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#include <u.h>
#include <libc.h>
#include <draw.h>
#include "../geometry.h"
#include "../graphics.h"
/* requires p to be in NDC */
int
isclipping(Point3 p)
{
if(p.x > p.w || p.x < -p.w ||
p.y > p.w || p.y < -p.w ||
p.z > p.w || p.z < 0)
return 1;
return 0;
}
static Point2
flatten(Camera *c, Point3 p)
{
Point2 p2;
Matrix S = {
Dx(c->viewport->r)/2, 0, 0,
0, Dy(c->viewport->r)/2, 0,
0, 0, 1,
}, T = {
1, 0, 1,
0, 1, 1,
0, 0, 1,
};
p2 = (Point2){p.x, p.y, p.w};
if(p2.w != 0)
p2 = divpt2(p2, p2.w);
mulm(S, T);
p2 = xform(p2, S);
return p2;
}
Point
toviewport(Camera *c, Point3 p)
{
Point2 p2;
RFrame rf = {
c->viewport->r.min.x, c->viewport->r.max.y, 1,
1, 0, 0,
0, -1, 0
};
p2 = invrframexform(flatten(c, p), rf);
return (Point){p2.x, p2.y};
}
Point2
fromviewport(Camera *c, Point p)
{
RFrame rf = {
c->viewport->r.min.x, c->viewport->r.max.y, 1,
1, 0, 0,
0, -1, 0
};
return rframexform(Pt2(p.x, p.y, 1), rf);
}
void
line3(Camera *c, Point3 p0, Point3 p1, int end0, int end1, Image *src)
{
p0 = WORLD2NDC(c, p0);
p1 = WORLD2NDC(c, p1);
if(isclipping(p0) || isclipping(p1))
return;
line(c->viewport, toviewport(c, p0), toviewport(c, p1), end0, end1, 0, src, ZP);
}
Point
string3(Camera *c, Point3 p, Image *src, Font *f, char *s)
{
p = WORLD2NDC(c, p);
if(isclipping(p))
return (Point){~0, ~0};
return string(c->viewport, toviewport(c, p), src, ZP, f, s);
}
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