packages feed

sdl2-cairo 0.1.0.0 → 0.1.0.1

raw patch · 9 files changed

+808/−799 lines, 9 filesdep +sdl2-cairodep ~sdl2

Dependencies added: sdl2-cairo

Dependency ranges changed: sdl2

Files

− Main.hs
@@ -1,168 +0,0 @@-{-# LANGUAGE OverloadedStrings #-}-module Main where-import Control.Monad (unless)--import SDL-import Linear.V2 (V2(..))-import Linear.V4 (V4(..))-import Linear.Affine (Point(..))--import SDL.Cairo-import SDL.Cairo.Canvas--main :: IO ()-main = do-  initializeAll-  window <- createWindow "SDL2 Cairo Canvas" defaultWindow-  renderer <- createRenderer window (-1) defaultRenderer--  -- create a texture suitable to use cairo on-  texture <- createCairoTexture' renderer window--  appLoop renderer texture 0 (V2 0 0)--appLoop :: Renderer -> Texture -> Int -> V2 Double -> IO ()-appLoop renderer texture framecount mousepos = do-  events <- pollEvents-  let quitEvent event = case eventPayload event of-                          QuitEvent -> True-                          _ -> False-      mouseMoveEvent e = case eventPayload e of-                          MouseMotionEvent _ -> True-                          _ -> False-      getMousePos (MouseMotionEvent (MouseMotionEventData _ _ _ (P p) _)) = fromIntegral <$> p-      getMousePos _ = V2 0 0-      mousePositions = map getMousePos $ map eventPayload $ filter mouseMoveEvent events-      quit = any quitEvent events-      mousepos' = if null mousePositions then mousepos else head mousePositions--  -- draw on the texture-  withCanvas texture $ do-    drawExample-    drawRndCircle-    drawStars (fromIntegral framecount)-    drawTriangleStrip mousepos'-    drawBezierTest--  -- apply texture and show on screen-  copy renderer texture Nothing Nothing-  present renderer--  delay $ 1000 `div` 60     -- slow down to approx. 60 FPS--  unless quit (appLoop renderer texture (framecount+1) mousepos')---- draw a circle in a random color-drawRndCircle :: Canvas ()-drawRndCircle = do-    rnd <- random (0,255)-    fill $ gray rnd-    circle (V2 700 500) 100-    fill $ gray 255---- some shapes, show some features-drawExample :: Canvas ()-drawExample = do-    background $ gray 102--    stroke $ blue 255-    point $ V2 500 10--    line (V2 0 0) (V2 100 100)-    line (V2 100 0) (V2 0 100)-    fill $ red 255 !@ 128-    noStroke-    rect $ D 200 200 100 100-    stroke $ green 255 !@ 128-    fill $ blue 255 !@ 128-    rect $ D 250 250 100 100-    triangle (V2 400 300) (V2 350 400) (V2 400 400)--    strokeWeight 5-    strokeJoin LineJoinRound-    stroke $ (blue 255 + red 255) !@ 128-    fill $ rgb 0 255 255 !@ 128-    polygon [V2 500 500,V2 510 505,V2 520 530, V2 500 530]--    circle (V2 200 500) 30--    strokeWeight 1-    ellipse $ D 300 500 30 50--    pushMatrix-    translate $ V2 600 500-    rotate $ pi/4-    ellipse $ D 0 0 100 50-    popMatrix-    ellipse $ D 0 0 100 50---- ported star example from Processing home page-drawStars :: Double -> Canvas ()-drawStars frameCount = do-  sz@(V2 w h) <- getCanvasSize-  stroke $ gray 0--  pushMatrix-  translate $ V2 (0.2*w) (0.3*h)-  rotate $ frameCount / 200-  star 0 0 5 70 3-  popMatrix--  pushMatrix-  translate $ V2 (0.5*w) (0.3*h)-  rotate $ frameCount / 400-  star 0 0 80 100 40-  popMatrix--  pushMatrix-  translate $ V2 (0.8*w) (0.3*h)-  rotate $ frameCount / (-100)-  star 0 0 30 70 5-  popMatrix--star :: Double -> Double -> Double -> Double -> Double -> Canvas ()-star x y r1 r2 n = do-  let angle = 2*pi/n-      halfAngle = angle/2-      p1 a = V2 (x+cos a*r2) (y+sin a*r2)-      p2 a = V2 (x+cos (a+halfAngle)*r1) (y+sin (a+halfAngle)*r1)-      vertices = concatMap snd $ takeWhile (\(a, _) -> a<2*pi+angle)-               $ iterate (\(a, _) -> (a+angle,[p1 a, p2 a])) (0,[])-  polygon vertices---- ported triangle strip example from Processing homepage-drawTriangleStrip :: V2 Double -> Canvas ()-drawTriangleStrip mousePos = do-  sz@(V2 w h) <- getCanvasSize-  let (V2 mouseX mouseY) = mousePos-      pos = V2 (w/2) (h/4*3)-      n = fromIntegral $ round $ mapRange mouseX (0,w) (6,60)-      astep = 180/n-      insideRadius = 100-      outsideRadius = 150-      cossin a = V2 (cos a) (sin a)-      makeVert a = [ pos+cossin (radians a) * outsideRadius-                   , pos+cossin (radians $ a+astep)*insideRadius-                   ]-      vertices = concatMap makeVert $ map (2*astep*) [0..n]-  shape ShapeTriangleStrip vertices-  return ()---- draw bezier curve examples-drawBezierTest :: Canvas ()-drawBezierTest = do-  pushMatrix-  translate $ V2 600 0-  stroke $ rgb 255 102 0-  line (V2 85 20) (V2 10 10)-  line (V2 90 90) (V2 15 80)-  stroke $ gray 0-  bezier (V2 85 20) (V2 10 10) (V2 90 90) (V2 15 80)-  translate $ V2 100 0-  stroke $ rgb 255 102 0-  noFill-  line (V2 30 20) (V2 80 5)-  line (V2 80 75) (V2 30 75)-  stroke $ gray 0-  bezier (V2 30 20) (V2 80 5) (V2 80 75) (V2 30 75)-  popMatrix
