cube-game-plus-plus/client/rendering/Triangle.cpp

#include "client/rendering/Triangle.h"

Triangle::Triangle() {
}

Triangle::Triangle(const Vertex& a, const Vertex& b, const Vertex& c) : a(a), b(b), c(c) {
    Vector3 ab = b.position - a.position;
    Vector3 ac = c.position - a.position;
    normalA = ab.cross(ac);
    normalB = normalA;
    normalC = normalA;
    
    Vector2 abt = b.texture - a.texture;
    Vector2 act = c.texture - a.texture;
    
    float f = 1.0f / (abt[0] * act[1] - act[0] * abt[1]);
    
    tangentA = f * (act[1] * ab - abt[1] * ac);
    tangentA.normalize();
    tangentB = tangentA;
    tangentC = tangentA;
}