1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
|
// Copyright 2014 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 "gpu/command_buffer/service/gles2_cmd_clear_framebuffer.h"
#include "base/basictypes.h"
#include "gpu/command_buffer/service/gl_utils.h"
#include "gpu/command_buffer/service/gles2_cmd_decoder.h"
namespace {
#define SHADER(src) \
"#ifdef GL_ES\n" \
"precision mediump float;\n" \
"#endif\n" #src
const char* g_vertex_shader_source = {
SHADER(
uniform float u_clear_depth;
attribute vec4 a_position;
void main(void) {
gl_Position = vec4(a_position.x, a_position.y, u_clear_depth, 1.0);
}
),
};
const char* g_fragment_shader_source = {
SHADER(
uniform vec4 u_clear_color;
void main(void) {
gl_FragColor = u_clear_color;
}
),
};
void CompileShader(GLuint shader, const char* shader_source) {
glShaderSource(shader, 1, &shader_source, 0);
glCompileShader(shader);
#if DCHECK_IS_ON
GLint compile_status = GL_FALSE;
glGetShaderiv(shader, GL_COMPILE_STATUS, &compile_status);
if (GL_TRUE != compile_status) {
char buffer[1024];
GLsizei length = 0;
glGetShaderInfoLog(shader, sizeof(buffer), &length, buffer);
std::string log(buffer, length);
DLOG(ERROR) << "Error compiling shader: " << log;
DLOG(ERROR) << "Shader compilation failure.";
}
#endif
}
} // namespace
namespace gpu {
ClearFramebufferResourceManager::ClearFramebufferResourceManager(
const gles2::GLES2Decoder* decoder)
: initialized_(false), program_(0u), buffer_id_(0u) {
Initialize(decoder);
}
ClearFramebufferResourceManager::~ClearFramebufferResourceManager() {
Destroy();
DCHECK(!buffer_id_);
}
void ClearFramebufferResourceManager::Initialize(
const gles2::GLES2Decoder* decoder) {
COMPILE_ASSERT(
kVertexPositionAttrib == 0u,
Position_attribs_must_be_0);
DCHECK(!buffer_id_);
glGenBuffersARB(1, &buffer_id_);
glBindBuffer(GL_ARRAY_BUFFER, buffer_id_);
const GLfloat kQuadVertices[] = {-1.0f, -1.0f,
1.0f, -1.0f,
1.0f, 1.0f,
-1.0f, 1.0f};
glBufferData(
GL_ARRAY_BUFFER, sizeof(kQuadVertices), kQuadVertices, GL_STATIC_DRAW);
decoder->RestoreBufferBindings();
initialized_ = true;
}
void ClearFramebufferResourceManager::Destroy() {
if (!initialized_)
return;
glDeleteProgram(program_);
glDeleteBuffersARB(1, &buffer_id_);
buffer_id_ = 0;
}
void ClearFramebufferResourceManager::ClearFramebuffer(
const gles2::GLES2Decoder* decoder,
const gfx::Size& framebuffer_size,
GLbitfield mask,
GLfloat clear_color_red,
GLfloat clear_color_green,
GLfloat clear_color_blue,
GLfloat clear_color_alpha,
GLfloat clear_depth_value,
GLint clear_stencil_value) {
if (!initialized_) {
DLOG(ERROR) << "Uninitialized manager.";
return;
}
if (!program_) {
program_ = glCreateProgram();
GLuint vertex_shader = glCreateShader(GL_VERTEX_SHADER);
CompileShader(vertex_shader, g_vertex_shader_source);
glAttachShader(program_, vertex_shader);
GLuint fragment_shader = glCreateShader(GL_FRAGMENT_SHADER);
CompileShader(fragment_shader, g_fragment_shader_source);
glAttachShader(program_, fragment_shader);
glBindAttribLocation(program_, kVertexPositionAttrib, "a_position");
glLinkProgram(program_);
#if DCHECK_IS_ON
GLint linked = GL_FALSE;
glGetProgramiv(program_, GL_LINK_STATUS, &linked);
if (GL_TRUE != linked)
DLOG(ERROR) << "Program link failure.";
#endif
depth_handle_ = glGetUniformLocation(program_, "u_clear_depth");
color_handle_ = glGetUniformLocation(program_, "u_clear_color");
glDeleteShader(fragment_shader);
glDeleteShader(vertex_shader);
}
glUseProgram(program_);
#if DCHECK_IS_ON
glValidateProgram(program_);
GLint validation_status = GL_FALSE;
glGetProgramiv(program_, GL_VALIDATE_STATUS, &validation_status);
if (GL_TRUE != validation_status)
DLOG(ERROR) << "Invalid shader.";
#endif
decoder->ClearAllAttributes();
glEnableVertexAttribArray(kVertexPositionAttrib);
glBindBuffer(GL_ARRAY_BUFFER, buffer_id_);
glVertexAttribPointer(kVertexPositionAttrib, 2, GL_FLOAT, GL_FALSE, 0, 0);
glUniform1f(depth_handle_, clear_depth_value);
glUniform4f(color_handle_, clear_color_red, clear_color_green,
clear_color_blue, clear_color_alpha);
if (!(mask & GL_COLOR_BUFFER_BIT)) {
glColorMask(GL_FALSE, GL_FALSE, GL_FALSE, GL_FALSE);
}
if (mask & GL_DEPTH_BUFFER_BIT) {
glEnable(GL_DEPTH_TEST);
glDepthFunc(GL_ALWAYS);
} else {
glDisable(GL_DEPTH_TEST);
glDepthMask(GL_FALSE);
}
if (mask & GL_STENCIL_BUFFER_BIT) {
glEnable(GL_STENCIL_TEST);
glStencilFunc(GL_ALWAYS, clear_stencil_value, 0xFF);
glStencilOp(GL_KEEP, GL_KEEP, GL_REPLACE);
} else {
glDisable(GL_STENCIL_TEST);
glStencilOp(GL_KEEP, GL_KEEP, GL_KEEP);
glStencilMask(0);
}
glDisable(GL_CULL_FACE);
glDisable(GL_BLEND);
glDisable(GL_POLYGON_OFFSET_FILL);
glViewport(0, 0, framebuffer_size.width(), framebuffer_size.height());
glDrawArrays(GL_TRIANGLE_FAN, 0, 4);
decoder->RestoreAllAttributes();
decoder->RestoreProgramBindings();
decoder->RestoreBufferBindings();
decoder->RestoreGlobalState();
}
} // namespace gpu
|
