mirror of
https://github.com/supleed2/EIE4-FYP.git
synced 2024-11-10 04:15:49 +00:00
69 lines
1.8 KiB
C
69 lines
1.8 KiB
C
// The donut code with fixed-point arithmetic; no sines, cosines, square roots, or anything.
|
|
// a1k0n 2020
|
|
// Code from: https://gist.github.com/a1k0n/80f48aa8911fffd805316b8ba8f48e83
|
|
// For more info:
|
|
// - https://www.a1k0n.net/2011/07/20/donut-math.html
|
|
// - https://www.youtube.com/watch?v=DEqXNfs_HhY
|
|
|
|
#include <stdio.h>
|
|
#include <stdlib.h>
|
|
#include <string.h>
|
|
|
|
#include <libbase/console.h>
|
|
|
|
#define R(mul,shift,x,y) \
|
|
_=x; \
|
|
x -= mul*y>>shift; \
|
|
y += mul*_>>shift; \
|
|
_ = 3145728-x*x-y*y>>11; \
|
|
x = x*_>>10; \
|
|
y = y*_>>10;
|
|
|
|
signed char b[1760], z[1760];
|
|
|
|
void donut(void);
|
|
void donut(void) {
|
|
int sA=1024,cA=0,sB=1024,cB=0,_;
|
|
for (;;) {
|
|
memset(b, 32, 1760); // text buffer
|
|
memset(z, 127, 1760); // z buffer
|
|
int sj=0, cj=1024;
|
|
for (int j = 0; j < 90; j++) {
|
|
int si = 0, ci = 1024; // sine and cosine of angle i
|
|
for (int i = 0; i < 324; i++) {
|
|
int R1 = 1, R2 = 2048, K2 = 5120*1024;
|
|
|
|
int x0 = R1*cj + R2,
|
|
x1 = ci*x0 >> 10,
|
|
x2 = cA*sj >> 10,
|
|
x3 = si*x0 >> 10,
|
|
x4 = R1*x2 - (sA*x3 >> 10),
|
|
x5 = sA*sj >> 10,
|
|
x6 = K2 + R1*1024*x5 + cA*x3,
|
|
x7 = cj*si >> 10,
|
|
x = 40 + 30*(cB*x1 - sB*x4)/x6,
|
|
y = 12 + 15*(cB*x4 + sB*x1)/x6,
|
|
N = (-cA*x7 - cB*((-sA*x7>>10) + x2) - ci*(cj*sB >> 10) >> 10) - x5 >> 7;
|
|
|
|
int o = x + 80 * y;
|
|
signed char zz = (x6-K2)>>15;
|
|
if (22 > y && y > 0 && x > 0 && 80 > x && zz < z[o]) {
|
|
z[o] = zz;
|
|
b[o] = ".,-~:;=!*#$@"[N > 0 ? N : 0];
|
|
}
|
|
R(5, 8, ci, si) // rotate i
|
|
}
|
|
R(9, 7, cj, sj) // rotate j
|
|
}
|
|
for (int k = 0; 1761 > k; k++)
|
|
putchar(k % 80 ? b[k] : 10);
|
|
R(5, 7, cA, sA);
|
|
R(5, 8, cB, sB);
|
|
if (readchar_nonblock()) {
|
|
getchar();
|
|
break;
|
|
}
|
|
fputs("\x1b[23A", stdout);
|
|
}
|
|
}
|