1 2 /* 3 * Copyright 2013 Google Inc. 4 * 5 * Use of this source code is governed by a BSD-style license that can be 6 * found in the LICENSE file. 7 */ 8 #ifndef SkGLContext_DEFINED 9 #define SkGLContext_DEFINED 10 11 #include "GrGLInterface.h" 12 13 /** 14 * Create an offscreen opengl context with an RGBA8 / 8bit stencil FBO. 15 * Provides a GrGLInterface struct of function pointers for the context. 16 */ 17 18 class SK_API SkGLContext : public SkRefCnt { 19 public: 20 SK_DECLARE_INST_COUNT(SkGLContext) 21 22 ~SkGLContext() override; 23 isValid()24 bool isValid() const { return NULL != gl(); } 25 gl()26 const GrGLInterface* gl() const { return fGL.get(); } 27 28 virtual void makeCurrent() const = 0; 29 30 /** 31 * The primary purpose of this function it to provide a means of scheduling 32 * work on the GPU (since all of the subclasses create primary buffers for 33 * testing that are small and not meant to be rendered to the screen). 34 * 35 * If the drawing surface provided by the platform is double buffered this 36 * call will cause the platform to swap which buffer is currently being 37 * targeted. If the current surface does not include a back buffer, this 38 * call has no effect. 39 */ 40 virtual void swapBuffers() const = 0; 41 42 /** 43 * This notifies the context that we are deliberately testing abandoning 44 * the context. It is useful for debugging contexts that would otherwise 45 * test that GPU resources are properly deleted. It also allows a debugging 46 * context to test that further GL calls are not made by Skia GPU code. 47 */ 48 void testAbandon(); 49 50 protected: 51 SkGLContext(); 52 53 /** Subclass provides the gl interface object if construction was 54 * successful. */ 55 SkAutoTUnref<const GrGLInterface> fGL; 56 57 typedef SkRefCnt INHERITED; 58 }; 59 60 /** Creates platform-dependent GL context object 61 * Returns a valid gl context object or NULL if such can not be created. 62 * Note: If Skia embedder needs a custom GL context that sets up the GL 63 * interface, this function should be implemented by the embedder. 64 * Otherwise, the default implementation for the platform should be compiled in 65 * the library. 66 */ 67 SK_API SkGLContext* SkCreatePlatformGLContext(GrGLStandard forcedGpuAPI); 68 69 /** 70 * Helper macros for using the GL context through the GrGLInterface. Example: 71 * SK_GL(glCtx, GenTextures(1, &texID)); 72 */ 73 #define SK_GL(ctx, X) (ctx).gl()->fFunctions.f ## X; \ 74 SkASSERT(0 == (ctx).gl()->fFunctions.fGetError()) 75 #define SK_GL_RET(ctx, RET, X) (RET) = (ctx).gl()->fFunctions.f ## X; \ 76 SkASSERT(0 == (ctx).gl()->fFunctions.fGetError()) 77 #define SK_GL_NOERRCHECK(ctx, X) (ctx).gl()->fFunctions.f ## X 78 #define SK_GL_RET_NOERRCHECK(ctx, RET, X) (RET) = (ctx).gl()->fFunctions.f ## X 79 80 #endif 81