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