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
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
|
#include "fbo.h"
#include "system-gl.h"
#include <stdio.h>
#include <iostream>
using namespace std;
fbo_t *fbo_new()
{
fbo_t *fbo = new fbo_t;
fbo->fbo_id = 0;
fbo->old_fbo_id = 0;
fbo->renderbuf_id = 0;
fbo->depthbuf_id = 0;
return fbo;
}
bool use_ext()
{
// do we need to use the EXT or ARB version?
if (!glewIsSupported("GL_ARB_framebuffer_object") &&
glewIsSupported("GL_EXT_framebuffer_object")) {
return true;
} else {
return false;
}
}
bool check_fbo_status()
{
/* This code is based on user V-man code from
http://www.opengl.org/wiki/GL_EXT_framebuffer_multisample
See also: http://www.songho.ca/opengl/gl_fbo.html */
GLenum status;
bool result = false;
if (use_ext())
status = glCheckFramebufferStatusEXT(GL_FRAMEBUFFER_EXT);
else
status = glCheckFramebufferStatus(GL_FRAMEBUFFER);
if (report_glerror("checking framebuffer status")) return false;
if (status == GL_FRAMEBUFFER_COMPLETE)
result = true;
else if (status == GL_FRAMEBUFFER_UNSUPPORTED)
cerr << "GL_FRAMEBUFFER_UNSUPPORTED\n";
else if (status == GL_FRAMEBUFFER_INCOMPLETE_ATTACHMENT)
cerr << "GL_FRAMEBUFFER_INCOMPLETE_ATTACHMENT\n";
else if (status == GL_FRAMEBUFFER_INCOMPLETE_MISSING_ATTACHMENT)
cerr << "GL_FRAMEBUFFER_INCOMPLETE_MISSING_ATTACHMENT\n";
else if (status == GL_FRAMEBUFFER_INCOMPLETE_DIMENSIONS_EXT)
cerr << "GL_FRAMEBUFFER_INCOMPLETE_DIMENSIONS_EXT\n";
else if (status == GL_FRAMEBUFFER_INCOMPLETE_FORMATS_EXT)
cerr << "GL_FRAMEBUFFER_INCOMPLETE_FORMATS_EXT\n";
else if (status == GL_FRAMEBUFFER_INCOMPLETE_DRAW_BUFFER_EXT)
cerr << "GL_FRAMEBUFFER_INCOMPLETE_DRAW_BUFFER_EXT\n";
else if (status == GL_FRAMEBUFFER_INCOMPLETE_READ_BUFFER_EXT)
cerr << "GL_FRAMEBUFFER_INCOMPLETE_READ_BUFFER_EXT\n";
else if (status == GL_FRAMEBUFFER_INCOMPLETE_MULTISAMPLE_EXT)
cerr << "GL_FRAMEBUFFER_INCOMPLETE_MULTISAMPLE_EXT\n";
else
cerr << "Unknown Code: glCheckFramebufferStatusEXT returned %i\n",status;
return result;
}
bool fbo_ext_init(fbo_t *fbo, size_t width, size_t height)
{
// Generate and bind FBO
glGenFramebuffersEXT(1, &fbo->fbo_id);
if (report_glerror("glGenFramebuffersEXT")) return false;
glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, fbo->fbo_id);
if (report_glerror("glBindFramebufferEXT")) return false;
// Generate depth and render buffers
glGenRenderbuffersEXT(1, &fbo->depthbuf_id);
glGenRenderbuffersEXT(1, &fbo->renderbuf_id);
// Create buffers with correct size
if (!fbo_resize(fbo, width, height)) return false;
// Attach render and depth buffers
glFramebufferRenderbufferEXT(GL_FRAMEBUFFER_EXT, GL_COLOR_ATTACHMENT0_EXT,
GL_RENDERBUFFER_EXT, fbo->renderbuf_id);
if (report_glerror("specifying color render buffer EXT")) return false;
if (!check_fbo_status()) {
cerr << "Problem with OpenGL EXT framebuffer after specifying color render buffer.\n";
return false;
}
glFramebufferRenderbufferEXT(GL_FRAMEBUFFER_EXT, GL_DEPTH_ATTACHMENT_EXT,
GL_RENDERBUFFER_EXT, fbo->depthbuf_id);
if (report_glerror("specifying depth render buffer EXT")) return false;
if (!check_fbo_status()) {
cerr << "Problem with OpenGL EXT framebuffer after specifying depth render buffer.\n";
