cc/layers/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_LAYERS_DRAW_PROPERTIES_H_
   6 #define CC_LAYERS_DRAW_PROPERTIES_H_
   7
   8 #include "base/memory/scoped_ptr.h"
   9 #include "cc/trees/occlusion.h"
  10 #include "third_party/skia/include/core/SkXfermode.h"
  11 #include "ui/gfx/geometry/rect.h"
  12 #include "ui/gfx/transform.h"
  13
  14 namespace cc {
  15 class LayerImpl;
  16
  17 // Container for properties that layers need to compute before they can be
  18 // drawn.
  19 struct CC_EXPORT DrawProperties {
  20   DrawProperties();
  21   ~DrawProperties();
  22
  23   // Transforms objects from content space to target surface space, where
  24   // this layer would be drawn.
  25   gfx::Transform target_space_transform;
  26
  27   // Transforms objects from content space to screen space (viewport space).
  28   gfx::Transform screen_space_transform;
  29
  30   // Known occlusion above the layer mapped to the content space of the layer.
  31   Occlusion occlusion_in_content_space;
  32
  33   // DrawProperties::opacity may be different than LayerImpl::opacity,
  34   // particularly in the case when a RenderSurface re-parents the layer's
  35   // opacity, or when opacity is compounded by the hierarchy.
  36   float opacity;
  37
  38   // xxx_is_animating flags are used to indicate whether the DrawProperties
  39   // are actually meaningful on the main thread. When the properties are
  40   // animating, the main thread may not have the same values that are used
  41   // to draw.
  42   bool screen_space_transform_is_animating;
  43
  44   // True if the layer can use LCD text.
  45   bool can_use_lcd_text;
  46
  47   // The layer whose coordinate space this layer draws into. This can be
  48   // either the same layer (draw_properties_.render_target == this) or an
  49   // ancestor of this layer.
  50   LayerImpl* render_target;
  51
  52   // This rect is a bounding box around what part of the layer is visible, in
  53   // the layer's coordinate space.
  54   gfx::Rect visible_layer_rect;
  55
  56   // In target surface space, the rect that encloses the clipped, drawable
  57   // content of the layer.
  58   gfx::Rect drawable_content_rect;
  59
  60   // In target surface space, the original rect that clipped this layer. This
  61   // value is used to avoid unnecessarily changing GL scissor state.
  62   gfx::Rect clip_rect;
  63
  64   // Number of descendants with a clip parent that is our ancestor. NB - this
  65   // does not include our clip children because they are clipped by us.
  66   size_t num_unclipped_descendants;
  67
  68   // If true, the layer or some layer in its sub-tree has a CopyOutputRequest
  69   // present on it.
  70   bool layer_or_descendant_has_copy_request;
  71
  72   // If true, the layer or one of its descendants has a wheel or touch handler.
  73   bool layer_or_descendant_has_input_handler;
  74
  75   // This is true if the layer has any direct child that has a scroll parent.
  76   // This layer will not be the scroll parent in this case. This information
  77   // lets us avoid work in CalculateDrawPropertiesInternal -- if none of our
  78   // children have scroll parents, we will not need to recur out of order.
  79   bool has_child_with_a_scroll_parent;
  80
  81   // Each time we generate a new render surface layer list, an ID is used to
  82   // identify it. |last_drawn_render_surface_layer_list_id| is set to the ID
  83   // that marked the render surface layer list generation which last updated
  84   // these draw properties and determined that this layer will draw itself.
  85   // If these draw properties are not a part of the render surface layer list,
  86   // or the layer doesn't contribute anything, then this ID will be either out
  87   // of date or 0.
  88   int last_drawn_render_surface_layer_list_id;
  89
  90   // The maximum scale during the layers current animation at which content
  91   // should be rastered at to be crisp.
  92   float maximum_animation_contents_scale;
  93
  94   // The scale during the layer animation start at which content should be
  95   // rastered at to be crisp.
  96   float starting_animation_contents_scale;
  97 };
  98
  99 }  // namespace cc
 100
 101 #endif  // CC_LAYERS_DRAW_PROPERTIES_H_