Home | History | Annotate | Download | only in output 
      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/output/geometry_binding.h"
      6 
      7 #include "cc/output/gl_renderer.h"  // For the GLC() macro.
      8 #include "third_party/WebKit/public/platform/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,
     15                                  const gfx::RectF& quad_vertex_rect)
     16     : context_(context),
     17       quad_vertices_vbo_(0),
     18       quad_elements_vbo_(0) {
     19   struct Vertex {
     20     float a_position[3];
     21     float a_texCoord[2];
     22     // Index of the vertex, divide by 4 to have the matrix for this quad.
     23     float a_index;
     24   };
     25   struct Quad {
     26     Vertex v0, v1, v2, v3;
     27   };
     28   struct QuadIndex {
     29     uint16 data[6];
     30   };
     31 
     32   COMPILE_ASSERT(
     33       sizeof(Quad) == 24 * sizeof(float),  // NOLINT(runtime/sizeof)
     34       struct_is_densely_packed);
     35   COMPILE_ASSERT(
     36       sizeof(QuadIndex) == 6 * sizeof(uint16_t),  // NOLINT(runtime/sizeof)
     37       struct_is_densely_packed);
     38 
     39   Quad quad_list[8];
     40   QuadIndex quad_index_list[8];
     41   for (int i = 0; i < 8; i++) {
     42     Vertex v0 = { { quad_vertex_rect.x(), quad_vertex_rect.bottom(), 0.0f, },
     43                   { 0.0f, 1.0f, },
     44                   i * 4.0f + 0.0f };
     45     Vertex v1 = { { quad_vertex_rect.x(), quad_vertex_rect.y(), 0.0f, },
     46                   { 0.0f, 0.0f, },
     47                   i * 4.0f + 1.0f };
     48     Vertex v2 = { { quad_vertex_rect.right(), quad_vertex_rect.y(), 0.0f, },
     49                   { 1.0f, .0f, },
     50                   i * 4.0f + 2.0f };
     51     Vertex v3 = { { quad_vertex_rect.right(),
     52                     quad_vertex_rect.bottom(),
     53                     0.0f, },
     54                   { 1.0f, 1.0f, },
     55                   i * 4.0f + 3.0f };
     56     Quad x = { v0, v1, v2, v3 };
     57     quad_list[i] = x;
     58     QuadIndex y = { { static_cast<uint16>(0 + 4 * i),
     59                       static_cast<uint16>(1 + 4 * i),
     60                       static_cast<uint16>(2 + 4 * i),
     61                       static_cast<uint16>(3 + 4 * i),
     62                       static_cast<uint16>(0 + 4 * i),
     63                       static_cast<uint16>(2 + 4 * i) } };
     64     quad_index_list[i] = y;
     65   }
     66 
     67   GLC(context_, quad_vertices_vbo_ = context_->createBuffer());
     68   GLC(context_, quad_elements_vbo_ = context_->createBuffer());
     69   GLC(context_, context_->bindBuffer(GL_ARRAY_BUFFER, quad_vertices_vbo_));
     70   GLC(context_,
     71       context_->bufferData(
     72           GL_ARRAY_BUFFER, sizeof(quad_list), quad_list, GL_STATIC_DRAW));
     73   GLC(context_,
     74       context_->bindBuffer(GL_ELEMENT_ARRAY_BUFFER, quad_elements_vbo_));
     75   GLC(context_,
     76       context_->bufferData(GL_ELEMENT_ARRAY_BUFFER,
     77                            sizeof(quad_index_list),
     78                            quad_index_list,
     79                            GL_STATIC_DRAW));
     80 }
     81 
     82 GeometryBinding::~GeometryBinding() {
     83   GLC(context_, context_->deleteBuffer(quad_vertices_vbo_));
     84   GLC(context_, context_->deleteBuffer(quad_elements_vbo_));
     85 }
     86 
     87 void GeometryBinding::PrepareForDraw() {
     88   GLC(context_,
     89       context_->bindBuffer(GL_ELEMENT_ARRAY_BUFFER, quad_elements_vbo_));
     90 
     91   GLC(context_, context_->bindBuffer(GL_ARRAY_BUFFER, quad_vertices_vbo_));
     92   GLC(context_,
     93       context_->vertexAttribPointer(
     94           PositionAttribLocation(),
     95           3,
     96           GL_FLOAT,
     97           false,
     98           6 * sizeof(float),  // NOLINT(runtime/sizeof)
     99           0));
    100   GLC(context_,
    101       context_->vertexAttribPointer(
    102           TexCoordAttribLocation(),
    103           2,
    104           GL_FLOAT,
    105           false,
    106           6 * sizeof(float),  // NOLINT(runtime/sizeof)
    107           3 * sizeof(float)));  // NOLINT(runtime/sizeof)
    108   GLC(context_,
    109       context_->vertexAttribPointer(
    110           TriangleIndexAttribLocation(),
    111           1,
    112           GL_FLOAT,
    113           false,
    114           6 * sizeof(float),  // NOLINT(runtime/sizeof)
    115           5 * sizeof(float)));  // NOLINT(runtime/sizeof)
    116   GLC(context_, context_->enableVertexAttribArray(PositionAttribLocation()));
    117   GLC(context_, context_->enableVertexAttribArray(TexCoordAttribLocation()));
    118   GLC(context_,
    119       context_->enableVertexAttribArray(TriangleIndexAttribLocation()));
    120 }
    121 
    122 }  // namespace cc
    123