mirror of
https://github.com/deater/dos33fsprogs.git
synced 2024-06-09 07:29:32 +00:00
192 lines
3.3 KiB
C
192 lines
3.3 KiB
C
#include <stdio.h>
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#include <stdlib.h>
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#include <unistd.h>
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#include "gr-sim.h"
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#define NUMSTARS 16
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struct fixed_type {
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char i;
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unsigned char f;
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};
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struct star_type {
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struct fixed_type x;
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struct fixed_type y;
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struct fixed_type z;
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int color;
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};
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static void double_to_fixed(double d, struct fixed_type *f) {
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int temp;
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temp=d*256;
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f->i=(temp>>8)&0xff;
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f->f=temp&0xff;
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}
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#if 0
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static void print_fixed(struct fixed_type *f) {
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printf("%02X.%02X",f->i,f->f);
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}
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#endif
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static void fixed_add(struct fixed_type *x, struct fixed_type *y, struct fixed_type *z) {
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int carry;
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short sum;
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sum=(short)(x->f)+(short)(y->f);
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if (sum>=256) carry=1;
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else carry=0;
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z->f=sum&0xff;
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z->i=x->i+y->i+carry;
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}
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static double fixed_to_double(struct fixed_type *f) {
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double d;
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d=f->i;
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d+=((double)(f->f))/256.0;
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// printf("(%02x.%02x)=%lf\n",f->i,f->f,*d);
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return d;
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}
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static struct star_type stars[NUMSTARS];
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static int random_table[256];
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static int random_pointer=0;
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static void random_star(int i) {
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/* -128 to 128 */
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/* Should we xor? */
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stars[i].x.i=random_table[random_pointer++];
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if (random_pointer>255) random_pointer=0;
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stars[i].x.f=random_table[random_pointer++];
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if (random_pointer>255) random_pointer=0;
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stars[i].y.i=random_table[random_pointer++];
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if (random_pointer>255) random_pointer=0;
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stars[i].y.f=random_table[random_pointer++];
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if (random_pointer>255) random_pointer=0;
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// double_to_fixed( (drand48()-0.5)*spreadx,&stars[i].x);
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// double_to_fixed( (drand48()-0.5)*spready,&stars[i].y);
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/* 0.1 to 16 */
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stars[i].z.i=random_table[random_pointer++]/16;
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if (random_pointer>255) random_pointer=0;
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stars[i].z.f=0x1;
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// double_to_fixed( ((drand48())*spreadz)+0.1,&stars[i].z);
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// print_fixed(&stars[i].x);
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// printf(",");
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// print_fixed(&stars[i].y);
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// printf(",");
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// print_fixed(&stars[i].z);
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// printf("\n");
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// double_to_fixed((drand48()-0.5)*spreadx,&stars[i].x);
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// double_to_fixed((drand48()-0.5)*spready,&stars[i].y);
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// stars[i].z.i=spreadz;
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}
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int main(int argc, char **argv) {
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int ch,i;
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// int spreadx=256;
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// int spready=256;
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int spreadz=16;
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struct fixed_type speedz;
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for(i=0;i<256;i++) {
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random_table[i]=rand()%256;
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printf("%d\n",random_table[i]);
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}
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double_to_fixed(-0.25,&speedz);
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grsim_init();
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/* Should NUMSTARS be prime to help with randomness */
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for(i=0;i<NUMSTARS;i++) {
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random_star(i);
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}
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home();
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gr();
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while(1) {
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gr();
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/* Set color */
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for(i=0;i<NUMSTARS;i++) {
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if (stars[i].z.i<(spreadz/3)) stars[i].color=15;
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else if (stars[i].z.i<(spreadz*2/3)) stars[i].color=13;
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else stars[i].color=5;
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}
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/* draw stars */
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for(i=0;i<NUMSTARS;i++) {
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int tempx,tempy;
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double dx,dy;
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dx=fixed_to_double(&stars[i].x)/
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fixed_to_double(&stars[i].z);
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tempx=dx+20;
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dy=fixed_to_double(&stars[i].y)/
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fixed_to_double(&stars[i].z);
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tempy=dy+20;
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if ((tempx<0) || (tempy<0) || (tempx>=40) ||
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(tempy>=40)) {
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random_star(i);
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}
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else {
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color_equals(stars[i].color);
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basic_plot(tempx,tempy);
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}
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}
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/* Move stars */
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for(i=0;i<NUMSTARS;i++) {
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fixed_add(&stars[i].z,&speedz,&stars[i].z);
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}
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grsim_update();
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ch=grsim_input();
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if (ch=='q') exit(0);
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usleep(10000);
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}
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return 0;
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}
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