C Raycaster Breakdown1

The White House urged to stop writing code in C/C++. Due to Garbage Collection, they found a servere safety issue. I always admired 1990s ~ 2000s developers. Of course, I wasn’t alive back then but I have some sort of Nostalgia and admiration on 1990s to 2000s developers. For all my respect, I decided to make a fps game using C and OpenGL.

Disclaimer

This code is written only in C. I used OpenGL to implement the 3D drawing in C. Shout out to ‘3D Sage’ who gave me an inspiration and way to make a game.

Code Breakdown

I am going to breakdown the code from now on. This is for my study and also those who want to make Raycaster in C.

main.c

#include <stdlib.h>
#include <glut.h>
#include <math.h>
#include "sprites.h"

#define PI 3.1415926535

float degToRad(float a) { return a * PI / 180.0; }
float FixAng(float a) { if (a > 359) { a -= 360; } if (a < 0) { a += 360; } return a; }
float distance(ax, ay, bx, by, ang) { return cos(degToRad(ang)) * (bx - ax) - sin(degToRad(ang)) * (by - ay); }
float px, py, pdx, pdy, pa;
float frame1, frame2, fps;

int currentFrame = 0;
float frameDuration = 200; // Duration each frame is displayed in milliseconds
float lastFrameSwitch = 0;

typedef struct
{
    int w, a, d, s;                     
}ButtonKeys; ButtonKeys Keys;

degToRad is a method from “math.h”.
FixAng part checks if the angle is between 0 to 360. If angle a is over 359 or 0, it corrects it by adding or subtracting 360.
distance function calculates the vector and direction. The result is scalar. If result is positive, then it means ang is in the same direction.
px, py is player position.
ButtonKeys is for controlling keys. It’s written in struct.