GPipe-2.0.2: Typesafe functional GPU graphics programming

Safe HaskellNone




A PrimitiveStream can be rasterized, i.e. chopped up in pixel sized fragments, each of which contains an interpolated value of the primitives vertices, producing a FragmentStream.


The data type

data FragmentStream a Source

A FragmentStream a is a stream of fragments of type a. You may append FragmentStreams using the Monoid instance, and you can operate a stream's values using the Functor instance (this will result in a shader running on the GPU).

class FragmentInput a where Source

This class constraints which vertex types can be turned into fragment values, and what type those values have.

Associated Types

type FragmentFormat a Source

The type the vertex value will be turned into once it becomes a fragment value.


toFragment :: ToFragment a (FragmentFormat a) Source

An arrow action that turns a value from it's vertex representation to it's fragment representation. Use toFragment from the GPipe provided instances to operate in this arrow. Also note that this arrow needs to be able to return a value lazily, so ensure you use

proc ~pattern -> do ....

data ToFragment a b Source

The arrow type for toFragment.

data FlatVFloat Source

A float value that is not interpolated (like integers), and all fragments will instead get the value of the primitive's last vertex


Flat VFloat 

data NoPerspectiveVFloat Source

A float value that doesn't get divided by the interpolated position's w-component during interpolation.


NoPerspective VFloat 

Creating FragmentStreams

rasterize :: forall p a s os f. FragmentInput a => (s -> (Side, ViewPort, DepthRange)) -> PrimitiveStream p (VPos, a) -> Shader os f s (FragmentStream (FragmentFormat a)) Source

Rasterize a stream of primitives into fragments, using a Side, Viewport and DepthRange from the shader environment. Primitives will be transformed from canonical view space, i.e. [(-1,-1,-1),(1,1,1)], to the 2D space defined by the ViewPort parameter and the depth range defined by the DepthRange parameter.

type VPos = V4 VFloat Source

data Side Source

Defines which side to rasterize. Non triangle primitives only has a front side.



data ViewPort Source

The viewport in pixel coordinates (where (0,0) is the lower left corner) in to which the canonical view volume [(-1,-1,-1),(1,1,1)] is transformed and clipped/scissored.




viewPortLowerLeft :: V2 Int
viewPortSize :: V2 Int

data DepthRange Source

The fragment depth range to map the canonical view volume's z-coordinate to. Depth values are clamped to [0,1], so DepthRange 0 1 gives maximum depth resolution.




minDepth :: Float
maxDepth :: Float

Various FragmentStream operations

filterFragments :: (a -> FBool) -> FragmentStream a -> FragmentStream a Source

Filter out fragments from the stream where the predicate in the first argument evaluates to true, and discard all other fragments.

withRasterizedInfo :: (a -> RasterizedInfo -> b) -> FragmentStream a -> FragmentStream b Source

Like fmap, but where various auto generated information from the rasterization is provided for each vertex.