OpenGLRenderer.h revision 3d58c03de0d8877b36cdb78b0ca8b5cac7f600e2 
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 <SkXfermode.h>
27
28#include <utils/RefBase.h>
29#include <utils/ResourceTypes.h>
30
31#include "Matrix.h"
32#include "Program.h"
33#include "Rect.h"
34#include "Snapshot.h"
35#include "TextureCache.h"
36#include "LayerCache.h"
37#include "PatchCache.h"
38#include "Vertex.h"
39
40namespace android {
41namespace uirenderer {
42
43///////////////////////////////////////////////////////////////////////////////
44// Support
45///////////////////////////////////////////////////////////////////////////////
46
47/**
48 * Structure mapping Skia xfermodes to OpenGL blending factors.
49 */
50struct Blender {
51    SkXfermode::Mode mode;
52    GLenum src;
53    GLenum dst;
54}; // struct Blender
55
56///////////////////////////////////////////////////////////////////////////////
57// Renderer
58///////////////////////////////////////////////////////////////////////////////
59
60/**
61 * OpenGL renderer used to draw accelerated 2D graphics. The API is a
62 * simplified version of Skia's Canvas API.
63 */
64class OpenGLRenderer {
65public:
66    OpenGLRenderer();
67    ~OpenGLRenderer();
68
69    void setViewport(int width, int height);
70    void prepare();
71
72    int getSaveCount() const;
73    int save(int flags);
74    void restore();
75    void restoreToCount(int saveCount);
76
77    int saveLayer(float left, float top, float right, float bottom, const SkPaint* p, int flags);
78    int saveLayerAlpha(float left, float top, float right, float bottom, int alpha, int flags);
79
80    void translate(float dx, float dy);
81    void rotate(float degrees);
82    void scale(float sx, float sy);
83
84    void setMatrix(SkMatrix* matrix);
85    void getMatrix(SkMatrix* matrix);
86    void concatMatrix(SkMatrix* matrix);
87
88    const Rect& getClipBounds();
89    bool quickReject(float left, float top, float right, float bottom);
90    bool clipRect(float left, float top, float right, float bottom);
91
92    void drawBitmap(SkBitmap* bitmap, float left, float top, const SkPaint* paint);
93    void drawBitmap(SkBitmap* bitmap, const SkMatrix* matrix, const SkPaint* paint);
94    void drawBitmap(SkBitmap* bitmap, float srcLeft, float srcTop, float srcRight, float srcBottom,
95            float dstLeft, float dstTop, float dstRight, float dstBottom, const SkPaint* paint);
96    void drawPatch(SkBitmap* bitmap, Res_png_9patch* patch, float left, float top,
97            float right, float bottom, const SkPaint* paint);
98    void drawColor(int color, SkXfermode::Mode mode);
99    void drawRect(float left, float top, float right, float bottom, const SkPaint* paint);
100
101private:
102    /**
103     * Saves the current state of the renderer as a new snapshot.
104     * The new snapshot is saved in mSnapshot and the previous snapshot
105     * is linked from mSnapshot->previous.
106     *
107     * @return The new save count. This value can be passed to #restoreToCount()
108     */
109    int saveSnapshot();
110
111    /**
112     * Restores the current snapshot; mSnapshot becomes mSnapshot->previous.
113     *
114     * @return True if the clip should be also reapplied by calling
115     *         #setScissorFromClip().
116     */
117    bool restoreSnapshot();
118
119    /**
120     * Sets the clipping rectangle using glScissor. The clip is defined by
121     * the current snapshot's clipRect member.
122     */
123    void setScissorFromClip();
124
125    /**
126     * Compose the layer defined in the current snapshot with the layer
127     * defined by the previous snapshot.
128     *
129     * The current snapshot *must* be a layer (flag kFlagIsLayer set.)
130     *
131     * @param curent The current snapshot containing the layer to compose
132     * @param previous The previous snapshot to compose the current layer with
133     */
134    void composeLayer(sp<Snapshot> current, sp<Snapshot> previous);
135
136    /**
137     * Creates a new layer stored in the specified snapshot.
138     *
139     * @param snapshot The snapshot associated with the new layer
140     * @param left The left coordinate of the layer
141     * @param top The top coordinate of the layer
142     * @param right The right coordinate of the layer
143     * @param bottom The bottom coordinate of the layer
144     * @param alpha The translucency of the layer
145     * @param mode The blending mode of the layer
146     * @param flags The layer save flags
147     *
148     * @return True if the layer was successfully created, false otherwise
149     */
150    bool createLayer(sp<Snapshot> snapshot, float left, float top, float right, float bottom,
151            int alpha, SkXfermode::Mode mode, int flags);
152
153    /**
154     * Draws a colored rectangle with the specified color. The specified coordinates
155     * are transformed by the current snapshot's transform matrix.
