/* 
**  File name:   OpenGLModelWidget.h
**  Author:      
**  Date:        2024-10-31
**  Brief:       读取模型文件并渲染的OpenGL控件
**  Copyright (C) 1392019713@qq.com All rights reserved.
*/

#ifndef OpenGLModelWidget_H
#define OpenGLModelWidget_H

#include <QOpenGLWidget>
#include <QOpenGlFunctions_3_3_Core>
#include <QMatrix4x4>
#include <QVector2D>
#include <QVector3D>
#include <QMouseEvent>
#include <array>
#include "glm/glm.hpp"
#include "glm/ext.hpp"

/*
*@brief 定义顶点、法线、纹理坐标、面数据结构
*/
struct Vertex {
   
	glm::vec3 position;
	glm::vec3 normal;
};

/*
*@brief 读取模型文件并渲染的OpenGL控件
*/
class COpenGLModelWidget : public QOpenGLWidget, QOpenGLFunctions_3_3_Core
{
   
	Q_OBJECT
public:
	COpenGLModelWidget(QWidget*parent = nullptr);

	virtual ~COpenGLModelWidget();

	/*
	* @brief 加载模型文件
	* @param strModelFile 模型文件路径
	* @return 无
	*/
	void LoadOBJModel(const std::string& strModelFile);

	void SetShaderFilePath(const std::string& strVertFilePath, const std::string& strfragFilePath); //设置着色器文件路径

protected:
	void initializeGL();

	void paintGL();

	void resizeGL(int width, int height);

	void mouseMoveEvent(QMouseEvent* event);

	void mousePressEvent(QMouseEvent* event);

	void wheelEvent(QWheelEvent* event);

	void mouseReleaseEvent(QMouseEvent* event);

	void keyPressEvent(QKeyEvent* event);

	void keyReleaseEvent(QKeyEvent* event);

private:
	void AutoNormal(); //计算法线

	std::string GetFileConTent(const std::string& strFilePath) const;

	glm::vec3 ComputeNormalBiased(glm::vec3 const& a, glm::vec3 const& b,
		glm::vec3 const& c); //计算平滑法线

	glm::mat4x4 GetViewMatrix() const; //视图矩阵

	glm::mat4x4 GetProjectionMatrix() const; //投影矩阵

	void NormalizeAngle(int &nAngle); //修正角度

	void Orbit(glm::vec2 delta, bool isDrift); //轨道旋转

	void Zoom(float delta, bool isHitchcock); //缩放

	void Pan(glm::vec2 delta);//平移

private:
	std::vector<Vertex> m_vecVertices; //顶点数据

	std::vector<glm::uvec3> m_vecFaces; //面数据

	unsigned int m_unVAO; //顶点数组对象
	unsigned int m_unVBO; //顶点缓冲对象
	unsigned int m_unEBO; //索引缓冲对象
	unsigned int m_unShaderProgram; //着色器程序

	std::string m_strFragFilePath; //片元着色器文件路径
	std::string m_strVertFilePath; //顶点着色器文件路径

	glm::vec2 lastpos;
	bool moving = false;
	glm::vec3 eye = {
    0, 0, 5 };
	glm::vec3 lookat = {
    0, 0, 0 };
	glm::vec3 up_vector = {
    0, 1, 0 };
	glm::vec3 keep_up_axis = {
    0, 1, 0 };
	float focal_len = 40.0f;
	float film_height = 24.0f;
	float film_width = 32.0f;
	float zoom_speed = 0.2f;
	float orbit_speed = 1.0f;
	float drift_speed = 1.0f;
	float pan_speed = 2.0f;
	int zoom_axis = 1;

	glm::vec2 mousePos;
};

#endif // !

#include "../Include/OpenGLModelWidget.h"
#include <iostream>
#include <fstream>
#include <sstream>
#include <QMatrix3x3>
    
COpenGLModelWidget::COpenGLModelWidget(QWidget* parent)
	: QOpenGLWidget(parent)
{
   

}

COpenGLModelWidget::~COpenGLModelWidget()
{
   
    makeCurrent(); 
    glDeleteBuffers(1, &m_unVBO);
    glDeleteVertexArrays(1, &m_unVAO);
    glDeleteProgram(m_unShaderProgram);
    doneCurrent();
}

void COpenGLModelWidget::LoadOBJModel(const std::string& strModelFile)
{
   
    std::ifstream file(strModelFile);
    if (!file.is_open()) {
   
        std::cerr << "Failed to open file: " << strModelFile << std::endl;
        return;
    }

    std::string line;
    while (std::getline(file, line)) 
    {
   
        if (line.substr(0, 2) == "v ") //顶点
        {
   
            std::istringstream s(line.substr(2));
            glm::vec3 vertex;
            s >> vertex.x >> vertex.y >> vertex.z;
            m_ve