SModelBee/Camera.cpp at master · DrWiki/SModelBee · GitHub

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#include "Camera.h"
#include <GL/glu.h>

 /* 构造函数 */
Camera::Camera()   {}

Camera::~Camera()  {}

/* 设置摄像机的位置,朝向和向上向量 */
void Camera::setCamera( float eyeX, float eyeY, float eyeZ,
                        float lookX, float lookY, float lookZ,
                        float upX, float upY, float upZ)
{
/* 构造向量 */
    eye.set(eyeX, eyeY, eyeZ);
    look.set(lookX, lookY, lookZ);
    up.set(upX, upY, upZ);
    Vector3 upvec(up.x-eye.x,up.y-eye.y,up.z-eye.z);

/* 计算n、u、v并归一化 */
    n.set(eye.x-look.x, eye.y-look.y, eye.z-look.z);
    u.set(upvec.cross(n).x,upvec.cross(n).y,upvec.cross(n).z);
    v.set(n.cross(u).x,n.cross(u).y,n.cross(u).z);

    u.normalize();
    v.normalize();
    n.normalize();
    setModelViewMatrix();
}
/* 获取eye到坐标原点的距离 */
float Camera::getDist()
{
    float dist=pow(eye.x,2)+pow(eye.y,2)+pow(eye.z,2);
    return pow(dist,0.5);
    //return 100.0;
}
/* 计算变换后的视点矩阵 */
void Camera::setModelViewMatrix()
{
    float m[16];
    Vector3 eVec(eye.x, eye.y,eye.z);
    m[0]=u.x; m[4]=u.y; m[8]=u.z; m[12]=-eVec.dot(u);
    m[1]=v.x; m[5]=v.y; m[9]=v.z; m[13]=-eVec.dot(v);
    m[2]=n.x; m[6]=n.y; m[10]=n.z; m[14]=-eVec.dot(n);
    m[3]=0;  m[7]=0;  m[11]=0;  m[15]=1.0;
    glMatrixMode(GL_MODELVIEW);
    glLoadMatrixf(m);     //用M矩阵替换原视点矩阵
}
/* 摄像机绕n、v、u轴旋转的计算函数*/
void Camera::roll(float angle)
{
    float cs=cos(angle*3.14159265/180);
    float sn=sin(angle*3.14159265/180);
    Vector3 t(u);
    Vector3 s(v);
    u.set(cs*t.x-sn*s.x, cs*t.y-sn*s.y, cs*t.z-sn*s.z);
    v.set(sn*t.x+cs*s.x, sn*t.y+cs*s.y, sn*t.z+cs*s.z);
    setModelViewMatrix();          //每次计算完坐标轴变化后调用此函数更新视点矩阵
}

void Camera::yaw(float angle)
{
    float cs=cos(angle*3.14159265/180);
    float sn=sin(angle*3.14159265/180);
    Vector3 t(n);
    Vector3 s(u);
    n.set(cs*t.x-sn*s.x, cs*t.y-sn*s.y, cs*t.z-sn*s.z);
    u.set(sn*t.x+cs*s.x, sn*t.y+cs*s.y, sn*t.z+cs*s.z);
    setModelViewMatrix();
}

void Camera::pitch(float angle)
{
    float cs=cos(angle*3.14159265/180);
    float sn=sin(angle*3.14159265/180);
    Vector3 t(v);
    Vector3 s(n);
    v.set(cs*t.x-sn*s.x, cs*t.y-sn*s.y, cs*t.z-sn*s.z);
    n.set(sn*t.x+cs*s.x, sn*t.y+cs*s.y, sn*t.z+cs*s.z);
    setModelViewMatrix();
}
/* 摄像机绕三个轴平移的计算函数 */
void Camera::slide(float du, float dv, float dn)
{
    eye.x+=du*u.x+dv*v.x+dn*n.x;
    eye.y+=du*u.y+dv*v.y+dn*n.y;
    eye.z+=du*u.z+dv*v.z+dn*n.z;
    look.x+=du*u.x+dv*v.x+dn*n.x;
    look.y+=du*u.y+dv*v.y+dn*n.y;
    look.z+=du*u.z+dv*v.z+dn*n.z;
    setModelViewMatrix();
}
/* 摄像机初始化 */
void Camera::setShape(float viewAngle, float aspect, float Near, float Far)
{
    glMatrixMode(GL_PROJECTION);
    glLoadIdentity();                                   //设置当前矩阵模式为投影矩阵并归一化
    gluPerspective(viewAngle,aspect, Near, Far);        //对投影矩阵进行透视变换
}