module Render ( setup
              , render
              ) where


import Paths_htanks
import Game
import MainLoop
import Level
import Player
import Tank
import Texture

import Control.Monad.State

import Data.Fixed
import Data.Maybe
import Data.Ratio
import qualified Data.Map as M

import Bindings.GLPng

import Graphics.Rendering.OpenGL.GL (($=), GLfloat, GLdouble, Capability(..), Vector3(..))
import Graphics.Rendering.OpenGL.GL.BeginEnd (unsafeRenderPrimitive, PrimitiveMode(..))
import Graphics.Rendering.OpenGL.GL.CoordTrans (matrixMode, MatrixMode(..), viewport, Position(..), Size(..), loadIdentity, unsafePreservingMatrix, ortho, translate, rotate)
import Graphics.Rendering.OpenGL.GL.Framebuffer (clear, ClearBuffer(..))
import Graphics.Rendering.OpenGL.GL.PerFragment (blend, blendFunc, BlendingFactor(..))
import Graphics.Rendering.OpenGL.GL.Texturing.Application (texture)
import Graphics.Rendering.OpenGL.GL.Texturing.Objects (textureBinding, TextureObject(..))
import Graphics.Rendering.OpenGL.GL.Texturing.Parameters (Repetition(..), Clamping(..), TextureFilter(..), MinificationFilter, MagnificationFilter)
import Graphics.Rendering.OpenGL.GL.Texturing.Specification (TextureTarget(..))
import Graphics.Rendering.OpenGL.GL.VertexSpec


texturePath :: Texture -> IO FilePath
texturePath t = getDataFileName $ path t
    where
      path TextureWood = "tex/Wood.png"
      path TextureTank = "tex/Tank.png"
      path TextureCannon = "tex/Cannon.png"
      path TextureBullet = "tex/Bullet.png"
      path TextureCrosshair = "tex/Crosshair.png"

getTexture :: Texture -> Main TextureObject
getTexture t = do
  ts <- gets textures
  let tobj = M.lookup t ts
  
  if (isJust tobj)
      then
          return $ fromJust tobj
      else do
          path <- liftIO $ texturePath t
          tex <- liftIO $ pngBind path BuildMipmap Alpha (Repeated, Repeat) (Linear', Just Linear') Linear' >>= return . TextureObject . fromIntegral . fst
          modify $ \state -> state {textures = M.insert t tex ts}
          return tex
                                               

setup :: Main ()
setup = do
  liftIO $ do
    blend $= Enabled
    blendFunc $= (SrcAlpha, OneMinusSrcAlpha)
  
  -- cache textures
  getTexture TextureWood
  getTexture TextureTank
  getTexture TextureCannon
  getTexture TextureBullet
  getTexture TextureCrosshair
  
  return ()


render :: Main ()
render = do
  tanklist <- gets $ tanks . gameState
  bulletlist <- gets $ bullets . gameState
  playerlist <- gets players
  
  textureWood <- getTexture TextureWood
  textureTank <- getTexture TextureTank
  textureCannon <- getTexture TextureCannon
  textureBullet <- getTexture TextureBullet
  textureCrosshair <- getTexture TextureCrosshair
  
  (lw, lh) <- gets (level . gameState) >>= \l -> return (fromIntegral . levelWidth $ l :: GLfloat, fromIntegral . levelHeight $ l :: GLfloat)
  
  liftIO $ do
           clear [ColorBuffer]
           
           texture Texture2D $= Enabled
           textureBinding Texture2D $= Just textureWood
           
           unsafeRenderPrimitive Quads $ do
             texCoord $ TexCoord2 (0 :: GLfloat) (0 :: GLfloat)
             vertex $ Vertex2 0 lh
             
             texCoord $ TexCoord2 (lw/2) 0
             vertex $ Vertex2 lw lh
             
             texCoord $ TexCoord2 (lw/2) (lh/2)
             vertex $ Vertex2 lw 0
             
             texCoord $ TexCoord2 0 (lh/2)
             vertex $ Vertex2 (0 :: GLfloat) (0 :: GLfloat)
             
           forM_ tanklist $ \tank -> unsafePreservingMatrix $ do
                                       let x = realToFrac . tankX $ tank
                                           y = realToFrac . tankY $ tank
                                           rotDir = realToFrac . tankDir $ tank
                                           rotAim = realToFrac . tankAim $ tank
                                       
