annoying border artifacts inside texture

Blitz3D Forums/Blitz3D Programming/annoying border artifacts inside texture

cyberyoyo(Posted 2012) [#1]
here is my problem:
I want to draw on the screen using a moving sprite (and not clearing the color buffer of the camera)
I first create a texture for the sprite, set the texturebuffer as the drawing buffer and then draw a filled oval inside of it

The problem is that the rendering will constantly create a very thin (subpixel) black border around the oval inside the sprite.
I made sure that there is no half value pixels inside the texture, it seems to be something related to either mip mapping or texture smoothing done by the camera render.
I tried to disable mipmapping but no change

in the following pic, you can see the artifact around the oval at several sizes


Any idea how to fix that?

Last edited 2012

Last edited 2012


cyberyoyo(Posted 2012) [#2]
I managed to fix the problem just a few minutes after posting.
In fact, I had already included the fix in my code a long time ago, but forgot about it.

When the texture is created it is filled with the argb values 0,0,0,0
What I do is fill it with the values 0,r,g,b where r,g,b are the color of the drawing I am about to make.
then I draw normally.
This way the texture aliasing still happens but the color is smoothed with itself, and the artifact disappears.