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{- Vivant: Haskell OpenGL game.
Copyright (C) 2020 Yann Herklotz
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
-}
module Main where
import Control.Lens ((.~), (^.))
import Control.Monad
import qualified Data.ByteString as BS
import Data.Fixed (mod')
import Data.Function ((&))
import Data.Int (Int32)
import Data.Set (Set)
import qualified Data.Set as Set
import qualified Data.Vector.Storable as V
import Data.Word (Word32)
import Foreign.C.Types
import Foreign.Marshal.Alloc (free, malloc)
import Foreign.Ptr
import Foreign.Storable (poke, sizeOf)
import qualified Graphics.GL.Functions as GL (glUniformMatrix4fv)
import qualified Graphics.Rendering.OpenGL as GL
import qualified Graphics.Rendering.OpenGL.GL.Shaders.Uniform as GL (UniformLocation (..))
import Linear
import Paths_vivant (getDataDir)
import Graphics.Rendering.OpenGL (($=))
import qualified SDL
import SDL.Raw.Enum as SDL
import SDL.Raw.Video as SDL (glSetAttribute)
import SDL.Time (ticks)
import SDL.Vect
import System.Exit (exitFailure)
import System.IO
import Vivant.Shader (createProgram)
import Vivant.Renderer
import Vivant.Terrain
screenWidth, screenHeight :: CInt
(screenWidth, screenHeight) = (640, 480)
data Camera = Camera
{ cameraPos :: V3 Float,
cameraUp :: V3 Float,
cameraFront :: V3 Float,
cameraSpeed :: Float,
cameraPitch :: Float,
cameraYaw :: Float
}
deriving (Show)
initialCamera :: Camera
initialCamera =
Camera
{ cameraPos = V3 0 (-10) 10,
cameraUp = normalize (V3 0 10 10),
cameraFront = normalize (V3 0 10 (-10)),
cameraSpeed = 0.05,
cameraPitch = 0,
cameraYaw = (-90)
}
data Game = Game
{ gameProgram :: Maybe GL.Program,
gameVao :: Maybe GL.VertexArrayObject,
gameModelP :: Ptr (M44 Float),
gameViewP :: Ptr (M44 Float),
gameProjectionP :: Ptr (M44 Float),
gameCamera :: Camera,
gameTerrain :: Maybe Terrain
}
deriving (Show)
initialGameState :: Game
initialGameState =
Game
{ gameProgram = Nothing,
gameVao = Nothing,
gameModelP = nullPtr,
gameViewP = nullPtr,
gameProjectionP = nullPtr,
gameCamera = initialCamera,
gameTerrain = Nothing
}
data MouseInputs = MouseInputs
{ mousePosition :: Point V2 Int32,
mouseRelative :: V2 Int32,
mousePositionOld :: Maybe (V2 Int32),
mousePressed :: Bool
}
deriving (Show)
initialMouse :: MouseInputs
initialMouse =
MouseInputs
{ mousePosition = P (V2 400 300),
mouseRelative = V2 0 0,
mousePositionOld = Nothing,
mousePressed = False
}
main :: IO ()
main = do
SDL.initialize [SDL.InitVideo]
SDL.HintRenderScaleQuality $= SDL.ScaleLinear
do
renderQuality <- SDL.get SDL.HintRenderScaleQuality
when (renderQuality /= SDL.ScaleLinear) $
putStrLn "Warning: Linear texture filtering not enabled!"