                                       translate $ Vector3 x y (0 :: GLfloat)
                                       rotate rotDir $ Vector3 0 0 (1 :: GLfloat)
                                       
                                       textureBinding Texture2D $= Just textureTank
                                       
                                       unsafeRenderPrimitive Quads $ do
                                                          texCoord $ TexCoord2 (0 :: GLfloat) (0 :: GLfloat)
                                                          vertex $ Vertex2 (-0.5 :: GLfloat) (-0.5 :: GLfloat)
                                                          
                                                          texCoord $ TexCoord2 (0 :: GLfloat) (1 :: GLfloat)
                                                          vertex $ Vertex2 (-0.5 :: GLfloat) (0.5 :: GLfloat)
                                                          
                                                          texCoord $ TexCoord2 (1 :: GLfloat) (1 :: GLfloat)
                                                          vertex $ Vertex2 (0.5 :: GLfloat) (0.5 :: GLfloat)
                                                          
                                                          texCoord $ TexCoord2 (1 :: GLfloat) (0 :: GLfloat)
                                                          vertex $ Vertex2 (0.5 :: GLfloat) (-0.5 :: GLfloat)
                                       
                                       rotate (rotAim-rotDir) $ Vector3 0 0 (1 :: GLfloat)
                                       
                                       textureBinding Texture2D $= Just textureCannon
                                       
                                       unsafeRenderPrimitive Quads $ do
                                                          texCoord $ TexCoord2 (0 :: GLfloat) (0 :: GLfloat)
                                                          vertex $ Vertex2 (-0.5 :: GLfloat) (-0.5 :: GLfloat)
                                                          
                                                          texCoord $ TexCoord2 (0 :: GLfloat) (1 :: GLfloat)
                                                          vertex $ Vertex2 (-0.5 :: GLfloat) (0.5 :: GLfloat)
                                                          
                                                          texCoord $ TexCoord2 (1 :: GLfloat) (1 :: GLfloat)
                                                          vertex $ Vertex2 (0.5 :: GLfloat) (0.5 :: GLfloat)
                                                          
                                                          texCoord $ TexCoord2 (1 :: GLfloat) (0 :: GLfloat)
                                                          vertex $ Vertex2 (0.5 :: GLfloat) (-0.5 :: GLfloat)
           
           forM_ bulletlist $ \bullet -> unsafePreservingMatrix $ do
                                       let x = realToFrac . bulletX $ bullet
                                           y = realToFrac . bulletY $ bullet
                                           rotDir = realToFrac . bulletDir $ bullet
                                       
                                       translate $ Vector3 x y (0 :: GLfloat)
                                       rotate rotDir $ Vector3 0 0 (1 :: GLfloat)
                                       
                                       textureBinding Texture2D $= Just textureBullet
                                       
                                       unsafeRenderPrimitive Quads $ do
                                                          texCoord $ TexCoord2 (0 :: GLfloat) (0 :: GLfloat)
                                                          vertex $ Vertex2 (-0.1 :: GLfloat) (-0.1 :: GLfloat)
                                                          
                                                          texCoord $ TexCoord2 (0 :: GLfloat) (1 :: GLfloat)
                                                          vertex $ Vertex2 (-0.1 :: GLfloat) (0.1 :: GLfloat)
                                                          
                                                          texCoord $ TexCoord2 (1 :: GLfloat) (1 :: GLfloat)
                                                          vertex $ Vertex2 (0.1 :: GLfloat) (0.1 :: GLfloat)
                                                          
                                                          texCoord $ TexCoord2 (1 :: GLfloat) (0 :: GLfloat)
                                                          vertex $ Vertex2 (0.1 :: GLfloat) (-0.1 :: GLfloat)
           
           textureBinding Texture2D $= Just textureCrosshair
           forM_ playerlist renderPlayer