michael@0: /* -*- Mode: c++; c-basic-offset: 4; indent-tabs-mode: nil; tab-width: 40; -*- */
michael@0: /* This Source Code Form is subject to the terms of the Mozilla Public
michael@0:  * License, v. 2.0. If a copy of the MPL was not distributed with this
michael@0:  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: 
michael@0: /* GLScreenBuffer is the abstraction for the "default framebuffer" used
michael@0:  * by an offscreen GLContext. Since it's only for offscreen GLContext's,
michael@0:  * it's only useful for things like WebGL, and is NOT used by the
michael@0:  * compositor's GLContext. Remember that GLContext provides an abstraction
michael@0:  * so that even if you want to draw to the 'screen', even if that's not
michael@0:  * actually the screen, just draw to 0. This GLScreenBuffer class takes the
michael@0:  * logic handling out of GLContext.
michael@0: */
michael@0: 
michael@0: #ifndef SCREEN_BUFFER_H_
michael@0: #define SCREEN_BUFFER_H_
michael@0: 
michael@0: #include "SurfaceTypes.h"
michael@0: #include "SurfaceStream.h"
michael@0: #include "GLContextTypes.h"
michael@0: #include "GLDefs.h"
michael@0: #include "mozilla/gfx/2D.h"
michael@0: #include "mozilla/gfx/Point.h"
michael@0: 
michael@0: // Forwards:
michael@0: class gfxImageSurface;
michael@0: 
michael@0: namespace mozilla {
michael@0:     namespace gfx {
michael@0:         class SurfaceStream;
michael@0:         class SharedSurface;
michael@0:     }
michael@0:     namespace gl {
michael@0:         class GLContext;
michael@0:         class SharedSurface_GL;
michael@0:         class SurfaceFactory_GL;
michael@0:     }
michael@0: }
michael@0: 
michael@0: namespace mozilla {
michael@0: namespace gl {
michael@0: 
michael@0: class DrawBuffer
michael@0: {
michael@0: protected:
michael@0:     typedef struct gfx::SurfaceCaps SurfaceCaps;
michael@0: 
michael@0: public:
michael@0:     // Infallible, may return null if unneeded.
michael@0:     static DrawBuffer* Create(GLContext* const gl,
michael@0:                               const SurfaceCaps& caps,
michael@0:                               const GLFormats& formats,
michael@0:                               const gfx::IntSize& size);
michael@0: 
michael@0: protected:
michael@0:     GLContext* const mGL;
michael@0:     const gfx::IntSize mSize;
michael@0:     const GLuint mFB;
michael@0:     const GLuint mColorMSRB;
michael@0:     const GLuint mDepthRB;
michael@0:     const GLuint mStencilRB;
michael@0: 
michael@0:     DrawBuffer(GLContext* gl,
michael@0:                const gfx::IntSize& size,
michael@0:                GLuint fb,
michael@0:                GLuint colorMSRB,
michael@0:                GLuint depthRB,
michael@0:                GLuint stencilRB)
michael@0:         : mGL(gl)
michael@0:         , mSize(size)
michael@0:         , mFB(fb)
michael@0:         , mColorMSRB(colorMSRB)
michael@0:         , mDepthRB(depthRB)
michael@0:         , mStencilRB(stencilRB)
michael@0:     {}
michael@0: 
michael@0: public:
michael@0:     virtual ~DrawBuffer();
michael@0: 
michael@0:     const gfx::IntSize& Size() const {
michael@0:         return mSize;
michael@0:     }
michael@0: 
michael@0:     GLuint FB() const {
michael@0:         return mFB;
michael@0:     }
michael@0: };
michael@0: 
michael@0: class ReadBuffer
michael@0: {
michael@0: protected:
michael@0:     typedef struct gfx::SurfaceCaps SurfaceCaps;
michael@0: 
michael@0: public:
michael@0:     // Infallible, always non-null.
michael@0:     static ReadBuffer* Create(GLContext* gl,
michael@0:                               const SurfaceCaps& caps,
michael@0:                               const GLFormats& formats,
michael@0:                               SharedSurface_GL* surf);
michael@0: 
michael@0: protected:
michael@0:     GLContext* const mGL;
michael@0: 
michael@0:     const GLuint mFB;
michael@0:     // mFB has the following attachments:
michael@0:     const GLuint mDepthRB;
michael@0:     const GLuint mStencilRB;
michael@0:     // note no mColorRB here: this is provided by mSurf.