window <-
SDL.createWindow
"SDL / OpenGL Example"
SDL.defaultWindow
{ SDL.windowInitialSize = V2 screenWidth screenHeight,
SDL.windowGraphicsContext = SDL.OpenGLContext SDL.defaultOpenGL
}
SDL.glSetAttribute SDL_GL_CONTEXT_PROFILE_MASK SDL_GL_CONTEXT_PROFILE_CORE
SDL.glSetAttribute SDL_GL_CONTEXT_MAJOR_VERSION 3
SDL.glSetAttribute SDL_GL_CONTEXT_MINOR_VERSION 2
SDL.glSetAttribute SDL_GL_DOUBLEBUFFER 1
SDL.glSetAttribute SDL_GL_DEPTH_SIZE 24
SDL.showWindow window
_ <- SDL.glCreateContext window
GL.viewport $= (GL.Position 0 0, GL.Size (fromIntegral screenWidth) (fromIntegral screenHeight))
game <- initResources
let loop game key mouse = do
(keys', mouse') <- parseEvents key mouse
let game' = updateMouse mouse' game
draw game'
SDL.glSwapWindow window
unless (Set.member escapeKey keys') (loop game' keys' mouse')
loop game Set.empty initialMouse
mapM_
free
[ gameModelP game,
gameViewP game,
gameProjectionP game
]
SDL.destroyWindow window
SDL.quit
noKeyModifier :: SDL.KeyModifier
noKeyModifier = SDL.KeyModifier False False False False False False False False False False False
escapeKey :: SDL.Keysym
escapeKey = SDL.Keysym SDL.ScancodeEscape SDL.KeycodeEscape noKeyModifier
parseEvents :: Set SDL.Keysym -> MouseInputs -> IO (Set SDL.Keysym, MouseInputs)
parseEvents keys mouse = do
events <- SDL.pollEvents
let events' = fmap SDL.eventPayload events
let isMoving = (> 0) . length $ filter mouseMoving events'
let (k, m) = foldr handleEvents (keys, mouse) events'
return (if isMoving
then (k, m)
else (k, m {mouseRelative = V2 0 0}))
where
mouseMoving (SDL.MouseMotionEvent{}) = True
mouseMoving _ = False
handleEvents ::
SDL.EventPayload ->
(Set SDL.Keysym, MouseInputs) ->
(Set SDL.Keysym, MouseInputs)
handleEvents event (k, m) =
case event of
SDL.KeyboardEvent
( SDL.KeyboardEventData
{ SDL.keyboardEventKeyMotion = e,
SDL.keyboardEventKeysym = k'
}
) ->
((if e == SDL.Released then Set.delete else Set.insert) k' k, m)
SDL.MouseMotionEvent
( SDL.MouseMotionEventData
{ SDL.mouseMotionEventPos = pos,
SDL.mouseMotionEventRelMotion = vel
}
) ->
(k, MouseInputs pos vel (mousePositionOld m) (mousePressed m))
SDL.MouseButtonEvent
(SDL.MouseButtonEventData
{ SDL.mouseButtonEventMotion = SDL.Pressed
}) ->
(k, m {mousePressed = True})
SDL.MouseButtonEvent
(SDL.MouseButtonEventData
{ SDL.mouseButtonEventMotion = SDL.Released
}) ->
(k, m {mousePressed = False})
SDL.QuitEvent {} ->
(Set.insert escapeKey k, m)
_ -> (k, m)
updateMouse :: MouseInputs -> Game -> Game
updateMouse mouse game =
game
{ gameCamera =
(gameCamera game)
{
cameraPos = newPos,
cameraFront = normalize (V3 0 0 0 ^-^ newPos),
cameraUp = newUp
}
}
where
rotation v
| mousePressed mouse = rotate (axisAngle (V3 0 0 1)
((/ 2) . toRadians . fromIntegral
$ - (mouseRelative mouse ^. _x))) v
| otherwise = v
newPos = rotation . cameraPos $ gameCamera game
newUp = rotation . cameraUp $ gameCamera game
initResources :: IO Game
initResources = do
