[rcore] IsMouseButton*(), random key codes return unexpected results

[jasoncnm]

Hi, today I've encountered a weird behaviour when I accidentally wrote

IsMouseButtonDown(KEY_S);

In my raylib project, it will sometimes return true when I'm moving my cursor. So I've written a simple test code as such

//------------------------------------------------------------------------------------
// Program main entry point
//------------------------------------------------------------------------------------
int main(void)
{
    // Initialization
    //--------------------------------------------------------------------------------------
    const int screenWidth = 1000;
    const int screenHeight = 1000;

    InitWindow(screenWidth, screenHeight, "raylib [shapes] example - starfield effect");

    Color bgColor = ColorLerp(DARKBLUE, BLACK, 0.69f);

    SetTargetFPS(60);               // Set our game to run at 60 frames-per-second
    //--------------------------------------------------------------------------------------
    
     unsigned int press_count = 0, down_count = 0, release_count = 0, up_count = 0;
    
    // Main game loop
    while (!WindowShouldClose())    // Detect window close button or ESC key
    {
        
        // Draw
        //----------------------------------------------------------------------------------
        BeginDrawing();
        
        ClearBackground(bgColor);
        
        if (IsMouseButtonPressed(KEY_S))
        {
            press_count++;
        }
        
        if (IsMouseButtonDown(KEY_S))
        {
            down_count++;
        }
        
        if (IsMouseButtonReleased(KEY_S))
        {
            release_count++;
        }
        
        DrawCircleV(GetMousePosition(), 5, RED);
        
        DrawText(TextFormat("KeyCode: %d\nPressed %d times\nDowned %d times\nReleased %d times", 
                            KEY_S, press_count, down_count, release_count), GetScreenWidth() / 2, GetScreenHeight() / 2, 20, RAYWHITE);
        
            DrawFPS(10, 10);
        EndDrawing();
        //----------------------------------------------------------------------------------
    }

    // De-Initialization
    //--------------------------------------------------------------------------------------
    CloseWindow();          // Close window and OpenGL context
    //--------------------------------------------------------------------------------------

    return 0;
}

And I got the same result, when I move around the cursor on the screen, it will increase down_count and press_count.
Here is the video of it.

2026-01-27.21-27-34.mp4

What I did to fix this was return false when the keycodes are not valid. i.e
if ((button < 0) || (button > MOUSE_BUTTON_BACK)) return false;

[raysan5]

@jasoncnm oh, interesting issue... thanks for the review. In raylib I try to avoid/minimiz the early returns, can you refactor it to be code to be:

if ((button < 0) || (button > MOUSE_BUTTON_BACK))
{
    if ((CORE.Input.Mouse.currentButtonState[button] == 1) && (CORE.Input.Mouse.previousButtonState[button] == 0)) pressed = true;
}

It will be consistent with IsKey*().

[jasoncnm]

@raysan5 I think

if ((button >= 0) && (button <= MOUSE_BUTTON_BACK))
{
    if ((CORE.Input.Mouse.currentButtonState[button] == 1) && (CORE.Input.Mouse.previousButtonState[button] == 0)) pressed = true;
}

Is the correct change, and that's updated. Thanks for the feedback!

[raysan5]

@jasoncnm Thanks for the review!