filters and
286     *        shaders into account
287     */
288    void setupTextureAlpha8(GLuint texture, uint32_t width, uint32_t height,
289            GLuint& textureUnit, float x, float y, float r, float g, float b, float a,
290            SkXfermode::Mode mode, bool transforms, bool applyFilters);
291
292    /**
293     * Draws text underline and strike-through if needed.
294     *
295     * @param text The text to decor
296     * @param bytesCount The number of bytes in the text
297     * @param length The length in pixels of the text, can be <= 0.0f to force a measurement
298     * @param x The x coordinate where the text will be drawn
299     * @param y The y coordinate where the text will be drawn
300     * @param paint The paint to draw the text with
301     */
302    void drawTextDecorations(const char* text, int bytesCount, float length,
303            float x, float y, SkPaint* paint);
304
305    /**
306     * Resets the texture coordinates stored in mMeshVertices. Setting the values
307     * back to default is achieved by calling:
308     *
309     * resetDrawTextureTexCoords(0.0f, 0.0f, 1.0f, 1.0f);
310     *
311     * @param u1 The left coordinate of the texture
312     * @param v1 The bottom coordinate of the texture
313     * @param u2 The right coordinate of the texture
314     * @param v2 The top coordinate of the texture
315     */
316    void resetDrawTextureTexCoords(float u1, float v1, float u2, float v2);
317
318    /**
319     * Gets the alpha and xfermode out of a paint object. If the paint is null
320     * alpha will be 255 and the xfermode will be SRC_OVER.
321     *
322     * @param paint The paint to extract values from
323     * @param alpha Where to store the resulting alpha
324     * @param mode Where to store the resulting xfermode
325     */
326    inline void getAlphaAndMode(const SkPaint* paint, int* alpha, SkXfermode::Mode* mode);
327
328    /**
329     * Binds the specified texture with the specified wrap modes.
330     */
331    inline void bindTexture(GLuint texture, GLenum wrapS, GLenum wrapT, GLuint textureUnit = 0);
332
333    /**
334     * Enable or disable blending as necessary. This function sets the appropriate
335     * blend function based on the specified xfermode.
336     */
337    inline void chooseBlending(bool blend, SkXfermode::Mode mode, ProgramDescription& description,
338            bool swapSrcDst = false);
339
340    /**
341     * Safely retrieves the mode from the specified xfermode. If the specified
342     * xfermode is null, the mode is assumed to be SkXfermode::kSrcOver_Mode.
343     */
344    inline SkXfermode::Mode getXfermode(SkXfermode* mode);
345
346    /**
347     * Use the specified program with the current GL context. If the program is already
348     * in use, it will not be bound again. If it is not in use, the current program is
349     * marked unused and the specified program becomes used and becomes the new
350     * current program.
351     *
352     * @param program The program to use
353     *
354     * @return true If the specified program was already in use, false otherwise.
355     */
356    inline bool useProgram(Program* program);
357
358    // Dimensions of the drawing surface
359    int mWidth, mHeight;
360
361    // Matrix used for ortho projection in shaders
362    mat4 mOrthoMatrix;
363
364    // Model-view matrix used to position/size objects
365    mat4 mModelView;
366
367    // Number of saved states
368    int mSaveCount;
369    // Base state
370    sp<Snapshot> mFirstSnapshot;
371    // Current state
372    sp<Snapshot> mSnapshot;
373
374    // Shaders
375    SkiaShader* mShader;
376
377    // Color filters
378    SkiaColorFilter* mColorFilter;
379
380    // Used to draw textured quads
381    TextureVertex mMeshVertices[4];
382
383    // GL extensions
384    Extensions mExtensions;
385
386    // Drop shadow
387    bool mHasShadow;
388    float mShadowRadius;
389    float mShadowDx;
390    float mShadowDy;
391    int mShadowColor;
392
393    // Various caches
394    Caches& mCaches;
395
396    // List of rectangles to clear due to calls to saveLayer()
397    Vector<Rect*> mLayers;
398
399}; // class OpenGLRenderer
400
401}; // namespace uirenderer
402}; // namespace android
403
404#endif // ANDROID_UI_OPENGL_RENDERER_H
405