megadrive_test2: tools/tunnel.c annotate

megadrive_test2

fixed gamepad input on real megadrive

author	John Tsiombikas <nuclear@member.fsf.org>
date	Sat, 24 Jun 2017 02:33:52 +0300
parents	72ab63f262bf
children

rev	line source
nuclear@4	1 #include <stdio.h>
nuclear@4	2 #include <stdlib.h>
nuclear@4	3 #include <math.h>
nuclear@4	4
nuclear@5	5 #define XSZ 320
nuclear@5	6 #define YSZ 240
nuclear@4	7
nuclear@4	8 int main(void)
nuclear@4	9 {
nuclear@4	10 int i, j;
nuclear@4	11 unsigned char pixels, pptr;
nuclear@5	12 float aspect = (float)XSZ / (float)YSZ;
nuclear@4	13
nuclear@4	14 pixels = malloc(XSZ * YSZ);
nuclear@4	15 pptr = pixels;
nuclear@4	16
nuclear@4	17 for(i=0; i<YSZ; i++) {
nuclear@4	18 float y = 2.0 * (float)i / (float)YSZ - 1.0;
nuclear@4	19 for(j=0; j<XSZ; j++) {
nuclear@5	20 float x = aspect * (2.0 * (float)j / (float)XSZ - 1.0);
nuclear@4	21 float tu = atan2(y, x) / M_PI * 0.5 + 0.5;
nuclear@4	22 float d = sqrt(x * x + y * y);
nuclear@5	23 float tv = d == 0.0 ? 0.0 : 0.5 / d;
nuclear@4	24
nuclear@5	25 int ty = (int)(tv * 64.0) % 14 + 1;
nuclear@4	26 int tx = (int)(tu * 256.0) & 0xf;
nuclear@4	27
nuclear@5	28 if(d < 0.2) {
nuclear@5	29 *pptr++ = 0;
nuclear@5	30 } else {
nuclear@5	31 *pptr++ = tx ? ty : 0xf;
nuclear@5	32 }
nuclear@4	33 }
nuclear@4	34 }
nuclear@4	35
nuclear@4	36 pptr = pixels;
nuclear@4	37 printf("P6\n%d %d\n15\n", XSZ, YSZ);
nuclear@4	38
nuclear@4	39 for(i=0; i<YSZ; i++) {
nuclear@4	40 for(j=0; j<XSZ; j++) {
nuclear@4	41 unsigned char c = *pptr++;
nuclear@4	42 putchar(c);
nuclear@4	43 putchar(c);
nuclear@4	44 putchar(c);
nuclear@4	45 }
nuclear@4	46 }
nuclear@4	47 fflush(stdout);
nuclear@4	48
nuclear@4	49 return 0;
nuclear@4	50 }