156     *
157     * @param left The left coordinate of the rectangle
158     * @param top The top coordinate of the rectangle
159     * @param right The right coordinate of the rectangle
160     * @param bottom The bottom coordinate of the rectangle
161     * @param color The rectangle's ARGB color, defined as a packed 32 bits word
162     * @param mode The Skia xfermode to use
163     * @param ignoreTransform True if the current transform should be ignored
164     */
165    void drawColorRect(float left, float top, float right, float bottom,
166    		int color, SkXfermode::Mode mode, bool ignoreTransform = false);
167
168    /**
169     * Draws a textured rectangle with the specified texture. 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 texture The texture name to map onto the rectangle
177     * @param alpha An additional translucency parameter, between 0.0f and 1.0f
178     * @param mode The blending mode
179     * @param blend True if the texture contains an alpha channel
180     */
181    void drawTextureRect(float left, float top, float right, float bottom, GLuint texture,
182            float alpha, SkXfermode::Mode mode, bool blend);
183
184    /**
185     * Draws a textured rectangle with the specified texture. The specified coordinates
186     * are transformed by the current snapshot's transform matrix.
187     *
188     * @param left The left coordinate of the rectangle
189     * @param top The top coordinate of the rectangle
190     * @param right The right coordinate of the rectangle
191     * @param bottom The bottom coordinate of the rectangle
192     * @param texture The texture to use
193     * @param paint The paint containing the alpha, blending mode, etc.
194     */
195    void drawTextureRect(float left, float top, float right, float bottom,
196            const Texture* texture, const SkPaint* paint);
197
198    /**
199     * Draws a textured mesh with the specified texture. If the indices are omitted, the
200     * mesh is drawn as a simple quad.
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 name to map onto the rectangle
207     * @param alpha An additional translucency parameter, between 0.0f and 1.0f
208     * @param mode The blending mode
209     * @param blend True if the texture contains an alpha channel
210     * @param vertices The vertices that define the mesh
211     * @param texCoords The texture coordinates of each vertex
212     * @param indices The indices of the vertices, can be NULL
213     * @param elementsCount The number of elements in the mesh, required by indices
214     */
215    void drawTextureMesh(float left, float top, float right, float bottom, GLuint texture,
216            float alpha, SkXfermode::Mode mode, bool blend,
217            GLvoid* vertices, GLvoid* texCoords, GLvoid* indices, GLsizei elementsCount = 0);
218
219    /**
220     * Resets the texture coordinates stored in mDrawTextureVertices. Setting the values
221     * back to default is achieved by calling:
222     *
223     * resetDrawTextureTexCoords(0.0f, 0.0f, 1.0f, 1.0f);
224     *
225     * @param u1 The left coordinate of the texture
226     * @param v1 The bottom coordinate of the texture
227     * @param u2 The right coordinate of the texture
228     * @param v2 The top coordinate of the texture
229     */
230    void resetDrawTextureTexCoords(float u1, float v1, float u2, float v2);
231
232    /**
233     * Gets the alpha and xfermode out of a paint object. If the paint is null
234     * alpha will be 255 and the xfermode will be SRC_OVER.
235     *
236     * @param paint The paint to extract values from
237     * @param alpha Where to store the resulting alpha
238     * @param mode Where to store the resulting xfermode
239     */
240    inline void getAlphaAndMode(const SkPaint* paint, int* alpha, SkXfermode::Mode* mode);
241
242    /**
243     * Enable or disable blending as necessary. This function sets the appropriate
244     * blend function based on the specified xfermode.
245     */
246    inline void chooseBlending(bool blend, SkXfermode::Mode mode, bool isPremultiplied = true);
247
248    /**
249     * Use the specified shader with the current GL context. If the shader is already
250     * in use, it will not be bound again. If it is not in use, the current shader is
251     * marked unused and the specified shader becomes used and becomes the new
252     * current shader.
253     *
254     * @return true If the specified shader was already in use, false otherwise.
255     */
256    inline bool useShader(const sp<Program>& shader);
257
258    // Dimensions of the drawing surface
259    int mWidth, mHeight;
260
261    // Matrix used for ortho projection in shaders
262    mat4 mOrthoMatrix;
263
264    // Model-view matrix used to position/size objects
265    mat4 mModelView;
266
267    // Number of saved states
268    int mSaveCount;
269    // Base state
270    Snapshot mFirstSnapshot;
271    // Current state
272    sp<Snapshot> mSnapshot;
273
274    // Shaders
275    sp<Program> mCurrentShader;
276    sp<DrawColorProgram> mDrawColorShader;
277    sp<DrawTextureProgram> mDrawTextureShader;
278
279    // Used to draw textured quads
280    TextureVertex mDrawTextureVertices[4];
281
282    // Last known blend state
283    bool mBlend;
284    GLenum mLastSrcMode;
285    GLenum mLastDstMode;
286
287    // Various caches
288    TextureCache mTextureCache;
289    LayerCache mLayerCache;
290    PatchCache mPatchCache;
291}; // class OpenGLRenderer
292
293}; // namespace uirenderer
294}; // namespace android
295
296#endif // ANDROID_UI_OPENGL_RENDERER_H
297