rotating, lit torus via vertex program

2001-12-15 22:33:59 +00:00
parent e3a0f39824
commit 9cb3947c56
1 changed files with 174 additions and 0 deletions
@@ -0,0 +1,174 @@
+/*
+ * A lit, rotating torus via vertex program
+ */
+
+#include <assert.h>
+#include <string.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <math.h>
+#define GL_GLEXT_PROTOTYPES
+#include <GL/glut.h>
+
+static float Xrot = 0.0, Yrot = 0.0, Zrot = 0.0;
+static GLboolean Anim = GL_TRUE;
+
+
+static void Idle( void )
+{
+   Xrot += .3;
+   Yrot += .4;
+   Zrot += .2;
+   glutPostRedisplay();
+}
+
+
+static void Display( void )
+{
+   glClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT );
+
+   glPushMatrix();
+      glRotatef(Xrot, 1, 0, 0);
+      glRotatef(Yrot, 0, 1, 0);
+      glRotatef(Zrot, 0, 0, 1);
+      glutSolidTorus(0.75, 2.0, 10, 20);
+   glPopMatrix();
+
+   glutSwapBuffers();
+}
+
+
+static void Reshape( int width, int height )
+{
+   glViewport( 0, 0, width, height );
+   glMatrixMode( GL_PROJECTION );
+   glLoadIdentity();
+   glFrustum( -2.0, 2.0, -2.0, 2.0, 5.0, 25.0 );
+   glMatrixMode( GL_MODELVIEW );
+   glLoadIdentity();
+   glTranslatef( 0.0, 0.0, -12.0 );
+}
+
+
+static void Key( unsigned char key, int x, int y )
+{
+   (void) x;
+   (void) y;
+   switch (key) {
+      case ' ':
+         Xrot = Yrot = Zrot = 0;
+         break;
+      case 'a':
+         Anim = !Anim;
+         if (Anim)
+            glutIdleFunc(Idle);
+         else
+            glutIdleFunc(NULL);
+         break;
+      case 'z':
+         Zrot -= 5.0;
+         break;
+      case 'Z':
+         Zrot += 5.0;
+         break;
+      case 27:
+         exit(0);
+         break;
+   }
+   glutPostRedisplay();
+}
+
+
+static void SpecialKey( int key, int x, int y )
+{
+   const GLfloat step = 3.0;
+   (void) x;
+   (void) y;
+   switch (key) {
+      case GLUT_KEY_UP:
+         Xrot -= step;
+         break;
+      case GLUT_KEY_DOWN:
+         Xrot += step;
+         break;
+      case GLUT_KEY_LEFT:
+         Yrot -= step;
+         break;
+      case GLUT_KEY_RIGHT:
+         Yrot += step;
+         break;
+   }
+   glutPostRedisplay();
+}
+
+
+static void Init( void )
+{
+   /* borrowed from an nvidia demo:
+    * c[0..3] = modelview matrix
+    * c[4..7] = inverse modelview matrix
+    * c[32] = light pos
+    * c[35] = diffuse color
+    */
+   static const char prog[] = 
+      "!!VP1.0\n"
+      "#Simple transform and diffuse lighting\n"
+      "\n"
+      "DP4   o[HPOS].x, c[0], v[OPOS] ;	# object x MVP -> clip\n"
+      "DP4   o[HPOS].y, c[1], v[OPOS] ;\n"
+      "DP4   o[HPOS].z, c[2], v[OPOS] ;\n"
+      "DP4   o[HPOS].w, c[3], v[OPOS] ;\n"
+
+      "DP3   R1.x, c[4], v[NRML] ;	# normal x MV-1T -> lighting normal\n"
+      "DP3   R1.y, c[5], v[NRML] ;\n"
+      "DP3   R1.z, c[6], v[NRML] ;\n"
+
+      "DP3   R0, c[32], R1 ;  		# L.N\n"
+      "MUL   o[COL0].xyz, R0, c[35] ;   # col = L.N * diffuse\n"
+      "MOV   o[TEX0], v[TEX0];\n"
+      "END";
+
+   if (!glutExtensionSupported("GL_NV_vertex_program")) {
+      printf("Sorry, this program requires GL_NV_vertex_program");
+      exit(1);
+   }
+
+   glLoadProgramNV(GL_VERTEX_PROGRAM_NV, 1,
+                   strlen(prog), (const GLubyte *) prog);
+   assert(glIsProgramNV(1));
+   glBindProgramNV(GL_VERTEX_PROGRAM_NV, 1);
+
+   /* Load the program registers */
+   glTrackMatrixNV(GL_VERTEX_PROGRAM_NV, 0, GL_MODELVIEW_PROJECTION_NV, GL_IDENTITY_NV);
+   glTrackMatrixNV(GL_VERTEX_PROGRAM_NV, 4, GL_MODELVIEW, GL_INVERSE_TRANSPOSE_NV);
+
+   /* Light position */
+   glProgramParameter4fNV(GL_VERTEX_PROGRAM_NV, 32, 2, 2, 4, 1);
+   /* Diffuse material color */
+   glProgramParameter4fNV(GL_VERTEX_PROGRAM_NV, 35, 0.25, 0, 0.25, 1);
+
+   glEnable(GL_VERTEX_PROGRAM_NV);
+   glEnable(GL_DEPTH_TEST);
+   glClearColor(0.3, 0.3, 0.3, 1);
+
+   printf("glGetError = %d\n", (int) glGetError());
+}
+
+
+int main( int argc, char *argv[] )
+{
+   glutInit( &argc, argv );
+   glutInitWindowPosition( 0, 0 );
+   glutInitWindowSize( 250, 250 );
+   glutInitDisplayMode( GLUT_RGB | GLUT_DOUBLE | GLUT_DEPTH );
+   glutCreateWindow(argv[0]);
+   glutReshapeFunc( Reshape );
+   glutKeyboardFunc( Key );
+   glutSpecialFunc( SpecialKey );
+   glutDisplayFunc( Display );
+   if (Anim)
+      glutIdleFunc(Idle);
+   Init();
+   glutMainLoop();
+   return 0;
+}