1/*
2 * Test GL_EXT_framebuffer_object
3 * Like fbotest2.c but use a texture for the Z buffer / renderbuffer.
4 * Note: the Z texture is never resized so that limits what can be
5 * rendered if the window is resized.
6 *
7 * This tests a bug reported by Christoph Bumiller on 1 Feb 2010
8 * on mesa3d-dev.
9 *
10 * XXX this should be made into a piglit test.
11 *
12 * Brian Paul
13 * 1 Feb 2010
14 */
15
16
17#include <assert.h>
18#include <stdio.h>
19#include <stdlib.h>
20#include <math.h>
21#include <GL/glew.h>
22#include "glut_wrap.h"
23
24
25static int Win = 0;
26static int Width = 400, Height = 400;
27static GLuint Tex = 0;
28static GLuint MyFB, ColorRb, DepthRb;
29static GLboolean Animate = GL_FALSE;
30static GLfloat Rotation = 0.0;
31
32
33static void
34CheckError(int line)
35{
36   GLenum err = glGetError();
37   if (err) {
38      printf("fbotest3: GL Error 0x%x at line %d\n", (int) err, line);
39   }
40}
41
42
43static void
44Display( void )
45{
46   GLubyte *buffer = malloc(Width * Height * 4);
47   GLenum status;
48
49   CheckError(__LINE__);
50
51   /* draw to user framebuffer */
52   glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, MyFB);
53   glDrawBuffer(GL_COLOR_ATTACHMENT0_EXT);
54   glReadBuffer(GL_COLOR_ATTACHMENT0_EXT);
55
56   status = glCheckFramebufferStatusEXT(GL_FRAMEBUFFER_EXT);
57   if (status != GL_FRAMEBUFFER_COMPLETE_EXT) {
58      printf("fbotest3: Error: Framebuffer is incomplete!!!\n");
59   }
60
61   CheckError(__LINE__);
62
63   glClearColor(0.5, 0.5, 1.0, 0.0);
64   glClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT );
65
66   glEnable(GL_DEPTH_TEST);
67   glEnable(GL_LIGHTING);
68   glEnable(GL_LIGHT0);
69
70   glPushMatrix();
71   glRotatef(30.0, 1, 0, 0);
72   glRotatef(Rotation, 0, 1, 0);
73   glutSolidTeapot(2.0);
74   glPopMatrix();
75
76   /* read from user framebuffer */
77   glReadPixels(0, 0, Width, Height, GL_RGBA, GL_UNSIGNED_BYTE, buffer);
78
79   /* draw to window */
80   glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, 0);
81   glDisable(GL_DEPTH_TEST);  /* in case window has depth buffer */
82   glWindowPos2iARB(0, 0);
83   glDrawPixels(Width, Height, GL_RGBA, GL_UNSIGNED_BYTE, buffer);
84
85   free(buffer);
86   glutSwapBuffers();
87   CheckError(__LINE__);
88}
89
90
91static void
92Reshape( int width, int height )
93{
94   float ar = (float) width / (float) height;
95
96   glViewport( 0, 0, width, height );
97   glMatrixMode( GL_PROJECTION );
98   glLoadIdentity();
99   glFrustum( -ar, ar, -1.0, 1.0, 5.0, 25.0 );
100
101   glMatrixMode( GL_MODELVIEW );
102   glLoadIdentity();
103   glTranslatef( 0.0, 0.0, -15.0 );
104
105   glBindRenderbufferEXT(GL_RENDERBUFFER_EXT, ColorRb);
106   glRenderbufferStorageEXT(GL_RENDERBUFFER_EXT, GL_RGB, width, height);
107
108   Width = width;
109   Height = height;
110}
111
112
113static void
114CleanUp(void)
115{
116   glDeleteFramebuffersEXT(1, &MyFB);
117   glDeleteRenderbuffersEXT(1, &ColorRb);
118   glDeleteRenderbuffersEXT(1, &DepthRb);
119   glDeleteTextures(1, &Tex);
120   assert(!glIsFramebufferEXT(MyFB));
121   assert(!glIsRenderbufferEXT(ColorRb));
122   assert(!glIsRenderbufferEXT(DepthRb));
123   glutDestroyWindow(Win);