michael@0:     SharedSurface_GL* mSurf; // Owned by GLScreenBuffer's SurfaceStream.
michael@0: 
michael@0:     ReadBuffer(GLContext* gl,
michael@0:                GLuint fb,
michael@0:                GLuint depthRB,
michael@0:                GLuint stencilRB,
michael@0:                SharedSurface_GL* surf)
michael@0:         : mGL(gl)
michael@0:         , mFB(fb)
michael@0:         , mDepthRB(depthRB)
michael@0:         , mStencilRB(stencilRB)
michael@0:         , mSurf(surf)
michael@0:     {}
michael@0: 
michael@0: public:
michael@0:     virtual ~ReadBuffer();
michael@0: 
michael@0:     // Cannot attach a surf of a different AttachType or Size than before.
michael@0:     void Attach(SharedSurface_GL* surf);
michael@0: 
michael@0:     const gfx::IntSize& Size() const;
michael@0: 
michael@0:     GLuint FB() const {
michael@0:         return mFB;
michael@0:     }
michael@0: 
michael@0:     SharedSurface_GL* SharedSurf() const {
michael@0:         return mSurf;
michael@0:     }
michael@0: };
michael@0: 
michael@0: 
michael@0: class GLScreenBuffer
michael@0: {
michael@0: protected:
michael@0:     typedef class gfx::SurfaceStream SurfaceStream;
michael@0:     typedef class gfx::SharedSurface SharedSurface;
michael@0:     typedef gfx::SurfaceStreamType SurfaceStreamType;
michael@0:     typedef gfx::SharedSurfaceType SharedSurfaceType;
michael@0:     typedef struct gfx::SurfaceCaps SurfaceCaps;
michael@0: 
michael@0: public:
michael@0:     // Infallible.
michael@0:     static GLScreenBuffer* Create(GLContext* gl,
michael@0:                                   const gfx::IntSize& size,
michael@0:                                   const SurfaceCaps& caps);
michael@0: 
michael@0: protected:
michael@0:     GLContext* const mGL;         // Owns us.
michael@0:     SurfaceCaps mCaps;
michael@0:     SurfaceFactory_GL* mFactory;  // Owned by us.
michael@0:     RefPtr<SurfaceStream> mStream;
michael@0: 
michael@0:     DrawBuffer* mDraw;            // Owned by us.
michael@0:     ReadBuffer* mRead;            // Owned by us.
michael@0: 
michael@0:     bool mNeedsBlit;
michael@0: 
michael@0:     // Below are the parts that help us pretend to be framebuffer 0:
michael@0:     GLuint mUserDrawFB;
michael@0:     GLuint mUserReadFB;
michael@0:     GLuint mInternalDrawFB;
michael@0:     GLuint mInternalReadFB;
michael@0: 
michael@0: #ifdef DEBUG
michael@0:     bool mInInternalMode_DrawFB;
michael@0:     bool mInInternalMode_ReadFB;
michael@0: #endif
michael@0: 
michael@0:     GLScreenBuffer(GLContext* gl,
michael@0:                    const SurfaceCaps& caps,
michael@0:                    SurfaceFactory_GL* factory,
michael@0:                    SurfaceStream* stream)
michael@0:         : mGL(gl)
michael@0:         , mCaps(caps)
michael@0:         , mFactory(factory)
michael@0:         , mStream(stream)
michael@0:         , mDraw(nullptr)
michael@0:         , mRead(nullptr)
michael@0:         , mNeedsBlit(true)
michael@0:         , mUserDrawFB(0)
michael@0:         , mUserReadFB(0)
michael@0:         , mInternalDrawFB(0)
michael@0:         , mInternalReadFB(0)
michael@0: #ifdef DEBUG
michael@0:         , mInInternalMode_DrawFB(true)
michael@0:         , mInInternalMode_ReadFB(true)
michael@0: #endif
michael@0:     {}
michael@0: 
michael@0: public:
michael@0:     virtual ~GLScreenBuffer();
michael@0: 
michael@0:     SurfaceStream* Stream() const {
michael@0:         return mStream;
michael@0:     }
michael@0: 
michael@0:     SurfaceFactory_GL* Factory() const {
michael@0:         return mFactory;
michael@0:     }
michael@0: 
michael@0:     SharedSurface_GL* SharedSurf() const {
michael@0:         MOZ_ASSERT(mRead);
michael@0:         return mRead->SharedSurf();
michael@0:     }
michael@0: 
michael@0:     bool PreserveBuffer() const {
michael@0:         return mCaps.preserve;
michael@0:     }
michael@0: 
michael@0:     const SurfaceCaps& Caps() const {
michael@0:         return mCaps;
michael@0:     }
michael@0: 
michael@0:     GLuint DrawFB() const {
michael@0:         if (!mDraw)
michael@0:             return ReadFB();
michael@0: 
michael@0:         return mDraw->FB();
michael@0:     }
michael@0: 
michael@0:     GLuint ReadFB() const {
michael@0:         return mRead->FB();
michael@0:     }
michael@0: 
michael@0:     void DeletingFB(GLuint fb);
michael@0: 
michael@0:     const gfx::IntSize& Size() const {
michael@0:         MOZ_ASSERT(mRead);
michael@0:         MOZ_ASSERT(!mDraw || mDraw->Size() == mRead->Size());
michael@0:         return mRead->Size();
michael@0:     }
michael@0: 
michael@0:     void BindAsFramebuffer(GLContext* const gl, GLenum target) const;
michael@0: 
michael@0:     void RequireBlit();
michael@0:     void AssureBlitted();
michael@0:     void AfterDrawCall();
michael@0:     void BeforeReadCall();
michael@0: 
michael@0:     /**
michael@0:      * Attempts to read pixels from the current bound framebuffer, if
michael@0:      * it is backed by a SharedSurface_GL.
