Sprite on screen transparency problem ...

[marc_256]

Hi,

for my new CAD/CAM program I use a lot of sprites,

1) Create windowed screen
2) I create sprites
3) Draw all the stuff on it, also some images in .PNG (icons) with Alpha channel.
4) I display the toolbars on the screen
5) on the screen I add the cross cursor (mouse posX and mouse posY)

All works fine if I do the follow:

1) DisplayTransparentSprite(ToolBar1, 100, 100, 80)
2) DisplayTransparentSprite(ToolBar2, 100, 150, 80)
3) DisplayTransparentSprite(ToolBar3, 100, 200, 80)

4) DisplaySprite(Mouse1, MouseX, MouseY)





If mouse is on a toolbar (example toolbar2)

2) DisplayTransparentSprite(ToolBar2, 100, 150, 255)

to highlight the toolbar and change the cross cursor in pointer cursor.

works fine if I use

4) DisplaySprite(Mouse2, MouseX, MouseY)



If I use:

4) DisplayTransparentSprite(Mouse2, MouseX, MouseY, 255)

I have the following problem
the cursor is no more alpha blended on the screen
is it OR alpha blended
OR transparent



What must I do to make the cursor transparent and alpha blended ?

Thanks,
marco

[#NULL]

difficult to say without some code, but here are some points:

Code: Select all

4) DisplaySprite(Mouse2, MouseX, MouseY)

you are probaly using TransparentSpriteColor() for that sprite to have the transparency working?
but on mouseover you are using DisplayTransparentSprite(), which needs the sprite to be created with the #PB_Sprite_AlphaBlending flag and the alpha channel to be prepared correctly. I had some problems once if used TransparentSpriteColor() in combination with an alpha channel. try the following:
- always create the sprite with the #PB_Sprite_AlphaBlending flag
- don't use TransparentSpriteColor() on the sprite
- before drawing on the sprite clear the alpha channel:

Code: Select all

DrawingMode(#PB_2DDrawing_AllChannels)
Box(0, 0, w, h, $00000000)
DrawingMode(#PB_2DDrawing_AlphaBlend)
...

- always display the sprite using DisplayTransparentSprite(..., alpha).

[marc_256]

Hi #NULL,

I did al kinds of tests with DrawingMode() and mixing these modes.
with the same results.
So, I do my png drawings with GIMP.
end export these to png with alpha channel.

I go to look this side ...
maybe the alpha channel is not correct ?

thanks,
Marc

[netmaestro]

What would help the most is if you could post a working snippet and a couple of images used by it that shows the problem. If you can do that someone will find a way to solve it pretty quick. As it is your request is too vague to get results imho.