another simple FBO test

progs/tests/fbotest2.c

@@ -0,0 +1,199 @@
+/*
+ * Test GL_EXT_framebuffer_object
+ *
+ * Brian Paul
+ * 19 Mar 2006
+ */
+
+
+#define GL_GLEXT_PROTOTYPES
+#include <assert.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <math.h>
+#include <GL/glut.h>
+
+static int Width = 400, Height = 400;
+static GLuint MyFB, ColorRb, DepthRb;
+static GLboolean Animate = GL_TRUE;
+static GLfloat Rotation = 0.0;
+
+
+static void
+CheckError(int line)
+{
+   GLenum err = glGetError();
+   if (err) {
+      printf("fbotest2: GL Error 0x%x at line %d\n", (int) err, line);
+   }
+}
+
+
+static void
+Display( void )
+{
+   GLubyte *buffer = malloc(Width * Height * 4);
+   GLenum status;
+
+   CheckError(__LINE__);
+
+   /* draw to user framebuffer */
+   glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, MyFB);
+   glDrawBuffer(GL_COLOR_ATTACHMENT1_EXT);
+   glReadBuffer(GL_COLOR_ATTACHMENT1_EXT);
+
+   status = glCheckFramebufferStatusEXT(GL_FRAMEBUFFER_EXT);
+   if (status != GL_FRAMEBUFFER_COMPLETE_EXT) {
+      printf("fbotest2: Error: Framebuffer is incomplete!!!\n");
+   }
+
+   CheckError(__LINE__);
+
+   glClearColor(0.5, 0.5, 1.0, 0.0);
+   glClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT );
+
+   glEnable(GL_DEPTH_TEST);
+   glEnable(GL_LIGHTING);
+   glEnable(GL_LIGHT0);
+
+   glPushMatrix();
+   glRotatef(30.0, 1, 0, 0);
+   glRotatef(Rotation, 0, 1, 0);
+   glutSolidTeapot(2.0);
+   glPopMatrix();
+
+   /* read from user framebuffer */
+   glReadPixels(0, 0, Width, Height, GL_RGBA, GL_UNSIGNED_BYTE, buffer);
+
+   /* draw to window */
+   glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, 0);
+   glWindowPos2iARB(0, 0);
+   glDrawPixels(Width, Height, GL_RGBA, GL_UNSIGNED_BYTE, buffer);
+
+   free(buffer);
+   glutSwapBuffers();
+   CheckError(__LINE__);
+}
+
+
+static void
+Reshape( int width, int height )
+{
+   float ar = (float) width / (float) height;
+
+   glViewport( 0, 0, width, height );
+   glMatrixMode( GL_PROJECTION );
+   glLoadIdentity();
+   glFrustum( -ar, ar, -1.0, 1.0, 5.0, 25.0 );
+
+   glMatrixMode( GL_MODELVIEW );
+   glLoadIdentity();
+   glTranslatef( 0.0, 0.0, -15.0 );
+
+   glBindRenderbufferEXT(GL_RENDERBUFFER_EXT, ColorRb);
+   glRenderbufferStorageEXT(GL_RENDERBUFFER_EXT, GL_RGB, width, height);
+   glBindRenderbufferEXT(GL_RENDERBUFFER_EXT, DepthRb);
+   glRenderbufferStorageEXT(GL_RENDERBUFFER_EXT, GL_DEPTH_COMPONENT,
+                            width, height);
+
+   Width = width;
+   Height = height;
+}
+
+
+static void
+CleanUp(void)
+{
+   glDeleteFramebuffersEXT(1, &MyFB);
+   glDeleteRenderbuffersEXT(1, &ColorRb);
+   glDeleteRenderbuffersEXT(1, &DepthRb);
+   assert(!glIsFramebufferEXT(MyFB));
+   assert(!glIsRenderbufferEXT(ColorRb));
+   assert(!glIsRenderbufferEXT(DepthRb));
+   exit(0);
+}
+
+
+static void
+Idle(void)
+{
+   Rotation = glutGet(GLUT_ELAPSED_TIME) * 0.1;
+   glutPostRedisplay();
+}
+
+
+static void
+Key( unsigned char key, int x, int y )
+{
+   (void) x;
+   (void) y;
+   switch (key) {
+   case 'a':
+      Animate = !Animate;
+      if (Animate)
+         glutIdleFunc(Idle);
+      else
+         glutIdleFunc(NULL);
+      break;
+   case 27:
+      CleanUp();
+      break;
+   }
+   glutPostRedisplay();
+}
+
+
+static void
+Init( void )
+{
+   if (!glutExtensionSupported("GL_EXT_framebuffer_object")) {
+      printf("fbotest2: GL_EXT_framebuffer_object not found!\n");
+      exit(0);
+   }
+   printf("fbotest2: GL_RENDERER = %s\n", (char *) glGetString(GL_RENDERER));
+
+   glGenFramebuffersEXT(1, &MyFB);
+   glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, MyFB);
+   assert(glIsFramebufferEXT(MyFB));
+
+   /* set color buffer */
+   glGenRenderbuffersEXT(1, &ColorRb);
+   glBindRenderbufferEXT(GL_RENDERBUFFER_EXT, ColorRb);
+   assert(glIsRenderbufferEXT(ColorRb));
+   glFramebufferRenderbufferEXT(GL_FRAMEBUFFER_EXT, GL_COLOR_ATTACHMENT1_EXT,
+                                GL_RENDERBUFFER_EXT, ColorRb);
+   glRenderbufferStorageEXT(GL_RENDERBUFFER_EXT, GL_RGB, Width, Height);
+
+   /* setup depth buffer */
+   glGenRenderbuffersEXT(1, &DepthRb);
+   glBindRenderbufferEXT(GL_RENDERBUFFER_EXT, DepthRb);
+   assert(glIsRenderbufferEXT(DepthRb));
+   glFramebufferRenderbufferEXT(GL_FRAMEBUFFER_EXT, GL_DEPTH_ATTACHMENT_EXT,
+                                GL_RENDERBUFFER_EXT, DepthRb);
+   glRenderbufferStorageEXT(GL_RENDERBUFFER_EXT, GL_DEPTH_COMPONENT, Width, Height);
+
+   CheckError(__LINE__);
+
+   /* restore to default */
+   glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, 0);
+   CheckError(__LINE__);
+}
+
+
+int
+main( int argc, char *argv[] )
+{
+   glutInit( &argc, argv );
+   glutInitWindowPosition( 0, 0 );
+   glutInitWindowSize(Width, Height);
+   glutInitDisplayMode( GLUT_RGB | GLUT_DOUBLE );
+   glutCreateWindow(argv[0]);
+   glutReshapeFunc( Reshape );
+   glutKeyboardFunc( Key );
+   glutDisplayFunc( Display );
+   if (Animate)
+      glutIdleFunc(Idle);
+   Init();
+   glutMainLoop();
+   return 0;
+}