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#include <u.h>
#include <libc.h>
#include <draw.h>
#include "libgeometry/geometry.h"
#include "dat.h"
#include "fns.h"
static void
sprite_step(Sprite *spr, ulong Δt)
{
if(spr->nframes < 2)
return;
spr->elapsed += Δt;
if(spr->elapsed >= spr->period){
spr->elapsed -= spr->period;
spr->curframe = ++spr->curframe % spr->nframes;
}
}
static void
sprite_draw(Sprite *spr, Image *dst, Point dp)
{
Point sp = (Point){
spr->curframe * Dx(spr->r),
0
};
sp = addpt(spr->sp, sp);
draw(dst, rectaddpt(spr->r, dp), spr->sheet, nil, sp);
}
Sprite *
newsprite(Image *sheet, Point sp, Rectangle r, int nframes, ulong period)
{
Sprite *spr;
spr = emalloc(sizeof(Sprite));
spr->sheet = sheet;
spr->sp = sp;
spr->r = r;
spr->nframes = nframes;
spr->curframe = 0;
spr->period = period;
spr->elapsed = 0;
spr->step = sprite_step;
spr->draw = sprite_draw;
return spr;
}
Sprite *
readsprite(char *sheetfile, Point sp, Rectangle r, int nframes, ulong period)
{
Image *sheet;
int fd;
fd = open(sheetfile, OREAD);
if(fd < 0)
sysfatal("readsprite: %r");
sheet = readimage(display, fd, 1);
close(fd);
return newsprite(sheet, sp, r, nframes, period);
}
void
delsprite(Sprite *spr)
{
freeimage(spr->sheet);
free(spr);
}
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