2 files changed, 73 insertions, 0 deletions
diff --git a/src/Utils/Geometry.elm b/src/Utils/Geometry.elm
new file mode 100644
index 0000000..085026f
--- /dev/null
+++ b/src/Utils/Geometry.elm
@@ -0,0 +1,27 @@
+module Utils.Geometry
+  ( polarToCartesian
+  , distance
+  , inBoard
+  ) where
+
+import Model.Vec2 (..)
+import Model.Board (boardSize)
+
+polarToCartesian : Float -> Float -> Vec2
+polarToCartesian angle dist =
+  { x = dist * (cos angle)
+  , y = dist * (sin angle)
+  }
+
+distance : Vec2 -> Vec2 -> Float
+distance v1 v2 = sqrt((v2.x - v1.x)^2 + (v2.y - v1.y)^2)
+
+inBoard : Float -> Vec2 -> Vec2
+inBoard size pos =
+  let leftX = -boardSize.x / 2 + size
+      rightX = boardSize.x / 2 - size
+      bottomY = -boardSize.y / 2 + size
+      topY = boardSize.y / 2 - size
+  in  { x = clamp leftX rightX pos.x
+      , y = clamp bottomY topY pos.y
+      }
diff --git a/src/Utils/Physics.elm b/src/Utils/Physics.elm
new file mode 100644
index 0000000..751af6c
--- /dev/null
+++ b/src/Utils/Physics.elm
@@ -0,0 +1,46 @@
+module Utils.Physics
+  ( getNewPosAndSpeed
+  , getMove
+  , getWaveMove
+  ) where
+
+import Model.Vec2 (..)
+
+getNewPosAndSpeed : Float -> Vec2 -> (Float -> Float) -> (Vec2, Vec2) -> (Vec2, Vec2)
+getNewPosAndSpeed dt dir computeSpeed (pos, speed) =
+  let move = getMove (computeSpeed dt) dir
+      acc = getAcc move speed
+      newPos = getNewPos dt acc speed pos
+      newSpeed = getNewSpeed dt acc speed
+  in  ( newPos
+      , newSpeed
+      )
+
+getMove : Float -> Vec2 -> Vec2
+getMove speed dir =
+  if (isNull dir)
+    then {x = 0, y = 0}
+    else
+      let angle = atan2 dir.y dir.x
+      in  { x = speed * cos angle
+          , y = speed * sin angle
+          }
+
+getWaveMove : Float -> Vec2 -> Float -> Float -> Vec2
+getWaveMove speed dir amplitude period =
+  let move = getMove speed dir
+      perpendMove =
+        getMove
+          (amplitude * (sin ((norm move) / period)))
+          (clockwiseRotate90 move)
+  in  move `add` perpendMove
+
+getAcc : Vec2 -> Vec2 -> Vec2
+getAcc move speed = (move `div` 300) `sub` (speed `div` 300)
+
+getNewPos : Float -> Vec2 -> Vec2 -> Vec2 -> Vec2
+getNewPos dt acc speed pos =
+  ((dt^2 / 2) `mul` acc) `add` ((dt `mul` speed) `add` pos)
+
+getNewSpeed : Float -> Vec2 -> Vec2 -> Vec2
+getNewSpeed dt acc speed = add (mul dt acc) speed