michael@0:      *
michael@0:      * Returns true if the pixel data has been read back, false
michael@0:      * otherwise.
michael@0:      */
michael@0:     bool ReadPixels(GLint x, GLint y, GLsizei width, GLsizei height,
michael@0:                     GLenum format, GLenum type, GLvoid *pixels);
michael@0: 
michael@0:     /* Morph swaps out our SurfaceStream mechanism and replaces it with
michael@0:      * one best suited to our platform and compositor configuration.
michael@0:      *
michael@0:      * Must be called on the producing thread.
michael@0:      * We haven't made any guarantee that rendering is actually
michael@0:      * done when Morph is run, just that it can't run concurrently
michael@0:      * with rendering. This means that we can't just drop the contents
michael@0:      * of the buffer, since we may only be partially done rendering.
michael@0:      *
michael@0:      * Once you pass newFactory into Morph, newFactory will be owned by
michael@0:      * GLScreenBuffer, so `forget` any references to it that still exist.
michael@0:      */
michael@0:     void Morph(SurfaceFactory_GL* newFactory, SurfaceStreamType streamType);
michael@0: 
michael@0: protected:
michael@0:     // Returns false on error or inability to resize.
michael@0:     bool Swap(const gfx::IntSize& size);
michael@0: 
michael@0: public:
michael@0:     bool PublishFrame(const gfx::IntSize& size);
michael@0: 
michael@0:     bool Resize(const gfx::IntSize& size);
michael@0: 
michael@0:     void Readback(SharedSurface_GL* src, gfx::DataSourceSurface* dest);
michael@0:     void DeprecatedReadback(SharedSurface_GL* src, gfxImageSurface* dest);
michael@0: 
michael@0: protected:
michael@0:     void Attach(SharedSurface* surface, const gfx::IntSize& size);
michael@0: 
michael@0:     DrawBuffer* CreateDraw(const gfx::IntSize& size);
michael@0:     ReadBuffer* CreateRead(SharedSurface_GL* surf);
michael@0: 
michael@0: public:
michael@0:     /* `fb` in these functions is the framebuffer the GLContext is hoping to
michael@0:      * bind. When this is 0, we intercept the call and bind our own
michael@0:      * framebuffers. As a client of these functions, just bind 0 when you want
michael@0:      * to draw to the default framebuffer/'screen'.
michael@0:      */
michael@0:     void BindFB(GLuint fb);
michael@0:     void BindDrawFB(GLuint fb);
michael@0:     void BindReadFB(GLuint fb);
michael@0:     GLuint GetFB() const;
michael@0:     GLuint GetDrawFB() const;
michael@0:     GLuint GetReadFB() const;
michael@0: 
michael@0:     // Here `fb` is the actual framebuffer you want bound. Binding 0 will
michael@0:     // bind the (generally useless) default framebuffer.
michael@0:     void BindDrawFB_Internal(GLuint fb);
michael@0:     void BindReadFB_Internal(GLuint fb);
michael@0: };
michael@0: 
michael@0: }   // namespace gl
michael@0: }   // namespace mozilla
michael@0: 
michael@0: #endif  // SCREEN_BUFFER_H_