− SDL/Cairo.hs
@@ -1,52 +0,0 @@-{-|-Module      : SDL.Cairo-Copyright   : Copyright (c) 2015 Anton Pirogov-License     : MIT-Maintainer  : anton.pirogov@gmail.com--This module exposes the functions to glue SDL2 'Texture's to the Cairo 'Render' monad.--}-module SDL.Cairo (-  createCairoTexture, createCairoTexture', withCairoTexture,-  withCairoTexture'-) where--import Foreign.C.Types (CInt)-import Foreign.Ptr (castPtr)--import Linear.V2 (V2(..))-import SDL hiding (Surface)-import Graphics.Rendering.Cairo---- |create new texture for Cairo with given size-createCairoTexture :: Renderer -> V2 CInt -> IO Texture-createCairoTexture r = createTexture r ARGB8888 TextureAccessStreaming---- |create new texture for Cairo with the size of the given window-createCairoTexture' :: Renderer -> Window -> IO Texture-createCairoTexture' r w = do-  surf <- getWindowSurface w-  sz@(V2 w h) <- surfaceDimensions surf-  createCairoTexture r sz---- |draw on SDL texture with Render monad from Cairo-withCairoTexture :: Texture -> Render () -> IO ()-withCairoTexture t m = withCairoTexture' t (\s -> renderWith s m)---------- | lock and unwrap SDL texture, get a Cairo surface, pass it to some function-withCairoTexture' :: Texture -> (Surface -> IO a) -> IO a-withCairoTexture' t m = do-  (TextureInfo f _ w h) <- queryTexture t-  case mapFormat f of-    Nothing -> error "ERROR: Invalid pixel format for cairo use!"-    Just f' -> do-      (pixels, pitch) <- lockTexture t Nothing-      ret <- withImageSurfaceForData (castPtr pixels) f'-               (fromIntegral w) (fromIntegral h) (fromIntegral pitch) m-      unlockTexture t-      return ret-  where mapFormat ARGB8888 = Just FormatARGB32-        mapFormat RGB888 = Just FormatRGB24-        mapFormat _ = Nothing
− SDL/Cairo/Canvas.hs
@@ -1,538 +0,0 @@-{-# LANGUAGE GeneralizedNewtypeDeriving #-}-{-|-Module      : SDL.Cairo.Canvas-Copyright   : Copyright (c) 2015 Anton Pirogov-License     : MIT-Maintainer  : anton.pirogov@gmail.com--This module defines the 'Canvas' monad, which is a convenience wrapper around-the underlying Cairo rendering and can be used with the same textures-created by 'createCairoTexture'. You can also mix both, if the need arises.--The Canvas API imitates most of the drawing functions-of the Processing language. See <http://processing.org/reference> for comparison.-While having the Processing spirit, this module does not aim for a perfect mapping and-deviates where necessary or appropriate. Nevertheless most Processing examples should be-trivial to port to the Canvas API. Example:-->import SDL->import Linear.V2 (V2(..))->import SDL.Cairo->import SDL.Cairo.Canvas->->main :: IO ()->main = do->  initializeAll->  window <- createWindow "SDL2 Cairo Canvas" defaultWindow->  renderer <- createRenderer window (-1) defaultRenderer->  texture <- createCairoTexture' renderer window->->  withCanvas texture $ do->    background $ gray 102->    fill $ red 255 !@ 128->    noStroke->    rect $ D 200 200 100 100->    stroke $ green 255 !@ 128->    fill $ blue 255 !@ 128->    rect $ D 250 250 100 100->    triangle (V2 400 300) (V2 350 400) (V2 400 400)->->  copy renderer texture Nothing Nothing->  present renderer->  delay 5000--}-module SDL.Cairo.Canvas (-  -- * Entry point-  Canvas, withCanvas, getCanvasSize, renderCairo,-  -- * Color and Style-  Color, Byte, gray, red, green, blue, rgb, (!@),-  stroke, fill, noStroke, noFill, strokeWeight, strokeJoin, strokeCap,-  -- * Coordinates-  Dim(..), toD, centered, corners,-  -- * Primitives-  background, point, line, triangle, rect, polygon, shape, ShapeMode(..),-  -- * Arcs and Curves-  circle, circle', arc, ellipse, bezier, bezierQ,-  -- * Transformations-  resetMatrix, pushMatrix, popMatrix, translate, rotate, scale,-  -- * Images-  Image(imageSize), createImage, loadImagePNG, saveImagePNG, image, image', blend, grab,-  -- * Text-  Font(..), textFont, textSize, text, textC, textR,-  -- * Math-  mapRange, radians, degrees,-  -- * Misc-  randomSeed, random, getTime, Time(..),-  module Graphics.Rendering.Cairo-) where--import Data.Monoid-import Control.Monad.State-import Data.Word (Word8)--import Data.Time.Clock (UTCTime(..),getCurrentTime)-import Data.Time.LocalTime (timeToTimeOfDay,TimeOfDay(..))