-- -- This code was created by Jeff Molofee '99 (ported to Haskell GHC 2005) -- module Main where import Graphics.UI.GLUT import System.Exit ( exitWith, ExitCode(..) ) import Monad ( liftM ) import Data.IORef ( IORef, newIORef ) import Util ( Image(..), bitmapLoad ) initGL :: IO TextureObject initGL = do tex <- loadGLTextures texture Texture2D $= Enabled clearColor $= Color4 0 0 0 0.5 -- Clear the background color to black clearDepth $= 1 -- enables clearing of the depth buffer depthFunc $= Just Less -- type of depth test shadeModel $= Smooth -- enables smooth color shading matrixMode $= Projection loadIdentity -- reset projection matrix Size width height <- get windowSize perspective 45 (fromIntegral width/fromIntegral height) 0.1 100 -- calculate the aspect ratio of the window matrixMode $= Modelview 0 flush -- finally, we tell opengl to do it. return tex loadGLTextures :: IO TextureObject loadGLTextures = do (Image (Size w h) pd) <- bitmapLoad "Data/NeHe.bmp" texName <- liftM head (genObjectNames 1) textureBinding Texture2D $= Just texName textureFilter Texture2D $= ((Nearest, Nothing), Nearest) texImage2D Nothing NoProxy 0 RGB' (TextureSize2D w h) 0 pd return texName resizeScene :: Size -> IO () resizeScene (Size w 0) = resizeScene (Size w 1) -- prevent divide by zero resizeScene s@(Size width height) = do viewport $= (Position 0 0, s) matrixMode $= Projection loadIdentity perspective 45 (fromIntegral width/fromIntegral height) 0.1 100 matrixMode $= Modelview 0 flush drawScene :: TextureObject -> IORef GLfloat -> IORef GLfloat -> IORef GLfloat -> IO () drawScene tex xrot yrot zrot = do clear [ColorBuffer, DepthBuffer] -- clear the screen and the depth bufer loadIdentity -- reset view translate (Vector3 0 0 (-5.0::GLfloat)) --Move left 5 Units into the screen xr <- get xrot yr <- get yrot zr <- get zrot rotate xr (Vector3 1 0 (0::GLfloat)) -- Rotate the triangle on the Y axis rotate yr (Vector3 0 1 (0::GLfloat)) -- Rotate the triangle on the Y axis rotate zr (Vector3 0 0 (1::GLfloat)) -- Rotate the triangle on the Y axis textureBinding Texture2D $= Just tex renderPrimitive Quads $ -- start drawing a polygon (4 sided) do -- first the front texCoord (TexCoord2 0 (0::GLfloat)) vertex (Vertex3 (-1) (-1) (1::GLfloat)) -- bottom left of quad (Front) texCoord (TexCoord2 1 (0::GLfloat)) vertex (Vertex3 1 (-1) (1::GLfloat)) -- bottom right of quad (Front) texCoord (TexCoord2 1 (1::GLfloat)) vertex (Vertex3 1 1 (1::GLfloat)) -- top right of quad (Front) texCoord (TexCoord2 0 (1::GLfloat)) vertex (Vertex3 (-1) 1 (1::GLfloat)) -- top left of quad (Front) -- now the back texCoord (TexCoord2 1 (0::GLfloat)) vertex (Vertex3 (-1) (-1) (-1::GLfloat)) -- bottom right of quad (Back) texCoord (TexCoord2 1 (1::GLfloat)) vertex (Vertex3 (-1) 1 (-1::GLfloat)) -- top right of quad (Back) texCoord (TexCoord2 0 (1::GLfloat)) vertex (Vertex3 1 1 (-1::GLfloat)) -- top left of quad (Back) texCoord (TexCoord2 0 (0::GLfloat)) vertex (Vertex3 1 (-1) (-1::GLfloat)) -- bottom left of quad (Back) -- now the top texCoord (TexCoord2 0 (1::GLfloat)) vertex (Vertex3 (-1) 1 (-1::GLfloat)) -- top left of quad (Top) texCoord (TexCoord2 0 (0::GLfloat)) vertex (Vertex3 (-1) 1 (1::GLfloat)) -- bottom left of quad (Top) texCoord (TexCoord2 1 (0::GLfloat)) vertex (Vertex3 1 1 (1::GLfloat)) -- bottom right of quad (Top) texCoord (TexCoord2 1 (1::GLfloat)) vertex (Vertex3 1 1 (-1::GLfloat)) -- top right of quad (Top) -- now the bottom texCoord (TexCoord2 1 (1::GLfloat)) vertex (Vertex3 1 (-1) (1::GLfloat)) -- top right of quad (Bottom) texCoord (TexCoord2 0 (1::GLfloat)) vertex (Vertex3 (-1) (-1) (1::GLfloat)) -- top left of quad (Bottom) texCoord (TexCoord2 0 (0::GLfloat)) vertex (Vertex3 (-1) (-1) (-1::GLfloat)) -- bottom left of quad (Bottom) texCoord (TexCoord2 1 (0::GLfloat)) vertex (Vertex3 1 (-1) (-1::GLfloat)) -- bottom right of quad (Bottom) -- now the right texCoord (TexCoord2 1 (0::GLfloat)) vertex (Vertex3 1 (-1) (-1::GLfloat)) -- bottom right of quad (Right) texCoord (TexCoord2 1 (1::GLfloat)) vertex (Vertex3 1 1 (-1::GLfloat)) -- top right of quad (Right) texCoord (TexCoord2 0 (1::GLfloat)) vertex (Vertex3 1 1 (1::GLfloat)) -- top left of quad (Right) texCoord (TexCoord2 0 (0::GLfloat)) vertex (Vertex3 1 (-1) (1::GLfloat)) -- bottom left of quad (Right) -- now the left texCoord (TexCoord2 0 (0::GLfloat)) vertex (Vertex3 (-1) (-1) (-1::GLfloat)) -- bottom left of quad (Left) texCoord (TexCoord2 1 (0::GLfloat)) vertex (Vertex3 (-1) 1 (-1::GLfloat)) -- top left of quad (Left) texCoord (TexCoord2 1 (1::GLfloat)) vertex (Vertex3 (-1) 1 (1::GLfloat)) -- top right of quad (Left) texCoord (TexCoord2 0 (1::GLfloat)) vertex (Vertex3 (-1) (-1) (1::GLfloat)) -- bottom right of quad (Left) xrot $= xr + 0.3 yrot $= yr + 0.2 zrot $= zr + 0.4 -- since this is double buffered, swap the buffers to display what was just -- drawn flush swapBuffers keyPressed :: KeyboardMouseCallback -- 27 is ESCAPE keyPressed (Char '\27') Down _ _ = exitWith ExitSuccess keyPressed _ _ _ _ = return () main :: IO () main = do -- Initialize GLUT state - glut will take any command line arguments -- that pertain to it or X windows -- look at its documentation at -- http://reality.sgi.com/mjk/spec3/spec3.html getArgsAndInitialize -- select type of display mode: -- Double buffer -- RGBA color -- Alpha components supported -- Depth buffer initialDisplayMode $= [ DoubleBuffered, RGBAMode, WithDepthBuffer, WithAlphaComponent ] -- get an 800 x 600 window initialWindowSize $= Size 800 600 -- window starts at upper left corner of the screen initialWindowPosition $= Position 0 0 -- open a window createWindow "Jeff Molofee's GL Code Tutorial ... NeHe '99" -- register the function to do all our OpenGL drawing xrot <- newIORef 0 yrot <- newIORef 0 zrot <- newIORef 0 -- initialize our window. tex <- initGL displayCallback $= (drawScene tex xrot yrot zrot) -- go fullscreen. This is as soon as possible. fullScreen -- even if there are no events, redraw our gl scene idleCallback $= Just (drawScene tex xrot yrot zrot) -- register the funciton called when our window is resized reshapeCallback $= Just resizeScene -- register the function called when the keyboard is pressed. keyboardMouseCallback $= Just keyPressed -- start event processing engine mainLoop