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#include <u.h>
#include <libc.h>
#include <draw.h>
#include <memdraw.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.fb != nil);
if(c->ptype == Ppersp)
assert(c->fov > 0 && c->fov < 360);
assert(c->clipn > 0 && c->clipn < c->clipf);
}
static void
updatefb(Camera *c, Rectangle r, ulong chan)
{
Memimage *fb;
fb = allocmemimage(r, chan);
if(fb == nil)
sysfatal("allocmemimage: %r");
c->viewport.fb = fb;
c->viewport.p = Pt2(r.min.x,r.max.y,1);
}
Camera*
alloccamera(Rectangle r, ulong chan)
{
Camera *c;
c = malloc(sizeof(Camera));
if(c == nil)
sysfatal("malloc: %r");
memset(c, 0, sizeof *c);
c->viewport.bx = Vec2(1,0);
c->viewport.by = Vec2(0,-1);
updatefb(c, r, chan);
c->updatefb = updatefb;
}
void
configcamera(Camera *c, double fov, double n, double f, Projection p)
{
c->fov = fov;
c->clipn = n;
c->clipf = 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.fb->r)/2;
t = Dy(c->viewport.fb->r)/2;
l = -r;
b = -t;
*/
l = t = 0;
r = Dx(c->viewport.fb->r);
b = Dy(c->viewport.fb->r);
orthographic(c->proj, l, r, b, t, c->clipn, c->clipf);
break;
case Ppersp:
a = (double)Dx(c->viewport.fb->r)/Dy(c->viewport.fb->r);
perspective(c->proj, c->fov, a, c->clipn, c->clipf);
break;
default: sysfatal("unknown projection type");
}
}
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