-import Data.Time.Calendar (toGregorian)--import System.Random (mkStdGen,setStdGen,randomRIO,Random)--import Linear.V2 (V2(..))-import Linear.V4 (V4(..))-import Linear.Affine (Point(..))--import SDL (Texture,TextureInfo(..),queryTexture)-import qualified Graphics.Rendering.Cairo as C-import Graphics.Rendering.Cairo (Render,LineJoin(..),LineCap(..),Format(..),Operator(..))--import SDL.Cairo (withCairoTexture')--type Byte = Word8---- | RGBA Color is just a byte vector. Colors can be added, subtracted, etc.-type Color = V4 Byte--data CanvasState = CanvasState{ csSize :: V2 Double, -- ^texture size-                                csSurface :: C.Surface, -- ^Cairo surface-                                csFG :: Maybe Color, -- ^stroke color-                                csBG :: Maybe Color, -- ^fill color-                                csFont :: Font,      -- ^current font-                                csActions :: Endo [Render ()], -- ^list of actions to perform-                                csImages :: [Image] -- ^keeping track of images to free later-                              }---- |get size of the canvas (Processing: @width(), height()@)-getCanvasSize :: Canvas (V2 Double)-getCanvasSize = gets csSize---- |wrapper around the Cairo 'Render' monad, providing a Processing-style API-newtype Canvas a = Canvas { unCanvas :: StateT CanvasState IO a }-  deriving (Functor, Applicative, Monad, MonadIO, MonadState CanvasState)---- |draw on a SDL texture using the 'Canvas' monad-withCanvas :: Texture -> Canvas a -> IO a-withCanvas t c = withCairoTexture' t $ \s -> do-  (TextureInfo _ _ w h) <- queryTexture t-  (ret, result) <- runStateT (unCanvas $ defaults >> c)-                  CanvasState{ csSize = V2 (fromIntegral w) (fromIntegral h)-                            , csSurface = s-                            , csFG = Just $ gray 0-                            , csBG = Just $ gray 255-                            , csFont = Font "" 10 False False-                            , csActions = mempty-                            , csImages = []-                            }-  let render = appEndo (csActions result) []-  C.renderWith s $ sequence_ render-  forM_ (csImages result) $ \(Image s _ _) -> C.surfaceFinish s-  return ret-  where defaults = do-          strokeWeight 1-          strokeCap C.LineCapRound---------- |set current stroke color-stroke :: Color -> Canvas ()-stroke clr = get >>= \cs -> put cs{csFG=Just clr}--- |set current fill color-fill :: Color -> Canvas ()-fill clr = get >>= \cs -> put cs{csBG=Just clr}--- |disable stroke (-> shapes without borders!), reenabled by using 'stroke'-noStroke :: Canvas ()-noStroke = get >>= \cs -> put cs{csFG=Nothing}--- |disable fill (-> shapes are not filled!), reenabled by using 'fill'-noFill :: Canvas ()-noFill = get >>= \cs -> put cs{csBG=Nothing}---- |create opaque gray color-gray :: Byte -> Color-gray c = V4 c c c 255--- |create opaque red color-red :: Byte -> Color-red c = V4 c 0 0 255--- |create opaque green color-green :: Byte -> Color-green c = V4 0 c 0 255--- |create opaque blue color-blue :: Byte -> Color-blue c = V4 0 0 c 255--- |create opaque mixed color-rgb :: Byte -> Byte -> Byte -> Color-rgb r g b = V4 r g b 255--- |set transparency of color (half red would be: @red 255 !\@ 128@)-(!@) :: Color -> Byte -> Color-(V4 r g b _) !@ a = V4 r g b a---- |set line width for shape borders etc.-strokeWeight :: Double -> Canvas ()-strokeWeight d = renderCairo $ C.setLineWidth d---- |set the style of connections between lines of shapes-strokeJoin :: C.LineJoin -> Canvas ()-strokeJoin l = renderCairo $ C.setLineJoin l--- |set the style of the line caps-strokeCap :: C.LineCap -> Canvas ()-strokeCap l = renderCairo $ C.setLineCap l---------- | position and size representation (X Y W H)-data Dim = D Double Double Double Double deriving (Show,Eq)---- | create dimensions from position and size vector-toD (V2 a b) (V2 c d) = D a b c d---- | takes dimensions with centered position, returns normalized (left corner)-centered (D cx cy w h) = D (cx-w/2) (cy-h/2) w h--- | takes dimensions with bottom-right corner instead of size, returns normalized (with size)-corners (D xl yl xh yh) = D xl yl (xh-xl) (yh-yl)---------- |replace current matrix with identity-resetMatrix :: Canvas ()-resetMatrix = renderCairo $ C.identityMatrix---- |push current matrix onto the