OpenGL学习笔记之摄像机跟随

//主函数
glutReshapeFunc(ReshapeFunc);//窗口改变时调用
//head.cpp
void ReshapeFunc(int iWidth,int iHeight)
{
    glMatrixMode(GL_PROJECTION);//将视口矩阵与投影矩阵设置为当前矩阵
    glLoadIdentity();
    glViewport(0,0,iWidth,iHeight);//视口矩阵
    //glOrtho(-1,1,-1,1,-1,1);//正交投影(2D)
    gluPerspective(90,(float)iWidth/(float)iHeight,0.3,1000);//透视投影（3D）
}
//摄像机类
#pragma once

#include "Vector3D.h"

class Camera
{
public:

    Vector3D m_vEye;//摄像机位置

    Vector3D m_vLookAt;//摄像机看向的点

    Vector3D m_vUp;

    Vector3D m_vOffset;

    Camera();

    void Update();
};

#include "Camera.h"

Camera::Camera():m_vEye(0,0,2),m_vLookAt(0,0,0),m_vUp(0,1,0),m_vOffset(0,3,6)
{

}

void Camera::Update()
{
    m_vEye = m_vLookAt + m_vOffset;
}

//游戏管理器

#pragma once

#include "Tool.h"
#include "Camera.h"

class CGameManager
{
    GLuint TextureID;//纹理编号

    Vector3D m_vPos;//平移

    float m_fAngle;//旋转角度

    Camera m_Camera;//摄像机

    BITMAPFILEHEADER* pBmpFileHeader;//指向位图文件的指针

    CGameManager();

    CGameManager(const CGameManager& that);

public:

    static CGameManager& GetInstance();

    void Init();

    void Darw();

    void Run();

    void End();

    void KeyboardFunc(unsigned char Key,int x,int y);

    void SpecialFunc(int Key,int x,int y);

    void MouseFunc(int button,int state,int x,int y);

    GLuint LoadTexture(const char* pFileName);//加载纹理

    BMP LoadBmp(const char* pFileName);//加载位图
};

#include "GameManager.h"

CGameManager::CGameManager()
{
    m_fAngle = 0.0f;
}

CGameManager::CGameManager(const CGameManager& that)
{
    m_fAngle = that.m_fAngle;
}

CGameManager& CGameManager::GetInstance()
{
    static CGameManager gameManager;
    return gameManager;
}

void CGameManager::Init()
{
    TextureID = LoadTexture("Texture.bmp");
}

void CGameManager::Darw()
{
    glBindTexture(GL_TEXTURE_2D,TextureID);//将TextureID所绑定的纹理作为当前绘图纹理

    glMatrixMode(GL_MODELVIEW);//将世界变换矩阵与摄像机矩阵设置为当前矩阵

    glLoadIdentity();//将当前矩阵设置为单位矩阵

    //设置摄像机变换矩阵
    gluLookAt(m_Camera.m_vEye.m_fX,m_Camera.m_vEye.m_fY,m_Camera.m_vEye.m_fZ,
        m_Camera.m_vLookAt.m_fX,m_Camera.m_vLookAt.m_fY,m_Camera.m_vLookAt.m_fZ,
        m_Camera.m_vUp.m_fX,m_Camera.m_vUp.m_fY,m_Camera.m_vUp.m_fZ);

    glTranslatef(m_vPos.m_fX,m_vPos.m_fY,m_vPos.m_fZ);//平移

    glRotated(m_fAngle,0,1,0);//旋转

    glBegin(GL_TRIANGLES);

    {
        glTexCoord2f(0,1);
        glVertex3f(0,5.0f,0);

        glTexCoord2f(1,1);
        glVertex3f(-5.0f,0.0f,0);

        glTexCoord2f(5.0,0);
        glVertex3f(0,0.0f,-5.0f);

        glTexCoord2f(0,1);
        glVertex3f(0,5.0f,0);

        glTexCoord2f(1,1);
        glVertex3f(-5.0f,0.0f,0);

        glTexCoord2f(5.0,0);
        glVertex3f(0,0.0f,5.0f);

        glTexCoord2f(0,1);
        glVertex3f(0,5.0f,0);

        glTexCoord2f(1,1);
        glVertex3f(5.0f,0.0f,0);

        glTexCoord2f(5.0,0);
        glVertex3f(0,0.0f,5.0f);

        glTexCoord2f(0,1);
        glVertex3f(0,5.0f,0);

        glTexCoord2f(1,1);
        glVertex3f(5.0f,0.0f,0);

        glTexCoord2f(5.0,0);
        glVertex3f(0,0.0f,-5.0f);
    }

    glEnd();

