Apple-2-SW/dos33fsprogs
1
0
Fork 0
mirror of https://github.com/deater/dos33fsprogs.git synced 2025-02-28 06:30:18 +00:00
Code Issues Projects Releases Wiki Activity

mode7: more work on starfield

Browse Source
This commit is contained in:
Vince Weaver 2017-12-28 13:17:16 -05:00
parent f99a73a2b8
commit 96cd7ac131
1 changed files with 110 additions and 23 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

133
gr-sim/starfield.c
View File

@ -4,59 +4,146 @@
#include "gr-sim.h"
#define NUMSTARS 64
#define NUMSTARS 16
struct fixed_type {
char i;
unsigned char f;
};
struct star_type {
double x;
double y;
double z;
struct fixed_type x;
struct fixed_type y;
struct fixed_type z;
int color;
};
static void double_to_fixed(double d, struct fixed_type *f) {
int temp;
temp=d*256;
f->i=(temp>>8)&0xff;
f->f=temp&0xff;
}
static void print_fixed(struct fixed_type *f) {
printf("%02X.%02X",f->i,f->f);
}
static void fixed_add(struct fixed_type *x, struct fixed_type *y, struct fixed_type *z) {
int carry;
short sum;
sum=(short)(x->f)+(short)(y->f);
if (sum>=256) carry=1;
else carry=0;
z->f=sum&0xff;
z->i=x->i+y->i+carry;
}
static double fixed_to_double(struct fixed_type *f) {
double d;
d=f->i;
d+=((double)(f->f))/256.0;
// printf("(%02x.%02x)=%lf\n",f->i,f->f,*d);
return d;
}
static struct star_type stars[NUMSTARS];
int main(int argc, char **argv) {
int ch,i;
int spreadx=40;
int spready=40;
int spreadz=5;
int spreadx=256;
int spready=256;
int spreadz=16;
struct fixed_type speedz;
double_to_fixed(-0.25,&speedz);
grsim_init();
for(i=0;i<NUMSTARS;i++) {
stars[i].x=(drand48()-0.5)*spreadx;
stars[i].y=(drand48()-0.5)*spready;
stars[i].z=((drand48())*spreadz)+0.1;
printf("%.2lf,%2lf,%.2lf\n",stars[i].x,stars[i].y,stars[i].z);
double_to_fixed( (drand48()-0.5)*spreadx,&stars[i].x);
double_to_fixed( (drand48()-0.5)*spready,&stars[i].y);
double_to_fixed( ((drand48())*spreadz)+0.1,&stars[i].z);
print_fixed(&stars[i].x);
printf(",");
print_fixed(&stars[i].y);
printf(",");
print_fixed(&stars[i].z);
printf("\n");
}
gr();
while(1) {
gr();
/* Set color */
for(i=0;i<NUMSTARS;i++) {
if (stars[i].z<2) color_equals(15);
else if (stars[i].z<3) color_equals(7);
else color_equals(5);
basic_plot(stars[i].x/stars[i].z+20,
stars[i].y/stars[i].z+20);
if (stars[i].z.i<(spreadz/3)) stars[i].color=15;
else if (stars[i].z.i<(spreadz*2/3)) stars[i].color=13;
else stars[i].color=5;
}
/* draw stars */
for(i=0;i<NUMSTARS;i++) {
stars[i].z+=-0.125;
if (stars[i].z<0) {
stars[i].x=(drand48()-0.5)*spreadx;
stars[i].y=(drand48()-0.5)*spready;
stars[i].z=((drand48())*spreadz)+0.1;
int tempx,tempy;
double dx,dy;
dx=fixed_to_double(&stars[i].x)/
fixed_to_double(&stars[i].z);
tempx=dx+20;
dy=fixed_to_double(&stars[i].y)/
fixed_to_double(&stars[i].z);
tempy=dy+20;
if ((tempx<0) || (tempy<0) || (tempx>=40) ||
(tempy>=40)) {
double_to_fixed((drand48()-0.5)*spreadx,
&stars[i].x);
double_to_fixed((drand48()-0.5)*spready,
&stars[i].y);
stars[i].z.i=spreadz;
}
else {
color_equals(stars[i].color);
basic_plot(tempx,tempy);
}
}
/* Move stars */
for(i=0;i<NUMSTARS;i++) {
fixed_add(&stars[i].z,&speedz,&stars[i].z);
}
grsim_update();
ch=grsim_input();
if (ch=='q') exit(0);
usleep(30000);
usleep(10000);
}
return 0;