1 files changed, 82 insertions, 0 deletions

diff --git a/Spear/Scene/Light.hs b/Spear/Scene/Light.hs
new file mode 100644
index 0000000..76ff074
--- /dev/null
+++ b/Spear/Scene/Light.hs
@@ -0,0 +1,82 @@
+module Spear.Scene.Light
+(
+    Light(..)
+)
+where
+
+
+import qualified Spear.Math.Matrix4 as M
+import qualified Spear.Math.Spatial as S
+import Spear.Math.Vector3
+import qualified Spear.Math.Vector4 as V4
+
+
+data Light
+    = PointLight
+    { ambient   :: Vector3
+    , diffuse   :: Vector3
+    , specular  :: Vector3
+    , transform :: M.Matrix4
+    }
+    | DirectionalLight
+    { ambient   :: Vector3
+    , diffuse   :: Vector3
+    , specular  :: Vector3
+    , direction :: Vector3
+    }
+    | SpotLight
+    { ambient   :: Vector3
+    , diffuse   :: Vector3
+    , specular  :: Vector3
+    , transform :: M.Matrix4
+    }
+
+
+instance S.Spatial Light where
+    move _ l@DirectionalLight {} = l
+    move v l = l { transform = M.translv v * transform l}
+    
+    moveFwd _ l@DirectionalLight {} = l
+    moveFwd f l = l { transform = M.translv (scale f $ S.fwd l) * transform l }
+    
+    moveBack _ l@DirectionalLight {} = l
+    moveBack f l = l { transform = M.translv (scale (-f) $ S.fwd l) * transform l }
+    
+    strafeLeft _ l@DirectionalLight {} = l
+    strafeLeft f l = l { transform = M.translv (scale (-f) $ S.right l) * transform l }
+    
+    strafeRight _ l@DirectionalLight {} = l
+    strafeRight f l = l { transform = M.translv (scale f $ S.right l) * transform l }
+    
+    pitch _ l@DirectionalLight {} = l
+    pitch a l = l { transform = transform l * M.axisAngle (S.right l) a }
+    
+    yaw _ l@DirectionalLight {} = l
+    yaw a l = l { transform = transform l * M.axisAngle (S.up l) a }
+    
+    roll _ l@DirectionalLight {} = l
+    roll a l = l { transform = transform l * M.axisAngle (S.fwd l) a }
+    
+    pos l@DirectionalLight {} = vec3 0 0 0
+    pos l = M.position . transform $ l
+    
+    fwd (DirectionalLight _ _ _ f) = f
+    fwd l = M.forward . transform $ l
+    
+    up l@DirectionalLight {} = vec3 0 1 0
+    up l = M.up . transform $ l
+    
+    right l@DirectionalLight {} = vec3 1 0 0
+    right l = M.right . transform $ l
+    
+    transform (PointLight _ _ _ transf) = transf
+    transform (DirectionalLight _ _ _ fwd) =
+        let up'   = vec3 0 1 0
+            right = up `cross` fwd
+            up    = fwd `cross` right
+        in
+            M.transform up right fwd (vec3 0 0 0)
+    transform (SpotLight _ _ _ transf) = transf
+    
+    setTransform _ l@DirectionalLight {} = l
+    setTransform t l = l { Spear.Scene.Light.transform = t }