cc/CCDrawQuad.h

   1 // Copyright 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 CCDrawQuad_h
   6 #define CCDrawQuad_h
   7
   8 #include "CCSharedQuadState.h"
   9
  10 namespace cc {
  11
  12 // WARNING! All CCXYZDrawQuad classes must remain PODs (plain old data).
  13 // They are intended to be "serializable" by copying their raw bytes, so they
  14 // must not contain any non-bit-copyable member variables!
  15 //
  16 // Furthermore, the class members need to be packed so they are aligned
  17 // properly and don't have paddings/gaps, otherwise memory check tools
  18 // like Valgrind will complain about uninitialized memory usage when
  19 // transferring these classes over the wire.
  20 #pragma pack(push, 4)
  21
  22 // CCDrawQuad is a bag of data used for drawing a quad. Because different
  23 // materials need different bits of per-quad data to render, classes that derive
  24 // from CCDrawQuad store additional data in their derived instance. The Material
  25 // enum is used to "safely" downcast to the derived class.
  26 class CCDrawQuad {
  27 public:
  28     enum Material {
  29         Invalid,
  30         Checkerboard,
  31         DebugBorder,
  32         IOSurfaceContent,
  33         RenderPass,
  34         TextureContent,
  35         SolidColor,
  36         TiledContent,
  37         YUVVideoContent,
  38         StreamVideoContent,
  39     };
  40
  41     IntRect quadRect() const { return m_quadRect; }
  42     const WebKit::WebTransformationMatrix& quadTransform() const { return m_sharedQuadState->quadTransform; }
  43     IntRect visibleContentRect() const { return m_sharedQuadState->visibleContentRect; }
  44     IntRect clippedRectInTarget() const { return m_sharedQuadState->clippedRectInTarget; }
  45     float opacity() const { return m_sharedQuadState->opacity; }
  46     // For the purposes of blending, what part of the contents of this quad are opaque?
  47     IntRect opaqueRect() const;
  48     bool needsBlending() const { return m_needsBlending || !opaqueRect().contains(m_quadVisibleRect); }
  49
  50     // Allows changing the rect that gets drawn to make it smaller. Parameter passed
  51     // in will be clipped to quadRect().
  52     void setQuadVisibleRect(const IntRect&);
  53     IntRect quadVisibleRect() const { return m_quadVisibleRect; }
  54     bool isDebugQuad() const { return m_material == DebugBorder; }
  55
  56     Material material() const { return m_material; }
  57
  58     // Returns transfer size of this object based on the derived class (by
  59     // looking at the material type).
  60     unsigned size() const;
  61
  62     PassOwnPtr<CCDrawQuad> copy(const CCSharedQuadState* copiedSharedQuadState) const;
  63
  64     const CCSharedQuadState* sharedQuadState() const { return m_sharedQuadState; }
  65     int sharedQuadStateId() const { return m_sharedQuadStateId; }
  66     void setSharedQuadState(const CCSharedQuadState*);
  67
  68 protected:
  69     CCDrawQuad(const CCSharedQuadState*, Material, const IntRect&);
  70
  71     // Stores state common to a large bundle of quads; kept separate for memory
  72     // efficiency. There is special treatment to reconstruct these pointers
  73     // during serialization.
  74     const CCSharedQuadState* m_sharedQuadState;
  75     int m_sharedQuadStateId;
  76
  77     Material m_material;
  78     IntRect m_quadRect;
  79     IntRect m_quadVisibleRect;
  80
  81     // By default, the shared quad state determines whether or not this quad is
  82     // opaque or needs blending. Derived classes can override with these
  83     // variables.
  84     bool m_quadOpaque;
  85     bool m_needsBlending;
  86
  87     // Be default, this rect is empty. It is used when the shared quad state and above
  88     // variables determine that the quad is not fully opaque but may be partially opaque.
  89     IntRect m_opaqueRect;
  90 };
  91
  92 #pragma pack(pop)
  93
  94 }
  95
  96 #endif