ui/surface/accelerated_surface_mac.h

   1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef UI_SURFACE_ACCELERATED_SURFACE_MAC_H_
   6 #define UI_SURFACE_ACCELERATED_SURFACE_MAC_H_
   7
   8 #include <CoreFoundation/CoreFoundation.h>
   9 #include <IOSurface/IOSurfaceAPI.h>
  10
  11 #include "base/callback.h"
  12 #include "base/mac/scoped_cftyperef.h"
  13 #include "base/memory/scoped_ptr.h"
  14 #include "ui/gfx/geometry/rect.h"
  15 #include "ui/gfx/geometry/size.h"
  16 #include "ui/gl/gl_context.h"
  17 #include "ui/gl/gl_surface.h"
  18 #include "ui/gl/gpu_preference.h"
  19 #include "ui/surface/surface_export.h"
  20
  21 // Should not include GL headers in a header file. Forward declare these types
  22 // instead.
  23 typedef struct _CGLContextObject* CGLContextObj;
  24 typedef unsigned int GLenum;
  25 typedef unsigned int GLuint;
  26
  27 namespace gfx {
  28 class Rect;
  29 }
  30
  31 // Encapsulates an accelerated GL surface that can be shared across processes
  32 // on systems that support it (10.6 and above).
  33
  34 class SURFACE_EXPORT AcceleratedSurface {
  35  public:
  36   AcceleratedSurface();
  37   virtual ~AcceleratedSurface();
  38
  39   // Set up internal buffers. |share_context|, if non-NULL, is a context
  40   // with which the internally created OpenGL context shares textures and
  41   // other resources. |allocate_fbo| indicates whether or not this surface
  42   // should allocate an offscreen frame buffer object (FBO) internally. If
  43   // not, then the user is expected to allocate one. NOTE that allocating
  44   // an FBO internally does NOT work properly with client code which uses
  45   // OpenGL (i.e., via GLES2 command buffers), because the GLES2
  46   // implementation does not know to bind the accelerated surface's
  47   // internal FBO when the default FBO is bound. |gpu_preference| indicates
  48   // the GPU preference for the internally allocated GLContext. If
  49   // |share_context| is non-NULL, then on platforms supporting dual GPUs,
  50   // its GPU preference must match the passed one. Returns false upon
  51   // failure.
  52   bool Initialize(gfx::GLContext* share_context,
  53                   bool allocate_fbo,
  54                   gfx::GpuPreference gpu_preference);
  55   // Tear down. Must be called before destructor to prevent leaks.
  56   void Destroy();
  57
  58   // These methods are used only once the accelerated surface is initialized.
  59
  60   // Sets the accelerated surface to the given size, creating a new one if
  61   // the height or width changes. Returns a unique id of the IOSurface to
  62   // which the surface is bound, or 0 if no changes were made or an error
  63   // occurred. MakeCurrent() will have been called on the new surface.
  64   uint32 SetSurfaceSize(const gfx::Size& size);
  65
  66   // Returns the id of this surface's IOSurface.
  67   uint32 GetSurfaceId();
  68
  69   // Sets the GL context to be the current one for drawing. Returns true if
  70   // it succeeded.
  71   bool MakeCurrent();
  72   // Clear the surface to be transparent. Assumes the caller has already called
  73   // MakeCurrent().
  74   void Clear(const gfx::Rect& rect);
  75   // Call after making changes to the surface which require a visual update.
  76   // Makes the rendering show up in other processes. Assumes the caller has
  77   // already called MakeCurrent().
  78   //
  79   // If this AcceleratedSurface is configured with its own FBO, then
  80   // this call causes the color buffer to be transmitted. Otherwise,
  81   // it causes the frame buffer of the current GL context to be copied
  82   // into an internal texture via glCopyTexSubImage2D.
  83   //
  84   // The size of the rectangle copied is the size last specified via
  85   // SetSurfaceSize.  If another GL context than the one this
  86   // AcceleratedSurface contains is responsible for the production of
  87   // the pixels, then when this entry point is called, the color
  88   // buffer must be in a state where a glCopyTexSubImage2D is
  89   // legal. (For example, if using multisampled FBOs, the FBO must
  90   // have been resolved into a non-multisampled color texture.)
  91   // Additionally, in this situation, the contexts must share
  92   // server-side GL objects, so that this AcceleratedSurface's texture
  93   // is a legal name in the namespace of the current context.
  94   void SwapBuffers();
  95
  96   CGLContextObj context() {
  97     return static_cast<CGLContextObj>(gl_context_->GetHandle());
  98   }
  99
 100   // Get the accelerated surface size.
 101   gfx::Size GetSize() const { return surface_size_; }
 102
 103  private:
 104   // Helper function to generate names for the backing texture and FBO.  On
 105   // return, the resulting names can be attached to |fbo_|.  |target| is
 106   // the target type for the color buffer.
 107   void AllocateRenderBuffers(GLenum target, const gfx::Size& size);
 108
 109   // Helper function to attach the buffers previously allocated by a call to
 110   // AllocateRenderBuffers().  On return, |fbo_| can be used for
 111   // rendering.  |target| must be the same value as used in the call to
 112   // AllocateRenderBuffers().  Returns |true| if the resulting framebuffer
 113   // object is valid.
 114   bool SetupFrameBufferObject(GLenum target);
 115
 116   gfx::Size ClampToValidDimensions(const gfx::Size& size);
 117
 118   // The OpenGL context, and pbuffer drawable, used to transfer data
 119   // to the shared region (IOSurface).
 120   scoped_refptr<gfx::GLSurface> gl_surface_;
 121   scoped_refptr<gfx::GLContext> gl_context_;
 122   base::ScopedCFTypeRef<IOSurfaceRef> io_surface_;
 123
 124   // The id of |io_surface_| or 0 if that's NULL.
 125   uint32 io_surface_id_;
 126
 127   gfx::Size surface_size_;
 128   // It's important to avoid allocating zero-width or zero-height
 129   // IOSurfaces and textures on the Mac, so we clamp each to a minimum
 130   // of 1. This is the real size of the surface; surface_size_ is what
 131   // the user requested.
 132   gfx::Size real_surface_size_;
 133   // TODO(kbr): the FBO management should not be in this class at all.
 134   // However, if it is factored out, care needs to be taken to not
 135   // introduce another copy of the color data on the GPU; the direct
 136   // binding of the internal texture to the IOSurface saves a copy.
 137   bool allocate_fbo_;
 138   // This texture object is always allocated, regardless of whether
 139   // the user requests an FBO be allocated.
 140   GLuint texture_;
 141   // The FBO and renderbuffer are only allocated if allocate_fbo_ is
 142   // true.
 143   GLuint fbo_;
 144 };
 145
 146 #endif  // UI_SURFACE_ACCELERATED_SURFACE_MAC_H_