cc/draw_properties.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 CC_DRAW_PROPERTIES_H_
   6 #define CC_DRAW_PROPERTIES_H_
   7
   8 #include "base/memory/scoped_ptr.h"
   9 #include "ui/gfx/rect.h"
  10 #include "ui/gfx/transform.h"
  11
  12 namespace cc {
  13
  14 // Container for properties that layers need to compute before they can be
  15 // drawn.
  16 template<typename LayerType, typename RenderSurfaceType>
  17 struct CC_EXPORT DrawProperties {
  18     DrawProperties()
  19         : opacity(0)
  20         , opacity_is_animating(false)
  21         , screen_space_opacity_is_animating(false)
  22         , target_space_transform_is_animating(false)
  23         , screen_space_transform_is_animating(false)
  24         , can_use_lcd_text(false)
  25         , is_clipped(false)
  26         , render_target(0)
  27         , contents_scale_x(1)
  28         , contents_scale_y(1)
  29         , num_descendants_that_draw_content(0)
  30         , descendants_can_clip_selves(false)
  31     {
  32     }
  33
  34     // Transforms objects from content space to target surface space, where
  35     // this layer would be drawn.
  36     gfx::Transform target_space_transform;
  37
  38     // Transforms objects from content space to screen space (viewport space).
  39     gfx::Transform screen_space_transform;
  40
  41     // DrawProperties::opacity may be different than LayerType::opacity,
  42     // particularly in the case when a renderSurface re-parents the layer's
  43     // opacity, or when opacity is compounded by the hierarchy.
  44     float opacity;
  45
  46     // XXXIsAnimating flags are used to indicate whether the drawProperties
  47     // are actually meaningful on the main thread. When the properties are
  48     // animating, the main thread may not have the same values that are used
  49     // to draw.
  50     bool opacity_is_animating;
  51     bool screen_space_opacity_is_animating;
  52     bool target_space_transform_is_animating;
  53     bool screen_space_transform_is_animating;
  54
  55     // True if the layer can use LCD text.
  56     bool can_use_lcd_text;
  57
  58     // True if the layer needs to be clipped by clipRect.
  59     bool is_clipped;
  60
  61     // The layer whose coordinate space this layer draws into. This can be
  62     // either the same layer (m_drawProperties.render_target == this) or an
  63     // ancestor of this layer.
  64     LayerType* render_target;
  65
  66     // The surface that this layer and its subtree would contribute to.
  67     scoped_ptr<RenderSurfaceType> render_surface;
  68
  69     // This rect is in the layer's content space.
  70     gfx::Rect visible_content_rect;
  71
  72     // In target surface space, the rect that encloses the clipped, drawable
  73     // content of the layer.
  74     gfx::Rect drawable_content_rect;
  75
  76     // In target surface space, the original rect that clipped this
  77     // layer. This value is used to avoid unnecessarily changing GL scissor
  78     // state.
  79     gfx::Rect clip_rect;
  80
  81     // The scale used to move between layer space and content space, and bounds
  82     // of the space. One is always a function of the other, but which one
  83     // depends on the layer type. For picture layers, this is an ideal scale,
  84     // and not always the one used.
  85     float contents_scale_x;
  86     float contents_scale_y;
  87     gfx::Size content_bounds;
  88
  89     // Does not include this layer itself, only its children and descendants.
  90     int num_descendants_that_draw_content;
  91
  92     // If true, every descendant in the sub-tree can clip itself without the
  93     // need to use hardware sissoring or a new render target.
  94     bool descendants_can_clip_selves;
  95 };
  96
  97 }  // namespace cc
  98
  99 #endif  // CC_DRAW_PROPERTIES_H_