OpenGLRenderer.h revision deba785f122a47915756ffd991f5540d952cf937 
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 "Texture.h"
36#include "Layer.h"
37#include "TextureCache.h"
38#include "LayerCache.h"
39
40namespace android {
41namespace uirenderer {
42
43///////////////////////////////////////////////////////////////////////////////
44// Support
45///////////////////////////////////////////////////////////////////////////////
46
47/**
48 * Simple structure to describe a vertex with a position.
49 * This is used to draw filled rectangles without a texture.
50 */
51struct SimpleVertex {
52    float position[2];
53}; // struct SimpleVertex
54
55/**
56 * Simple structure to describe a vertex with a position and a texture.
57 */
58struct TextureVertex {
59    float position[2];
60    float texture[2];
61}; // struct TextureVertex
62
63/**
64 * Structure mapping Skia xfermodes to OpenGL blending factors.
65 */
66struct Blender {
67    SkXfermode::Mode mode;
68    GLenum src;
69    GLenum dst;
70}; // struct Blender
71
72///////////////////////////////////////////////////////////////////////////////
73// Renderer
74///////////////////////////////////////////////////////////////////////////////
75
76/**
77 * OpenGL renderer used to draw accelerated 2D graphics. The API is a
78 * simplified version of Skia's Canvas API.
79 */
80class OpenGLRenderer {
81public:
82    OpenGLRenderer();
83    ~OpenGLRenderer();
84
85    void setViewport(int width, int height);
86    void prepare();
87
88    int getSaveCount() const;
89    int save(int flags);
90    void restore();
91    void restoreToCount(int saveCount);
92
93    int saveLayer(float left, float top, float right, float bottom, const SkPaint* p, int flags);
94    int saveLayerAlpha(float left, float top, float right, float bottom, int alpha, int flags);
95
96    void translate(float dx, float dy);
97    void rotate(float degrees);
98    void scale(float sx, float sy);
99
100    void setMatrix(SkMatrix* matrix);
101    void getMatrix(SkMatrix* matrix);
102    void concatMatrix(SkMatrix* matrix);
103
104    const Rect& getClipBounds();
105    bool quickReject(float left, float top, float right, float bottom);
106    bool clipRect(float left, float top, float right, float bottom);
107
108    void drawBitmap(SkBitmap* bitmap, float left, float top, const SkPaint* paint);
109    void drawBitmap(SkBitmap* bitmap, const SkMatrix* matrix, const SkPaint* paint);
110    void drawBitmap(SkBitmap* bitmap, float srcLeft, float srcTop, float srcRight, float srcBottom,
111            float dstLeft, float dstTop, float dstRight, float dstBottom, const SkPaint* paint);
112    void drawPatch(SkBitmap* bitmap, Res_png_9patch* patch, float left, float top,
113            float right, float bottom, const SkPaint* paint);
114    void drawColor(int color, SkXfermode::Mode mode);
115    void drawRect(float left, float top, float right, float bottom, const SkPaint* paint);
116
117private:
118    /**
119     * Saves the current state of the renderer as a new snapshot.
120     * The new snapshot is saved in mSnapshot and the previous snapshot
121     * is linked from mSnapshot->previous.
122     *
123     * @return The new save count. This value can be passed to #restoreToCount()
124     */
125    int saveSnapshot();
126
127    /**
128     * Restores the current snapshot; mSnapshot becomes mSnapshot->previous.
129     *
130     * @return True if the clip should be also reapplied by calling
131     *         #setScissorFromClip().
132     */
133    bool restoreSnapshot();
134
135    /**
136     * Sets the clipping rectangle using glScissor. The clip is defined by
137     * the current snapshot's clipRect member.
138     */
139    void setScissorFromClip();
140
141    /**
142     * Compose the layer defined in the current snapshot with the layer
143     * defined by the previous snapshot.
144     *
145     * The current snapshot *must* be a layer (flag kFlagIsLayer set.)
