When using al_set_new_display_flags(ALLEGRO_RESIZABLE), is there a way to do the following:

1) Have a program detect the size of the window as it's being manually changed by the player using the mouse. I understand the actual created display size remains the same, but would like to change certain objects size and position for collision detection to work correctly between the mouse pointer and those objects after the window has been resized by the player, otherwise the collision detection between the mouse pointer and those objects remains in the same position relative to the initially created display, whilst the graphics change size and position as the display window size is manually adjusted. In other words the collision detection happens in the wrong visual place on screen.

2) After initializing al_set_new_display_flags(ALLEGRO_RESIZABLE) and creating the display, is there a way to program the window display size as opposed to the player adjusting it using the mouse. It's just that if a player adjusts the window size, then switches into fullscreen, and then back to resizable, I'd like to know what the previous resizable size was so I can set it back to that size, rather than it be initiated at the actual created display size.

Part of My Next Entry Quoted Below, Which I can't Edit Now, Is BALONEY

So far I've found resizing the window with the mouse (whilst playing the game) when using ALLEGRO_RESIZABLE only shrinks or expands the graphics, which I guess is essential, as if a player manually changed the window size in this way during play and the created display al_create_display(WIDTH, HEIGHT) was to change also, then the game/programming would crash.

So what I'm finding (during play) is that even though the graphics shrink and expand as they should when using the mouse to adjust the window size, the mouse pointer collision detection isn't aligned with the graphics because the mouse pointer still references the created display al_create_display(WIDTH, HEIGHT) which understandably doesn't change as the window is resized. To describe this, if the window gets smaller the collision detection happens to the right of the objects as graphically they are displayed more to the left (the window shrinks along with the displayed graphics within it, but al_create_display(WIDTH, HEIGHT) stays the same). Similarly if the window gets larger the collision detection happens to the left of the objects.

I'm guessing now the features which I'm after don't exist within ALLEGRO. Please note this does not stop my main game from playing at all, but just messes up the various stages where I need to have the mouse effectively click on certain button images.

If access to the ALLEGRO_RESIZABLE window were available as parameters Width and Height, then I guess there would be various ways to compensate. For example if the window was made smaller, the int x = al_get_mouse_state_axis(&state, 0) could be increased proportionally to the window getting smaller effectively making int x collision detect correctly relative to al_create_display(WIDTH, HEIGHT).

With regards to my initial post where I suggested changing the size and positions of various objects, I'm now thinking that would only work if there was a second copy of the objects, one unchanged for the graphics (ALLEGRO_RESIZABLE), and one which does change proportionally to the resized window.

I think the easiest way (because of less work to do) might be the first way, adding or subtracting to the x = al_get_mouse_state_axis(&state, 0) values.

So it seems that for my question 1) I need access to the ALLEGRO_RESIABLE manually adjusted window width and height in the form of parameters, to work with within my programming, and for my question 2) I guess this also is not possible for me to do.

Are you saying if you have an object exactly in the middle of the display which can be collision detected with the mouse pointer, that when in ALLEGRO_RESIZABLE if you manually resize the window (using the mouse) to approximately half the size whilst playing, that your object which is now half the size and still in the middle of the display (like it is for me), still has the collision detection with the mouse pointer working correctly, both being aligned.

For me changing the window size does not affect the mouse position returned. If it did so proportionally to the window size being changed as I've described, that might be the perfect solution.

I've rewritten some of my last post to try and make it a bit clearer, as some of it was not good.

Thank you jmasterx for helping with this

Right, so you are proportionally resizing your elements.

Whereas in my case, in my gui, I literally have an algorithm running that says:

onResize:
position = screen / 2; //center
size = screen * 0.25f;

And thus, my mouse coordinates make sense.

I suspect that regardless of the size of your screen, your elements just RENDER proportionally, so you do not actually change their location and size.

This is the class I made that can transform your mouse.

https://github.com/jmasterx/Agui/blob/master/src/Agui/Transform.cpp

My gui uses it like this:

So the idea is, whatever transformation is applied to upscale the rendering must be applied to your mouse position.

The alternative, as I had mentioned is to change the size and position of your gui elements so that the mouse coordinates are screen-relative rather than world-oriented.

One important thing, do you call al_acknowledge_resize ?

If you do not you will get the issues you seem to be describing because the internal buffer might not resize itself if you do not acknowledge the resize event.

http://alleg.sourceforge.net/a5docs/refman/display.html#al_acknowledge_resize

It only works with that display flag
in your event loop:

case ALLEGRO_EVENT_DISPLAY_RESIZE:
//call here
break;

http://alleg.sourceforge.net/a5docs/refman/events.html#allegro_event_display_resize

What does your main loop look like?

This is old and dated but might help https://www.allegro.cc/forums/thread/603224

What if you tried:

if(ev.type == ALLEGRO_EVENT_DISPLAY_RESIZE)
{
   al_acknowledge_resize(display);
}

Also, you should really use al_wait_for_event()

That will make your game more robust, consume less cpu, and you'll know the event is real.

Thanks, think I just got a handle wich I asked for in my thread, something a NOOB to allegro 5 can understand.

The way you've done your main loop is a bit chaotic and I can't spot the problem from just looking. I would have to run it through a debugger but I don't have time right now.

Could you try to use al_wait_for_event() and sort of try to make your loop a bit more like my template one. I know the template behaves correctly.

But right now you are making an infinite while loop and not waiting for events which might be causing problems.

When you resize to half the size, it should look like when closing one eye; objects should be same size/position, just you do not see as much of them as you decrease the size.

When you acknowledge the resize event, the al_get_display_* functions should return the actual size of the backbuffer if I am not mistaken, and jmasterx seems to confirm this (and he is a much more trustable source )

I guess you should use that to transfom mouse input accordingly.

IIRC, Edgar Reynaldo had a system where the button coordinates were a percentage of the screen dimensions.

And you'll get to do it all over again if you switch to OpenGL.