OpenGLRenderer.h revision a979474f15b454c8e2963f239a3770e200bb227c 
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     */
164    void drawColorRect(float left, float top, float right, float bottom,
165    		int color, SkXfermode::Mode mode);
166
167    /**
168     * Draws a textured rectangle with the specified texture. The specified coordinates
169     * are transformed by the current snapshot's transform matrix.
170     *
171     * @param left The left coordinate of the rectangle
172     * @param top The top coordinate of the rectangle
173     * @param right The right coordinate of the rectangle
174     * @param bottom The bottom coordinate of the rectangle
175     * @param texture The texture name to map onto the rectangle
176     * @param alpha An additional translucency parameter, between 0.0f and 1.0f
177     * @param mode The blending mode
178     * @param blend True if the texture contains an alpha channel
179     */
180    void drawTextureRect(float left, float top, float right, float bottom, GLuint texture,
181            float alpha, SkXfermode::Mode mode, bool blend);
182
183    /**
184     * Draws a textured rectangle with the specified texture. The specified coordinates
185     * are transformed by the current snapshot's transform matrix.
186     *
187     * @param left The left coordinate of the rectangle
188     * @param top The top coordinate of the rectangle
189     * @param right The right coordinate of the rectangle
190     * @param bottom The bottom coordinate of the rectangle
191     * @param texture The texture to use
192     * @param paint The paint containing the alpha, blending mode, etc.
193     */
194    void drawTextureRect(float left, float top, float right, float bottom,
195            const Texture* texture, const SkPaint* paint);
196
197    /**
198     * Draws a textured mesh with the specified texture. If the indices are omitted, the
199     * mesh is drawn as a simple quad.
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 name to map onto the rectangle
206     * @param alpha An additional translucency parameter, between 0.0f and 1.0f
207     * @param mode The blending mode
208     * @param blend True if the texture contains an alpha channel
209     * @param vertices The vertices that define the mesh
210     * @param texCoords The texture coordinates of each vertex
211     * @param indices The indices of the vertices, can be NULL
212     * @param elementsCount The number of elements in the mesh, required by indices
213     */
214    void drawTextureMesh(float left, float top, float right, float bottom, GLuint texture,
215            float alpha, SkXfermode::Mode mode, bool blend,
216            GLvoid* vertices, GLvoid* texCoords, GLvoid* indices, GLsizei elementsCount = 0);
217
218    /**
219     * Resets the texture coordinates stored in mDrawTextureVertices. Setting the values
220     * back to default is achieved by calling:
221     *
222     * resetDrawTextureTexCoords(0.0f, 0.0f, 1.0f, 1.0f);
223     *
224     * @param u1 The left coordinate of the texture
225     * @param v1 The bottom coordinate of the texture
226     * @param u2 The right coordinate of the texture
227     * @param v2 The top coordinate of the texture
228     */
229    void resetDrawTextureTexCoords(float u1, float v1, float u2, float v2);
230
231    /**
232     * Gets the alpha and xfermode out of a paint object. If the paint is null
233     * alpha will be 255 and the xfermode will be SRC_OVER.
234     *
235     * @param paint The paint to extract values from
236     * @param alpha Where to store the resulting alpha
237     * @param mode Where to store the resulting xfermode
238     */
239    inline void getAlphaAndMode(const SkPaint* paint, int* alpha, SkXfermode::Mode* mode);
240
241    /**
242     * Enable or disable blending as necessary. This function sets the appropriate
243     * blend function based on the specified xfermode.
244     */
245    inline void chooseBlending(bool blend, SkXfermode::Mode mode, bool isPremultiplied = true);
246
247    /**
248     * Use the specified shader with the current GL context. If the shader is already
249     * in use, it will not be bound again. If it is not in use, the current shader is
250     * marked unused and the specified shader becomes used and becomes the new
251     * current shader.
252     *
253     * @return true If the specified shader was already in use, false otherwise.
254     */
255    inline bool useShader(const sp<Program>& shader);
256
257    // Dimensions of the drawing surface
258    int mWidth, mHeight;
259
260    // Matrix used for ortho projection in shaders
261    mat4 mOrthoMatrix;
262
263    // Model-view matrix used to position/size objects
264    mat4 mModelView;
265
266    // Number of saved states
267    int mSaveCount;
268    // Base state
269    Snapshot mFirstSnapshot;
270    // Current state
271    sp<Snapshot> mSnapshot;
272
273    // Shaders
274    sp<Program> mCurrentShader;
275    sp<DrawColorProgram> mDrawColorShader;
276    sp<DrawTextureProgram> mDrawTextureShader;
277
278    // Used to draw textured quads
279    TextureVertex mDrawTextureVertices[4];
280
281    // Last known blend state
282    bool mBlend;
283    GLenum mLastSrcMode;
284    GLenum mLastDstMode;
285
286    // Various caches
287    TextureCache mTextureCache;
288    LayerCache mLayerCache;
289    PatchCache mPatchCache;
290}; // class OpenGLRenderer
291
292}; // namespace uirenderer
293}; // namespace android
294
295#endif // ANDROID_UI_OPENGL_RENDERER_H
296