vao <- GL.genObjectName
GL.bindVertexArrayObject $= Just vao
vbo <- GL.genObjectName
GL.bindBuffer GL.ArrayBuffer $= Just vbo
V.unsafeWith square $ \ptr ->
GL.bufferData GL.ArrayBuffer $= (vectorSize square, castPtr ptr, GL.StaticDraw)
prog <- createProgram
setVertexAttribute prog "position" 3 0 0
modelP <- malloc
viewP <- malloc
projectionP <- malloc
terrain <- initTerrain [[1, 2, 3, 4], [3, 2, 1, 4], [2, 5, 2, 3], [3, 1, 2, 4]] prog
return $
initialGameState
{ gameProgram = Just prog,
gameVao = Just vao,
gameModelP = modelP,
gameViewP = viewP,
gameProjectionP = projectionP,
gameTerrain = Just terrain
}
-- | Convert degrees to radians
toRadians :: Float -> Float
toRadians = (*) (pi / 180)
scaledMat :: V4 (V4 Float) -> V4 (V4 Float)
scaledMat n = ((n * identity) & _w . _w .~ 1)
draw :: Game -> IO ()
draw game@(Game {gameProgram = Just p, gameVao = Just v, gameTerrain = Just t}) = do
tick <- ticks
GL.clearColor $= GL.Color4 1 1 1 1
GL.clear [GL.ColorBuffer, GL.DepthBuffer]
GL.currentProgram $= gameProgram game
GL.bindVertexArrayObject $= rendererVao (terrainRenderer t)
model <- getUniformLocation <$> GL.uniformLocation p "model"
view <- getUniformLocation <$> GL.uniformLocation p "view"
projection <- getUniformLocation <$> GL.uniformLocation p "projection"
let camera = gameCamera game
cameraPosition = cameraPos camera
targetPosition = cameraPosition ^+^ cameraFront camera
viewMatrix = lookAt cameraPosition targetPosition (cameraUp camera)
projectionMatrix = perspective (toRadians 45) (640 / 480) 0.1 100
poke (gameViewP game) viewMatrix
poke (gameProjectionP game) projectionMatrix
GL.glUniformMatrix4fv view 1 1 (castPtr (gameViewP game))
GL.glUniformMatrix4fv projection 1 1 (castPtr (gameProjectionP game))
ourColorLoc <- GL.uniformLocation p "ourColour"
GL.uniform ourColorLoc $= (GL.Vector4 (1 :: Float) 0.5 1 1)
render $ terrainRenderer t
GL.bindVertexArrayObject $= Nothing
return ()
vectorSize :: (Num b, V.Storable a) => V.Vector a -> b
vectorSize array = fromIntegral $ V.length array * sizeOf (1.0 :: Float)
vertices :: V.Vector Float
vertices =
V.fromList
[ 0.5, -0.5, 0,
-0.5, -0.5, 0,
0.5, 0.5, 0,
-0.5, 0.5, 0,
-0.5, -0.5, 0,
0.5, 0.5, 0
]
square :: V.Vector Float
square =
V.fromList
[ -0.5, -0.5, -0.5,
0.5, -0.5, -0.5,
0.5, 0.5, -0.5,
0.5, 0.5, -0.5,
-0.5, 0.5, -0.5,
-0.5, -0.5, -0.5,
-0.5, -0.5, 0.5,
0.5, -0.5, 0.5,
0.5, 0.5, 0.5,
0.5, 0.5, 0.5,
-0.5, 0.5, 0.5,
-0.5, -0.5, 0.5,
-0.5, 0.5, 0.5,
-0.5, 0.5, -0.5,
-0.5, -0.5, -0.5,
-0.5, -0.5, -0.5,
-0.5, -0.5, 0.5,
-0.5, 0.5, 0.5,
0.5, 0.5, 0.5,
0.5, 0.5, -0.5,
0.5, -0.5, -0.5,
0.5, -0.5, -0.5,
0.5, -0.5, 0.5,
0.5, 0.5, 0.5,
-0.5, -0.5, -0.5,
0.5, -0.5, -0.5,
0.5, -0.5, 0.5,
0.5, -0.5, 0.5,
-0.5, -0.5, 0.5,
-0.5, -0.5, -0.5,
-0.5, 0.5, -0.5,
0.5, 0.5, -0.5,
0.5, 0.5, 0.5,
0.5, 0.5, 0.5,
-0.5, 0.5, 0.5,
-0.5, 0.5, -0.5
]
locs :: [V3 Float]
locs =
[ V3 0 0 0
]
texCoords :: V.Vector Float
texCoords =
V.fromList
[ 0,
0,
1,
0,
0.5,
1
]
|