initial commit

oscar64/samples/fractals/mbhires.c

@@ -0,0 +1,65 @@
+#include <string.h>
+#include <c64/vic.h>
+#include <c64/memmap.h>
+#include <conio.h>
+
+// Address of hires buffer and color buffer
+#define Screen	((char *)0xe000)
+#define Color	((char *)0xc800)
+
+int main(void)
+{
+	// Install the IRQ trampoline
+	mmap_trampoline();
+
+	// Turn of the kernal ROM
+	mmap_set(MMAP_NO_ROM);
+
+	// Switch VIC into hires mode
+	vic_setmode(VICM_HIRES, Color, Screen);
+
+	// Clear the screen
+	memset(Screen, 0, 8000);
+	memset(Color, 0x10, 1000);
+
+	// Loop over all pixels
+	int	py, px;
+	
+	for(py=0; py<200; py++)
+	{
+		for(px=0; px<320; px++)
+		{
+			// Value in the complex plane
+
+			float	xz = (float)px * (3.5 / 320.0)- 2.5;
+			float	yz = (float)py * (2.0 / 200.0) - 1.0;
+			
+			// Iterate up to 32 times
+			float	x = 0.0, y = 0.0;
+			int		i;
+			for(i=0; i<32; i++)
+			{
+				if (x * x + y * y > 4.0) break;
+						
+				float	xt = x * x - y * y + xz;
+				y = 2 * x * y + yz;
+				x = xt;
+			}
+		
+			// Set a pixel if exceeds bound in less than 32 iterations
+			if (i < 32)
+				Screen[320 * (py >> 3) + (py & 7) + (px & ~7)] |= 0x80 >> (px & 7);
+		}
+	}
+	
+	// Re-enable the kernal
+	mmap_set(MMAP_NO_BASIC);
+
+	// Wait for key press
+	getch();	
+
+	// Restore VIC state
+	vic_setmode(VICM_TEXT, (char *)0x0400, (char *)0x1000);
+
+	return 0;
+}