cc/output/static_geometry_binding.cc

   1 // Copyright 2015 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/output/static_geometry_binding.h"
   6
   7 #include "gpu/command_buffer/client/gles2_interface.h"
   8 #include "ui/gfx/geometry/rect_f.h"
   9
  10 namespace cc {
  11
  12 StaticGeometryBinding::StaticGeometryBinding(gpu::gles2::GLES2Interface* gl,
  13                                              const gfx::RectF& quad_vertex_rect)
  14     : gl_(gl), quad_vertices_vbo_(0), quad_elements_vbo_(0) {
  15   GeometryBindingQuad quads[8];
  16   GeometryBindingQuadIndex quad_indices[8];
  17
  18   static_assert(sizeof(GeometryBindingQuad) == 24 * sizeof(float),
  19                 "struct Quad should be densely packed");
  20   static_assert(sizeof(GeometryBindingQuadIndex) == 6 * sizeof(uint16_t),
  21                 "struct QuadIndex should be densely packed");
  22
  23   for (size_t i = 0; i < 8; i++) {
  24     GeometryBindingVertex v0 = {
  25         {quad_vertex_rect.x(), quad_vertex_rect.bottom(), 0.0f},
  26         {0.0f, 1.0f},
  27         i * 4.0f + 0.0f};
  28     GeometryBindingVertex v1 = {
  29         {quad_vertex_rect.x(), quad_vertex_rect.y(), 0.0f},
  30         {0.0f, 0.0f},
  31         i * 4.0f + 1.0f};
  32     GeometryBindingVertex v2 = {
  33         {quad_vertex_rect.right(), quad_vertex_rect.y(), 0.0f},
  34         {1.0f, 0.0f},
  35         i * 4.0f + 2.0f};
  36     GeometryBindingVertex v3 = {
  37         {quad_vertex_rect.right(), quad_vertex_rect.bottom(), 0.0f},
  38         {1.0f, 1.0f},
  39         i * 4.0f + 3.0f};
  40     GeometryBindingQuad x(v0, v1, v2, v3);
  41     quads[i] = x;
  42     GeometryBindingQuadIndex y(
  43         static_cast<uint16>(0 + 4 * i), static_cast<uint16>(1 + 4 * i),
  44         static_cast<uint16>(2 + 4 * i), static_cast<uint16>(3 + 4 * i),
  45         static_cast<uint16>(0 + 4 * i), static_cast<uint16>(2 + 4 * i));
  46     quad_indices[i] = y;
  47   }
  48
  49   gl_->GenBuffers(1, &quad_vertices_vbo_);
  50   gl_->GenBuffers(1, &quad_elements_vbo_);
  51
  52   gl_->BindBuffer(GL_ARRAY_BUFFER, quad_vertices_vbo_);
  53   gl_->BufferData(GL_ARRAY_BUFFER, sizeof(GeometryBindingQuad) * 8, quads,
  54                   GL_STATIC_DRAW);
  55
  56   gl_->BindBuffer(GL_ELEMENT_ARRAY_BUFFER, quad_elements_vbo_);
  57   gl_->BufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(GeometryBindingQuadIndex) * 8,
  58                   &quad_indices, GL_STATIC_DRAW);
  59 }
  60
  61 StaticGeometryBinding::~StaticGeometryBinding() {
  62   gl_->DeleteBuffers(1, &quad_vertices_vbo_);
  63   gl_->DeleteBuffers(1, &quad_elements_vbo_);
  64 }
  65
  66 void StaticGeometryBinding::PrepareForDraw() {
  67   SetupGLContext(gl_, quad_elements_vbo_, quad_vertices_vbo_);
  68 }
  69
  70 }  // namespace cc