geometry3d.cpp

/*
 *  Tessy - An Exploration in Four Dimensions
 *  geometry3d.cpp
 *  Copyright (C) 2017  Benjamin P. Jones
 *
 *  This program is free software: you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation, either version 3 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#include "geometry3d.h"
#include "graphics.h"
#include "color.h"
#include <iostream>

Point3D::Point3D(double x, double y, double z) {
  this -> x = x;
  this -> y = y;
  this -> z = z;
}

Pixel Point3D::Projection2D(const Graphics& graphics) {
  // TODO: figure out a good place to put the "scaling" constant
  // will depend on viewer distance from screen and screen size
  // eyeballing a good size for now
  return {static_cast<int>(100*(x/z) + graphics.screenWidth/2),
          static_cast<int>(100*(y/z) + graphics.screenHeight/2)};
}

LineSegment3D::LineSegment3D(Point3D startPt, Point3D endPt)
  :
  pt0(startPt),
  pt1(endPt)
{
}

void LineSegment3D::Draw(Graphics const& graphics) {
  Pixel px0 = pt0.Projection2D(graphics);
  Pixel px1 = pt1.Projection2D(graphics);
  graphics.DrawLine(px0, px1, Colors::Red);
}

Point3D& Point3D::operator+=(const Point3D& rhs) {
  this->x += rhs.x;
  this->y += rhs.y;
  this->z += rhs.z;
  return *this;
}

Point3D& Point3D::operator-=(const Point3D& rhs) {
  this->x -= rhs.x;
  this->y -= rhs.y;
  this->z -= rhs.z;
  return *this;
}

Point3D Point3D::operator+(const Point3D& rhs) {
  return Point3D(x+rhs.x, y+rhs.y, z+rhs.z);
}

Point3D Point3D::operator-(const Point3D& rhs) {
  return Point3D(x-rhs.x, y-rhs.y, z-rhs.z);
}

void Polyhedron::DrawWireFrame(Graphics& graphics) {
  for (int i = 0; i < edges.size(); i++) {
    LineSegment3D(vertices[edges[i][0]], vertices[edges[i][1]]).Draw(graphics);
  }
}