Multiple graphics windows

BlitzMax Forums/BlitzMax Programming/Multiple graphics windows

Punksmurf

(Posted 2006) [#1]

Hello all,

At first, I'm sorry if a similar topic already showed up, but I didn't find any so I hereby give it a try.

I've been hacking around a bit to create more than one graphics window. I do not use (or own, for that matter) the GUI-module.

This is my code:

SuperStrict

SetGraphicsDriver GLMax2DDriver() 'this doesn't work with DirectX-drivers

AppTitle = "window a"
Local a:TGraphics = CreateGraphics (320,240,0,0,GRAPHICS_BACKBUFFER)

AppTitle = "window b"
Local b:TGraphics = CreateGraphics (240,320,0,0,GRAPHICS_BACKBUFFER)

EnablePolledInput() 'Manually enable polled input

While Not AppTerminate() Or Not Confirm( "Terminate?" )

	SetGraphics(a)
	SetColor (Rand(0,255),Rand(0,255),Rand(0,255))
	Plot (Rand(0,319),Rand(0,239))
	Flip

	Print "a - x: " + MouseX() + ", y: " + MouseY()

	SetGraphics(b)
	SetColor (Rand(0,255),Rand(0,255),Rand(0,255))
	DrawLine (Rand(0,239),Rand(0,319),Rand(0,239),Rand(0,319))
	Flip
	
	Print "b - x: " + MouseX() + ", y: " + MouseY()
	
Wend

As you can see, it is possible to render graphics to more than one window, altough it crashes when using more than one DirectX-window (it should be possible even to use different drivers for each window, as SetGraphics would change the driver accordingly, but I haven't tried that).

However, it doesn't seem possible to differentiate the input generated by each window. MouseX() and MouseY() just depend on over which window the mouse is.

I tried looking up EnablePolledInput:

Rem
Currently only called by Graphics/bglCreateContext.
Private for now, as it really needs a source:object parameter.
End Rem
Function EnablePolledInput( source:Object=Null )
	If enabled Return
	inputSource=source
	FlushKeys
	FlushMouse
	AddHook EmitEventHook,Hook,Null,0
	enabled=True
End Function

It says it requires an object, yet the 'Graphics' function doesn't pass an object - in contrary to what the comment here says. I tried to 'EnablePolledInput(a)', hoping that it then only would return input from 'window a', but that doesn't work.

Does any of you have a clue how I can differentiate the input from the two windows?

Dreamora

(Posted 2006) [#2]

Only by using event based programming. In this case you could use EventSource() (or currentevent.source

Punksmurf

(Posted 2006) [#3]

Thanks for your answer, bud sadly enough, it doesn't work out..

I removed the EnablePulledInput and the 'print mousex()' stuff and added the following:

Function Hook:Object(id:Int,data:Object,context:Object)

	Local ev:TEvent=TEvent(data)
	If Not ev Return data
	Print ev.id
	If ev.source Print "event has a source" Else Print "event didn't have a source"
	
	Return data	

End Function

AddHook EmitEventHook,Hook,Null,0

As it turns out, the events show up nicely but the events don't have a source. This is also why the 'EnablePolledInput(a)' doesn't work, see in polledinput.bmx:

Function Hook:Object( id,data:Object,context:Object )

	Local ev:TEvent=TEvent(data)
	If Not ev Return data
	
	If inputSource And inputSource<>ev.source Return data

	'more stuff
End Function

InputSource is set to 'source' object in the EnablePolledInput(source:Object) function, so in my example it'd be 'a:TGraphics', but since the EventSource is empty, the function quits.

I'm sorry if I'm not clear enough, I find these things hard to explain in Human.

Punksmurf

(Posted 2006) [#4]

Some other funny thing: if you close one window, the graphics meant for the closed window will be drawn on the remaining window. I guessed this is because the TGraphics object would be destroyed as the window closes and that setGraphics won't switch to a non-existing TGraphics object. This, however, is not true - the object still exists (even if both windows are closed).

Punksmurf

(Posted 2006) [#5]

Does anyone have a clue?