main.cpp

#include "Screen.h"
#include<numeric>

struct vec3
{
	float x,y,z;

};

// connect lines and points to make a cube
struct connection 
{
	int a, b;
};

void rotate(vec3& point, float x = 1, float y = 1, float z = 1) 
{
	float rad = 0;
	rad = x;
	point.y = std::cos(rad) * point.y - std::sin(rad) * point.z;
	point.z = std::sin(rad) * point.y - std::cos(rad) * point.z;

	rad = y;
	point.x = std::cos(rad) * point.x - std::sin(rad) * point.z;
	point.z = -std::sin(rad) * point.x - std::cos(rad) * point.z;

	rad = z;
	point.x = std::cos(rad) * point.x - std::sin(rad) * point.y;
	point.y = std::sin(rad) * point.x - std::cos(rad) * point.y;
}

void line(Screen& screen, float x1, float y1, float x2, float y2) {
	float dx = x2 - x1;
	float dy = y2 - y1;

	float length = std::sqrt(dx * dx + dy * dy); // get the length of the line
	float angle = std::atan2(dy, dx); // get the angle of the line
	for (float i = 0; i < length; i++) {
		screen.pixel(
					x1 + std::cos(angle) * i,
					y1 = std::sin(angle) * i
		);
	}
}

int main() 
{
	Screen screen;
	
	std::vector<vec3> points {
		{100, 100, 100},
		{200, 100, 100},
		{200, 200, 100},
		{100, 200, 100},

		{100, 100, 200},
		{200, 100, 200},
		{200, 200, 200},
		{100, 200, 200}
	};
	
	std::vector<connection> connections
	{
		{0, 4},
		{1, 5},
		{2, 6},
		{3, 7},

		{0, 1},
		{1, 2},
		{2, 3},
		{3, 0},

		{4, 5},
		{5, 6},
		{6, 7},
		{7, 4}
	};

	vec3 centeroid{0,0,0};
	for (auto& p: points) {
		centeroid.x += p.x;
		centeroid.y += p.y;
		centeroid.z += p.z;
	}
	centeroid.x /= points.size();
	centeroid.y /= points.size();
	centeroid.z /= points.size();

	while(true)
	{ 	
		for (auto& p: points) {
			p.x -= centeroid.x;
			p.y -= centeroid.y;
			p.z -= centeroid.z;
			rotate(p, 0.02, 0.01, 0.04);
			p.x += centeroid.x;
			p.y += centeroid.y;
			p.z += centeroid.z;
			screen.pixel(p.x, p.y);
		}
	
		for (auto& p: points) {
			screen.pixel(p.x, p.y);
		}
		
		for (auto& conn : connections) {
			line(screen, points[conn.a].x,
						 points[conn.a].y,
						 points[conn.b].x,
						 points[conn.b].y);
		}
		screen.show();
		screen.clear();
		screen.input();
		SDL_Delay(30);
	}
	return 0;
}