APP绘图离不开Canvas，它支持硬件加速（OpenGL），本文对其底层实现进行深入分析。
1 CanvasJava层封装了Skia Canvas
| Canvas | frameworks/base/graphics/java/android/graphics/Canvas.java frameworks/base/core/jni/android/graphics/Canvas.cpp |
| CompatibleCanvas | frameworks/base/core/java/android/view/Surface.java |
| RecordingCanvas | frameworks/base/graphics/java/android/graphics/Picture.java |
| HardwareC |
