#include <string.h> // for memcpy
#include "NodeCamera.h"
#include <math.h>

static void loadIdentity(double * matrix){
    int i;

    // Build Identity matrix
    for(i=0;i<16;++i){
        double value ;
        if((i % 5) == 0)
            value = 1.0;
        else
            value = 0;
        matrix[i] = value;
    }
}

NodeCamera::NodeCamera(CameraType camera_type)
:camera_type_(camera_type){
    loadIdentity(modelview_matrix_);
    loadIdentity(projection_matrix_);
}

NodeCamera::NodeCamera(const NodeCamera& iBrother)
:camera_type_(iBrother.camera_type_){
    memcpy(modelview_matrix_, iBrother.modelview_matrix_, 16*sizeof(double));
    memcpy(projection_matrix_, iBrother.projection_matrix_, 16*sizeof(double));
}

void NodeCamera::accept(SceneVisitor& v){
    v.visitNodeCamera(*this)   ;
}

void NodeCamera::setModelViewMatrix(double modelview_matrix[16]){
    memcpy(modelview_matrix_, modelview_matrix,16*sizeof(double));
}

void NodeCamera::setProjectionMatrix(double projection_matrix[16]){
    memcpy(projection_matrix_, projection_matrix,16*sizeof(double));
}

NodeOrthographicCamera::NodeOrthographicCamera()
:NodeCamera(NodeCamera::ORTHOGRAPHIC),
left_(0),right_(0),bottom_(0),top_(0),zNear_(0),zFar_(0){
    loadIdentity(projection_matrix_);
    loadIdentity(modelview_matrix_);
}

NodeOrthographicCamera::NodeOrthographicCamera(double left
                                                , double right
                                                , double bottom
                                                , double top
                                                , double zNear
                                                , double zFar
                                                )
:NodeCamera(NodeCamera::ORTHOGRAPHIC),
left_(left),
right_(right),
bottom_(bottom),
top_(top),
zNear_(zNear),
zFar_(zFar){

    loadIdentity(projection_matrix_);

    projection_matrix_[0] = 2.0/(right-left);
    projection_matrix_[3] = -(right + left) / (right - left) ;
    projection_matrix_[5] = 2.0/(top-bottom);
    projection_matrix_[7] = -(top + bottom) / (top - bottom) ;
    projection_matrix_[10] = -2.0/(zFar-zNear);
    projection_matrix_[11] = -(zFar + zNear) / (zFar - zNear);

}

NodeOrthographicCamera::NodeOrthographicCamera(const NodeOrthographicCamera& iBrother)
:NodeCamera(iBrother),left_(iBrother.left_),right_(iBrother.right_),bottom_(iBrother.bottom_),top_(iBrother.top_),zNear_(iBrother.zNear_),zFar_(iBrother.zFar_){
}

NodePerspectiveCamera::NodePerspectiveCamera()
:NodeCamera(NodeCamera::PERSPECTIVE){
}

NodePerspectiveCamera::NodePerspectiveCamera(double fovy
                                        , double aspect
                                        , double zNear
                                        , double zFar)
:NodeCamera(NodeCamera::PERSPECTIVE){
    loadIdentity(projection_matrix_);

    double f = cos(fovy/2.0)/sin(fovy/2.0); // cotangent

    projection_matrix_[0] = f/aspect;
    projection_matrix_[5] = f;
    projection_matrix_[10] = (zNear+zFar)/(zNear-zFar);
    projection_matrix_[11] = (2.0*zNear*zFar)/(zNear-zFar);
    projection_matrix_[14] = -1.0;
    projection_matrix_[15] = 0;

}

NodePerspectiveCamera::NodePerspectiveCamera(double left,
                                        double right,
                                        double bottom,
                                        double top,
                                        double zNear,
                                        double zFar)
:NodeCamera(NodeCamera::PERSPECTIVE){
    loadIdentity(projection_matrix_);

    projection_matrix_[0] = (2.0*zNear)/(right-left);
    projection_matrix_[2] = (right+left)/(right-left);
    projection_matrix_[5] = (2.0*zNear)/(top-bottom);
    projection_matrix_[6] = (top+bottom)/(top-bottom);
    projection_matrix_[10] = - (zFar+zNear)/(zFar-zNear);
    projection_matrix_[11] = - (2.0*zFar*zNear)/(zFar-zNear);
    projection_matrix_[14] = -1.0;
    projection_matrix_[15] = 0;
}