cc/geometry_binding.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 "config.h"
   6
   7 #include "cc/geometry_binding.h"
   8
   9 #include "cc/gl_renderer.h" // For the GLC() macro.
  10 #include "third_party/khronos/GLES2/gl2.h"
  11 #include "ui/gfx/rect_f.h"
  12 #include <public/WebGraphicsContext3D.h>
  13
  14 namespace cc {
  15
  16 GeometryBinding::GeometryBinding(WebKit::WebGraphicsContext3D* context, const gfx::RectF& quadVertexRect)
  17     : m_context(context)
  18     , m_quadVerticesVbo(0)
  19     , m_quadElementsVbo(0)
  20     , m_initialized(false)
  21 {
  22     // Vertex positions and texture coordinates for the 4 corners of a 1x1 quad.
  23     float vertices[] = { quadVertexRect.x(), quadVertexRect.bottom(), 0.0f, 0.0f,  1.0f,
  24                          quadVertexRect.x(), quadVertexRect.y(), 0.0f, 0.0f,  0.0f,
  25                          quadVertexRect.right(), quadVertexRect.y(), 0.0f, 1.0f,  0.0f,
  26                          quadVertexRect.right(),  quadVertexRect.bottom(), 0.0f, 1.0f,  1.0f };
  27     uint16_t indices[] = { 0, 1, 2, 0, 2, 3, // The two triangles that make up the layer quad.
  28                            0, 1, 2, 3}; // A line path for drawing the layer border.
  29
  30     GLC(m_context, m_quadVerticesVbo = m_context->createBuffer());
  31     GLC(m_context, m_quadElementsVbo = m_context->createBuffer());
  32     GLC(m_context, m_context->bindBuffer(GL_ARRAY_BUFFER, m_quadVerticesVbo));
  33     GLC(m_context, m_context->bufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW));
  34     GLC(m_context, m_context->bindBuffer(GL_ELEMENT_ARRAY_BUFFER, m_quadElementsVbo));
  35     GLC(m_context, m_context->bufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(indices), indices, GL_STATIC_DRAW));
  36
  37     m_initialized = true;
  38 }
  39
  40 GeometryBinding::~GeometryBinding()
  41 {
  42     GLC(m_context, m_context->deleteBuffer(m_quadVerticesVbo));
  43     GLC(m_context, m_context->deleteBuffer(m_quadElementsVbo));
  44 }
  45
  46 void GeometryBinding::prepareForDraw()
  47 {
  48     GLC(m_context, m_context->bindBuffer(GL_ARRAY_BUFFER, quadVerticesVbo()));
  49     GLC(m_context, m_context->bindBuffer(GL_ELEMENT_ARRAY_BUFFER, quadElementsVbo()));
  50     unsigned offset = 0;
  51     GLC(m_context, m_context->vertexAttribPointer(positionAttribLocation(), 3, GL_FLOAT, false, 5 * sizeof(float), offset));
  52     offset += 3 * sizeof(float);
  53     GLC(m_context, m_context->vertexAttribPointer(texCoordAttribLocation(), 2, GL_FLOAT, false, 5 * sizeof(float), offset));
  54     GLC(m_context, m_context->enableVertexAttribArray(positionAttribLocation()));
  55     GLC(m_context, m_context->enableVertexAttribArray(texCoordAttribLocation()));
  56 }
  57
  58 }  // namespace cc