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// Copyright 2011 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "cc/output/geometry_binding.h"
#include "cc/output/gl_renderer.h" // For the GLC() macro.
#include "gpu/command_buffer/client/gles2_interface.h"
#include "ui/gfx/geometry/rect_f.h"
namespace cc {
GeometryBinding::GeometryBinding(gpu::gles2::GLES2Interface* gl,
const gfx::RectF& quad_vertex_rect)
: gl_(gl), quad_vertices_vbo_(0), quad_elements_vbo_(0) {
struct Vertex {
float a_position[3];
float a_texCoord[2];
// Index of the vertex, divide by 4 to have the matrix for this quad.
float a_index;
};
struct Quad {
Vertex v0, v1, v2, v3;
};
struct QuadIndex {
uint16 data[6];
};
COMPILE_ASSERT(sizeof(Quad) == 24 * sizeof(float), // NOLINT(runtime/sizeof)
struct_is_densely_packed);
COMPILE_ASSERT(
sizeof(QuadIndex) == 6 * sizeof(uint16_t), // NOLINT(runtime/sizeof)
struct_is_densely_packed);
Quad quad_list[8];
QuadIndex quad_index_list[8];
for (int i = 0; i < 8; i++) {
Vertex v0 = {{quad_vertex_rect.x(), quad_vertex_rect.bottom(), 0.0f, },
{0.0f, 1.0f, }, i * 4.0f + 0.0f};
Vertex v1 = {{quad_vertex_rect.x(), quad_vertex_rect.y(), 0.0f, },
{0.0f, 0.0f, }, i * 4.0f + 1.0f};
Vertex v2 = {{quad_vertex_rect.right(), quad_vertex_rect.y(), 0.0f, },
{1.0f, .0f, }, i * 4.0f + 2.0f};
Vertex v3 = {{quad_vertex_rect.right(), quad_vertex_rect.bottom(), 0.0f, },
{1.0f, 1.0f, }, i * 4.0f + 3.0f};
Quad x = {v0, v1, v2, v3};
quad_list[i] = x;
QuadIndex y = {
{static_cast<uint16>(0 + 4 * i), static_cast<uint16>(1 + 4 * i),
static_cast<uint16>(2 + 4 * i), static_cast<uint16>(3 + 4 * i),
static_cast<uint16>(0 + 4 * i), static_cast<uint16>(2 + 4 * i)}};
quad_index_list[i] = y;
}
gl_->GenBuffers(1, &quad_vertices_vbo_);
gl_->GenBuffers(1, &quad_elements_vbo_);
GLC(gl_, gl_->BindBuffer(GL_ARRAY_BUFFER, quad_vertices_vbo_));
GLC(gl_,
gl_->BufferData(
GL_ARRAY_BUFFER, sizeof(quad_list), quad_list, GL_STATIC_DRAW));
GLC(gl_, gl_->BindBuffer(GL_ELEMENT_ARRAY_BUFFER, quad_elements_vbo_));
GLC(gl_,
gl_->BufferData(GL_ELEMENT_ARRAY_BUFFER,
sizeof(quad_index_list),
quad_index_list,
GL_STATIC_DRAW));
}
GeometryBinding::~GeometryBinding() {
gl_->DeleteBuffers(1, &quad_vertices_vbo_);
gl_->DeleteBuffers(1, &quad_elements_vbo_);
}
void GeometryBinding::PrepareForDraw() {
GLC(gl_, gl_->BindBuffer(GL_ELEMENT_ARRAY_BUFFER, quad_elements_vbo_));
GLC(gl_, gl_->BindBuffer(GL_ARRAY_BUFFER, quad_vertices_vbo_));
// OpenGL defines the last parameter to VertexAttribPointer as type
// "const GLvoid*" even though it is actually an offset into the buffer
// object's data store and not a pointer to the client's address space.
const void* offsets[3] = {
0, reinterpret_cast<const void*>(
3 * sizeof(float)), // NOLINT(runtime/sizeof)
reinterpret_cast<const void*>(5 *
sizeof(float)), // NOLINT(runtime/sizeof)
};
GLC(gl_,
gl_->VertexAttribPointer(PositionAttribLocation(),
3,
GL_FLOAT,
false,
6 * sizeof(float), // NOLINT(runtime/sizeof)
offsets[0]));
GLC(gl_,
gl_->VertexAttribPointer(TexCoordAttribLocation(),
2,
GL_FLOAT,
false,
6 * sizeof(float), // NOLINT(runtime/sizeof)
offsets[1]));
GLC(gl_,
gl_->VertexAttribPointer(TriangleIndexAttribLocation(),
1,
GL_FLOAT,
false,
6 * sizeof(float), // NOLINT(runtime/sizeof)
offsets[2]));
GLC(gl_, gl_->EnableVertexAttribArray(PositionAttribLocation()));
GLC(gl_, gl_->EnableVertexAttribArray(TexCoordAttribLocation()));
GLC(gl_, gl_->EnableVertexAttribArray(TriangleIndexAttribLocation()));
}
} // namespace cc
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