Mon 14 Oct 23:09:15 CEST 2024

user/fractal.c

@@ -0,0 +1,79 @@
+/*
+Copyright (C) 2016-2019 The University of Notre Dame
+This software is distributed under the GNU General Public License.
+See the file LICENSE for details.
+*/
+
+
+#include "library/syscalls.h"
+#include "library/string.h"
+#include "library/nwindow.h"
+
+#define MAX_ITERS 2000
+
+int in_set( float x, float y );
+void plot_point(int iter, int j, int k);
+
+struct nwindow *nw = 0;
+
+int main(int argc, char *argv[])
+{
+	/* Setup the window */
+	nw = nw_create_default();
+
+	int xsize = nw_width(nw);
+	int ysize = nw_height(nw);
+
+	nw_clear(nw,0,0,xsize,ysize);
+
+	float xlow = -2.0;
+	float ylow = -1.5;
+	float xfactor = 2.5/xsize;
+	float yfactor = 3.0/ysize;
+
+
+	/* For each point, see if it is in the Mandelbrot set */
+	int iter,i,j;
+
+	for(i=0;i<xsize;i++) {
+		for(j=0;j<ysize;j++) {
+			float x = i*xfactor + xlow;
+			float y = j*yfactor + ylow;
+			iter = in_set(x,y);
+			plot_point(iter,i,j);
+			nw_flush(nw);
+		}
+		syscall_process_yield();
+	}
+
+	return 0;
+}
+
+int in_set( float x0, float y0 )
+{
+	int i=0;
+	float x=x0;
+	float y=y0;
+
+	while( x*x + y*y < 4 && i<MAX_ITERS) {
+		float t = x*x - y*y + x0;
+		y = 2*x*y + y0;
+		x = t;
+		i++;
+	}
+	return i;
+}
+
+void plot_point(int iter, int j, int k)
+{
+	if(iter==MAX_ITERS) {
+		nw_fgcolor(nw,0,0,0);
+	} else {
+		int color[3];
+		color[0] = iter   % 256;
+		color[1] = iter*3 % 256;
+		color[2] = iter*7 % 256;
+		nw_fgcolor(nw,color[0],color[1],color[2]);
+	}
+	nw_rect(nw,j,k,1,1);
+}