skia2/include/gpu/gl/SkGLContext.h

81 lines
2.7 KiB
C++

/*
* Copyright 2013 Google Inc.
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#ifndef SkGLContext_DEFINED
#define SkGLContext_DEFINED
#include "GrGLInterface.h"
/**
* Create an offscreen opengl context with an RGBA8 / 8bit stencil FBO.
* Provides a GrGLInterface struct of function pointers for the context.
*/
class SK_API SkGLContext : public SkRefCnt {
public:
SK_DECLARE_INST_COUNT(SkGLContext)
~SkGLContext() override;
bool isValid() const { return NULL != gl(); }
const GrGLInterface* gl() const { return fGL.get(); }
virtual void makeCurrent() const = 0;
/**
* The primary purpose of this function it to provide a means of scheduling
* work on the GPU (since all of the subclasses create primary buffers for
* testing that are small and not meant to be rendered to the screen).
*
* If the drawing surface provided by the platform is double buffered this
* call will cause the platform to swap which buffer is currently being
* targeted. If the current surface does not include a back buffer, this
* call has no effect.
*/
virtual void swapBuffers() const = 0;
/**
* This notifies the context that we are deliberately testing abandoning
* the context. It is useful for debugging contexts that would otherwise
* test that GPU resources are properly deleted. It also allows a debugging
* context to test that further GL calls are not made by Skia GPU code.
*/
void testAbandon();
protected:
SkGLContext();
/** Subclass provides the gl interface object if construction was
* successful. */
SkAutoTUnref<const GrGLInterface> fGL;
typedef SkRefCnt INHERITED;
};
/** Creates platform-dependent GL context object
* Returns a valid gl context object or NULL if such can not be created.
* Note: If Skia embedder needs a custom GL context that sets up the GL
* interface, this function should be implemented by the embedder.
* Otherwise, the default implementation for the platform should be compiled in
* the library.
*/
SK_API SkGLContext* SkCreatePlatformGLContext(GrGLStandard forcedGpuAPI);
/**
* Helper macros for using the GL context through the GrGLInterface. Example:
* SK_GL(glCtx, GenTextures(1, &texID));
*/
#define SK_GL(ctx, X) (ctx).gl()->fFunctions.f ## X; \
SkASSERT(0 == (ctx).gl()->fFunctions.fGetError())
#define SK_GL_RET(ctx, RET, X) (RET) = (ctx).gl()->fFunctions.f ## X; \
SkASSERT(0 == (ctx).gl()->fFunctions.fGetError())
#define SK_GL_NOERRCHECK(ctx, X) (ctx).gl()->fFunctions.f ## X
#define SK_GL_RET_NOERRCHECK(ctx, RET, X) (RET) = (ctx).gl()->fFunctions.f ## X
#endif