getteximage.c revision 32001f49 
1/**
2 * Test glGetTexImage()
3 * Brian Paul
4 * 9 June 2009
5 */
6
7
8#include <stdio.h>
9#include <stdlib.h>
10#include <math.h>
11#include <GL/glew.h>
12#include "glut_wrap.h"
13
14static int Win;
15
16
17static void
18TestGetTexImage(GLboolean npot)
19{
20   GLuint iter;
21   GLubyte *data = (GLubyte *) malloc(1024 * 1024 * 4);
22   GLubyte *data2 = (GLubyte *) malloc(1024 * 1024 * 4);
23
24   glEnable(GL_TEXTURE_2D);
25
26   printf("glTexImage2D + glGetTexImage:\n");
27
28   for (iter = 0; iter < 8; iter++) {
29      GLint p = (iter % 8) + 3;
30      GLint w = npot ? (p * 20) : (1 << p);
31      GLint h = npot ? (p * 10) : (1 << p);
32      GLuint i;
33      GLint level = 0;
34
35      printf("  Testing %d x %d tex image\n", w, h);
36
37      /* fill data */
38      for (i = 0; i < w * h * 4; i++) {
39         data[i] = i & 0xff;
40         data2[i] = 0;
41      }
42
43      glTexImage2D(GL_TEXTURE_2D, level, GL_RGBA, w, h, 0,
44                   GL_RGBA, GL_UNSIGNED_BYTE, data);
45
46      glBegin(GL_POINTS);
47      glVertex2f(0, 0);
48      glEnd();
49
50      /* get */
51      glGetTexImage(GL_TEXTURE_2D, level, GL_RGBA, GL_UNSIGNED_BYTE, data2);
52
53      /* compare */
54      for (i = 0; i < w * h * 4; i++) {
55         if (data2[i] != data[i]) {
56            printf("glTexImage + glGetTexImage failure!\n");
57            printf("Expected value %d, found %d\n", data[i], data2[i]);
58            abort();
59         }
60      }
61
62      /* get as BGRA */
63      glGetTexImage(GL_TEXTURE_2D, level, GL_BGRA, GL_UNSIGNED_BYTE, data2);
64
65      /* compare */
66      {
67         const GLubyte *rgba = (GLubyte *) data;
68         const GLubyte *bgra = (GLubyte *) data2;
69         for (i = 0; i < w * h; i += 4) {
70            if (rgba[i+0] != bgra[i+2] ||
71                rgba[i+1] != bgra[i+1] ||
72                rgba[i+2] != bgra[i+0] ||
73                rgba[i+3] != bgra[i+3]) {
74               printf("glTexImage + glGetTexImage(GL_BGRA) failure!\n");
75               printf("Expected value %d, found %d\n", data[i], data2[i]);
76               abort();
77            }
78         }
79      }
80
81   }
82
83   printf("Passed\n");
84   glDisable(GL_TEXTURE_2D);
85   free(data);
86   free(data2);
87}
88
89
90static GLboolean
91ColorsEqual(const GLubyte ref[4], const GLubyte act[4])
92{
93   if (abs((int) ref[0] - (int) act[0]) > 1 ||
94       abs((int) ref[1] - (int) act[1]) > 1 ||
95       abs((int) ref[2] - (int) act[2]) > 1 ||
96       abs((int) ref[3] - (int) act[3]) > 1) {
97      printf("expected %d %d %d %d\n", ref[0], ref[1], ref[2], ref[3]);
98      printf("found    %d %d %d %d\n", act[0], act[1], act[2], act[3]);
99      return GL_FALSE;
100   }
101   return GL_TRUE;
102}
103
104
105static void
106TestGetTexImageRTT(GLboolean npot)
107{
108   GLuint iter;
109
110   printf("Render to texture + glGetTexImage:\n");
111
112   for (iter = 0; iter < 8; iter++) {
113
114      GLuint fb, tex;
115      GLint w, h;
116      GLint level = 0;
117
118      if (npot) {
119         w = 200 + iter * 40;
120         h = 200 + iter * 12;
121      }
122      else {
123         w = 4 << iter;
124         h = 4 << iter;
125      }
126
127      glGenTextures(1, &tex);
128      glGenFramebuffersEXT(1, &fb);
129
130      glBindTexture(GL_TEXTURE_2D, tex);
131      glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
132      glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
133      glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, w, h, 0,
134                   GL_RGBA, GL_UNSIGNED_BYTE, NULL);