return false;
}
return true;
}
bool fbo_arb_init(fbo_t *fbo, size_t width, size_t height)
{
// Generate and bind FBO
glGenFramebuffers(1, &fbo->fbo_id);
if (report_glerror("glGenFramebuffers")) return false;
glBindFramebuffer(GL_FRAMEBUFFER, fbo->fbo_id);
if (report_glerror("glBindFramebuffer")) return false;
// Generate depth and render buffers
glGenRenderbuffers(1, &fbo->depthbuf_id);
glGenRenderbuffers(1, &fbo->renderbuf_id);
// Create buffers with correct size
if (!fbo_resize(fbo, width, height)) return false;
// Attach render and depth buffers
glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0,
GL_RENDERBUFFER, fbo->renderbuf_id);
if (report_glerror("specifying color render buffer")) return false;
if (!check_fbo_status()) {
cerr << "Problem with OpenGL framebuffer after specifying color render buffer.\n";
return false;
}
glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT,
GL_RENDERBUFFER, fbo->depthbuf_id);
if (report_glerror("specifying depth render buffer")) return false;
if (!check_fbo_status()) {
cerr << "Problem with OpenGL framebuffer after specifying depth render buffer.\n";
return false;
}
return true;
}
bool fbo_init(fbo_t *fbo, size_t width, size_t height)
{
/*
Some OpenGL drivers include the framebuffer functions but not with
core or ARB names, only with the EXT name. This has been worked-around
by deciding at runtime, using GLEW, which version needs to be used. See also:
http://www.opengl.org/wiki/Framebuffer_Object
http://stackoverflow.com/questions/6912988/glgenframebuffers-or-glgenframebuffersex
http://www.devmaster.net/forums/showthread.php?t=10967
*/
bool result = false;
if (glewIsSupported("GL_ARB_framebuffer_object"))
result = fbo_arb_init(fbo, width, height);
else if (use_ext())
result = fbo_ext_init(fbo, width, height);
else
cerr << "Framebuffer Object extension not found by GLEW\n";
return result;
}
bool fbo_resize(fbo_t *fbo, size_t width, size_t height)
{
if (use_ext()) {
glBindRenderbufferEXT(GL_RENDERBUFFER, fbo->depthbuf_id);
glRenderbufferStorageEXT(GL_RENDERBUFFER, GL_DEPTH_COMPONENT24, width, height);
if (report_glerror("creating depth render buffer")) return false;
glBindRenderbufferEXT(GL_RENDERBUFFER, fbo->renderbuf_id);
glRenderbufferStorageEXT(GL_RENDERBUFFER, GL_RGBA8, width, height);
if (report_glerror("creating color render buffer")) return false;
} else {
glBindRenderbuffer(GL_RENDERBUFFER, fbo->depthbuf_id);
glRenderbufferStorage(GL_RENDERBUFFER, GL_DEPTH_COMPONENT24, width, height);
if (report_glerror("creating depth render buffer")) return false;
glBindRenderbuffer(GL_RENDERBUFFER, fbo->renderbuf_id);
glRenderbufferStorage(GL_RENDERBUFFER, GL_RGBA8, width, height);
if (report_glerror("creating color render buffer")) return false;
}
return true;
}
void fbo_delete(fbo_t *fbo)
{
delete fbo;
}
GLuint fbo_bind(fbo_t *fbo)
{
glGetIntegerv(GL_FRAMEBUFFER_BINDING, (GLint *)&fbo->old_fbo_id);
if (use_ext())
glBindFramebufferEXT(GL_FRAMEBUFFER, fbo->fbo_id);
else
glBindFramebuffer(GL_FRAMEBUFFER, fbo->fbo_id);
return fbo->old_fbo_id;
}
void fbo_unbind(fbo_t *fbo)
{
if (use_ext())
glBindFramebufferEXT(GL_FRAMEBUFFER, fbo->old_fbo_id);
else
glBindFramebuffer(GL_FRAMEBUFFER, fbo->old_fbo_id);
}
|
