Blitz3D and PNG's

[Steve Elliott]

Just ran Blitz3D and loaded a png.  The alpha isn't showing, so I get a white block around the sprite.  A blend mode needs to be set? 

[RemiD]

i use the flag 2 or flag 1+2 (and of course your image must be "clean" (=no progressive outlines))

if you want to be sure, you can use one or several mask colors, and identify each mask color in Blitz3d, and rewrite the alpha value that you want.

See my code examples here :
https://www.syntaxbomb.com/index.php/topic,1962.msg2951.html#msg2951

[Steve Elliott]

i use the flag 2 or flag 1+2

And the command to do this is?  I'm not a Blitz3D user.

[RemiD]

Texture = LoadTexture("filename.png",flags) (1 = color | 1+2 = color+alpha | 1+4 = color+mask (hide black texels) )

add flag 256 if you want to write alpha on a texture, it prevents bugs on some computers...
so LoadTexture("filename.png",1+2+256) or CreateTexture(Width,Height,1+2+256)

[Steve Elliott]

LoadTexture??  That sounds like a 3D command, not a 2D one.

[RemiD]

Oh, there is no alpha on images in Blitz3d, only masking of black pixels... You have to use a texture if you want a variable transparency...

[Steve Elliott]

Oh, so Blitz3D doesn't really support 2D PNG then?  Just old skool hard edge (pick a colour to be transparent)?

[RemiD]

For images (2D), the pixels with a black color (000,000,000) will be masked (fully transparent)

For textures loaded with the alpha flag, the texels with an alpha value less than 255 will have the defined transparency
For textures loaded with the mask flag, the texels with a black color (000,000,000), will be masked (fully transparent)

Note that you can produce pixel perfect "images" using quads and textures if you disable bilinear filtering... So you can have alpha on "images" (but they would be quads + textures)

[Steve Elliott]

ok, thanks.