progs: Port fp programs to GLEW.

progs/fp/tri-depthwrite2.c

@@ -2,7 +2,7 @@
 #include <stdio.h>
 #include <string.h>
 #include <stdlib.h>
-#define GL_GLEXT_PROTOTYPES
+#include <GL/glew.h>
 #include <GL/glut.h>
 
 
@@ -16,7 +16,7 @@ static void Init(void)
       ;
    GLuint modulateProg;
 
-   if (!glutExtensionSupported("GL_ARB_fragment_program")) {
+   if (!GLEW_ARB_fragment_program) {
       printf("Error: GL_ARB_fragment_program not supported!\n");
       exit(1);
    }
@@ -97,6 +97,8 @@ int main(int argc, char **argv)
 	exit(1);
     }
 
+    glewInit();
+
     Init();
 
     glutReshapeFunc(Reshape);