GL_EXT_fog_coord test

diff --git a/progs/tests/fogcoord.c b/progs/tests/fogcoord.c
new file mode 100644 (file)
index 0000000..e5a24d8
--- /dev/null
+++ b/progs/tests/fogcoord.c
@@ -0,0 +1,99 @@
+/*
+ * Exercise GL_EXT_fog_coord
+ */
+
+
+#define GL_GLEXT_PROTOTYPES
+#include <stdio.h>
+#include <stdlib.h>
+#include <math.h>
+#include <GL/glut.h>
+
+static int Width = 600;
+static int Height = 200;
+static GLfloat Near = 5.0, Far = 25.0;
+
+
+static void Display( void )
+{
+   GLfloat t;
+
+   glClearColor(0.2, 0.2, 0.8, 0);
+   glClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT );
+
+   for (t = 0.0; t <= 1.0; t += 0.25) {
+      GLfloat f = -(Near + t * (Far - Near));
+      glFogCoordfEXT(f);
+
+      glPushMatrix();
+         glTranslatef(t * 10.0 - 5.0, 0, 0);
+         glBegin(GL_POLYGON);
+         glVertex2f(-1, -1);
+         glVertex2f( 1, -1);
+         glVertex2f( 1,  1);
+         glVertex2f(-1,  1);
+         glEnd();
+      glPopMatrix();
+   }
+   glutSwapBuffers();
+}
+
+
+static void Reshape( int width, int height )
+{
+   GLfloat ar = (float) width / (float) height;
+   Width = width;
+   Height = height;
+   glViewport( 0, 0, width, height );
+   glMatrixMode( GL_PROJECTION );
+   glLoadIdentity();
+   glFrustum( -ar, ar, -1.0, 1.0, Near, Far );
+   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:
+         exit(0);
+         break;
+   }
+   glutPostRedisplay();
+}
+
+
+static void Init( void )
+{
+   /* setup lighting, etc */
+   if (!glutExtensionSupported("GL_EXT_fog_coord")) {
+      printf("Sorry, this program requires GL_EXT_fog_coord\n");
+      exit(1);
+   }
+   glFogi(GL_FOG_COORDINATE_SOURCE_EXT, GL_FOG_COORDINATE_EXT);
+   glFogi(GL_FOG_MODE, GL_LINEAR);
+   glFogf(GL_FOG_START, Near);
+   glFogf(GL_FOG_END, Far);
+   glEnable(GL_FOG);
+   printf("Squares should be colored from white -> gray -> black.\n");
+}
+
+
+int main( int argc, char *argv[] )
+{
+   glutInit( &argc, argv );
+   glutInitWindowPosition( 0, 0 );
+   glutInitWindowSize( Width, Height );
+   glutInitDisplayMode( GLUT_RGB | GLUT_DOUBLE | GLUT_DEPTH );
+   glutCreateWindow(argv[0]);
+   glutReshapeFunc( Reshape );
+   glutKeyboardFunc( Key );
+   glutDisplayFunc( Display );
+   Init();
+   glutMainLoop();
+   return 0;
+}