stack-pushMatrix :: Canvas ()-pushMatrix = renderCairo $ C.save---- |pop a matrix-popMatrix :: Canvas ()-popMatrix = renderCairo $ C.restore---- |translate coordinate system-translate :: V2 Double -> Canvas ()-translate (V2 x y) = renderCairo $ C.translate x y---- |scale coordinate system-scale :: V2 Double -> Canvas ()-scale (V2 x y) = renderCairo $ C.scale x y---- |rotate coordinate system-rotate :: Double -> Canvas ()-rotate a = renderCairo $ C.rotate a---------- |clear the canvas with given color-background :: Color -> Canvas ()-background c = do-  (V2 w h) <- gets csSize-  renderCairo $ setColor c >> C.rectangle 0 0 w h >> C.fill---- |draw a point with stroke color (cairo emulates this with 1x1 rects!)-point :: V2 Double -> Canvas ()-point (V2 x y) = ifColor csFG $ \c -> do-      C.rectangle x y 1 1-      setColor c-      C.fill---- |draw a line between two points with stroke color-line :: V2 Double -> V2 Double -> Canvas ()-line (V2 x1 y1) (V2 x2 y2) = ifColor csFG $ \c -> do-      C.moveTo x1 y1-      C.lineTo x2 y2-      setColor c-      C.stroke---- |draw a triangle connecting three points-triangle :: V2 Double -> V2 Double -> V2 Double -> Canvas ()-triangle (V2 x1 y1) (V2 x2 y2) (V2 x3 y3) = drawShape $ do-    C.moveTo x1 y1-    C.lineTo x2 y2-    C.lineTo x3 y3-    C.lineTo x1 y1---- |draw a rectangle-rect :: Dim -> Canvas ()-rect (D x y w h) = drawShape $ C.rectangle x y w h---- |draw a polygon connecting given points (equivalent to @'shape' ('ShapeRegular' True)@)-polygon :: [V2 Double] -> Canvas ()-polygon = shape (ShapeRegular True)---- | Shape mode to use-data ShapeMode = ShapeRegular Bool  -- ^regular path. flag decides whether the first and last point are connected-               | ShapePoints -- ^just draw the points, no lines-               | ShapeLines -- ^interpret points as pairs, draw lines-               | ShapeTriangles -- ^interpret points as triples, draw triangles-               | ShapeTriangleStrip -- ^draw triangle for every neighborhood of 3 points-               | ShapeTriangleFan -- ^fix first point, draw triangles with every neighboring pair and first point-               deriving (Show,Eq)---- |draw shape along a given path using given @'ShapeMode'@.--- (Processing: @beginShape(),vertex(),endShape()@)-shape :: ShapeMode -> [V2 Double] -> Canvas ()-shape (ShapeRegular closed) ((V2 x y):ps) = drawShape $ do-  C.moveTo x y-  forM_ ps $ \(V2 x' y') -> C.lineTo x' y'-  when closed $ C.closePath-shape ShapePoints ps = forM_ ps point-shape ShapeLines (p1:p2:ps) = do-  line p1 p2-  shape ShapeLines ps-shape ShapeLines _ = return ()-shape ShapeTriangles (p1:p2:p3:ps) = do-  triangle p1 p2 p3-  shape ShapeTriangles ps-shape ShapeTriangles _ = return ()-shape ShapeTriangleStrip (p1:p2:p3:ps) = do-  triangle p1 p2 p3-  shape ShapeTriangleStrip (p2:p3:ps)-shape ShapeTriangleStrip _ = return ()-shape ShapeTriangleFan (p1:p2:p3:ps) = do-  triangle p1 p2 p3-  shape ShapeTriangleFan (p1:p3:ps)-shape ShapeTriangleFan _ = return ()---------- |draw arc: @arc dimensions startAngle endAngle@-arc :: Dim -> Double -> Double -> Canvas ()-arc (D x y w h) sa ea = drawShape $ do-  C.save-  C.translate x y-  C.scale (w/2) (h/2)-  C.arc 0 0 1 sa ea-  C.restore---- |draw ellipse-ellipse :: Dim -> Canvas ()-ellipse dim = arc dim 0 (2*pi)---- |draw circle: @circle leftCorner diameter@-circle :: V2 Double -> Double -> Canvas ()-circle (V2 x y) d = ellipse (D x y d d)---- |draw circle: @circle centerPoint diameter@-circle' :: V2 Double -> Double -> Canvas ()-circle' (V2 x y) d = ellipse $ centered (D x y d d)---- |draw cubic bezier spline: @bezier fstAnchor fstControl sndControl sndAnchor@-bezier :: V2 Double -> V2 Double -> V2 Double -> V2 Double -> Canvas ()-bezier (V2 x1 y1) (V2 x2 y2) (V2 x3 y3) (V2 x4 y4) = drawShape $ do-  C.moveTo x1 y1-  C.curveTo x2 y2 x3 y3 x4 y4---- |draw quadratic bezier spline: @bezier fstAnchor control sndAnchor@-bezierQ :: V2 Double -> V2 Double -> V2 Double -> Canvas ()-bezierQ p0 p12 p3 = bezier p0 p1 p2 p3-  where p1 = p0 + 2/3*(p12-p0)-        p2 = p3 + 2/3*(p12-p3)---------- |map a value from one range onto another-mapRange :: Double -> (Double,Double) -> (Double,Double) -> Double-mapRange v (l1,r1) (l2,r2) = (v-l1)*fac + l2-  where fac = (r2-l2)/(r1-l1)---- |convert degrees to radians-radians :: Double -> Double-radians d = d*pi/180--- |convert radians to degrees-degrees :: Double -> Double-degrees r = r/pi*180--- |force value v into given range-constrain :: Double -> (Double,Double) -> Double-constrain v (l,h) = max l $ min h v---- |set new random seed-randomSeed :: Int -> Canvas ()-randomSeed s = liftIO $ setStdGen $ mkStdGen s---- |get new random number-random :: (Random a) => (a,a) -> Canvas a-random = liftIO . randomRIO---- |date and time as returned by getTime-data Time = Time { year :: Int, month :: Int, day :: Int-                 , hour :: Int, minute :: Int, second :: Int } deriving (Show,Eq)---- |get current system time. Use the 'Time' accessors for specific components.