d08c2860da
ysyx_22040000 李心杨 Linux calcite 6.6.19 #1-NixOS SMP PREEMPT_DYNAMIC Fri Mar 1 12:35:11 UTC 2024 x86_64 GNU/Linux 16:26:21 up 4 days 3:32, 2 users, load average: 0.85, 0.91, 0.95
82 lines
2 KiB
C
82 lines
2 KiB
C
/**
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* Original author:
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* https://twitter.com/a1k0n
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* https://www.a1k0n.net/2021/01/13/optimizing-donut.html
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*
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* Change Logs:
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* Date Author Notes
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* 2006-09-15 Andy Sloane First version
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* 2011-07-20 Andy Sloane Second version
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* 2021-01-13 Andy Sloane Third version
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* 2021-03-25 Meco Man Port to RT-Thread RTOS
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*/
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include <io.h>
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#define R(mul,shift,x,y) \
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_=x; \
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x -= mul*y>>shift; \
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y += mul*_>>shift; \
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_ = (3145728-x*x-y*y)>>11; \
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x = x*_>>10; \
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y = y*_>>10;
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static char b[1760];
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static signed char z[1760];
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void donut(void) {
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int sA = 1024, cA = 0, sB = 1024, cB = 0, _;
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while(1) {
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memset(b, 32, 1760); // text buffer
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memset(z, 127, 1760); // z buffer
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int sj = 0, cj = 1024;
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for (int j = 0; j < 90; j++) {
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int si = 0, ci = 1024; // sine and cosine of angle i
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for (int i = 0; i < 324; i++) {
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int R1 = 1, R2 = 2048, K2 = 5120*1024;
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int x0 = R1*cj + R2,
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x1 = ci*x0 >> 10,
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x2 = cA*sj >> 10,
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x3 = si*x0 >> 10,
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x4 = R1*x2 - (sA*x3 >> 10),
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x5 = sA*sj >> 10,
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x6 = K2 + R1*1024*x5 + cA*x3,
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x7 = cj*si >> 10,
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x = 25 + 30*(cB*x1 - sB*x4)/x6,
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y = 12 + 15*(cB*x4 + sB*x1)/x6,
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N = (((-cA*x7 - cB*((-sA*x7>>10) + x2) - ci*(cj*sB >> 10)) >> 10) - x5) >> 7;
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int o = x + 80 * y;
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signed char zz = (x6-K2)>>15;
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if (22 > y && y > 0 && x > 0 && 80 > x && zz < z[o]) {
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z[o] = zz;
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b[o] = ".,-~:;=!*#$@"[N > 0 ? N : 0];
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}
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R(5, 8, ci, si) // rotate i
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}
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R(9, 7, cj, sj) // rotate j
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}
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R(5, 7, cA, sA);
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R(5, 8, cB, sB);
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screen_clear();
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int y = 0, x = 0;
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for (int k = 0; 1761 > k; k++) {
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if (k % 80) {
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if (x < 50) print_char(b[k], y, x);
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x ++;
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} else {
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y ++;
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x = 1;
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}
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}
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screen_refresh();
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usleep(100000);
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}
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}
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