Not drawing fully transparent

[kelvin]

when I draw a textured poly that has fully transparent parts I get dithering. Am I doing something wrong or is there no way to get fully transparent textures?
http://www.variableaspect.com/gallery/polkadotproblem.jpg :(

[ghettotek]

can we see what code youre using?

[OneSadCookie]

Make sure the color channels of the transparent parts match the color channels of the surrounding opaque parts.

What's causing those dots? They must be in your texture...

[kelvin]

as far as I know, the dots are dithering.

for generating the texture here's my code:[debugImage lockFocus];
[[[[NSColor whiteColor] colorWithAlphaComponent:0.0] colorUsingColorSpaceName:NSDeviceRGBColorSpace] set];
NSRectFill(NSMakeRect(0,0,size.width,size.height)) ;
[debugImage unlockFocus];
...
[debugImage lockFocus];
[[text_view layoutManager] drawGlyphsForGlyphRange:NSMakeRange(0,1)
atPoint:NSMakePoint(image_offset.x,
image_offset.y +
[aFont boundingRectForFont].origin.y)];

[debugImage unlockFocus];

[OneSadCookie]

Are you drawing to a 32-bit texture and rendering to a 16-bit screen on a Rage 128?

[kelvin]

yes.

[OneSadCookie]

LOL :D I didn't expect to be right :rolleyes:

The Rage 128's dithering is appalling. Try matching your texture depth to your screen depth.

[Tycho]

I don't have my Rage 128 anymore, but it always seemed that dithering looked WAY better in OS 9 than it did in OS X. In OS 9 it seemed to be using a sort of random diffuse dither while OS X used a sort of pattern based dithering if you know what I mean.

[Skorche]

Yuck, I guess I never noticed that on my family's G4, but then again I haven't really ever played openGL games under OSX.

[kelvin]

My issue is: should ALL pixels with 0.0 alpha be transparent? guh... I need a new mac.