added improved flyingdots to repo

animations/flyingdots.c

@@ -0,0 +1,73 @@
+#include <inttypes.h>
+#include "../config.h"
+#include "../random/prng.h"
+#include "../pixel.h"
+#include "../util.h"
+
+//dots flying from left to right
+void flyingdots()
+{
+	uint8_t rowbuffer[NUM_ROWS], i, j;
+	pixel p;
+
+	clear_screen(0);
+	
+	//set the pixels to the leftmost columns
+	p.x = NUM_COLS-1;
+	
+	//clear rowbuffer
+	for(i = 0; i < NUM_ROWS; i++)
+	{
+		rowbuffer[i] = 0;
+	}
+
+	//produce 200 dots
+	for (i = 0; i < 200; i++)
+	{	
+		//the idea is to use a buffer for one row
+		//first all pixels that are in the rowbuffer
+		//will be reduced in brightness
+		//(as you can assume that they were
+		// drawn in the last round and need to be dimmed
+		// to produce the trail effect)
+		//and then a new one will be added
+		//finally the rowbuffer is drawn
+		
+		//loop through all pixels in our rowbuffer
+		for(j = 0; j < NUM_ROWS; j++)
+		{			
+			//add a trail or remove the pixel, if it was bright enough
+			if(rowbuffer[j] > 0)
+			{
+				rowbuffer[j]--;
+			}
+		}
+				
+		//choose row and brightness
+		p.y = random8() % NUM_ROWS;
+		rowbuffer[p.y] += (random8() % (NUMPLANE)) + 1;	
+		
+		//cap max brightness
+		if(rowbuffer[p.y] > NUMPLANE)
+		{
+			rowbuffer[p.y] = NUMPLANE;
+		}
+		
+		//draw all pixels in our rowbuffer
+		for(j = 0; j < NUM_ROWS; j++)
+		{
+			if(rowbuffer[j] > 0)
+			{
+				p.y = j;
+				setpixel(p, rowbuffer[j]);
+			}
+		}
+		
+		//shift the picture right
+		//(yes, shift_pixmap_l shifts the picture right)
+		shift_pixmap_l();						
+		
+		//wait a bit
+		wait(100);		
+	}  
+}

animations/flyingdots.h

@@ -0,0 +1,7 @@
+#ifndef FLYINGDOTS_H_
+#define FLYINGDOTS_H_
+
+// dots fly from left to right
+void flyingdots();
+
+#endif /* FLYINGDOTS_H_ */