cc/CCLayerQuad.cpp

   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
   6 #include "config.h"
   7
   8 #if USE(ACCELERATED_COMPOSITING)
   9
  10 #include "CCLayerQuad.h"
  11
  12 namespace cc {
  13
  14 CCLayerQuad::Edge::Edge(const FloatPoint& p, const FloatPoint& q)
  15 {
  16     ASSERT(p != q);
  17
  18     FloatPoint tangent(p.y() - q.y(), q.x() - p.x());
  19     float cross2 = p.x() * q.y() - q.x() * p.y();
  20
  21     set(tangent.x(), tangent.y(), cross2);
  22     scale(1.0f / tangent.length());
  23 }
  24
  25 CCLayerQuad::CCLayerQuad(const FloatQuad& quad)
  26 {
  27     // Create edges.
  28     m_left = Edge(quad.p4(), quad.p1());
  29     m_right = Edge(quad.p2(), quad.p3());
  30     m_top = Edge(quad.p1(), quad.p2());
  31     m_bottom = Edge(quad.p3(), quad.p4());
  32
  33     float sign = quad.isCounterclockwise() ? -1 : 1;
  34     m_left.scale(sign);
  35     m_right.scale(sign);
  36     m_top.scale(sign);
  37     m_bottom.scale(sign);
  38 }
  39
  40 FloatQuad CCLayerQuad::floatQuad() const
  41 {
  42     return FloatQuad(m_left.intersect(m_top),
  43                      m_top.intersect(m_right),
  44                      m_right.intersect(m_bottom),
  45                      m_bottom.intersect(m_left));
  46 }
  47
  48 void CCLayerQuad::toFloatArray(float flattened[12]) const
  49 {
  50     flattened[0] = m_left.x();
  51     flattened[1] = m_left.y();
  52     flattened[2] = m_left.z();
  53     flattened[3] = m_top.x();
  54     flattened[4] = m_top.y();
  55     flattened[5] = m_top.z();
  56     flattened[6] = m_right.x();
  57     flattened[7] = m_right.y();
  58     flattened[8] = m_right.z();
  59     flattened[9] = m_bottom.x();
  60     flattened[10] = m_bottom.y();
  61     flattened[11] = m_bottom.z();
  62 }
  63
  64 } // namespace cc
  65
  66 #endif // USE(ACCELERATED_COMPOSITING)