--- (Processing: @year(),month(),day(),hour(),minute(),second()@)-getTime :: IO Time-getTime = do-  (UTCTime day time) <- getCurrentTime-  let (y,m,d) = toGregorian day-      (TimeOfDay h mins s) = timeToTimeOfDay time-  return $ Time (fromIntegral y::Int) m d h mins (round s :: Int)--------data Image = Image {imageSurface::C.Surface, imageSize::(V2 Int), imageFormat::Format}---- | create a new empty image of given size-createImage :: V2 Int -> Canvas Image-createImage (V2 w h) = do-  s <- liftIO $ C.createImageSurface FormatARGB32 w h-  let img = Image s (V2 w h) FormatARGB32-  track img-  return img----TODO: add checks (file exists, correct format, etc.)--- | load a PNG image from given path.-loadImagePNG :: FilePath -> Canvas Image-loadImagePNG path = do-  s <- liftIO $ C.imageSurfaceCreateFromPNG path-  w <- C.imageSurfaceGetWidth s-  h <- C.imageSurfaceGetHeight s-  f <- C.imageSurfaceGetFormat s-  let img = Image s (V2 w h) f-  track img-  return img---- | Save an image as PNG to given file path-saveImagePNG :: Image -> FilePath -> Canvas ()-saveImagePNG (Image s _ _) fp = renderCairo $ liftIO (C.surfaceWriteToPNG s fp)---- | Render complete image on given coordinates-image :: Image -> V2 Double -> Canvas ()-image img@(Image _ (V2 w h) _) (V2 x y) =-  image' img (D x y (fromIntegral w) (fromIntegral h))---- | Render complete image inside given dimensions-image' :: Image -> Dim -> Canvas ()-image' img@(Image s (V2 ow oh) _) =-  blend OperatorSource img (D 0 0 (fromIntegral ow) (fromIntegral oh))---- | Copy given part of image to given part of screen, using given blending--- operator and resizing when necessary. Use 'OperatorSource' to copy without--- blending effects. (Processing: @copy(),blend()@)-blend :: Operator -> Image -> Dim -> Dim -> Canvas ()-blend op (Image s (V2 ow oh) _) sdim ddim = do-  surf <- gets csSurface-  renderCairo $ copyFromToSurface op s sdim surf ddim---- | get a copy of the image from current window (Processing: @get()@)-grab :: Dim -> Canvas Image-grab dim@(D x y w h) = do-  surf <- gets csSurface-  i@(Image s _ _) <- createImage (V2 (round w) (round h))-  renderCairo $ copyFromToSurface OperatorSource surf dim s (D 0 0 w h)-  return i---------- | Font definition-data Font = Font{fontFace::String-                ,fontSize::Double-                ,fontBold::Bool-                ,fontItalic::Bool} deriving (Show,Eq)---- | set current font for text rendering-textFont :: Font -> Canvas ()-textFont f = do-  get >>= \cs -> put cs{csFont=f}-  renderCairo $ setFont f---- | get the size of the text when rendered in current font-textSize :: String -> Canvas (V2 Double)-textSize s = gets csSurface >>= \cs -> do-  font <- gets csFont-  (C.TextExtents _ _ w h _ _) <- C.renderWith cs $ setFont font >> C.textExtents s-  return $ V2 w h---- | render text left-aligned (coordinate is top-left corner)-text :: String -> V2 Double -> Canvas ()-text str (V2 x y) = ifColor csFG $ \c -> do-  (C.TextExtents _ yb _ h _ _) <- C.textExtents str-  setColor c-  C.moveTo x (y-yb)-  C.showText str---- | render text right-aligned (coordinate is top-right corner)-textR :: String -> V2 Double -> Canvas ()-textR str (V2 x y) = do-  (V2 w h) <- textSize str-  text str $ V2 (x-w) y---- | render text centered (coordinate is central)-textC :: String -> V2 Double -> Canvas ()-textC str (V2 x y) = do-  (V2 w h) <- textSize str-  text str $ V2 (x-(w/2)) (y-(h/2))----- helpers ------ | execute a raw Cairo Render action-renderCairo :: Render () -> Canvas ()-renderCairo m = get >>= \cs -> put cs{csActions = csActions cs <> Endo ([m]++)}---- |draw a shape - first fill with bg color, then draw border with stroke color-drawShape :: Render a -> Canvas ()-drawShape m = do- ifColor csBG $ \c -> m >> setColor c >> C.fill- ifColor csFG $ \c -> m >> setColor c >> C.stroke---- |if color (csFG/csBG) is set, perform given render block-ifColor :: (CanvasState -> Maybe Color) -> (Color -> Render ()) -> Canvas ()-ifColor cf m = get >>= \cs -> forM_ (cf cs) $ \c -> renderCairo (m c)---- |convert from 256-value RGBA to Double representation, set color-setColor :: Color -> Render ()-setColor c@(V4 r g b a) = C.setSourceRGBA (conv r) (conv g) (conv b) (conv a)-  where conv = ((1.0/256)*).fromIntegral---- | Add to garbage collection list-track :: Image -> Canvas ()-track img = get >>= \cs -> put cs{csImages=img:csImages cs}---- cairo helpers ------ | helper: returns new surface with scaled content. does NOT cleanup!