TransparentSpriteColor fails with DirectX9 subsystem?

Fluid Byte · Post by **Fluid Byte** » Thu Mar 05, 2009 11:56 pm

InitSprite() : InitKeyboard()

OpenWindow(0,0,0,640,480,"void",#PB_Window_SystemMenu | #PB_Window_ScreenCentered)
OpenWindowedScreen(WindowID(0),0,0,640,480,0,0,0)

CreateSprite(0,300,300)
StartDrawing(SpriteOutput(0))
Box(0,0,300,300,RGB(0,128,128))
Box(50,50,200,200,#Red)
StopDrawing()

TransparentSpriteColor(0,RGB(0,128,128))

Repeat
	Repeat
		EventID = WindowEvent()
	
		Select EventID
			Case #PB_Event_CloseWindow : End 
		EndSelect
	Until EventID = 0
		
	ExamineKeyboard()
	
	ClearScreen(#White)
	DisplayTransparentSprite(0,50,50)
	FlipBuffers()
Until KeyboardPushed(#PB_Key_Escape)

This doesn't display the sprite transparent with activated DX9 subsystem.

Am I missing something obvious here?

Kaeru Gaman · Post by **Kaeru Gaman** » Fri Mar 06, 2009 12:14 am

maybe an incoherence with the RGB-function?

when I replace it with $800080, it works. please test this.

PS:
ups... when I use $808000, it does not work. dunno whats up there.

Fluid Byte · Post by **Fluid Byte** » Fri Mar 06, 2009 12:24 am

Kaeru Gaman wrote:ups... when I use $808000, it does not work. dunno whats up there.

No, you are right! You just mixed up the value. It would be $808000, not $800080.

So you need to check for the pixel format (#PB_PixelFormat_32Bits_BGR).

Kaeru Gaman · Post by **Kaeru Gaman** » Fri Mar 06, 2009 12:29 am

yes, but the problem occurs with medium cyan, like your example, not with medium purple.
thus I said "dunno whats up there"...

at first glance I would have guessed on a 16bit desktop, but I use 32bit,
and the 16bit problem would occur with every color not with some specific.

the pixel format should be the same for drawing and for transparency,
so this could also not be the cause...

Fluid Byte · Post by **Fluid Byte** » Fri Mar 06, 2009 12:41 am

Kaeru Gaman wrote:yes, but the problem occurs with medium cyan, like your example, not with medium purple.

Indeed. With medium purple you don't need to swap values, but with medium cyan. So this is not reliable ...

netmaestro · Post by **netmaestro** » Fri Mar 06, 2009 12:45 am

Seems a bug with DX9 possibly. TransparentSpriteColor() takes an RGB value but the DX9 subsystem uses it in BGR format. So TransparentSpriteColor(RGB(0,128,128)) will work with a sprite boxed with RGB(128,128,0). Should do, anyhow. But - it isn't really an expected thing, so probably a bug.

Kaeru Gaman · Post by **Kaeru Gaman** » Fri Mar 06, 2009 12:45 am

¿swap values?

PS:
oh, I see...
when I change the color in the transparency command to BGR, it works...
strange! I would have guessed the pixel format should be the same.

netmaestro · Post by **netmaestro** » Fri Mar 06, 2009 1:04 am

I guess you can avoid it for now by using transparent sprite colors where the Red value is equal to the Blue value, ie. RGB(255,0,255) like the GeeBee2 picture in the examples.

Kaeru Gaman · Post by **Kaeru Gaman** » Fri Mar 06, 2009 1:26 am

now knowing it, I could use every color again, just have to swap channels for the transparency...

but it's strange anyways, I don't know how it could be repaired if the command is just a DX-API wrapper...