{-# OPTIONS -fwarn-incomplete-patterns #-} {-# OPTIONS_HADDOCK hide #-} {-# LANGUAGE ImplicitParams, ScopedTypeVariables #-} module Graphics.Gloss.Internals.Render.Picture (renderPicture) where import Graphics.Gloss.Data.Picture import Graphics.Gloss.Data.Color import Graphics.Gloss.Internals.Interface.Backend import Graphics.Gloss.Internals.Interface.ViewPort import Graphics.Gloss.Internals.Render.State import Graphics.Gloss.Internals.Render.Common import Graphics.Gloss.Internals.Render.Circle import Graphics.Gloss.Internals.Render.Bitmap import System.Mem.StableName import Foreign.ForeignPtr import Data.IORef import Data.List import Control.Monad import Graphics.Rendering.OpenGL (($=), get) import qualified Graphics.Rendering.OpenGL.GL as GL import qualified Graphics.Rendering.OpenGL.GLU.Errors as GLU import qualified Graphics.UI.GLUT as GLUT -- | Render a picture using the given render options and viewport. renderPicture :: forall a . Backend a => IORef a -> State -- ^ The render state -> ViewPort -- ^ The current viewport. -> Picture -- ^ The picture to render. -> IO () renderPicture backendRef renderS viewS picture = do -- This GL state doesn't change during rendering, -- so we can just read it once here (matProj_ :: GL.GLmatrix GL.GLdouble) <- get $ GL.matrix (Just GL.Projection) viewport_ <- get $ GL.viewport windowSize_ <- getWindowDimensions backendRef -- let ?modeWireframe = stateWireframe renderS ?modeColor = stateColor renderS ?refTextures = stateTextures renderS ?matProj = matProj_ ?viewport = viewport_ ?windowSize = windowSize_ -- setup render state for world setLineSmooth (stateLineSmooth renderS) setBlendAlpha (stateBlendAlpha renderS) checkErrors "before drawPicture." drawPicture (viewPortScale viewS) picture checkErrors "after drawPicture." drawPicture :: ( ?modeWireframe :: Bool , ?modeColor :: Bool , ?refTextures :: IORef [Texture]) => Float -> Picture -> IO () drawPicture circScale picture = {-# SCC "drawComponent" #-} case picture of -- nothin' Blank -> return () -- line Line path -> GL.renderPrimitive GL.LineStrip $ vertexPFs path -- polygon (where?) Polygon path | ?modeWireframe -> GL.renderPrimitive GL.LineLoop $ vertexPFs path | otherwise -> GL.renderPrimitive GL.Polygon $ vertexPFs path -- circle Circle radius -> renderCircle 0 0 circScale radius 0 ThickCircle radius thickness -> renderCircle 0 0 circScale radius thickness -- arc Arc a1 a2 radius -> renderArc 0 0 circScale radius a1 a2 0 ThickArc a1 a2 radius thickness -> renderArc 0 0 circScale radius a1 a2 thickness -- stroke text -- text looks weird when we've got blend on, -- so disable it during the renderString call. Text str -> do GL.blend $= GL.Disabled GL.preservingMatrix $ GLUT.renderString GLUT.Roman str GL.blend $= GL.Enabled -- colors with float components. Color col p | ?modeColor -> do oldColor <- get GL.currentColor let (r, g, b, a) = rgbaOfColor col GL.currentColor $= GL.Color4 (gf r) (gf g) (gf b) (gf a) drawPicture circScale p GL.currentColor $= oldColor | otherwise -> drawPicture circScale p -- Translation -------------------------- -- Easy translations are done directly to avoid calling GL.perserveMatrix. Translate posX posY (Circle radius) -> renderCircle posX posY circScale radius 0 Translate posX posY (ThickCircle radius thickness) -> renderCircle posX posY circScale radius thickness Translate posX posY (Arc a1 a2 radius) -> renderArc posX posY circScale radius a1 a2 0 Translate posX posY (ThickArc a1 a2 radius thickness) -> renderArc posX posY circScale radius a1 a2 thickness Translate tx ty (Rotate deg p) -> GL.preservingMatrix $ do GL.translate (GL.Vector3 (gf tx) (gf ty) 0) GL.rotate (gf deg) (GL.Vector3 0 0 (-1)) drawPicture circScale p Translate tx ty p -> GL.preservingMatrix $ do GL.translate (GL.Vector3 (gf tx) (gf ty) 0) drawPicture circScale p -- Rotation ----------------------------- -- Easy rotations are done directly to avoid calling GL.perserveMatrix. Rotate _ (Circle radius) -> renderCircle 0 0 circScale radius 0 Rotate _ (ThickCircle radius thickness) -> renderCircle 0 0 circScale radius thickness Rotate deg (Arc a1 a2 radius) -> renderArc 0 0 circScale radius (a1-deg) (a2-deg) 0 Rotate deg (ThickArc a1 a2 radius thickness) -> renderArc 0 0 circScale radius (a1-deg) (a2-deg) thickness Rotate deg p -> GL.preservingMatrix $ do GL.rotate (gf deg) (GL.Vector3 0 0 (-1)) drawPicture circScale p -- Scale -------------------------------- Scale sx sy p -> GL.preservingMatrix $ do GL.scale (gf sx) (gf sy) 1 let mscale = max sx sy drawPicture (circScale * mscale) p -- Bitmap ------------------------------- Bitmap width height imgData cacheMe -> do -- Load the image data into a texture, -- or grab it from the cache if we've already done that before. tex <- loadTexture ?refTextures width height imgData cacheMe -- Set up wrap and filtering mode GL.textureWrapMode GL.Texture2D GL.S $= (GL.Repeated, GL.Repeat) GL.textureWrapMode GL.Texture2D GL.T $= (GL.Repeated, GL.Repeat) GL.textureFilter GL.Texture2D $= ((GL.Nearest, Nothing), GL.Nearest) -- Enable texturing GL.texture GL.Texture2D $= GL.Enabled GL.textureFunction $= GL.Combine -- Set current texture GL.textureBinding GL.Texture2D $= Just (texObject tex) -- Set to opaque GL.currentColor $= GL.Color4 1.0 1.0 1.0 1.0 -- Draw textured polygon GL.renderPrimitive GL.Polygon $ zipWithM_ (\(pX, pY) (tX, tY) -> do GL.texCoord $ GL.TexCoord2 (gf tX) (gf tY) GL.vertex $ GL.Vertex2 (gf pX) (gf pY)) (bitmapPath (fromIntegral width) (fromIntegral height)) [(0,0), (1.0,0), (1.0,1.0), (0,1.0)] -- Disable texturing GL.texture GL.Texture2D $= GL.Disabled -- Free uncachable texture objects. freeTexture tex Pictures ps -> mapM_ (drawPicture circScale) ps -- Errors --------------------------------------------------------------------- checkErrors :: String -> IO () checkErrors place = do errors <- get $ GLU.errors when (not $ null errors) $ mapM_ (handleError place) errors handleError :: String -> GLU.Error -> IO () handleError place err = case err of GLU.Error GLU.StackOverflow _ -> error $ unlines [ "Gloss / OpenGL Stack Overflow " ++ show place , " This program uses the Gloss vector graphics library, which tried to" , " draw a picture using more nested transforms (Translate/Rotate/Scale)" , " than your OpenGL implementation supports. The OpenGL spec requires" , " all implementations to have a transform stack depth of at least 32," , " and Gloss tries not to push the stack when it doesn't have to, but" , " that still wasn't enough." , "" , " You should complain to your harware vendor that they don't provide" , " a better way to handle this situation at the OpenGL API level." , "" , " To make this program work you'll need to reduce the number of nested" , " transforms used when defining the Picture given to Gloss. Sorry." ] -- Issue #32: Spurious "Invalid Operation" errors under Windows 7 64-bit. -- When using GLUT under Windows 7 it complains about InvalidOperation, -- but doesn't provide any other details. All the examples look ok, so -- we're just ignoring the error for now. GLU.Error GLU.InvalidOperation _ -> return () _ -> error $ unlines [ "Gloss / OpenGL Internal Error " ++ show place , " Please report this on haskell-gloss@googlegroups.com." , show err ] -- Textures ------------------------------------------------------------------- -- | Load a texture. -- If we've seen it before then use the pre-installed one from the texture -- cache, otherwise load it into OpenGL. loadTexture :: IORef [Texture] -> Int -> Int -> BitmapData -> Bool -> IO Texture loadTexture refTextures width height imgData cacheMe = do textures <- readIORef refTextures -- Try and find this same texture in the cache. name <- makeStableName imgData let mTexCached = find (\tex -> texName tex == name && texWidth tex == width && texHeight tex == height) textures case mTexCached of Just tex -> return tex Nothing -> do tex <- installTexture width height imgData cacheMe when cacheMe $ writeIORef refTextures (tex : textures) return tex -- | Install a texture into OpenGL. installTexture :: Int -> Int -> BitmapData -> Bool -> IO Texture installTexture width height bitmapData@(BitmapData _ fptr) cacheMe = do -- Allocate texture handle for texture [tex] <- GL.genObjectNames 1 GL.textureBinding GL.Texture2D $= Just tex -- Sets the texture in imgData as the current texture -- This copies the data from the pointer into OpenGL texture memory, -- so it's ok if the foreignptr gets garbage collected after this. withForeignPtr fptr $ \ptr -> GL.texImage2D Nothing GL.NoProxy 0 GL.RGBA8 (GL.TextureSize2D (gsizei width) (gsizei height)) 0 (GL.PixelData GL.RGBA GL.UnsignedInt8888 ptr) -- Make a stable name that we can use to identify this data again. -- If the user gives us the same texture data at the same size then we -- can avoid loading it into texture memory again. name <- makeStableName bitmapData return Texture { texName = name , texWidth = width , texHeight = height , texData = fptr , texObject = tex , texCacheMe = cacheMe } -- | If this texture does not have its `cacheMe` flag set then delete it from -- OpenGL and free the memory. freeTexture :: Texture -> IO () freeTexture tex | texCacheMe tex = return () | otherwise = GL.deleteObjectNames [texObject tex] -- Utils ---------------------------------------------------------------------- -- | Turn alpha blending on or off setBlendAlpha :: Bool -> IO () setBlendAlpha state | state = do GL.blend $= GL.Enabled GL.blendFunc $= (GL.SrcAlpha, GL.OneMinusSrcAlpha) | otherwise = do GL.blend $= GL.Disabled GL.blendFunc $= (GL.One, GL.Zero) -- | Turn line smoothing on or off setLineSmooth :: Bool -> IO () setLineSmooth state | state = GL.lineSmooth $= GL.Enabled | otherwise = GL.lineSmooth $= GL.Disabled vertexPFs :: [(Float, Float)] -> IO () {-# INLINE vertexPFs #-} vertexPFs [] = return () vertexPFs ((x, y) : rest) = do GL.vertex $ GL.Vertex2 (gf x) (gf y) vertexPFs rest