#include "face.h"
#include <cmath>

float Face::sign (QVector2D p1, QVector2D p2, QVector2D p3)
{
    return (p1.x() - p3.x()) * (p2.y() - p3.y()) - (p2.x() - p3.x()) * (p1.y() - p3.y());
}

bool Face::PointInFace (QVector2D pt)
{
    Q_UNUSED(pt);
    return true;
}

Face::Face(Vertex *v1,TileVertexInfo *vi1,  Vertex *v2,TileVertexInfo *vi2,Vertex *v3,TileVertexInfo *vi3)
{m_subface= NULL;
    setSettings(v1,vi1,v2,vi2,v3,vi3);
}

void Face::setSettings(Vertex *v1, TileVertexInfo *vi1, Vertex *v2, TileVertexInfo *vi2, Vertex *v3, TileVertexInfo *vi3)
{
    m_v1 = v1;
    m_v2 = v2;
    m_v3 = v3;
    m_vi1 = vi1;
    m_vi2 = vi2;
    m_vi3 = vi3;
    recalcNormal();
}

void Face::recalcNormal()
{
    QVector3D v1=QVector3D(m_v1->position().x(),m_v1->position().y(),m_vi1->height());
    QVector3D v2=QVector3D(m_v2->position().x(),m_v2->position().y(),m_vi2->height());
    QVector3D v3=QVector3D(m_v3->position().x(),m_v3->position().y(),m_vi3->height());

    QVector3D va = v1 - v2;
    QVector3D vb = v3 - v2;
    m_normal = QVector3D::crossProduct(va,vb);
    if (m_normal.z() < 0.0f) {
        m_normal = -m_normal;
    }
    m_normal.normalize();
}

QVector3D Face::normal()
{
    return m_normal;
}

static inline bool pointMatch(const QVector2D& p1, const QVector2D& p2)
{
    return (std::abs(p1.x() - p2.x()) < 1e-4f) && (std::abs(p1.y() - p2.y()) < 1e-4f);
}

void Face::findFaces(std::vector<Face *> &vec, QVector2D s)
{
    if (m_subface!=NULL) {
        for (int i=0; i<4;i++) {
            m_subface[i].findFaces(vec,s);
        }
    }
    else {
        if (m_v1 && m_v2 && m_v3 && (
                pointMatch(m_v1->position(), s) ||
                pointMatch(m_v2->position(), s) ||
                pointMatch(m_v3->position(), s))) {
            vec.push_back(this);
        }
    }
}