hw/examples/example00/Main.hs

{-# LANGUAGE OverloadedStrings, RecordWildCards #-}

module Main where

import Affection

import SDL (($=))
import qualified SDL

import qualified Graphics.Rendering.OpenGL as GL
import qualified Graphics.GLUtil as GLU

import Physics.Bullet.Raw

import Control.Concurrent.STM (atomically)
import Control.Concurrent.STM.TVar

import Control.Monad (when)
import Control.Monad.IO.Class (liftIO)

import Linear as L

import System.Random (randomRIO)

import SpatialMath

import Init
import Types

import Debug.Trace as T

main :: IO ()
main =
  withAffection (AffectionConfig
    { initComponents = All
    , windowTitle    = "hw"
    , windowConfigs  =
      [ ( 0
        , SDL.defaultWindow
          { SDL.windowInitialSize = SDL.V2 1600 900
          , SDL.windowGraphicsContext = SDL.OpenGLContext SDL.defaultOpenGL
            { SDL.glProfile = SDL.Compatibility SDL.Debug 4 0
            }
          }
        , SDL.Fullscreen
        )
      ]
    } :: AffectionConfig StateData)

instance Affectionate StateData where
  loadState = load
  preLoop _ = return ()
  handleEvents sd = mapM_ (handle sd)
  update = Main.update
  draw = Main.draw
  cleanUp = const (return ())
  hasNextStep = liftIO . readTVarIO . quitGame

quit = liftIO . atomically . (\sd -> writeTVar (quitGame sd) False)

update :: StateData -> Double -> Affection ()
update sd dt = do
  let phys = physics sd
      physos = physicsObjects sd
  (phys, physos) <- liftIO $ atomically $
    (,)
      <$> readTVar (physics sd)
      <*> readTVar (physicsObjects sd)
  liftIO $ stepSimulation (pWorld phys) dt 10 Nothing
  posrots <- mapM ((\ball -> do
    ms <- liftIO $ getMotionState ball
    npos <- liftIO $ return . fmap realToFrac =<< getPosition ms
    nrot <- liftIO $ return . fmap realToFrac =<< getRotation ms
    return (npos, nrot))
    . bodyRigidBody) (poBalls physos)
  let nships shipss = map (\(ship, (pos, rot)) ->
        ship
          { shipRot = rot
          , shipPos = pos
          }
        ) (zip shipss posrots)
  liftIO $ atomically $ modifyTVar (ships sd) $ \shs -> nships shs

draw :: StateData -> Affection ()
draw sd = do
  (cam, p, ships, program) <- liftIO $ do
    cam <- readTVarIO (camera sd)
    p <- readTVarIO (proj sd)
    ships <- readTVarIO (ships sd)
    program <- readTVarIO (program sd)
    return (cam, p, ships, program)
  GL.viewport $= (GL.Position 0 0, GL.Size 1600 900)
  GL.currentProgram $= (Just . GLU.program $ program)
  mapM_ (\Ship{..} -> do
    let view = lookAt
          (cameraFocus cam +
            rotVecByEulerB2A
            (cameraRot cam)
            (V3 0 0 (-cameraDist cam)))
          (cameraFocus cam)
          (V3 0 1 0)
        model = mkTransformation shipRot shipPos
        pvm = p !*! view !*! model
    liftIO $ GLU.setUniform program "mvp" pvm
    GL.bindVertexArrayObject $= Just shipVao
    liftIO $ GL.drawArrays GL.Triangles 0 (fromIntegral shipVaoLen)
    ) ships

handle :: StateData -> SDL.EventPayload -> Affection ()
handle sd (SDL.WindowClosedEvent _) = quit sd

handle sd (SDL.KeyboardEvent dat) = do
  let key = SDL.keysymKeycode (SDL.keyboardEventKeysym dat)
  when (SDL.keyboardEventKeyMotion dat == SDL.Pressed) $
    handleKey sd key
handle sd (SDL.MouseMotionEvent dat) = do
  let (V2 rx ry) = fromIntegral <$> SDL.mouseMotionEventRelMotion dat
  liftIO $ atomically $ modifyTVar (camera sd) $ \c ->
    case SDL.mouseMotionEventState dat of
      [SDL.ButtonRight] ->
        let (V3 sx sy sz) = rotVecByEuler (cameraRot c) (V3 (rx / 10) 0 (ry / 10))
        in  c {cameraFocus = cameraFocus c + V3 sx 0 sy}
      [] ->
        let dphi = pi / 4 / 45 / 10
            (Euler yaw pitch roll) = cameraRot c
            nangle
              | nangle' >= qc = qc - mu
              | nangle' <= -qc = -qc + mu
              | otherwise     = nangle'
              where
                nangle' = (dphi * ry) + roll
                qc = pi / 2
                mu = 0.01
            nrot =
              Euler
                yaw
                (pitch + (rx * dphi))
                nangle
        in  c
          { cameraRot = nrot
          }
      _ ->
        c

handle _ _ = return ()

handleKey :: StateData -> SDL.Keycode -> Affection ()
handleKey sd code
  | code == SDL.KeycodeR =
    GL.clearColor $= GL.Color4 1 0 0 1
  | code == SDL.KeycodeG =
    GL.clearColor $= GL.Color4 0 1 0 1
  | code == SDL.KeycodeB =
    GL.clearColor $= GL.Color4 0 0 1 1
  | code == SDL.KeycodeP = do
    r <- liftIO $ randomRIO (0, 1)
    g <- liftIO $ randomRIO (0, 1)
    b <- liftIO $ randomRIO (0, 1)
    a <- liftIO $ randomRIO (0, 1)
    GL.clearColor $= GL.Color4 r g b a
  | code == SDL.KeycodeEscape =
    quit sd
  | code == SDL.KeycodeF = do
    dt <- deltaTime <$> get
    liftIO $ putStrLn $ show (1 / dt) ++ " FPS"
  | code == SDL.KeycodeT =
    toggleScreen 0
  | code `elem`
    [ SDL.KeycodeW
    , SDL.KeycodeS
    , SDL.KeycodeA
    , SDL.KeycodeD
    , SDL.KeycodeQ
    , SDL.KeycodeE
    ]
    = do
      shipss <- liftIO $ atomically $ readTVar (ships sd)
      let ship = head shipss
          rot = shipRot ship
          dphi = pi / 2 / 45
          nquat = case code of
            SDL.KeycodeW -> rot * axisAngle (V3 1 0 0) (-dphi)
            SDL.KeycodeS -> rot * axisAngle (V3 1 0 0) dphi
            SDL.KeycodeA -> rot * axisAngle (V3 0 1 0) (-dphi)
            SDL.KeycodeD -> rot * axisAngle (V3 0 1 0) dphi
            SDL.KeycodeE -> rot * axisAngle (V3 0 0 1) (-dphi)
            SDL.KeycodeQ -> rot * axisAngle (V3 0 0 1) dphi
            _            -> rot
      liftIO $ atomically $ modifyTVar (ships sd) $ \shipss ->
        ship
          { shipRot = nquat
          } : tail shipss
  | otherwise =
    return ()