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#include <u.h>
#include <libc.h>
#include <draw.h>
#include <geometry.h>
#include <graphics.h>
static int
max(int a, int b)
{
return a > b ? a : b;
}
static void
verifycfg(Camera *c)
{
assert(c->viewport != nil);
if(c->ptype == Ppersp)
assert(c->fov > 0 && c->fov < 360);
assert(c->clip.n > 0 && c->clip.n < c->clip.f);
}
void
configcamera(Camera *c, Image *v, double fov, double n, double f, Projection p)
{
c->viewport = v;
c->fov = fov;
c->clip.n = n;
c->clip.f = f;
c->ptype = p;
reloadcamera(c);
}
void
placecamera(Camera *c, Point3 p, Point3 focus, Point3 up)
{
c->p = p;
if(focus.w == 0)
c->bz = focus;
else
c->bz = normvec3(subpt3(c->p, focus));
c->bx = normvec3(crossvec3(up, c->bz));
c->by = crossvec3(c->bz, c->bx);
}
void
aimcamera(Camera *c, Point3 focus)
{
placecamera(c, c->p, focus, c->by);
}
void
reloadcamera(Camera *c)
{
double a;
double l, r, b, t;
verifycfg(c);
switch(c->ptype){
case Portho:
/*
r = Dx(c->viewport->r)/2;
t = Dy(c->viewport->r)/2;
l = -r;
b = -t;
*/
l = t = 0;
r = Dx(c->viewport->r);
b = Dy(c->viewport->r);
orthographic(c->proj, l, r, b, t, c->clip.n, c->clip.f);
break;
case Ppersp:
a = (double)Dx(c->viewport->r)/Dy(c->viewport->r);
perspective(c->proj, c->fov, a, c->clip.n, c->clip.f);
break;
default: sysfatal("unknown projection type");
}
}
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