cc/output/dynamic_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/dynamic_geometry_binding.h"
   6
   7 #include "gpu/command_buffer/client/gles2_interface.h"
   8 #include "ui/gfx/geometry/quad_f.h"
   9 #include "ui/gfx/geometry/rect_f.h"
  10
  11 namespace cc {
  12
  13 DynamicGeometryBinding::DynamicGeometryBinding(gpu::gles2::GLES2Interface* gl)
  14     : gl_(gl), quad_vertices_vbo_(0), quad_elements_vbo_(0) {
  15   GeometryBindingQuad quads[1];
  16   GeometryBindingQuadIndex quad_indices[1];
  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   gl_->GenBuffers(1, &quad_vertices_vbo_);
  24   gl_->GenBuffers(1, &quad_elements_vbo_);
  25
  26   gl_->BindBuffer(GL_ARRAY_BUFFER, quad_vertices_vbo_);
  27   gl_->BufferData(GL_ARRAY_BUFFER, sizeof(GeometryBindingQuad) * 1, quads,
  28                   GL_DYNAMIC_DRAW);
  29
  30   gl_->BindBuffer(GL_ELEMENT_ARRAY_BUFFER, quad_elements_vbo_);
  31   gl_->BufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(GeometryBindingQuadIndex) * 1,
  32                   &quad_indices, GL_DYNAMIC_DRAW);
  33 }
  34
  35 void DynamicGeometryBinding::InitializeCustomQuad(const gfx::QuadF& quad) {
  36   float uv[] = {0.0f, 0.0f, 1.0f, 0.0f, 1.0f, 1.0f, 0.0f, 1.0f};
  37   InitializeCustomQuadWithUVs(quad, uv);
  38 }
  39
  40 void DynamicGeometryBinding::InitializeCustomQuadWithUVs(const gfx::QuadF& quad,
  41                                                          const float uv[8]) {
  42   GeometryBindingVertex v0 = {
  43       {quad.p1().x(), quad.p1().y(), 0.0f}, {uv[0], uv[1]}, 0.0f};
  44   GeometryBindingVertex v1 = {
  45       {quad.p2().x(), quad.p2().y(), 0.0f}, {uv[2], uv[3]}, 1.0f};
  46   GeometryBindingVertex v2 = {
  47       {quad.p3().x(), quad.p3().y(), 0.0f}, {uv[4], uv[5]}, 2.0f};
  48   GeometryBindingVertex v3 = {
  49       {quad.p4().x(), quad.p4().y(), 0.0f}, {uv[6], uv[7]}, 3.0f};
  50
  51   GeometryBindingQuad local_quad = {v0, v1, v2, v3};
  52   GeometryBindingQuadIndex quad_index(
  53       static_cast<uint16>(0), static_cast<uint16>(1), static_cast<uint16>(2),
  54       static_cast<uint16>(3), static_cast<uint16>(0), static_cast<uint16>(2));
  55
  56   gl_->BufferSubData(GL_ARRAY_BUFFER, 0, sizeof(GeometryBindingQuad),
  57                      &local_quad);
  58   gl_->BufferSubData(GL_ELEMENT_ARRAY_BUFFER, 0,
  59                      sizeof(GeometryBindingQuadIndex), &quad_index);
  60 }
  61
  62 void DynamicGeometryBinding::PrepareForDraw() {
  63   SetupGLContext(gl_, quad_elements_vbo_, quad_vertices_vbo_);
  64 }
  65
  66 }  // namespace cc