}

void CGameManager::Run()
{
    m_Camera.m_vLookAt = m_vPos;//让摄像机看向英雄
    m_Camera.Update();//更新摄像机位置
}

void CGameManager::End()
{
}
void CGameManager::KeyboardFunc(unsigned char Key,int x,int y)
{
    if(Key == 'w' || Key == 'W')
    {
        m_vPos.m_fZ--;
        std::cout<<"向前走"<if(Key == 's' || Key == 'S')
    {
        m_vPos.m_fZ++;
    }

    if(Key == 'a' || Key == 'A')
    {
        m_fAngle++;
    }

    if(Key == 'd' || Key == 'D')
    {
        m_fAngle--;
    }
}

void CGameManager::SpecialFunc(int Key,int x,int y)
{
    if(Key == GLUT_KEY_UP)
    {

    }

    if(Key == GLUT_KEY_DOWN)
    {
    }

    if(Key == GLUT_KEY_LEFT)
    {

    }

    if(Key == GLUT_KEY_RIGHT)
    {

    }
}

void CGameManager::MouseFunc(int button,int state,int x,int y)
{
    if(button == 0)
    {
        if(state == 0)
        {
            std::cout<<"鼠标左键按下"<if(state == 1)
        {
            std::cout<<"鼠标左键抬起"<if(button == 1)
    {
        if(state == 0)
        {
            std::cout<<"鼠标中键按下"<if(state == 1)
        {
            std::cout<<"鼠标中键抬起"<if(button == 2)
    {
        if(state == 0)
        {
            std::cout<<"鼠标右键按下"<if(state == 1)
        {
            std::cout<<"鼠标右键抬起"<const char* pFileName)//加载纹理
{
    GLuint TextureID;//

    glGenTextures(1,&TextureID);//在显存创建一个空间，并得到空间编号

    glBindTexture(GL_TEXTURE_2D,TextureID);//将创建的空间与TextureID号绑定

    BMP bmp = LoadBmp(pFileName);//加载位图

    glTexParameterf(GL_TEXTURE_2D/*二维纹理*/,GL_TEXTURE_MIN_FILTER/*缩小*/,GL_LINEAR/*线性采样*/);//设置纹理参数

    glTexParameterf(GL_TEXTURE_2D/*二维纹理*/,GL_TEXTURE_MAG_FILTER/*放大*/,GL_LINEAR/*线性采样*/);//设置纹理参数

    //把图片处理为纹理
    glTexImage2D(GL_TEXTURE_2D/*二维纹理*/,0/*表示不创建多级渐进纹理*/,GL_RGB/*RGB模式*/,
        bmp.iWidth/*纹理像素宽*/,bmp.iHeight/*纹理像素高*/,0/*不设置纹理边界*/,
        GL_BGR_EXT/*表示纹理像素的格式为B、G、R的排列*/,GL_UNSIGNED_BYTE,bmp.pColor/*纹理像素颜色的起始地址*/);

    return TextureID;
}

BMP CGameManager::LoadBmp(const char* pFileName)
{
    FILE* pFile;//文件指针
    fopen_s(&pFile,pFileName,"rb");//打开文件名为pFileName的文件
    if(pFile == NULL)
        std::cout<<"文件不存在！"<0,SEEK_END);//让文件指针偏向文件尾
    int iFileLength = ftell(pFile);//得到文件的大小
    rewind(pFile);//让文件指针指向文件头
    pBmpFileHeader = (BITMAPFILEHEADER*)new char[iFileLength];
    fread(pBmpFileHeader,1,iFileLength,pFile);//将文件读取到pBmpFileHeader指向的内存中
    fclose(pFile);//关闭文件

    if(pBmpFileHeader->bfType != 'MB')//如果文件的类型的不是位图文件（MB--代表位图）
    {
        delete [] pBmpFileHeader;//释放内存
        return BMP(0,0,0);//返回空位图
    }
    BMP bmp;//定义一个BMP结构体的对象bmp
    bmp.iWidth = ((BITMAPINFOHEADER*)(pBmpFileHeader + 1))->biWidth;
    bmp.iHeight = ((BITMAPINFOHEADER*)(pBmpFileHeader + 1))->biHeight;
    bmp.pColor = (char*)pBmpFileHeader + pBmpFileHeader->bfOffBits;//颜色的偏移量

    return bmp;
}

//代码很多都是重复的，下次我只粘贴部分代码