146     *
147     * @param curent The current snapshot containing the layer to compose
148     * @param previous The previous snapshot to compose the current layer with
149     */
150    void composeLayer(sp<Snapshot> current, sp<Snapshot> previous);
151
152    /**
153     * Creates a new layer stored in the specified snapshot.
154     *
155     * @param snapshot The snapshot associated with the new layer
156     * @param left The left coordinate of the layer
157     * @param top The top coordinate of the layer
158     * @param right The right coordinate of the layer
159     * @param bottom The bottom coordinate of the layer
160     * @param alpha The translucency of the layer
161     * @param mode The blending mode of the layer
162     * @param flags The layer save flags
163     *
164     * @return True if the layer was successfully created, false otherwise
165     */
166    bool createLayer(sp<Snapshot> snapshot, float left, float top, float right, float bottom,
167            int alpha, SkXfermode::Mode mode, int flags);
168
169    /**
170     * Draws a colored rectangle with the specified color. The specified coordinates
171     * are transformed by the current snapshot's transform matrix.
172     *
173     * @param left The left coordinate of the rectangle
174     * @param top The top coordinate of the rectangle
175     * @param right The right coordinate of the rectangle
176     * @param bottom The bottom coordinate of the rectangle
177     * @param color The rectangle's ARGB color, defined as a packed 32 bits word
178     * @param mode The Skia xfermode to use
179     */
180    void drawColorRect(float left, float top, float right, float bottom,
181    		int color, SkXfermode::Mode mode);
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 name to map onto the rectangle
192     * @param alpha An additional translucency parameter, between 0.0f and 1.0f
193     * @param mode The blending mode
194     * @param blend True if the texture contains an alpha channel
195     * @param isPremultiplied Indicates whether the texture has premultiplied alpha
196     */
197    void drawTextureRect(float left, float top, float right, float bottom, GLuint texture,
198            float alpha, SkXfermode::Mode mode, bool blend, bool isPremultiplied = false);
199
200    /**
201     * Resets the texture coordinates stored in mDrawTextureVertices. Setting the values
202     * back to default is achieved by calling:
203     *
204     * resetDrawTextureTexCoords(0.0f, 0.0f, 1.0f, 1.0f);
205     *
206     * @param u1 The left coordinate of the texture
207     * @param v1 The bottom coordinate of the texture
208     * @param u2 The right coordinate of the texture
209     * @param v2 The top coordinate of the texture
210     */
211    void resetDrawTextureTexCoords(float u1, float v1, float u2, float v2);
212
213    /**
214     * Gets the alpha and xfermode out of a paint object. If the paint is null
215     * alpha will be 255 and the xfermode will be SRC_OVER.
216     *
217     * @param paint The paint to extract values from
218     * @param alpha Where to store the resulting alpha
219     * @param mode Where to store the resulting xfermode
220     */
221    inline void getAlphaAndMode(const SkPaint* paint, int* alpha, SkXfermode::Mode* mode);
222
223    // Dimensions of the drawing surface
224    int mWidth, mHeight;
225
226    // Matrix used for ortho projection in shaders
227    float mOrthoMatrix[16];
228
229    // Model-view matrix used to position/size objects
230    mat4 mModelView;
231
232    // Number of saved states
233    int mSaveCount;
234    // Base state
235    Snapshot mFirstSnapshot;
236    // Current state
237    sp<Snapshot> mSnapshot;
238
239    // Shaders
240    sp<DrawColorProgram> mDrawColorShader;
241    sp<DrawTextureProgram> mDrawTextureShader;
242
243    // Used to draw textured quads
244    TextureVertex mDrawTextureVertices[4];
245
246    // Used to cache all drawBitmap textures
247    TextureCache mTextureCache;
248    LayerCache mLayerCache;
249}; // class OpenGLRenderer
250
251}; // namespace uirenderer
252}; // namespace android
253
254#endif // ANDROID_UI_OPENGL_RENDERER_H
255