cc/quads/draw_polygon.h

   1 // Copyright 2014 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_QUADS_DRAW_POLYGON_H_
   6 #define CC_QUADS_DRAW_POLYGON_H_
   7
   8 #include <vector>
   9
  10 #include "cc/base/math_util.h"
  11 #include "cc/output/bsp_compare_result.h"
  12 #include "ui/gfx/geometry/point3_f.h"
  13 #include "ui/gfx/geometry/quad_f.h"
  14 #include "ui/gfx/geometry/rect_f.h"
  15 #include "ui/gfx/geometry/vector3d_f.h"
  16 #include "ui/gfx/transform.h"
  17
  18 namespace cc {
  19
  20 class DrawQuad;
  21
  22 class CC_EXPORT DrawPolygon {
  23  public:
  24   DrawPolygon();
  25   ~DrawPolygon();
  26
  27   DrawPolygon(const DrawQuad* original_ref,
  28               const std::vector<gfx::Point3F>& in_points,
  29               const gfx::Vector3dF& normal,
  30               int draw_order_index = 0);
  31   DrawPolygon(const DrawQuad* original_ref,
  32               const gfx::RectF& visible_content_rect,
  33               const gfx::Transform& transform,
  34               int draw_order_index = 0);
  35
  36   // Split takes this DrawPolygon and splits it into two pieces that are on
  37   // either side of |splitter|. Any edges of this polygon that cross the plane
  38   // of |splitter| will have an intersection point that is shared by both
  39   // polygons on either side.
  40   // Split will only return true if it determines that we got back 2
  41   // intersection points. Only when it returns true will front and back both be
  42   // valid new polygons that are on opposite sides of the splitting plane.
  43   bool Split(const DrawPolygon& splitter,
  44              scoped_ptr<DrawPolygon>* front,
  45              scoped_ptr<DrawPolygon>* back);
  46   float SignedPointDistance(const gfx::Point3F& point) const;
  47   // Checks polygon a against polygon b and returns which side it lies on, or
  48   // whether it crosses (necessitating a split in the BSP tree).
  49   static BspCompareResult SideCompare(const DrawPolygon& a,
  50                                       const DrawPolygon& b);
  51   void ToQuads2D(std::vector<gfx::QuadF>* quads) const;
  52   void TransformToScreenSpace(const gfx::Transform& transform);
  53   void TransformToLayerSpace(const gfx::Transform& inverse_transform);
  54
  55   const std::vector<gfx::Point3F>& points() const { return points_; }
  56   const gfx::Vector3dF& normal() const { return normal_; }
  57   const DrawQuad* original_ref() const { return original_ref_; }
  58   int order_index() const { return order_index_; }
  59   bool is_split() const { return is_split_; }
  60   scoped_ptr<DrawPolygon> CreateCopy();
  61
  62  private:
  63   void ApplyTransform(const gfx::Transform& transform);
  64   void ApplyTransformToNormal(const gfx::Transform& transform);
  65
  66   std::vector<gfx::Point3F> points_;
  67   // Normalized, necessitated by distance calculations and tests of coplanarity.
  68   gfx::Vector3dF normal_;
  69   // This is an index that can be used to test whether a quad comes before or
  70   // after another in document order, useful for tie-breaking when it comes
  71   // to coplanar surfaces.
  72   int order_index_;
  73   // The pointer to the original quad, which gives us all the drawing info
  74   // we need.
  75   // This DrawQuad is owned by the caller and its lifetime must be preserved
  76   // as long as this DrawPolygon is alive.
  77   const DrawQuad* original_ref_;
  78   bool is_split_;
  79 };
  80
  81 }  // namespace cc
  82
  83 #endif  // CC_QUADS_DRAW_POLYGON_H_