project for a (works on my devices) demo

sources/glut_graphics.c

@@ -0,0 +1,53 @@
+#include <stddef.h>	/* NULL */
+
+#include "../headers/glut_graphics.h"
+
+/* each request simply sets a flag to be consumed by the main loop, (no need for more than one redraw per cycle) */
+int must_redraw = 0;
+const int REDRAW_TIMER_INIT = 16;
+int redraw_timer = 0;
+
+void (*redraw_callback) (void) = NULL;
+
+void assignRedrawCallback( void ( *callback) ( void)){
+	if( NULL != redraw_callback){
+		return;
+	}
+
+	redraw_callback = callback;
+}
+
+void issueRedraw(){
+	must_redraw = 1;
+}
+
+void consume_redraws(){
+	/* ensuring a minimum interval of 1/FPS secs between redraws
+		if the timer 
+	*/
+	redraw_timer--;
+	if( redraw_timer < 0){
+		redraw_timer = 0;
+	}
+	else{
+		return;
+	}
+
+	if( 0 == must_redraw){
+		return;
+	}
+
+	must_redraw = 0;
+
+	/* what to do if the redraw callback is not set? 
+		is not necessarily an error
+	*/
+	if( NULL == redraw_callback){
+		return;
+	}
+
+	redraw_timer = REDRAW_TIMER_INIT;
+	/* here the drawing implementation */
+	
+	redraw_callback();
+}