#include <cmath>
#include <iostream>
#include <sstream>
#include <GL/freeglut.h>
#include "Point.h"


#define X_MIN_RANGE 0.0
#define X_MAX_RANGE 10.0
#define Y_MIN_RANGE 0.0
#define Y_MAX_RANGE 10.0

using namespace std;

void initGLUT () {
    glutInitDisplayMode(GLUT_SINGLE | GLUT_RGB);
    glutInitWindowSize(400, 400);
    glutInitWindowPosition(100, 100);
    glutCreateWindow("triunghi cu punct");
}

void drawAxis() {
    glLineWidth(2.0);
    glColor3f(0.0, 0.0, 0.0);
    glBegin(GL_LINES);
        glVertex2f(0.0, 0.0);
        glVertex2f(X_MAX_RANGE, 0.0);
        glVertex2f(0.0, 0.0);
        glVertex2f(0.0, Y_MAX_RANGE);

        for (int i = 0; i <= 10; i++) {
            glVertex2f(i, 0.0);
            glVertex2f(i, 0.3);

            glVertex2f(0.0, i);
            glVertex2f(0.3, i);
        }
    glEnd();
}

Point A, B, C, M;
void draw() {
    glClearColor(1.0, 1.0, 1.0, 0.0);
    glClear(GL_COLOR_BUFFER_BIT);

    drawAxis();

    glColor3f(0.0, 0.0, 0.0);
    glLineWidth(2.0);
    glPolygonMode(GL_FRONT_AND_BACK, GL_LINE);
    glBegin(GL_TRIANGLES);
        glVertex2f(A.getX(), A.getY());
        glVertex2f(B.getX(), B.getY());
        glVertex2f(C.getX(), C.getY());
    glEnd();

    M.draw();

    glFlush();
}

float computeArea (Point A, Point B, Point C) {
    float xA = A.getX();
    float yA = A.getY();
    float xB = B.getX();
    float yB = B.getY();
    float xC = C.getX();
    float yC = C.getY();

    float delta = xA * (yB - yC) +
                  xB * (yC - yA) +
                  xC * (yA - yB);
    float area = abs(delta)/2;

    return area;
}

void checkIfInside () {
    float areaABC = computeArea (A, B, C);
    float areaAMB = computeArea (A, M, B);
    float areaBMC = computeArea (B, M, C);
    float areaCMA = computeArea (C, M, A);

    cout << areaABC << endl;
    cout << areaAMB + areaBMC + areaCMA << endl;
    cout << areaAMB * areaBMC * areaCMA << endl;

    M.setSize(5.0);
    if (areaABC == areaAMB + areaBMC + areaCMA) {
        // set M's color and size as green
        M.setColor(0.0, 1.0, 0.0);
        if (areaAMB * areaBMC * areaCMA == 0) {
            // set M's color as blue
            M.setColor(0.0, 0.0, 1.0);
        }
    }
    else {
        // set M's color and size as red
        M.setColor(1.0, 0.0, 0.0);
    }

}

void initPoints(int nargs, char* args[]) {
    stringstream converter;
    for (int i = 1; i < nargs; i++) {
        converter << ' ' << args[i];
    }

    GLfloat x, y;
    converter >> x >> y;
    A = Point(x, y);

    converter >> x >> y;
    B = Point(x, y);

    converter >> x >> y;
    C = Point(x, y);

    converter >> x >> y;
    M = Point(x, y);
}

void initGL () {
    glMatrixMode(GL_PROJECTION);
    gluOrtho2D(X_MIN_RANGE, X_MAX_RANGE, Y_MIN_RANGE, Y_MAX_RANGE);

    glutDisplayFunc(draw);
}

int main (int nargs, char* args[]) {
    glutInit(&nargs, args);
    initGLUT();
    initGL();

    initPoints(nargs, args);
    checkIfInside();

    glutMainLoop();
    return 0;
}