// CC-BY Edouard.Thiel@univ-amu.fr - 22/01/2019

#ifndef GLAREA_H
#define GLAREA_H

#include <QKeyEvent>
#include <QTimer>
#include <QOpenGLWidget>
#include <QOpenGLFunctions>
#include <QOpenGLShaderProgram>

#include <scene.h>


class GLArea : public QOpenGLWidget,
               protected QOpenGLFunctions
{
    Q_OBJECT

public:
    explicit GLArea(QWidget *parent = 0);
    ~GLArea();

	static constexpr double distance_min = 0;
	static constexpr double distance_max = 5;
	static constexpr double distance_step = .1;

	static constexpr double focal_length_min = 0;
	static constexpr double focal_length_max = .2;
	static constexpr double focal_length_step = .005;

	static constexpr double near_clip_min = 0;
	static constexpr double near_clip_max = 1;
	static constexpr double near_clip_step = .05;

	static constexpr double far_clip_min = 2;
	static constexpr double far_clip_max = 7;
	static constexpr double far_clip_step = .1;

	static constexpr double angle_min = 0;
	static constexpr double angle_max = 360;
	static constexpr double angle_step = 1;

	double getDistance() const { return distance; }
	double getFocalLength() const { return focal_length; }
	double getNearClip() const { return near_clip; }
	double getFarClip() const { return far_clip; }
	double getAngle() const { return angle; }


public slots:
	void setDistance(double d);
    void setFocalLength(double f);
	void setNearClip(double n);
	void setFarClip(double f);
	void setAngle(double a);

signals:
	void distanceChanged(double d);
    void focalLengthChanged(double f);
	void nearClipChanged(double n);
	void farClipChanged(double f);
	void angleChanged(double a);

protected slots:
    void onTimeout();

protected:
    void initializeGL() override;
    void doProjection();
    void resizeGL(int w, int h) override;
    void paintGL() override;
    void keyPressEvent(QKeyEvent *ev) override;
    void mousePressEvent(QMouseEvent *ev) override;
    void mouseMoveEvent(QMouseEvent *ev) override;
	void wheelEvent(QWheelEvent *ev) override;

private:
    QTimer *timer = nullptr;
    double anim = 0;
    double ratio = 1;

    // Pour utiliser les shaders
    QOpenGLShaderProgram *program;
    int posAttr;
    int colAttr;
    int matrix_uniform;

	Scene scene;

	float mouse_last[2] = {0, 0};
	double horiz_angle = 0;
	double vert_angle = 0;

	double distance = 3;
	double focal_length = .1;
	double near_clip = .1;
	double far_clip = 5;
	double angle = 0;
};

#endif // GLAREA_H