OpenGLRenderer.h revision 06f96e2652e4855b6520ad9dd70583677605b79a 
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
33#include "Extensions.h"
34#include "Matrix.h"
35#include "Program.h"
36#include "Rect.h"
37#include "Snapshot.h"
38#include "TextureCache.h"
39#include "LayerCache.h"
40#include "GradientCache.h"
41#include "PatchCache.h"
42#include "Vertex.h"
43#include "FontRenderer.h"
44#include "ProgramCache.h"
45#include "SkiaShader.h"
46
47namespace android {
48namespace uirenderer {
49
50///////////////////////////////////////////////////////////////////////////////
51// Renderer
52///////////////////////////////////////////////////////////////////////////////
53
54/**
55 * OpenGL renderer used to draw accelerated 2D graphics. The API is a
56 * simplified version of Skia's Canvas API.
57 */
58class OpenGLRenderer {
59public:
60    OpenGLRenderer();
61    ~OpenGLRenderer();
62
63    void setViewport(int width, int height);
64    void prepare();
65
66    int getSaveCount() const;
67    int save(int flags);
68    void restore();
69    void restoreToCount(int saveCount);
70
71    int saveLayer(float left, float top, float right, float bottom, const SkPaint* p, int flags);
72    int saveLayerAlpha(float left, float top, float right, float bottom, int alpha, int flags);
73
74    void translate(float dx, float dy);
75    void rotate(float degrees);
76    void scale(float sx, float sy);
77
78    void setMatrix(SkMatrix* matrix);
79    void getMatrix(SkMatrix* matrix);
80    void concatMatrix(SkMatrix* matrix);
81
82    const Rect& getClipBounds();
83    bool quickReject(float left, float top, float right, float bottom);
84    bool clipRect(float left, float top, float right, float bottom, SkRegion::Op op);
85
86    void drawBitmap(SkBitmap* bitmap, float left, float top, const SkPaint* paint);
87    void drawBitmap(SkBitmap* bitmap, const SkMatrix* matrix, const SkPaint* paint);
88    void drawBitmap(SkBitmap* bitmap, float srcLeft, float srcTop, float srcRight, float srcBottom,
89            float dstLeft, float dstTop, float dstRight, float dstBottom, const SkPaint* paint);
90    void drawPatch(SkBitmap* bitmap, Res_png_9patch* patch, float left, float top,
91            float right, float bottom, const SkPaint* paint);
92    void drawColor(int color, SkXfermode::Mode mode);
93    void drawRect(float left, float top, float right, float bottom, const SkPaint* paint);
94
95    void resetShader();
96    void setupShader(SkiaShader* shader);
97
98    void drawText(const char* text, int bytesCount, int count, float x, float y, SkPaint* paint);
99
100private:
101    /**
102     * Saves the current state of the renderer as a new snapshot.
103     * The new snapshot is saved in mSnapshot and the previous snapshot
104     * is linked from mSnapshot->previous.
105     *
106     * @return The new save count. This value can be passed to #restoreToCount()
107     */
108    int saveSnapshot();
109
110    /**
111     * Restores the current snapshot; mSnapshot becomes mSnapshot->previous.
112     *
113     * @return True if the clip should be also reapplied by calling
114     *         #setScissorFromClip().
115     */
116    bool restoreSnapshot();
117
118    /**
119     * Sets the clipping rectangle using glScissor. The clip is defined by
120     * the current snapshot's clipRect member.
121     */
122    void setScissorFromClip();
123
124    /**
125     * Compose the layer defined in the current snapshot with the layer
126     * defined by the previous snapshot.
127     *
128     * The current snapshot *must* be a layer (flag kFlagIsLayer set.)
129     *
130     * @param curent The current snapshot containing the layer to compose
131     * @param previous The previous snapshot to compose the current layer with
132     */
133    void composeLayer(sp<Snapshot> current, sp<Snapshot> previous);
134
135    /**
136     * Creates a new layer stored in the specified snapshot.
137     *
138     * @param snapshot The snapshot associated with the new layer
139     * @param left The left coordinate of the layer
140     * @param top The top coordinate of the layer
141     * @param right The right coordinate of the layer
142     * @param bottom The bottom coordinate of the layer
143     * @param alpha The translucency of the layer
144     * @param mode The blending mode of the layer
145     * @param flags The layer save flags
146     *
147     * @return True if the layer was successfully created, false otherwise
148     */
149    bool createLayer(sp<Snapshot> snapshot, float left, float top, float right, float bottom,
150            int alpha, SkXfermode::Mode mode, int flags);
151
152    /**
153     * Draws a colored rectangle with the specified color. The specified coordinates
154     * are transformed by the current snapshot's transform matrix.
155     *
156     * @param left The left coordinate of the rectangle
157     * @param top The top coordinate of the rectangle
158     * @param right The right coordinate of the rectangle
159     * @param bottom The bottom coordinate of the rectangle
160     * @param color The rectangle's ARGB color, defined as a packed 32 bits word
161     * @param mode The Skia xfermode to use
162     * @param ignoreTransform True if the current transform should be ignored
163     */
164    void drawColorRect(float left, float top, float right, float bottom,
165    		int color, SkXfermode::Mode mode, bool ignoreTransform = false);
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 mMeshVertices. 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     * Binds the specified texture with the specified wrap modes.
243     */
244    inline void bindTexture(GLuint texture, GLenum wrapS, GLenum wrapT, GLuint textureUnit = 0);
245
246    /**
247     * Enable or disable blending as necessary. This function sets the appropriate
248     * blend function based on the specified xfermode.
249     */
250    inline void chooseBlending(bool blend, SkXfermode::Mode mode, bool isPremultiplied = true);
251
252    /**
253     * Use the specified program with the current GL context. If the program is already
254     * in use, it will not be bound again. If it is not in use, the current program is
255     * marked unused and the specified program becomes used and becomes the new
256     * current program.
257     *
258     * @param program The program to use
259     *
260     * @return true If the specified program was already in use, false otherwise.
261     */
262    inline bool useProgram(Program* program);
263
264    // Dimensions of the drawing surface
265    int mWidth, mHeight;
266
267    // Matrix used for ortho projection in shaders
268    mat4 mOrthoMatrix;
269
270    // Model-view matrix used to position/size objects
271    mat4 mModelView;
272
273    // Number of saved states
274    int mSaveCount;
275    // Base state
276    sp<Snapshot> mFirstSnapshot;
277    // Current state
278    sp<Snapshot> mSnapshot;
279
280    // Shaders
281    Program* mCurrentProgram;
282    SkiaShader* mShader;
283
284    // Used to draw textured quads
285    TextureVertex mMeshVertices[4];
286
287    // Last known blend state
288    bool mBlend;
289    GLenum mLastSrcMode;
290    GLenum mLastDstMode;
291
292    // GL extensions
293    Extensions mExtensions;
294
295    // Font renderer
296    FontRenderer mFontRenderer;
297
298    // Various caches
299    TextureCache mTextureCache;
300    LayerCache mLayerCache;
301    GradientCache mGradientCache;
302    ProgramCache mProgramCache;
303    PatchCache mPatchCache;
304}; // class OpenGLRenderer
305
306}; // namespace uirenderer
307}; // namespace android
308
309#endif // ANDROID_UI_OPENGL_RENDERER_H
310