124   exit(0);
125}
126
127
128static void
129Idle(void)
130{
131   Rotation = glutGet(GLUT_ELAPSED_TIME) * 0.1;
132   glutPostRedisplay();
133}
134
135
136static void
137Key( unsigned char key, int x, int y )
138{
139   (void) x;
140   (void) y;
141   switch (key) {
142   case 'a':
143      Animate = !Animate;
144      if (Animate)
145         glutIdleFunc(Idle);
146      else
147         glutIdleFunc(NULL);
148      break;
149   case 27:
150      CleanUp();
151      break;
152   }
153   glutPostRedisplay();
154}
155
156
157static void
158Init( void )
159{
160   if (!glutExtensionSupported("GL_EXT_framebuffer_object")) {
161      printf("fbotest3: GL_EXT_framebuffer_object not found!\n");
162      exit(0);
163   }
164   printf("fbotest3: GL_RENDERER = %s\n", (char *) glGetString(GL_RENDERER));
165
166   /* create initial tex obj as an RGBA texture */
167   glGenTextures(1, &Tex);
168   glBindTexture(GL_TEXTURE_2D, Tex);
169   glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, 256, 256, 0,
170                GL_RGBA, GL_UNSIGNED_BYTE, NULL);
171   glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
172   glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
173   glEnable(GL_TEXTURE_2D);
174
175   /* draw something to make sure the texture is used */
176   glBegin(GL_POINTS);
177   glVertex2f(0, 0);
178   glEnd();
179
180   /* done w/ texturing */
181   glDisable(GL_TEXTURE_2D);
182
183   /* Create my Framebuffer Object */
184   glGenFramebuffersEXT(1, &MyFB);
185   glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, MyFB);
186   assert(glIsFramebufferEXT(MyFB));
187
188   /* Setup color renderbuffer */
189   glGenRenderbuffersEXT(1, &ColorRb);
190   glBindRenderbufferEXT(GL_RENDERBUFFER_EXT, ColorRb);
191   assert(glIsRenderbufferEXT(ColorRb));
192   glFramebufferRenderbufferEXT(GL_FRAMEBUFFER_EXT, GL_COLOR_ATTACHMENT0_EXT,
193                                GL_RENDERBUFFER_EXT, ColorRb);
194   glRenderbufferStorageEXT(GL_RENDERBUFFER_EXT, GL_RGB, Width, Height);
195
196   /* Setup depth renderbuffer (a texture) */
197   glGenRenderbuffersEXT(1, &DepthRb);
198   glBindRenderbufferEXT(GL_RENDERBUFFER_EXT, DepthRb);
199   assert(glIsRenderbufferEXT(DepthRb));
200   /* replace RGBA texture with Z texture */
201   glTexImage2D(GL_TEXTURE_2D, 0, GL_DEPTH_COMPONENT, Width, Height, 0,
202                GL_DEPTH_COMPONENT, GL_UNSIGNED_INT, NULL);
203   glFramebufferTexture2DEXT(GL_FRAMEBUFFER_EXT, GL_DEPTH_ATTACHMENT_EXT,
204                             GL_TEXTURE_2D, Tex, 0);
205
206   CheckError(__LINE__);
207
208   /* restore to default */
209   glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, 0);
210   CheckError(__LINE__);
211}
212
213
214int
215main( int argc, char *argv[] )
216{
217   glutInit( &argc, argv );
218   glutInitWindowPosition( 0, 0 );
219   glutInitWindowSize(Width, Height);
220   glutInitDisplayMode( GLUT_RGB | GLUT_DOUBLE );
221   Win = glutCreateWindow(argv[0]);
222   glewInit();
223   glutReshapeFunc( Reshape );
224   glutKeyboardFunc( Key );
225   glutDisplayFunc( Display );
226   if (Animate)
227      glutIdleFunc(Idle);
228   Init();
229   glutMainLoop();
230   return 0;
231}
232