101 lines
2.1 KiB
C
101 lines
2.1 KiB
C
#include <string.h>
|
|
#include <c64/vic.h>
|
|
#include <c64/memmap.h>
|
|
#include <conio.h>
|
|
#include <fixmath.h>
|
|
|
|
// Address of hires buffer and color buffers
|
|
#define Screen ((char *)0xe000)
|
|
#define Color ((char *)0xc800)
|
|
#define Color2 ((char *)0xd800)
|
|
|
|
// Bit patterns for eight different color pairs
|
|
char colors[] = {
|
|
0xff, 0xff,
|
|
0xee, 0xbb,
|
|
0xaa, 0xaa,
|
|
0x88, 0x22,
|
|
|
|
0x44, 0x11,
|
|
0x55, 0x55,
|
|
0xdd, 0x77,
|
|
0x33, 0xcc
|
|
};
|
|
|
|
int main(void)
|
|
{
|
|
// Install the IRQ trampoline
|
|
mmap_trampoline();
|
|
|
|
// Turn of the kernal ROM
|
|
mmap_set(MMAP_NO_ROM);
|
|
|
|
// Switch VIC into multicolor bitmap mode
|
|
vic_setmode(VICM_HIRES_MC, Color, Screen);
|
|
|
|
// Clear the screen and set the colors
|
|
vic.color_back = 0x00;
|
|
|
|
memset(Screen, 0, 8000);
|
|
memset(Color, 0x27, 1000);
|
|
memset(Color2, 0x03, 1000);
|
|
|
|
// Loop over all pixels
|
|
int py, px;
|
|
|
|
for(py=0; py<100; py++)
|
|
{
|
|
for(px=0; px<160; px++)
|
|
{
|
|
// Value in the complex plane
|
|
|
|
// int xz = (int)(((float)px * (3.5 / 160.0) - 2.5) * 4096 + 0.5);
|
|
// int yz = (int)(((float)py * (2.4 / 100.0) - 1.2) * 4096 + 0.5);
|
|
|
|
int xz = lmul8f8s(px, (int)((3.5 / 160.0) * 4096 * 256)) - (int)(2.5 * 4096);
|
|
int yz = lmul8f8s(py, (int)((2.4 / 100.0) * 4096 * 256)) - (int)(1.2 * 4096);
|
|
|
|
// Iterate up to 32 times
|
|
int x = 0, y = 0;
|
|
int i;
|
|
for(i=0; i<32; i++)
|
|
{
|
|
unsigned long xq = lsqr4f12s(x), yq = lsqr4f12s(y);
|
|
|
|
if (xq + yq >= 0x04000000UL) break;
|
|
|
|
int xt = (int)(xq >> 12) - (int)(yq >> 12) + xz;
|
|
y = 2 * lmul4f12s(x, y) + yz;
|
|
x = xt;
|
|
}
|
|
|
|
if (i < 32)
|
|
{
|
|
// Position on screen
|
|
char * dp = Screen + 320 * (py >> 2) + 2 * (py & 3) + 2 * (px & ~3);
|
|
|
|
// Mask of pixels to change
|
|
char mask = 0xc0 >> (2 * (px & 3));
|
|
|
|
// Get the two color patterns for upper and lower half
|
|
char c0 = colors[2 * (i & 7)], c1 = colors[2 * (i & 7) + 1];
|
|
|
|
// Put the pixels into the image
|
|
dp[0] |= c0 & mask;
|
|
dp[1] |= c1 & mask;
|
|
}
|
|
}
|
|
}
|
|
|
|
// 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;
|
|
}
|