utils.cpp

#include <SDL2/SDL.h>
#include <SDL2/SDL_image.h>
#include <SDL2/SDL_timer.h>
#include <bits/stdc++.h>
using namespace std;

class vertex
{
public:
    double globalheight = 1000;
    double x = 0;
    double y = 0;
    double z = 0;
    vector<double> pt = {x, y, z};

    vertex(vector<double> i)
    {
        x = i[0];
        y = i[1];
        z = i[2];
        cout << "Vertex input successful" << endl;
    }

    vertex projected()
    {
        float fov = 30.0f;
        float scale = globalheight / 62.0f;
        vertex v = *this;

        // Perspective projection based on the Z value
        float invZ = 1.0f / (z + globalheight / 200); // Fix Z to account for the global height
        v.x = x * invZ * fov * scale + globalheight / 2.0f;
        v.y = -y * invZ * fov * scale + globalheight / 2.0f;

        // Prevent the cube from drifting
        return v;
    }

    void rotateX(float theta, vertex center)
    {
        x -= center.x;
        y -= center.y;
        z -= center.z;
        double y0 = y, z0 = z;
        y = y0 * cos(theta) - z0 * sin(theta);
        z = y0 * sin(theta) + z0 * cos(theta);
    }

    void rotateY(float theta, vertex center)
    {
        x -= center.x;
        y -= center.y;
        z -= center.z;
        double x0 = x, z0 = z;
        x = x0 * cos(theta) + z0 * sin(theta);
        z = -x0 * sin(theta) + z0 * cos(theta);
    }

    void rotateZ(float theta, vertex center)
    {
        x -= center.x;
        y -= center.y;
        z -= center.z;
        double x0 = x, y0 = y;
        x = x0 * cos(theta) - y0 * sin(theta);
        y = x0 * sin(theta) + y0 * cos(theta);
    }
};

vertex calculateCenter(const vector<vertex> &vertices)
{
    double xSum = 0, ySum = 0, zSum = 0;
    int count = vertices.size();
    for (const auto &v : vertices)
    {
        xSum += v.x;
        ySum += v.y;
        zSum += v.z;
    }
    return vertex({xSum / count, ySum / count, zSum / count});
}

bool isSafe(double x, double y)
{
    return !isnan(x) && !isnan(y) && x >= 0 && x < 1000 && y >= 0 && y < 1000;
}

void plot(vertex A, vertex B, SDL_Renderer *rend)
{
    if (!isSafe(A.x, A.y) || !isSafe(B.x, B.y))
        return;
    SDL_SetRenderDrawColor(rend, 255, 255, 255, 255);
    SDL_RenderDrawLine(rend, A.x, A.y, B.x, B.y);
}

void plotTriangle(vertex A, vertex B, vertex C, SDL_Renderer *rend)
{
    plot(A, B, rend);
    plot(C, B, rend);
    plot(A, C, rend);
}