From 58f17cd082d813dafe5839dc00f80d18649cf654 Mon Sep 17 00:00:00 2001
From: Jens Arnold <amiconn@rockbox.org>
Date: Wed, 16 Jun 2004 20:51:05 +0000
Subject: [PATCH] Mandelbrot didn't yield() at all, leading to playback
 problems when heavily calculating mandelbrots

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@4759 a1c6a512-1295-4272-9138-f99709370657
---
 apps/plugins/mandelbrot.c | 20 +++++++++++++-------
 1 file changed, 13 insertions(+), 7 deletions(-)

diff --git a/apps/plugins/mandelbrot.c b/apps/plugins/mandelbrot.c
index 450a4ebfee..786e31dc40 100644
--- a/apps/plugins/mandelbrot.c
+++ b/apps/plugins/mandelbrot.c
@@ -48,14 +48,14 @@ void init_mandelbrot_set(void){
 
 void calc_mandelbrot_set(void){
     
-    unsigned int start_tick;
+    unsigned int start_tick, last_yield;
     int n_iter;
     int x_pixel, y_pixel;
     int x, x2, y, y2, a, b;
     int x_fact, y_fact;
     int brightness;
     
-    start_tick = *rb->current_tick;  
+    start_tick = last_yield = *rb->current_tick;
     
     gray_clear_display();
 
@@ -63,9 +63,9 @@ void calc_mandelbrot_set(void){
     y_fact = (y_max - y_min) / LCD_HEIGHT;
     
     for (x_pixel = 0; x_pixel<LCD_WIDTH; x_pixel++){
-    a = (x_pixel * x_fact) + x_min;
-    for(y_pixel = LCD_HEIGHT-1; y_pixel>=0; y_pixel--){    
-        b = (y_pixel * y_fact) + y_min;
+        a = (x_pixel * x_fact) + x_min;
+        for(y_pixel = LCD_HEIGHT-1; y_pixel>=0; y_pixel--){
+            b = (y_pixel * y_fact) + y_min;
             x = 0;
             y = 0;
             n_iter = 0;
@@ -89,9 +89,15 @@ void calc_mandelbrot_set(void){
             } else {
                 brightness = 255 - (31 * (n_iter & 7));
             }
-        graybuffer[y_pixel]=brightness;
+            graybuffer[y_pixel]=brightness;
+            /* be nice to other threads:
+             * if at least one tick has passed, yield */
+            if  (*rb->current_tick > last_yield){
+                rb->yield();
+                last_yield = *rb->current_tick;
+            }
         }
-    gray_drawgraymap(graybuffer, x_pixel, 0, 1, LCD_HEIGHT, 1);
+        gray_drawgraymap(graybuffer, x_pixel, 0, 1, LCD_HEIGHT, 1);
     }
 }