1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/gfx/skia/trunk/include/gpu/gl/SkGLContextHelper.h Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,87 @@
1.4 +
1.5 +/*
1.6 + * Copyright 2013 Google Inc.
1.7 + *
1.8 + * Use of this source code is governed by a BSD-style license that can be
1.9 + * found in the LICENSE file.
1.10 + */
1.11 +#ifndef SkGLContextHelper_DEFINED
1.12 +#define SkGLContextHelper_DEFINED
1.13 +
1.14 +#include "GrGLInterface.h"
1.15 +
1.16 +/**
1.17 + * Create an offscreen opengl context with an RGBA8 / 8bit stencil FBO.
1.18 + * Provides a GrGLInterface struct of function pointers for the context.
1.19 + */
1.20 +
1.21 +class SK_API SkGLContextHelper : public SkRefCnt {
1.22 +public:
1.23 + SK_DECLARE_INST_COUNT(SkGLContextHelper)
1.24 +
1.25 + SkGLContextHelper();
1.26 + virtual ~SkGLContextHelper();
1.27 +
1.28 + /**
1.29 + * Initializes the context and makes it current.
1.30 + */
1.31 + bool init(const int width, const int height);
1.32 +
1.33 + int getFBOID() const { return fFBO; }
1.34 +
1.35 + const GrGLInterface* gl() const { return fGL; }
1.36 +
1.37 + virtual void makeCurrent() const = 0;
1.38 +
1.39 + /**
1.40 + * The primary purpose of this function it to provide a means of scheduling
1.41 + * work on the GPU (since all of the subclasses create primary buffers for
1.42 + * testing that are small and not meant to be rendered to the screen).
1.43 + *
1.44 + * If the drawing surface provided by the platform is double buffered this
1.45 + * call will cause the platform to swap which buffer is currently being
1.46 + * targeted. If the current surface does not include a back buffer, this
1.47 + * call has no effect.
1.48 + */
1.49 + virtual void swapBuffers() const = 0;
1.50 +
1.51 + bool hasExtension(const char* extensionName) const {
1.52 + SkASSERT(NULL != fGL);
1.53 + return fGL->hasExtension(extensionName);
1.54 + }
1.55 +
1.56 +protected:
1.57 + /**
1.58 + * Subclass implements this to make a GL context. The returned GrGLInterface
1.59 + * should be populated with functions compatible with the context. The
1.60 + * format and size of backbuffers does not matter since an FBO will be
1.61 + * created.
1.62 + */
1.63 + virtual const GrGLInterface* createGLContext() = 0;
1.64 +
1.65 + /**
1.66 + * Subclass should destroy the underlying GL context.
1.67 + */
1.68 + virtual void destroyGLContext() = 0;
1.69 +
1.70 +private:
1.71 + GrGLuint fFBO;
1.72 + GrGLuint fColorBufferID;
1.73 + GrGLuint fDepthStencilBufferID;
1.74 + const GrGLInterface* fGL;
1.75 +
1.76 + typedef SkRefCnt INHERITED;
1.77 +};
1.78 +
1.79 +/**
1.80 + * Helper macros for using the GL context through the GrGLInterface. Example:
1.81 + * SK_GL(glCtx, GenTextures(1, &texID));
1.82 + */
1.83 +#define SK_GL(ctx, X) (ctx).gl()->fFunctions.f ## X; \
1.84 + SkASSERT(GR_GL_NO_ERROR == (ctx).gl()->fFunctions.fGetError())
1.85 +#define SK_GL_RET(ctx, RET, X) (RET) = (ctx).gl()->fFunctions.f ## X; \
1.86 + SkASSERT(GR_GL_NO_ERROR == (ctx).gl()->fFunctions.fGetError())
1.87 +#define SK_GL_NOERRCHECK(ctx, X) (ctx).gl()->fFunctions.f ## X
1.88 +#define SK_GL_RET_NOERRCHECK(ctx, RET, X) (RET) = (ctx).gl()->fFunctions.f ## X
1.89 +
1.90 +#endif
