spectrum_cmbrot

annotate test.c @ 1:c2815c765fea

done
author John Tsiombikas <nuclear@member.fsf.org>
date Mon, 17 Feb 2014 11:00:23 +0200
parents e56d8b0eee4b
children
rev   line source
nuclear@0 1 #define FB_ADDR ((unsigned char*)0x4000)
nuclear@0 2 #define ATTR_ADDR ((unsigned char*)0x5800)
nuclear@0 3 #define LINESKIP (256 / 8)
nuclear@0 4
nuclear@0 5 unsigned char mbrot(int px, int py);
nuclear@0 6
nuclear@0 7 int main()
nuclear@0 8 {
nuclear@0 9 unsigned int i, j, k, start;
nuclear@0 10
nuclear@0 11 for(;;) {
nuclear@0 12 start = 0;
nuclear@0 13
nuclear@0 14 for(i=0; i<192; i++) {
nuclear@0 15 unsigned int banky = i & 0x3f;
nuclear@1 16 unsigned int cell = banky >> 3;
nuclear@1 17 unsigned int cline = banky & 0x7;
nuclear@1 18 unsigned int memline = cell + (cline << 3);
nuclear@0 19 unsigned char *ptr = FB_ADDR + (start + memline) * LINESKIP;
nuclear@0 20
nuclear@0 21 for(j=0; j<32; j++) { /* 256 pixels, 8 pixels per byte */
nuclear@0 22 unsigned char pixel = 0;
nuclear@0 23 for(k=0; k<8; k++) {
nuclear@0 24 unsigned char res = mbrot((j << 3) + k, i);
nuclear@0 25 pixel = pixel | (res & 1);
nuclear@0 26 if(k < 7) pixel <<= 1;
nuclear@0 27 }
nuclear@0 28 *ptr++ = pixel;
nuclear@0 29 }
nuclear@0 30
nuclear@0 31 if((i & 0x3f) == 0x3f) {
nuclear@0 32 start += 0x40;
nuclear@0 33 }
nuclear@0 34 }
nuclear@0 35 }
nuclear@0 36 }
nuclear@0 37
nuclear@0 38 #define int2fix8_8(i) ((i) << 8)
nuclear@0 39 #define fix_mul8_8(a, b) ((a >> 4) * (b >> 4))
nuclear@0 40 #define int2fix5_11(i) ((i) << 11)
nuclear@0 41 #define fix_mul5_11(a, b) ((a >> 5) * (b >> 6))
nuclear@0 42
nuclear@0 43 unsigned char mbrot(int px, int py)
nuclear@0 44 {
nuclear@0 45 unsigned char i;
nuclear@0 46 int cx, cy, zx, zy, x, y, len;
nuclear@1 47 int xop1, xop2, yop1, yop2;
nuclear@1 48 int zxop1, zxop2, zyop1, zyop2;
nuclear@0 49
nuclear@0 50 cx = int2fix8_8(px - 192) >> 6;
nuclear@0 51 cy = int2fix8_8(py - 96) >> 6;
nuclear@0 52
nuclear@0 53 cx <<= 3;
nuclear@0 54 cy <<= 3;
nuclear@0 55
nuclear@0 56 zx = cx;
nuclear@0 57 zy = cy;
nuclear@0 58
nuclear@0 59 for(i=0; i<32; i++) {
nuclear@1 60 /*x = fix_mul5_11(zx, zx) - fix_mul5_11(zy, zy) + cx;
nuclear@1 61 y = fix_mul5_11(zy, zx) + fix_mul5_11(zx, zy) + cy;*/
nuclear@1 62 zxop1 = zx >> 5;
nuclear@1 63 zxop2 = zxop1 >> 1;
nuclear@1 64 zyop1 = zy >> 5;
nuclear@1 65 zyop2 = zyop1 >> 1;
nuclear@0 66
nuclear@1 67 x = zxop1 * zxop2 - zyop1 * zyop2 + cx;
nuclear@1 68 y = zyop1 * zxop2 + zxop1 * zyop2 + cy;
nuclear@1 69
nuclear@1 70 /*len = fix_mul5_11(x, x) + fix_mul5_11(y, y);*/
nuclear@1 71 xop1 = x >> 5;
nuclear@1 72 xop2 = xop1 >> 1;
nuclear@1 73 yop1 = y >> 5;
nuclear@1 74 yop2 = yop1 >> 1;
nuclear@1 75 len = xop1 * xop2 + yop1 * yop2;
nuclear@1 76
nuclear@1 77 /*if(len > int2fix5_11(4)) return 0;*/
nuclear@1 78 if(len > 8192) return 0;
nuclear@0 79
nuclear@0 80 zx = x;
nuclear@0 81 zy = y;
nuclear@0 82 }
nuclear@0 83
nuclear@0 84 return 1;
nuclear@0 85 }