cc/layer_quad.cc

   1 // Copyright 2011 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 #include "cc/layer_quad.h"
   6
   7 #include "base/logging.h"
   8 #include "ui/gfx/quad_f.h"
   9
  10 namespace cc {
  11
  12 LayerQuad::Edge::Edge(const gfx::PointF& p, const gfx::PointF& q)
  13 {
  14     DCHECK(p != q);
  15
  16     gfx::Vector2dF tangent(p.y() - q.y(), q.x() - p.x());
  17     float cross2 = p.x() * q.y() - q.x() * p.y();
  18
  19     set(tangent.x(), tangent.y(), cross2);
  20     scale(1.0f / tangent.Length());
  21 }
  22
  23 LayerQuad::LayerQuad(const gfx::QuadF& quad)
  24 {
  25     // Create edges.
  26     m_left = Edge(quad.p4(), quad.p1());
  27     m_right = Edge(quad.p2(), quad.p3());
  28     m_top = Edge(quad.p1(), quad.p2());
  29     m_bottom = Edge(quad.p3(), quad.p4());
  30
  31     float sign = quad.IsCounterClockwise() ? -1 : 1;
  32     m_left.scale(sign);
  33     m_right.scale(sign);
  34     m_top.scale(sign);
  35     m_bottom.scale(sign);
  36 }
  37
  38 LayerQuad::LayerQuad(const Edge& left, const Edge& top, const Edge& right, const Edge& bottom)
  39     : m_left(left)
  40     , m_top(top)
  41     , m_right(right)
  42     , m_bottom(bottom)
  43 {
  44 }
  45
  46 gfx::QuadF LayerQuad::ToQuadF() const
  47 {
  48     return gfx::QuadF(m_left.intersect(m_top),
  49                      m_top.intersect(m_right),
  50                      m_right.intersect(m_bottom),
  51                      m_bottom.intersect(m_left));
  52 }
  53
  54 void LayerQuad::toFloatArray(float flattened[12]) const
  55 {
  56     flattened[0] = m_left.x();
  57     flattened[1] = m_left.y();
  58     flattened[2] = m_left.z();
  59     flattened[3] = m_top.x();
  60     flattened[4] = m_top.y();
  61     flattened[5] = m_top.z();
  62     flattened[6] = m_right.x();
  63     flattened[7] = m_right.y();
  64     flattened[8] = m_right.z();
  65     flattened[9] = m_bottom.x();
  66     flattened[10] = m_bottom.y();
  67     flattened[11] = m_bottom.z();
  68 }
  69
  70 }  // namespace cc