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
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
|
/**
* Test glFramebufferBlit()
* Brian Paul
* 27 Oct 2009
*/
#include <assert.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <math.h>
#include <GL/glew.h>
#include <GL/glut.h>
static int Win;
static int WinWidth = 1100, WinHeight = 600;
static int SrcWidth = 512, SrcHeight = 512;
static int DstWidth = 512, DstHeight = 512;
static GLuint SrcFB, DstFB;
static GLuint SrcTex, DstTex;
#if 0
static GLenum SrcTexTarget = GL_TEXTURE_2D, SrcTexFace = GL_TEXTURE_2D;
#else
static GLenum SrcTexTarget = GL_TEXTURE_CUBE_MAP, SrcTexFace = GL_TEXTURE_CUBE_MAP_POSITIVE_X;
#endif
static GLenum DstTexTarget = GL_TEXTURE_2D, DstTexFace = GL_TEXTURE_2D;
static GLuint SrcTexLevel = 01, DstTexLevel = 0;
static void
Draw(void)
{
GLboolean rp = GL_FALSE;
GLubyte *buf;
GLint srcWidth = SrcWidth >> SrcTexLevel;
GLint srcHeight = SrcHeight >> SrcTexLevel;
GLint dstWidth = DstWidth >> DstTexLevel;
GLint dstHeight = DstHeight >> DstTexLevel;
GLenum status;
/* clear window */
glBindFramebufferEXT(GL_FRAMEBUFFER, 0);
glClearColor(0.5, 0.5, 0.5, 1.0);
glClear(GL_COLOR_BUFFER_BIT);
/* clear src buf */
glBindFramebufferEXT(GL_FRAMEBUFFER, SrcFB);
status = glCheckFramebufferStatusEXT(GL_FRAMEBUFFER_EXT);
assert(status == GL_FRAMEBUFFER_COMPLETE_EXT);
glClearColor(0, 1, 0, 0);
glClear(GL_COLOR_BUFFER_BIT);
/* clear dst buf */
glBindFramebufferEXT(GL_FRAMEBUFFER, DstFB);
status = glCheckFramebufferStatusEXT(GL_FRAMEBUFFER_EXT);
assert(status == GL_FRAMEBUFFER_COMPLETE_EXT);
glClearColor(1, 0, 0, 0);
glClear(GL_COLOR_BUFFER_BIT);
/* blit src -> dst */
glBindFramebufferEXT(GL_READ_FRAMEBUFFER, SrcFB);
glBindFramebufferEXT(GL_DRAW_FRAMEBUFFER, DstFB);
glBlitFramebufferEXT(0, 0, srcWidth, srcHeight,
0, 0, dstWidth, dstHeight,
GL_COLOR_BUFFER_BIT, GL_NEAREST);
#if 01
/* read src results */
buf = malloc(4 * srcWidth * srcHeight);
memset(buf, 0x88, 4 * srcWidth * srcHeight);
glBindFramebufferEXT(GL_FRAMEBUFFER, SrcFB);
if (rp)
glReadPixels(0, 0, srcWidth, srcHeight, GL_RGBA, GL_UNSIGNED_BYTE, buf);
else {
glBindTexture(SrcTexTarget, SrcTex);
glGetTexImage(SrcTexFace, SrcTexLevel, GL_RGBA, GL_UNSIGNED_BYTE, buf);
}
/* draw dst in window */
glBindFramebufferEXT(GL_FRAMEBUFFER, 0);
glWindowPos2i(0, 0);
glDrawPixels(srcWidth, srcHeight, GL_RGBA, GL_UNSIGNED_BYTE, buf);
printf("Src Pix[0] = %d %d %d %d\n", buf[0], buf[1], buf[2], buf[3]);
free(buf);
#endif
glFinish();
/* read dst results */
buf = malloc(4 * dstWidth * dstHeight);
memset(buf, 0x88, 4 * dstWidth * dstHeight);
glBindFramebufferEXT(GL_FRAMEBUFFER, DstFB);
if (rp)
glReadPixels(0, 0, dstWidth, dstHeight, GL_RGBA, GL_UNSIGNED_BYTE, buf);
else {
glBindTexture(DstTexTarget, DstTex);
glGetTexImage(DstTexFace, DstTexLevel, GL_RGBA, GL_UNSIGNED_BYTE, buf);
