Camera.cpp

#include "Camera.h"
#include <string>
#include <iostream>
#include <iomanip>

using namespace std;

Camera::Camera() {}

Camera::Camera(int cameraId,
               int projectionType,
               Vec3 pos, Vec3 gaze,
               Vec3 u, Vec3 v, Vec3 w,
               double left, double right, double bottom, double top,
               double near, double far,
               int horRes, int verRes,
               string outputFileName) {

    this->cameraId = cameraId;
    this->projectionType = projectionType;
    this->pos = pos;
    this->gaze = gaze;
    this->u = u;
    this->v = v;
    this->w = w;
    this->left = left;
    this->right = right;
    this->bottom = bottom;
    this->top = top;
    this->near = near;
    this->far = far;
    this->horRes = horRes;
    this->verRes = verRes;
    this->outputFileName = outputFileName;
}

Camera::Camera(const Camera &other) {
    this->cameraId = other.cameraId;
    this->projectionType = other.projectionType;
    this->pos = other.pos;
    this->gaze = other.gaze;
    this->u = other.u;
    this->v = other.v;
    this->w = other.w;
    this->left = other.left;
    this->right = other.right;
    this->bottom = other.bottom;
    this->top = other.top;
    this->near = other.near;
    this->far = other.far;
    this->horRes = other.horRes;
    this->verRes = other.verRes;
    this->outputFileName = other.outputFileName;
}

void Camera::computeTransforms() {
    this->computeCameraTransform();
    this->computeProjectionTransform();
    this->computeViewportTransform();

    this->perCamTransform = multiplyMatrixWithMatrix(this->projectionTransform, this->cameraTransform);
}

void Camera::computeCameraTransform() {
    double translate[4][4] = {{1, 0, 0, -(this->pos.x)},
                              {0, 1, 0, -(this->pos.y)},
                              {0, 0, 1, -(this->pos.z)},
                              {0, 0, 0, 1}};
    double rotate[4][4] = {{this->u.x, this->u.y, this->u.z, 0},
                           {this->v.x, this->v.y, this->v.z, 0},
                           {this->w.x, this->w.y, this->w.z, 0},
                           {0,         0,         0,         1}};
    this->cameraTransform = multiplyMatrixWithMatrix(rotate, translate);
}

void Camera::computeProjectionTransform() {
    switch (this->projectionType) {
        case 0: {
            double orthographic[4][4] = {{2/(this->right-this->left),0,0,-((this->right+this->left)/(this->right-this->left))},
                                         {0, 2/(this->top-this->bottom),0,-((this->top+this->bottom)/(this->top-this->bottom))},
                                         {0,0, -(2/(this->far-this->near)),-((this->far+this->near)/(this->far-this->near))},
                                         {0,0,0,1}};
            this->projectionTransform = Matrix4(orthographic);
            break;
        }
        case 1: {
            double perspective[4][4] = {{(2*this->near)/(this->right-this->left),0,(this->right+this->left)/(this->right-this->left),0},
                                        {0,(2*this->near)/(this->top-this->bottom),(this->top+this->bottom)/(this->top-this->bottom),0},
                                        {0,0,-((this->far+this->near)/(this->far-this->near)),-((2*this->far*this->near)/(this->far-this->near))},
                                        {0,0,-1,0}};
            this->projectionTransform = Matrix4(perspective);
            break;
        }
    }
}

void Camera::computeViewportTransform() {
    double viewport[4][4] = {{this->horRes / 2.0, 0,                  0,   (this->horRes - 1) / 2.0},
                             {0,                  this->verRes / 2.0, 0,   (this->verRes - 1) / 2.0},
                             {0,                  0,                  0.5, 0.5},
                             {0,                  0,                  0,   1}};
    this->viewportTransform = Matrix4(viewport);
}

ostream &operator<<(ostream &os, const Camera &c) {
    const char *camType = c.projectionType ? "perspective" : "orthographic";

    os << fixed << setprecision(6) << "Camera " << c.cameraId << " (" << camType << ") => pos: " << c.pos << " gaze: "
       << c.gaze << endl
       << "\tu: " << c.u << " v: " << c.v << " w: " << c.w << endl
       << fixed << setprecision(3) << "\tleft: " << c.left << " right: " << c.right << " bottom: " << c.bottom
       << " top: " << c.top << endl
       << "\tnear: " << c.near << " far: " << c.far << " resolutions: " << c.horRes << "x" << c.verRes << " fileName: "
       << c.outputFileName;

    return os;
}