pioneers/src/Render/Types.hs
2014-04-22 01:27:01 +02:00

79 lines
3.1 KiB
Haskell

{-# LANGUAGE RankNTypes #-}
module Render.Types (createFlatCam, createSphereCam, Camera, GLCamera(..)) where
import Linear
import Foreign.C (CFloat)
import Render.Misc (lookAt)
type Distance = Double
type Pitch = Double
type Yaw = Double
class GLCamera a where
getCam :: a -> Distance -> Pitch -> Yaw -> M44 CFloat
moveBy :: a -> (Position -> Position) -> a
move :: a -> Position -> a
type Position = (Double, Double)
type Radius = Double
data Camera = Flat Position
| Sphere Position Radius
-- | create a Flatcam-Camera starting at given x/z-Coordinates
createFlatCam :: Double -> Double -> Camera
createFlatCam x z = Flat (x,z)
-- | create a Flatcam-Camera starting at given pitch/azimuth/radius
createSphereCam :: Double -> Double -> Double -> Camera
createSphereCam p a r = Sphere (p,a) r
instance GLCamera Camera where
getCam (Flat (x',z')) dist' xa' ya' =
lookAt (cpos ^+^ at') at' up
where
at' = V3 x 0 z
cpos = crot !* (V3 0 0 (-dist))
crot = (
(fromQuaternion $ axisAngle upmap (xa::CFloat))
!*!
(fromQuaternion $ axisAngle (V3 0 1 0) (ya::CFloat))
) ::M33 CFloat
upmap = ((fromQuaternion $ axisAngle (V3 0 1 0) (ya::CFloat)) :: M33 CFloat)
!* (V3 1 0 0)
x = realToFrac x'
z = realToFrac z'
dist = realToFrac dist'
xa = realToFrac xa'
ya = realToFrac ya'
up = V3 0 1 0
getCam (Sphere (inc',az') r') dist' xa' ya' = --inclination (pitch), azimuth (yaw)
lookAt (cpos ^+^ at') at' up
where
at' = sphereToCart r inc az
cpos = crot !* (V3 0 0 (-dist))
crot = (
(fromQuaternion $ axisAngle upmap (xa::CFloat))
!*!
(fromQuaternion $ axisAngle (V3 0 1 0) (ya::CFloat))
) ::M33 CFloat
upmap = ((fromQuaternion $ axisAngle (V3 0 1 0) (ya::CFloat)) :: M33 CFloat)
!* (V3 1 0 0)
up = (sphereToCart (r+1) inc az) ^-^ at'
r = realToFrac r'
inc = realToFrac inc'
az = realToFrac az'
dist = realToFrac dist'
xa = realToFrac xa'
ya = realToFrac ya'
moveBy (Sphere (inc, az) r) f = undefined
moveBy (Flat (x', z')) f = Flat (f (x',z'))
move c (x', z') = moveBy c (\(x,z) -> (x+x',z+z'))
sphereToCart :: (Floating a) => a -> a -> a -> V3 a
sphereToCart r inc az = V3
(r * (sin inc) * (cos az))
(r * (sin inc) * (sin az))
(r * (cos inc))