-createScaledSurface :: C.Surface -> (V2 Double) -> Render C.Surface-createScaledSurface s (V2 w h) = do-  ow <- C.imageSurfaceGetWidth s-  oh <- C.imageSurfaceGetHeight s-  s' <- liftIO $ C.createSimilarSurface s C.ContentColorAlpha (round w) (round h)-  C.renderWith s' $ do-    C.scale (w/fromIntegral ow) (h/fromIntegral oh)-    C.setSourceSurface s 0 0-    pat <- C.getSource-    C.patternSetExtend pat C.ExtendPad-    C.setOperator C.OperatorSource-    C.paint-  return s'---- | helper: returns new surface with only part of original content. does NOT cleanup!-createTrimmedSurface :: C.Surface -> Dim -> Render C.Surface-createTrimmedSurface s (D x y w h) = do-  ow <- C.imageSurfaceGetWidth s-  oh <- C.imageSurfaceGetHeight s-  s' <- liftIO $ C.createSimilarSurface s C.ContentColorAlpha (round w) (round h)-  C.renderWith s' $ do-    C.setSourceSurface s (-x) (-y)-    C.setOperator C.OperatorSource-    C.rectangle 0 0 w h-    C.fill-  return s'--copyFromToSurface :: Operator -> C.Surface -> Dim -> C.Surface -> Dim -> Render ()-copyFromToSurface op src sdim@(D sx sy sw sh) dest (D x y w h) = do-  ow <- C.imageSurfaceGetWidth src-  oh <- C.imageSurfaceGetHeight src-  let needsTrim = sx/=0 || sy/=0 || round sw/=oh || round sh/=oh-      needsRescale = round sw/=round w || round sh/=round h-  s' <- if needsTrim then createTrimmedSurface src sdim else return src-  s'' <- if needsRescale then createScaledSurface s' (V2 w h) else return s'-  C.renderWith dest $ do-    C.save-    C.setSourceSurface s'' x y-    C.setOperator op-    C.rectangle x y w h-    C.fill-    C.restore-  when needsTrim $ C.surfaceFinish s'-  when needsRescale $ C.surfaceFinish s''---- | Set the current font-setFont :: Font -> Render ()-setFont (Font face sz bold italic) = do-  C.selectFontFace face-                   (if italic then C.FontSlantItalic else C.FontSlantNormal)-                   (if bold then C.FontWeightBold else C.FontWeightNormal)-  C.setFontSize sz-
− SDL/Cairo/Canvas/Interactive.hs
@@ -1,36 +0,0 @@-{-# LANGUAGE OverloadedStrings #-}-{-|-Module      : SDL.Cairo-Copyright   : Copyright (c) 2015 Anton Pirogov-License     : MIT-Maintainer  : anton.pirogov@gmail.com--This module provides convenience functions for interactive development with ghci.--}-module SDL.Cairo.Canvas.Interactive where--import Control.Monad (forever)-import Control.Concurrent (forkIO)--import SDL--import SDL.Cairo (createCairoTexture')-import SDL.Cairo.Canvas (Canvas, withCanvas)---- |for testing and debugging usage with ghci. Starts up an SDL window,--- forks a rendering loop and returns a function to draw in this window.-getInteractive :: IO (Canvas () -> IO ())-getInteractive = do-  initializeAll-  w <- createWindow "SDL2 Cairo Canvas Interactive" defaultWindow-  r <- createRenderer w (-1) defaultRenderer-  t <- createCairoTexture' r w-  forkIO $ forever $ do-    lockTexture t Nothing-    copy r t Nothing Nothing-    unlockTexture t-    present r-  return $ draw t-  where draw :: Texture -> Canvas () -> IO ()-        draw = withCanvas-
+ example/Main.hs view
@@ -0,0 +1,168 @@+{-# LANGUAGE OverloadedStrings #-}+module Main where+import Control.Monad (unless)++import SDL+import Linear.V2 (V2(..))+import Linear.V4 (V4(..))+import Linear.Affine (Point(..))++import SDL.Cairo+import SDL.Cairo.Canvas++main :: IO ()+main = do+  initialize [InitEverything]+  window <- createWindow "SDL2 Cairo Canvas" defaultWindow+  renderer <- createRenderer window (-1) defaultRenderer++  -- create a texture suitable to use cairo on+  texture <- createCairoTexture' renderer window++  appLoop renderer texture 0 (V2 0 0)++appLoop :: Renderer -> Texture -> Int -> V2 Double -> IO ()+appLoop renderer texture framecount mousepos = do+  events <- pollEvents+  let quitEvent event = case eventPayload event of+                          QuitEvent -> True+                          _ -> False+      mouseMoveEvent e = case eventPayload e of+                          MouseMotionEvent _ -> True+                          _ -> False+      getMousePos (MouseMotionEvent (MouseMotionEventData _ _ _ (P p) _)) = fromIntegral <$> p+      getMousePos _ = V2 0 0+      mousePositions = map getMousePos $ map eventPayload $ filter mouseMoveEvent events+      quit = any quitEvent events+      mousepos' = if null mousePositions then mousepos else head mousePositions++  -- draw on the texture+  withCanvas texture $ do+    drawExample+    drawRndCircle+    drawStars (fromIntegral framecount)+    drawTriangleStrip mousepos'+    drawBezierTest++  -- apply texture and show on screen+  copy renderer texture Nothing Nothing+  present renderer++  delay $ 1000 `div` 60     -- slow down to approx. 60 FPS++  unless quit (appLoop renderer texture (framecount+1) mousepos')++-- draw a circle in a random color+drawRndCircle :: Canvas ()+drawRndCircle = do+    rnd <- random (0,255)+    fill $ gray rnd+    circle (V2 700 500) 100+    fill $ gray 255++-- some shapes, show some features+drawExample :: Canvas ()+drawExample = do+    background $ gray 102++    stroke $ blue 255+    point $ V2 500 10++    line (V2 0 0) (V2 100 100)+    line (V2 100 0) (V2 0 100)+    fill $ red 255 !@ 128+    noStroke+    rect $ D 200 200 100 100+    stroke $ green 255 !@ 128+    fill $ blue 255 !@ 128+    rect $ D 250 250 100 100+    triangle (V2 400 300) (V2 350 400) (V2 400 400)++    strokeWeight 5+    strokeJoin LineJoinRound+    stroke $ (blue 255 + red 255) !@ 128+    fill $ rgb 0 255 255 !@ 128+    polygon [V2 500 500,V2 510 505,V2 520 530, V2 500 530]++    circle (V2 200 500) 30++    strokeWeight 1+    ellipse $ D 300 500 30 50++    pushMatrix+    translate $ V2 600 500+    rotate $ pi/4+    ellipse $ D 0 0 100 50+    popMatrix+    ellipse $ D 0 0 100 50++-- ported star example from Processing home page+drawStars :: Double -> Canvas ()+drawStars frameCount = do+  sz@(V2 w h) <- getCanvasSize+  stroke $ gray 0++  pushMatrix+  translate $ V2 (0.2*w) (0.3*h)+  rotate $ frameCount / 200+  star 0 0 5 70 3+  popMatrix++  pushMatrix+  translate $ V2 (0.5*w) (0.3*h)+  rotate $ frameCount / 400+  star 0 0 80 100 40+  popMatrix++  pushMatrix+  translate $ V2 (0.8*w) (0.3*h)+  rotate $ frameCount / (-100)+  star 0 0 30 70 5+  popMatrix++star :: Double -> Double -> Double -> Double -> Double -> Canvas ()+star x y r1 r2 n = do+  let angle = 2*pi/n+      halfAngle = angle/2+      p1 a = V2 (x+cos a*r2) (y+sin a*r2)+      p2 a = V2 (x+cos (a+halfAngle)*r1) (y+sin (a+halfAngle)*r1)+      vertices = concatMap snd $ takeWhile (\(a, _) -> a<2*pi+angle)+               $ iterate (\(a, _) -> (a+angle,[p1 a, p2 a])) (0,[])+  polygon vertices++-- ported triangle strip example from Processing homepage+drawTriangleStrip :: V2 Double -> Canvas ()+drawTriangleStrip mousePos = do+  sz@(V2 w h) <- getCanvasSize+  let (V2 mouseX mouseY) = mousePos+      pos = V2 (w/2) (h/4*3)+      n = fromIntegral $ round $ mapRange mouseX (0,w) (6,60)+      astep = 180/n+      insideRadius = 100+      outsideRadius = 150+      cossin a = V2 (cos a) (sin a)+      makeVert a = [ pos+cossin (radians a) * outsideRadius+                   , pos+cossin (radians $ a+astep)*insideRadius+                   ]+      vertices = concatMap makeVert $ map (2*astep*) [0..n]+  shape ShapeTriangleStrip vertices+  return ()++-- draw bezier curve examples+drawBezierTest :: Canvas ()+drawBezierTest = do+  pushMatrix+  translate $ V2 600 0+  stroke $ rgb 255 102 0+  line (V2 85 20) (V2 10 10)+  line (V2 90 90) (V2 15 80)+  stroke $ gray 0+  bezier (V2 85 20) (V2 10 10) (V2 90 90) (V2 15 80)+  translate $ V2 100 0+  stroke $ rgb 255 102 0+  noFill+  line (V2 30 20) (V2 80 5)+  line (V2 80 75) (V2 30 75)+  stroke $ gray 0+  bezier (V2 30 20) (V2 80 5) (V2 80 75) (V2 30 75)+  popMatrix
sdl2-cairo.cabal view
@@ -2,7 +2,7 @@ -- documentation, see http://haskell.org/cabal/users-guide/  name:                sdl2-cairo-version:             0.1.0.0+version:             0.1.0.1 synopsis:            Binding to render with Cairo on SDL textures                      and optional convenience drawing API. description:         This small library provides convenience functions to draw@@ -21,6 +21,7 @@ cabal-version:       >=1.10  library+  hs-source-dirs:      src   default-language:    Haskell2010   exposed-modules:     SDL.Cairo, SDL.Cairo.Canvas, SDL.Cairo.Canvas.Interactive   --other-modules:@@ -32,18 +33,26 @@                      , random                      , time +flag builddemo+  description:       Build the little demo+  default:           