}
/* draw dst in window */
glBindFramebufferEXT(GL_FRAMEBUFFER, 0);
glWindowPos2i(srcWidth + 2, 0);
glDrawPixels(dstWidth, dstHeight, GL_RGBA, GL_UNSIGNED_BYTE, buf);
printf("Dst Pix[0] = %d %d %d %d\n", buf[0], buf[1], buf[2], buf[3]);
free(buf);
glFinish();
glutSwapBuffers();
}
static void
Reshape(int width, int height)
{
WinWidth = width;
WinHeight = height;
glViewport(0, 0, width, height);
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
glFrustum(-1.0, 1.0, -1.0, 1.0, 5.0, 25.0);
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
glTranslatef(0.0, 0.0, -15.0);
}
static void
Key(unsigned char key, int x, int y)
{
(void) x;
(void) y;
switch (key) {
case 27:
glutDestroyWindow(Win);
exit(0);
break;
}
glutPostRedisplay();
}
static void
SpecialKey(int key, int x, int y)
{
(void) x;
(void) y;
switch (key) {
}
glutPostRedisplay();
}
static void
InitFBOs(void)
{
GLuint w, h, lvl;
/* Src */
glGenTextures(1, &SrcTex);
glBindTexture(SrcTexTarget, SrcTex);
w = SrcWidth;
h = SrcHeight;
lvl = 0;
for (lvl = 0; ; lvl++) {
if (SrcTexTarget == GL_TEXTURE_CUBE_MAP) {
GLuint f;
for (f = 0; f < 6; f++) {
glTexImage2D(GL_TEXTURE_CUBE_MAP_POSITIVE_X + f, lvl, GL_RGBA8,
w, h, 0, GL_RGBA, GL_UNSIGNED_BYTE, NULL);
}
}
else {
/* single face */
glTexImage2D(SrcTexFace, lvl, GL_RGBA8, w, h, 0,
GL_RGBA, GL_UNSIGNED_BYTE, NULL);
}
if (w == 1 && h == 1)
break;
if (w > 1)
w /= 2;
if (h > 1)
h /= 2;
}
glGenFramebuffersEXT(1, &SrcFB);
glBindFramebufferEXT(GL_FRAMEBUFFER, SrcFB);
glFramebufferTexture2DEXT(GL_FRAMEBUFFER_EXT, GL_COLOR_ATTACHMENT0_EXT,
SrcTexFace, SrcTex, SrcTexLevel);
/* Dst */
glGenTextures(1, &DstTex);
glBindTexture(DstTexTarget, DstTex);
w = DstWidth;
h = DstHeight;
lvl = 0;
for (lvl = 0; ; lvl++) {
glTexImage2D(DstTexFace, lvl, GL_RGBA8, w, h, 0,
GL_RGBA, GL_UNSIGNED_BYTE, NULL);
if (w == 1 && h == 1)
break;
if (w > 1)
w /= 2;
if (h > 1)
h /= 2;
}
glGenFramebuffersEXT(1, &DstFB);
glBindFramebufferEXT(GL_FRAMEBUFFER, DstFB);
glFramebufferTexture2DEXT(GL_FRAMEBUFFER_EXT, GL_COLOR_ATTACHMENT0_EXT,
DstTexFace, DstTex, DstTexLevel);
}
static void
Init(void)
{
if (!glutExtensionSupported("GL_EXT_framebuffer_object")) {
fprintf(stderr, "This test requires GL_EXT_framebuffer_object\n");
exit(1);
}
if (!glutExtensionSupported("GL_EXT_framebuffer_blit")) {
fprintf(stderr, "This test requires GL_EXT_framebuffer_blit,\n");
exit(1);
}
InitFBOs();
printf("Left rect = src FBO, Right rect = dst FBO.\n");
printf("Both should be green.\n");
}
int
main(int argc, char *argv[])
{
glutInit(&argc, argv);
glutInitWindowSize(WinWidth, WinHeight);
glutInitDisplayMode(GLUT_RGB | GLUT_DOUBLE | GLUT_DEPTH);
Win = glutCreateWindow(argv[0]);
glewInit();
glutReshapeFunc(Reshape);
glutKeyboardFunc(Key);
glutSpecialFunc(SpecialKey);
glutDisplayFunc(Draw);
Init();
glutMainLoop();
return 0;
}
|
