Files
SoftwareRenderer/polygon.hpp

65 lines
1.8 KiB
C++

#ifndef POLYGON_H
#define POLYGON_H
#include "fastmath.hpp"
struct polygon {
vec3 points[3];
decimal delta[9];
bool skip = false;
decimal bounding[4]; // min x, max x, min y, max y
polygon(const vec3 &v1, const vec3 &v2, const vec3 &v3)
: points{v1, v2, v3}, delta{} {}
polygon() : points{}, delta{} {}
void calcDelta() {
for (int i = 0; i < 3; i++) {
int n = (i + 1) % 3;
delta[i * 3] = points[i].y() - points[n].y();
delta[i * 3 + 1] = points[n].x() - points[i].x();
delta[i * 3 + 2] =
points[i].x() * points[n].y() - points[i].y() * points[n].x();
}
bounding[0] = points[0].x();
bounding[1] = points[0].x();
bounding[2] = points[0].y();
bounding[3] = points[0].y();
for (int i = 1; i < 3; i++) {
if (bounding[0] > points[i].x())
bounding[0] = points[i].x();
if (bounding[1] < points[i].x())
bounding[1] = points[i].x();
if (bounding[2] > points[i].y())
bounding[2] = points[i].y();
if (bounding[3] < points[i].y())
bounding[3] = points[i].y();
}
}
const bool contains(const vec3 &p) {
// if (skip)
// return false;
for (int i = 0; i < 3; i++) {
vec3 d = p;
if ((((d.x().i >> SHIFT_AMOUNT) * delta[i * 3].i +
(d.y().i >> SHIFT_AMOUNT) * delta[i * 3 + 1].i +
delta[i * 3 + 2].i) >>
SHIFT_AMOUNT) > 0)
return false;
}
return true;
}
friend std::ostream &operator<<(std::ostream &os, const polygon &p) {
for (int i = 0; i < 3; i++) {
os << p.points[i];
}
return os;
}
};
#endif