#include "Camera.h"


CCamera::CCamera(void)
{
    Position = vec3(0,0,0);
    Look = vec3(0,0,-1);
    Up = vec3(0,1,0);
    Projection = mat4_identity;
}


CCamera::~CCamera(void)
{
}

inline void CCamera::Create(float x, float y, float z)
{
    Position = vec3(x, y, z);
}

void CCamera::Perspective(float fov, float aspect, float znear, float zfar)
{
//  Projection=GLPerspective(fov,aspect,znear,zfar);
    float f = (float) 1.0f/tanf(fov*(math_pi/90));
    Projection.set((float)f/aspect, 0, 0, 0,
                    0,  f,  0,  0,
                    0,  0,  (float)(zfar+znear)/(znear-zfar), -1.0,
                    0, 0, (float)(zfar*znear*2)/(znear-zfar), 0);
}

 void CCamera::Rotate(float Yaw, float Pitch)
{
    m_fYaw +=Yaw;
    m_fPitch +=Pitch;
}

void CCamera::Move(float x, float y, float z)
{
    Position +=vec3(x,y,z);
}

void CCamera::Setup(GLuint shaderProgramID)
{
    GLfloat cosYaw = cosf(3.1415*180.0/m_fYaw);
    GLfloat sinYaw = sinf(3.1415*180.0/m_fYaw);
    GLfloat cosPitch = cosf(3.1415*180.0/m_fPitch);
    GLfloat sinPitch = sinf(3.1415*180.0/m_fPitch);

    vec3 Forward(sinYaw*cosPitch, sinPitch, cosPitch*(-cosYaw));

    vec3 Look = Position + Forward;

    mat4 viewProjection =LookAt(Position,Look,Up)*Projection ;


//      mat4 asd =GLLookAt(Position,Look,Up) * Projection ;

    glUniformMatrix4fv(glGetUniformLocation(shaderProgramID,"viewProjection"),1,GL_TRUE,viewProjection.m);
}

mat4 CCamera::LookAt(vec3 Eye, vec3 Look, vec3 Up)
{
    vec3 zAxis = normalize(Eye-Look);
    vec3 xAxis = normalize(cross(Up,zAxis));
    vec3 yAxis = cross(zAxis,xAxis);

    return mat4(xAxis.x, xAxis.y, xAxis.z, (-dot(xAxis,Eye)),
                xAxis.x, xAxis.y, xAxis.z, (-dot(xAxis,Eye)),
                xAxis.x, xAxis.y, xAxis.z, (-dot(xAxis,Eye)),
                0,          0,      0,      1);
}