This document provides a comprehensive walkthrough of the OpenGL-based animation project. The goal is to understand the structure, purpose, and flow of each component in the code.

🔹 1. Preprocessor and Includes

#define STB_IMAGE_IMPLEMENTATION

This macro tells the compiler to include the actual implementation of the stb_image library functions. Without this, the header file would only provide function declarations.

#include "stb_image.h"

Includes the STB image library, which is used for loading image files (e.g., PNGs) into memory.

#include <GLUT/glut.h>

This includes the GLUT (OpenGL Utility Toolkit) library. GLUT provides cross-platform support for creating windows, handling input, and managing rendering loops.

#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#include <stdbool.h>

These are standard C libraries for input/output, memory management, mathematical operations, and boolean data types.

🔹 2. Global Variables

GLuint bg1, bg2, rocketTex;

OpenGL texture IDs that store the references for our background and rocket textures.

bool animationStarted = false;
bool rocketMode = false;
bool isPaused = false;

Booleans for controlling animation state: whether it's started, currently showing the rocket, or paused.

int frame = 0;
float ballX = 0.0f;
float ballY = -0.3f;
float ballVelocity = 0.025f;
float gravity = -0.001f;
float rocketY = -0.3f;
int bounceCount = 0;

Physics variables. ballY and rocketY track vertical positions, while ballVelocity and gravity simulate motion.

float bgAspect = 1.0f;