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OpenGl & max2D in GUI App

BlitzMax Forums/MaxGUI Module/OpenGl & max2D in GUI App

matibee(Posted 2009) [#1]
I just brought the GUI kit last night but I'm missing some fundamentals here.

How can I mix OpenGL (as in the glcube example) and Max2d functionality (DrawImage etc)? I've tried searching without any luck.

Thanks in advance.


Brucey(Posted 2009) [#2]
Use a Canvas gadget.


matibee(Posted 2009) [#3]
Thanks Brucey. That's what the glcube sample is doing..

...
SetGraphicsDriver GLGraphicsDriver(),GRAPHICS_BACKBUFFER|GRAPHICS_DEPTHBUFFER
...
Local c:TGadget = CreateCanvas(0,0,w.ClientWidth(),w.ClientHeight(),w,0)
c.setlayout 1,1,1,1
CreateTimer( 60 )
While True
	WaitEvent()
	Select EventID()
		Case EVENT_WINDOWCLOSE
			End
		Case EVENT_TIMERTICK
			RedrawGadget c       
		Case EVENT_GADGETPAINT
			SetGraphics CanvasGraphics( c )
			'loads of gl specific stuff...
			'but it crashes on any max2d calls
			DrawRect( 0, 0, 100, 100 )                                
			Flip                           
	EndSelect
Wend



matibee(Posted 2009) [#4]
I've done some more digging. It seems there is no valid Max2d graphics object created in this example (usually created with a Graphics w,h command) while there are GLDrawRect and GLDrawPixmap functions.

Does this mean; a) I have to find another way of initialising Max2d, or b) i have to stick to using opengl?


Brucey(Posted 2009) [#5]
Use this - GLMax2DGraphicsDriver() - instead of GLGraphicsDriver().


matibee(Posted 2009) [#6]
Close :) It's GLMax2DDriver. I scanned for GLMax2DGraphicsDriver and found nothing, so scanned for GLGraphicsDriver and GLMax2DDriver in with it.

The next issue is that it doesn't automatically handle window resize. I solved that with capturing WINDOWSIZE events and completely recreating the gadget to the new client size;

Case EVENT_WINDOWSIZE
    FreeGadget( c )
    c = CreateCanvas(0,0,w.ClientWidth(),w.ClientHeight(),w,0)


Is there anything wrong with this?

I was losing loaded images tho (so, I guess they're tied to a canvas?) Loading them after recreating the canvas somehow didn't stop them from being garbage collected a few frames later. This only worked when I suspended GC..
Case EVENT_WINDOWSIZE
    FreeGadget( c )
    c = CreateCanvas(0,0,w.ClientWidth(),w.ClientHeight(),w,0)
    r = LoadImage( "iconstrip1.png" )


So ultimately I had to ensure the image was completely deleted and recreated..
Case EVENT_WINDOWSIZE
    r = Null
    FreeGadget( c )
    GCCollect 
    c = CreateCanvas(0,0,w.ClientWidth(),w.ClientHeight(),w,0)
    r = LoadImage( "iconstrip1.png" )


I think I've about hacked this to death :/


Brucey(Posted 2009) [#7]
When you resize, you need to reset your ViewPort() to the correct dimensions.

Close :) It's GLMax2DDriver

Apologies... I should look them up rather than try to remember stuff ;-)


matibee(Posted 2009) [#8]
ViewPort() -- that's more like it! I think you'll agree this is a bit cleaner...
case EVENT_WINDOWSIZE
    SetViewport( 0, 0, w.ClientWidth(), w.ClientHeight() )


Apologies... I should look them up rather than try to remember stuff ;-)


No worries, your memory is a lot more effective than my ignorant fumbling.

Cheers Brucey!