CODEWITHSUNDEEP
c#colorsxnadrawalphablending
kbirk
kbirk

Reputation: 4022

Custom BlendState to avoid AlphaBlending artifacts

I am essentially drawing a texture onto itself every frame, each time i draw it i want to decrement the alpha so that it eventually hits 0 so no artifacts are left.

The basic equation is:

result = (source * sourceBlendFactor) blendFunction (destination * destinationBlendFactor)

And since my destination is Color.Transparent I figure i need:

result = 0 = (source * sourceBlendFactor);

Im racking my brain going over the different BlendState components but I cant seem to acheive this...

Is there any way to have the alpha decrement linearly?

Upvotes: 0

Views: 372

Answers (1)

Polity
Polity

Reputation: 15130

Sure you can. Define a value that holds the current alpha state between 1 and 0. Decrement that value each frame untill it hits 0. In the draw method, you determine the alpha value of the tint color.

byte alpha = 255 - (currentAlphaState * 255);
spriteBatch.Draw(...., new Color( 255, 255, 255, alpha) ...); // assuming white is your default tint color

Upvotes: 1

Related Questions