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 "cc/geometry_binding.h"
   6
   7 #include "cc/gl_renderer.h" // For the GLC() macro.
   8 #include "third_party/WebKit/Source/Platform/chromium/public/WebGraphicsContext3D.h"
   9 #include "third_party/khronos/GLES2/gl2.h"
  10 #include "ui/gfx/rect_f.h"
  11
  12 namespace cc {
  13
  14 GeometryBinding::GeometryBinding(WebKit::WebGraphicsContext3D* context, const gfx::RectF& quadVertexRect)
  15     : m_context(context)
  16     , m_quadVerticesVbo(0)
  17     , m_quadElementsVbo(0)
  18     , m_initialized(false)
  19 {
  20     float vertices[] = { quadVertexRect.x(), quadVertexRect.bottom(), 0.0f, 0.0f,  1.0f,
  21                          quadVertexRect.x(), quadVertexRect.y(), 0.0f, 0.0f,  0.0f,
  22                          quadVertexRect.right(), quadVertexRect.y(), 0.0f, 1.0f,  0.0f,
  23                          quadVertexRect.right(), quadVertexRect.bottom(), 0.0f, 1.0f,  1.0f };
  24
  25     struct Vertex {
  26         float a_position[3];
  27         float a_texCoord[2];
  28         float a_index; // index of the vertex, divide by 4 to have the matrix for this quad
  29     };
  30     struct Quad { Vertex v0, v1, v2, v3; };
  31     struct QuadIndex { uint16_t data[6]; };
  32
  33     COMPILE_ASSERT(sizeof(Quad) == 24 * sizeof(float), struct_is_densely_packed);
  34     COMPILE_ASSERT(sizeof(QuadIndex) == 6 * sizeof(uint16_t), struct_is_densely_packed);
  35
  36     Quad quad_list[8];
  37     QuadIndex quad_index_list[8];
  38     for (int i = 0; i < 8; i++) {
  39         Vertex v0 = { quadVertexRect.x()    , quadVertexRect.bottom(), 0.0f,  0.0f, 1.0f, i * 4.0f + 0.0f };
  40         Vertex v1 = { quadVertexRect.x()    , quadVertexRect.y()     , 0.0f,  0.0f, 0.0f, i * 4.0f + 1.0f };
  41         Vertex v2 = { quadVertexRect.right(), quadVertexRect.y()     , 0.0f,  1.0f, 0.0f, i * 4.0f + 2.0f };
  42         Vertex v3 = { quadVertexRect.right(), quadVertexRect.bottom(), 0.0f,  1.0f, 1.0f, i * 4.0f + 3.0f };
  43         Quad x = { v0, v1, v2, v3 };
  44         quad_list[i] = x;
  45         QuadIndex y = { 0 + 4 * i, 1 + 4 * i, 2 + 4 * i, 3 + 4 * i, 0 + 4 * i, 2 + 4 * i };
  46         quad_index_list[i] = y;
  47     }
  48
  49     GLC(m_context, m_quadVerticesVbo = m_context->createBuffer());
  50     GLC(m_context, m_quadElementsVbo = m_context->createBuffer());
  51     GLC(m_context, m_quadListVerticesVbo = m_context->createBuffer());
  52     GLC(m_context, m_context->bindBuffer(GL_ARRAY_BUFFER, m_quadVerticesVbo));
  53     GLC(m_context, m_context->bufferData(GL_ARRAY_BUFFER, sizeof(quad_list), quad_list, GL_STATIC_DRAW));
  54     GLC(m_context, m_context->bindBuffer(GL_ELEMENT_ARRAY_BUFFER, m_quadElementsVbo));
  55     GLC(m_context, m_context->bufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(quad_index_list), quad_index_list, GL_STATIC_DRAW));
  56
  57     m_initialized = true;
  58 }
  59
  60 GeometryBinding::~GeometryBinding()
  61 {
  62     GLC(m_context, m_context->deleteBuffer(m_quadVerticesVbo));
  63     GLC(m_context, m_context->deleteBuffer(m_quadElementsVbo));
  64 }
  65
  66 void GeometryBinding::prepareForDraw()
  67 {
  68     GLC(m_context, m_context->bindBuffer(GL_ELEMENT_ARRAY_BUFFER, quadElementsVbo()));
  69
  70     GLC(m_context, m_context->bindBuffer(GL_ARRAY_BUFFER, quadVerticesVbo()));
  71     GLC(m_context, m_context->vertexAttribPointer(positionAttribLocation(), 3, GL_FLOAT, false, 6 * sizeof(float), 0));
  72     GLC(m_context, m_context->vertexAttribPointer(texCoordAttribLocation(), 2, GL_FLOAT, false, 6 * sizeof(float), 3 * sizeof(float)));
  73     GLC(m_context, m_context->vertexAttribPointer(triangleIndexAttribLocation(), 1, GL_FLOAT, false, 6 * sizeof(float), 5 * sizeof(float)));
  74     GLC(m_context, m_context->enableVertexAttribArray(positionAttribLocation()));
  75     GLC(m_context, m_context->enableVertexAttribArray(texCoordAttribLocation()));
  76     GLC(m_context, m_context->enableVertexAttribArray(triangleIndexAttribLocation()));
  77 }
  78
  79 }  // namespace cc