I have made my own collision checker system for a demo but my collisions are not interacting properly

Question

So I have made a simple demo for rect collision checking but when it comes to stopping the objects from going through each other, my code leaves a small gap between the two objects for no apparent reason even though there should be no space left when the objects collide. I do not fully know why this happens yet but I know the bug is in the checkCollisionRect() function as it is the one that is in charge of handling the behaviour of the rects.

Code:

#include <stdio.h>
#include <stdlib.h>
#include <GL/glut.h>

#define or ||
#define and &&
#define pCharacter "%c \n"
#define pInteger "%d \n"
#define pFloat "%f \n"
#define pDouble "%lf \n"
#define pUnsighned "%u \n"
#define pString "%s \n"

/*
format string:| input type:
      %c      | character
      %d      | digit (integer)
      %f      | float
      %lf     | double
      %u      | unsigned
      %s      | string
*/

int width=1000; //Screen width
int height=500; //Screen height
int px=200; //Player pos x
int py=100; //Player pos y
float playerSpeed=5.0;

void drawRect(int tlx,int tly,int boxWidth,int boxHeight){
 glBegin(GL_POLYGON);
 glVertex2f(tlx,tly+boxHeight); //Bottom Left
 glVertex2f(tlx,tly); //Top Left
 glVertex2f(tlx+boxWidth,tly); //Top Right
 glVertex2f(tlx+boxWidth,tly+boxHeight); //Bottom Right
 glEnd();
}

void checkCollisionRect(x1,y1,w1,h1,x2,y2,w2,h2){
 if(x1>x2+w2 or x1+w1<x2 or y1>y2+h2 or y1+h1<y2){
  glColor3f(0,1,0);
 }
 else{
  glColor3f(1,0,0);
  if(x1<x2+w2 and x1+w1>x2 and y1<y2+h2){
   py-=playerSpeed;
   printf("top\n");
  }
  if(y1+h1>y2 and y1<y2+h2 and x1<x2+w2){
   px-=playerSpeed;
   printf("left\n");
  }
  if(x1<x2+w2 and x1+w1>x2 and y1+h1>y2){
   py+=playerSpeed;
   printf("bottom\n");
  }
  if(y1+h1>y2 and y1<y2+h2 and x1+w1>x2){
   px+=playerSpeed;
   printf("right\n");
  }
 }
}
    
void drawSquare(px,py,size){
 glPointSize(size);
 glBegin(GL_POINTS);
 glVertex2i(px,py);
 glEnd();
}

void Buttons(unsigned char key,int x,int y){
 if(key=='a'){px-=playerSpeed;}     
 if(key=='d'){px+=playerSpeed;} 
 if(key=='w'){py-=playerSpeed;}
 if(key=='s'){py+=playerSpeed;}
}               
 
void display(){
 glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
 //-----------------------Draw----------------------
 checkCollisionRect(px,py,10,10,200,200,100,100);
 drawRect(200,200,100,100); //rect
 drawRect(px,py,10,10); //player
 //-------------------------------------------------
 glutSwapBuffers();
 glutPostRedisplay();
}

void init(){
 glClearColor(0.3,0.3,0.3,0);
 gluOrtho2D(0,width,height,0);
}

void main(int argc, char** argv){ 
 glutInit(&argc, argv);
 glutInitDisplayMode(GLUT_DOUBLE | GLUT_RGBA);
 glutInitWindowSize(width,height);
 glutCreateWindow("OpenGL");
 init();
 glutDisplayFunc(display);
 glutKeyboardFunc(Buttons);
 glutMainLoop();
}

Answer 1

I have found the final solution, there is still a small gap but there is nothing I can do about it, basically once you collide with the other rect you will enter a loop where the game will check if you are in the rect and push you back by one pixel, it will do this continuously.

void checkCollisionRect(x1, y1, w1, h1, x2, y2, w2, h2) {
    if(x1>x2+w2 or x1+w1<x2 or y1>y2+h2 or y1+h1<y2)
        glColor3f(0, 1, 0);
    else {
        glColor3f(1, 0, 0);
        if (x1 < x2) {       // player hit the left wall
            printf("Left\n");
            px -= 1;
        }
        if (x1+w1 > x2+w2) { // player hit the right wall
            printf("Right\n");
            px += 1;
        }
        if (y1 < y2) {       // player hit the top wall
            printf("Top\n");
            py -= 1;
        }
        if (y1+h1 > y2+h2) { // player hit the bottom wall
            printf("Bottom\n");
            py += 1;
        }
    }
}