module Physics.Hpysics.Visualization where

import Graphics.Rendering.OpenGL hiding (Sphere,Plane)
import qualified Graphics.UI.GLUT as GLUT
import Physics.Hpysics.Types
import Physics.Hpysics.Utils
import Physics.Hpysics.Body
import Physics.Hpysics.Poly

withTranslatedCoords :: Vec -> IO () -> IO ()
withTranslatedCoords shift action = do
    matrixMode $= Modelview 0
    let vecToGL (Vec x y z) = Vector3 x y z
    translate $ vecToGL $ shift
    action
    translate $ vecToGL $ neg shift
withTransformedCoords :: Vec -> Quaternion -> IO () -> IO ()
withTransformedCoords shift rot action = preservingMatrix $ do
    rotationMatrix <- quaternionToGLMatrix rot
    withTranslatedCoords shift $ do
        multMatrix rotationMatrix
        action

renderShape :: Shape -> IO ()
renderShape p = renderPrimitive Lines $ mapM_ ((\(Vec x1 y1 z1,Vec x2 y2 z2) -> (vertex$Vertex3 x1 y1 z1)>>(vertex$Vertex3 x2 y2 z2)).computeEdge) (edges p)

renderBody :: Body -> IO ()
renderBody = renderShape . getShape

renderWorld w = sequence_ $ map renderBody $ bodies w

-- utils
mat33ToGLMatrix :: Mat33 -> IO (GLmatrix FloatType)
mat33ToGLMatrix (Mat33
    a11 a12 a13
    a21 a22 a23
    a31 a32 a33) =
    newMatrix RowMajor [
    a11, a12, a13, 0,
    a21, a22, a23, 0,
    a31, a32, a33, 0,
    0,   0,   0,   1]
quaternionToGLMatrix :: Quaternion -> IO (GLmatrix FloatType)
quaternionToGLMatrix = mat33ToGLMatrix . quaternionToMatrix