GPipe
Revision as of 07:43, 10 October 2009 by TobiasBexelius (talk | contribs)
This is the official wiki for the GPipe package.
Example
This is a simple GPipe example that animates a spinning box. Besides GPipe, it uses the Vec-Transform package for the transformation matrices.
I will continue adding examples to this page, so check back every once in a while. If you have any questions, feel free to mail me.
module Main where
import Graphics.GPipe
import Data.Monoid
import Data.IORef
import qualified Data.Vec as Vec
import Data.Vec.Nat
import Data.Vec.LinAlg.Transform3D
import Graphics.UI.GLUT
(mainLoop,
postRedisplay,
idleCallback,
getArgsAndInitialize,
($=))
sidePosX = toGPUStream TriangleStrip $ map (flip (,) (1:.0:.0:.())) [1:.0:.0:.(), 1:.1:.0:.(), 1:.0:.1:.(), 1:.1:.1:.()]
sideNegX = toGPUStream TriangleStrip $ map (flip (,) ((-1):.0:.0:.())) [0:.0:.1:.(), 0:.1:.1:.(), 0:.0:.0:.(), 0:.1:.0:.()]
sidePosY = toGPUStream TriangleStrip $ map (flip (,) (0:.1:.0:.())) [0:.1:.1:.(), 1:.1:.1:.(), 0:.1:.0:.(), 1:.1:.0:.()]
sideNegY = toGPUStream TriangleStrip $ map (flip (,) (0:.(-1):.0:.())) [0:.0:.0:.(), 1:.0:.0:.(), 0:.0:.1:.(), 1:.0:.1:.()]
sidePosZ = toGPUStream TriangleStrip $ map (flip (,) (0:.0:.1:.())) [1:.0:.1:.(), 1:.1:.1:.(), 0:.0:.1:.(), 0:.1:.1:.()]
sideNegZ = toGPUStream TriangleStrip $ map (flip (,) (0:.0:.(-1):.())) [0:.0:.0:.(), 0:.1:.0:.(), 1:.0:.0:.(), 1:.1:.0:.()]
cube = mconcat [sidePosX, sideNegX, sidePosY, sideNegY, sidePosZ, sideNegZ]
transformedCube a = fmap (transform a) cube
transform :: Float -> (Vec3 (Vertex Float), Vec3 (Vertex Float)) -> (Vec4 (Vertex Float), Vec3 (Vertex Float))
transform a (pos, norm) = (transformedPos, transformedNorm)
where
modelMat = rotationVec (normalize (1:.0.5:.0.3:.())) a `multmm` translation (-0.5)
viewMat = translation (-(0:.0:.2:.()))
projMat = perspective 1 100 (pi/3) (4/3)
viewProjMat = projMat `multmm` viewMat
transformedPos = toGPU (viewProjMat `multmm` modelMat) `multmv` homPoint pos
transformedNorm = toGPU (Vec.map (Vec.take n3) $ Vec.take n3 $ modelMat) `multmv` norm
coloredFragments a = fmap (RGB . Vec.vec . dot (toGPU (0:.0:.1:.()))) $ rasterizeFront $ transformedCube a
paintSolid = paintColor NoBlending (RGB $ Vec.vec True)
main = do getArgsAndInitialize
angleRef <- newIORef 0.0
newWindow "Spinning box" (100:.100:.()) (800:.600:.())
(do angle <- readIORef angleRef
writeIORef angleRef ((angle + 0.01) `mod'` (2*pi))
return $ paintSolid (coloredFragments angle) (newFrameBufferColor (RGB 0))
)
(\ w -> idleCallback $= Just (postRedisplay (Just w)))
mainLoop