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#include <SDL.h>
#include <math.h>
#include "vorconfig.h"
#include "globals.h"
#include "dust.h"
#include "float.h"
#include "mt.h"
struct dust_mote {
float x,y,z;
Uint16 color;
};
struct dust_mote motes[N_DUST_MOTES];
void
init_dust(void)
{
int i, b;
for(i=0; i<N_DUST_MOTES; i++) {
motes[i].x = frnd()*(XSIZE-5);
motes[i].y = frnd()*(YSIZE-5);
motes[i].z = MAX_DUST_DEPTH*sqrt(frnd());
b = (MAX_DUST_DEPTH - motes[i].z) * 255.0 / MAX_DUST_DEPTH;
motes[i].color = SDL_MapRGB(surf_screen->format, b, b, b);
}
}
void
move_dust(void)
{
int i;
float xscroll = screendx * t_frame;
float yscroll = screendy * t_frame;
for(i=0; i<N_DUST_MOTES; i++) {
motes[i].x -= xscroll / (1.3 + motes[i].z);
motes[i].x = fwrap(motes[i].x, XSIZE);
motes[i].y -= yscroll / (1.3 + motes[i].z);
motes[i].y = fwrap(motes[i].y, YSIZE);
}
}
void
draw_dust(void)
{
int i;
uint16_t *pixels = surf_screen->pixels;
for(i=0; i<N_DUST_MOTES; i++) {
pixels[surf_screen->pitch/2*(int)motes[i].y + (int)motes[i].x] = motes[i].color;
}
}
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