module Topkata.Render (render, mkRenderInfo, renderInit) where

import Graphics.Rendering.OpenGL 
import Topkata.Textures
import Topkata.State ( State(..) )
import Topkata.Topka.Topka (topView, genTopkataCallList, 
                                   showTopkata)
import qualified Labygen.Render

data RenderInfo = RenderInfo {
      renderInfoLabyDL :: !DisplayList
     ,renderInfoTopkata :: !GLuint
}

hit = False

whereToLook state =
    let (x, y, z, phi) = topView $ stTopka state in
      (x, 3, z-2, 0)

render renderInfo state = do
  matrixMode $= Projection
  depthRange $= (0.5, 20)
  loadIdentity
  --hit <- return False -- get (showHit state)
  frustum (-0.2) 0.5 (-0.2) (0.5) (0.5) (if hit then 0.5 else 20)

  matrixMode $= Modelview 0
  loadIdentity

  let (x, y, z, phi) = whereToLook state
  --lookAt (Vertex3 x y z) (Vertex3 (x+1) (0.5) (z+2*cos phi)) (Vector3 0 1 0)
  lookAt (Vertex3 x y z) (Vertex3 (x+2*sin phi) (0.5) (z+2*cos phi)) (Vector3 0 1 0)
  clear [ ColorBuffer, DepthBuffer ]


  preservingMatrix $ callList $ renderInfoLabyDL renderInfo
  
  let ts = stTopka state
  showTopkata ts $ renderInfoTopkata  renderInfo

mkRenderInfo state = do
   brickTex <- loadBrickTex
   labyDL <- defineNewList Compile $ Labygen.Render.render brickTex laby
   topTex <-  loadEyes "eyes"
   ghostTex <- loadEyes "geyes"
   tops <- genTopkataCallList topTex ghostTex
   return $ RenderInfo { 
          renderInfoLabyDL = labyDL
         ,renderInfoTopkata = tops
   }
 where
   laby = stLaby state

renderInit :: IO ()
renderInit = do
       clearColor $= Color4 0 0 0 0
       polygonMode $= (Fill, Fill)

       shadeModel $= Smooth

       materialSpecular FrontAndBack $= Color4 1 1 1 1
       materialShininess FrontAndBack $= 25
       colorMaterial $= Just (FrontAndBack, Diffuse)

       position (Light 1) $= Vertex4 0 0.5 (-0.5) 1
       position (Light 0) $= Vertex4 1 2 (-8) 0

       lighting $= Enabled
       light (Light 0) $= Enabled
       light (Light 1) $= Enabled
       depthFunc $= Just Less

       ambient (Light 0) $= Color4 0.2 0.2 0.2 1.0
       diffuse (Light 0) $= Color4 1 1 1 1
       diffuse (Light 1) $= Color4 1 1 1 1
       specular (Light 1) $= Color4 1 1 1 1
       --position (Light 0) $= Vertex4 0 3 2 0

       lightModelAmbient $= Color4 0.4 0.4 0.4 1
       lightModelLocalViewer $= Enabled
       lightModelTwoSide $= Enabled

       -- blend $= Enabled
       -- blendFunc $= (SrcAlpha, OneMinusSrcAlpha)
       -- hint PolygonSmooth $= Nicest
       --polygonSmooth $= Enabled

       -- hint LineSmooth $= Nicest
       -- lineSmooth $= Enabled

       normalize $= Enabled