Player doesn't move when colliding with the floor

Question

I am making a game with raylib. Collision seems to work except I can't move when I am touching the ground.

//including raylib

#include<raylib.h>

//defining the G - gravity
#define G 3.0f

//main function
int main()
{
        // player struct
        //SetExitKey();
        struct player
        {
                // old position used for colision
                Vector2 oldPos;

                //new position used for colision
                Vector2 newPos;

                // simply the player color
                Color color;
        };

        //constants
        const int screenWidth=800;
        const int screenHeight=450;

        float plSpeed=5.0f;

        //objects
        struct player pl;
        pl.newPos.x=screenWidth/2;
        pl.newPos.y=screenHeight/2;

        pl.color=MAROON;

        //player rectangle for colision
        Rectangle plr;

        //the obsacle
        Rectangle floor={
        0,400,screenWidth,55,
        };

        //creating the window

        InitWindow(screenWidth,screenHeight,"Raylib Tutorial P1");

        //target fps
        SetTargetFPS(60);

        //Main Game Loop 
        //heart of the game

        while(!WindowShouldClose())
        {
                // update position
                if (IsKeyDown(KEY_RIGHT)) pl.newPos.x += plSpeed;
                if (IsKeyDown(KEY_LEFT)) pl.newPos.x -= plSpeed;
                if (IsKeyDown(KEY_UP)) pl.newPos.y -= plSpeed;

                pl.newPos.y += G;

                //colision detection
                int coliding=0;

                if (CheckCollisionRecs(plr,floor))
                {
                coliding=1;
                }

                if(!coliding) pl.oldPos=pl.newPos;
                else pl.newPos=pl.oldPos;

                //set player rect

                plr.x=pl.newPos.x;
                plr.y=pl.newPos.y;
                plr.width=30;
                plr.height=30;


                //drawing

                BeginDrawing();

                //set background color
                ClearBackground(RAYWHITE);

                DrawRectangleRec(floor,GREEN);

                //draw player
                DrawRectangleRec(plr,pl.color);

                EndDrawing();


        }

        // De-initialization
        CloseWindow();

        return 0;
}

Here I move the player and if they collide I teleport them back to the last point. If not I update the oldPos variable.

Gnoom · Answer 1 · 2021-02-12T13:19:00.640

Because you're constantly colliding with the floor if you're on it. Then the position doesn't get updated.

I thought this:

pl.newPos.y += G;

was a problem, because I thought G should accelerate you, not move you, but apparently the player doesn't really have a speed, just a position. Currently your player can only make steps of 5 sideways, 5 up and 3 down. It seems like you can't hit the floor once you jump, because you'll stay at height 2.

Maybe you should handle your x and y directions separately when checking collisions (to fix your original problem). Your minimum step sizes also seem big, but that depends on the rest of the game.

Player doesn't move when colliding with the floor

1 Answers1