| Safe Haskell | None |
|---|---|
| Language | Haskell2010 |
Graphics.GL.Low.Blending
Description
When blending is enabled, colors written to the color buffer will be blended using a formula with the color already there. The three options for the formula are:
- S*s + D*d (
FuncAdd, the default) - S*s - D*d (
FuncSubtract) - D*d - S*s (
FuncReverseSubtract)
where S and D are source and destination color components respectively. The
factors s and d are computed blending factors which can depend on the alpha
component of the source pixel, the destination pixel, or a specified
constant color. See basicBlending for a common choice.
The order of rendering matters when using blending. The farther-away primitives should be rendered first to get transparent materials to look right. This means a depth test is unhelpful when using blending. Also blending many layers of transparent primitives can significantly degrade performance. For these reasons transparency effects may be better accomplished with an off-screen rendering pass followed by a suitable shader.
blending example program here
- enableBlending :: Blending -> IO ()
- disableBlending :: IO ()
- basicBlending :: Blending
- data Blending = Blending {
- sFactor :: BlendFactor
- dFactor :: BlendFactor
- blendFunc :: BlendEquation
- blendColor :: (Float, Float, Float, Float)
- data BlendEquation
- data BlendFactor
Documentation
enableBlending :: Blending -> IO () Source
Enable blending with the specified blending parameters.
disableBlending :: IO () Source
Disable alpha blending.
basicBlending :: Blending Source
This blending configuration is suitable for ordinary alpha blending transparency effects.
Blending
{ sFactor = BlendSourceAlpha
, dFactor = BlendOneMinusSourceAlpha
, blendFunc = FuncAdd }
Blending parameters.
Constructors
| Blending | |
Fields
| |
data BlendEquation Source
Blending functions.
Constructors
| FuncAdd | the default |
| FuncSubtract | |
| FuncReverseSubtract |
Instances
data BlendFactor Source
Blending factors.
Constructors
Instances