135
136      glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, fb);
137      glFramebufferTexture2DEXT(GL_FRAMEBUFFER_EXT, GL_COLOR_ATTACHMENT0_EXT,
138                                GL_TEXTURE_2D, tex, level);
139
140      glViewport(0, 0, w, h);
141
142      printf("  Testing %d x %d tex image\n", w, h);
143      {
144         static const GLubyte blue[4] = {0, 0, 255, 255};
145         GLubyte color[4];
146         GLubyte *data2 = (GLubyte *) malloc(w * h * 4);
147         GLuint i;
148
149         /* random clear color */
150         for (i = 0; i < 4; i++) {
151            color[i] = rand() % 256;
152         }
153
154         glClearColor(color[0] / 255.0,
155                      color[1] / 255.0,
156                      color[2] / 255.0,
157                      color[3] / 255.0);
158
159         glClear(GL_COLOR_BUFFER_BIT);
160
161         /* draw polygon over top half, in blue */
162         glColor4ubv(blue);
163         glRectf(0, 0.5, 1.0, 1.0);
164
165         /* get */
166         glGetTexImage(GL_TEXTURE_2D, level, GL_RGBA, GL_UNSIGNED_BYTE, data2);
167
168         /* compare */
169         for (i = 0; i < w * h; i += 4) {
170            if (i < w * h / 2) {
171               /* lower half */
172               if (!ColorsEqual(color, data2 + i * 4)) {
173                  printf("Render to texture failure (expected clear color)!\n");
174                  abort();
175               }
176            }
177            else {
178               /* upper half */
179               if (!ColorsEqual(blue, data2 + i * 4)) {
180                  printf("Render to texture failure (expected blue)!\n");
181                  abort();
182               }
183            }
184         }
185
186         free(data2);
187      }
188
189      glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, 0);
190      glDeleteFramebuffersEXT(1, &fb);
191      glDeleteTextures(1, &tex);
192
193   }
194
195   printf("Passed\n");
196}
197
198
199
200
201static void
202Draw(void)
203{
204   glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
205
206   TestGetTexImage(GL_FALSE);
207   if (glutExtensionSupported("GL_ARB_texture_non_power_of_two"))
208      TestGetTexImage(GL_TRUE);
209
210   if (glutExtensionSupported("GL_EXT_framebuffer_object") ||
211       glutExtensionSupported("GL_ARB_framebuffer_object")) {
212      TestGetTexImageRTT(GL_FALSE);
213      if (glutExtensionSupported("GL_ARB_texture_non_power_of_two"))
214         TestGetTexImageRTT(GL_TRUE);
215   }
216
217   glutDestroyWindow(Win);
218   exit(0);
219
220   glutSwapBuffers();
221}
222
223
224static void
225Reshape(int width, int height)
226{
227   glViewport(0, 0, width, height);
228   glMatrixMode(GL_PROJECTION);
229   glLoadIdentity();
230   glOrtho(0, 1, 0, 1, -1, 1);
231   glMatrixMode(GL_MODELVIEW);
232   glLoadIdentity();
233   glTranslatef(0.0, 0.0, 0.0);
234}
235
236
237static void
238Key(unsigned char key, int x, int y)
239{
240   (void) x;
241   (void) y;
242   switch (key) {
243      case 27:
244         glutDestroyWindow(Win);
245         exit(0);
246         break;
247   }
248   glutPostRedisplay();
249}
250
251
252static void
253Init(void)
254{
255}
256
257
258int
259main(int argc, char *argv[])
260{
261   glutInit(&argc, argv);
262   glutInitWindowPosition(0, 0);
263   glutInitWindowSize(400, 400);
264   glutInitDisplayMode(GLUT_RGB | GLUT_DOUBLE | GLUT_DEPTH);
265   Win = glutCreateWindow(argv[0]);
266   glewInit();
267   glutReshapeFunc(Reshape);
268   glutKeyboardFunc(Key);
269   glutDisplayFunc(Draw);
270   Init();
271   glutMainLoop();
272   return 0;
273}
274