False+ executable sdl2-cairo-test-  ghc-options:        -fPIC+  hs-source-dirs:      example+  main-is:             Main.hs   default-language:    Haskell2010   default-extensions:  OverloadedStrings-  main-is:             Main.hs-  build-depends:       base >=4 && <=5-                     , sdl2 >=2.0.0+  if flag(builddemo)+    build-depends:     base >=4 && <=5+                     , sdl2 >=2.0.0 && <2.1                      , cairo >=0.13+                     , sdl2-cairo                      , linear                      , mtl                      , random                      , time+  else+    buildable:         False  source-repository head   type:     git
+ src/SDL/Cairo.hs view
@@ -0,0 +1,52 @@+{-|+Module      : SDL.Cairo+Copyright   : Copyright (c) 2015 Anton Pirogov+License     : MIT+Maintainer  : anton.pirogov@gmail.com++This module exposes the functions to glue SDL2 'Texture's to the Cairo 'Render' monad.+-}+module SDL.Cairo (+  createCairoTexture, createCairoTexture', withCairoTexture,+  withCairoTexture'+) where++import Foreign.C.Types (CInt)+import Foreign.Ptr (castPtr)++import Linear.V2 (V2(..))+import SDL hiding (Surface)+import Graphics.Rendering.Cairo++-- |create new texture for Cairo with given size+createCairoTexture :: Renderer -> V2 CInt -> IO Texture+createCairoTexture r = createTexture r ARGB8888 TextureAccessStreaming++-- |create new texture for Cairo with the size of the given window+createCairoTexture' :: Renderer -> Window -> IO Texture+createCairoTexture' r w = do+  surf <- getWindowSurface w+  sz@(V2 w h) <- surfaceDimensions surf+  createCairoTexture r sz++-- |draw on SDL texture with Render monad from Cairo+withCairoTexture :: Texture -> Render () -> IO ()+withCairoTexture t m = withCairoTexture' t (\s -> renderWith s m)++----++-- | lock and unwrap SDL texture, get a Cairo surface, pass it to some function+withCairoTexture' :: Texture -> (Surface -> IO a) -> IO a+withCairoTexture' t m = do+  (TextureInfo f _ w h) <- queryTexture t+  case mapFormat f of+    Nothing -> error "ERROR: Invalid pixel format for cairo use!"+    Just f' -> do+      (pixels, pitch) <- lockTexture t Nothing+      ret <- withImageSurfaceForData (castPtr pixels) f'+               (fromIntegral w) (fromIntegral h) (fromIntegral pitch) m+      unlockTexture t+      return ret+  where mapFormat ARGB8888 = Just FormatARGB32+        mapFormat RGB888 = Just FormatRGB24+        mapFormat _ = Nothing
+ src/SDL/Cairo/Canvas.hs view
@@ -0,0 +1,538 @@+{-# LANGUAGE GeneralizedNewtypeDeriving #-}+{-|+Module      : SDL.Cairo.Canvas+Copyright   : Copyright (c) 2015 Anton Pirogov+License     : MIT+Maintainer  : anton.pirogov@gmail.com++This module defines the 'Canvas' monad, which is a convenience wrapper around+the underlying Cairo rendering and can be used with the same textures+created by 'createCairoTexture'. You can also mix both, if the need arises.++The Canvas API imitates most of the drawing functions+of the Processing language. See <http://processing.org/reference> for comparison.+While having the Processing spirit, this module does not aim for a perfect mapping and+deviates where necessary or appropriate. Nevertheless most Processing examples should be+trivial to port to the Canvas API. Example:++>import SDL+>import Linear.V2 (V2(..))+>import SDL.Cairo+>import SDL.Cairo.Canvas+>+>main :: IO ()+>main = do+>  initialize [InitEverything]+>  window <- createWindow "SDL2 Cairo Canvas" defaultWindow+>  renderer <- createRenderer window (-1) defaultRenderer+>  texture <- createCairoTexture' renderer window+>+>  withCanvas texture $ do+>    background $ gray 102+>    fill $ red 255 !@ 128+>    noStroke+>    rect $ D 200 200 100 100+>    stroke $ green 255 !@ 128+>    fill $ blue 255 !@ 128+>    rect $ D 250 250 100 100+>    triangle (V2 400 300) (V2 350 400) (V2 400 400)+>+>  copy renderer texture Nothing Nothing+>  present renderer+>  delay 5000+-}+module SDL.Cairo.Canvas (+  -- * Entry point+  Canvas, withCanvas, getCanvasSize, renderCairo,+  -- * Color and Style+  Color, Byte, gray, red, green, blue, rgb, (!@),+  stroke, fill, noStroke, noFill, strokeWeight, strokeJoin, strokeCap,+  -- * Coordinates+  Dim(..), toD, centered, corners,+  -- * Primitives+  background, point, line, triangle, rect, polygon, shape, ShapeMode(..),+  -- * Arcs and Curves+  circle, circle', arc, ellipse, bezier, bezierQ,+  -- * Transformations+  resetMatrix, pushMatrix, popMatrix, translate, rotate, scale,+  -- * Images+  Image(imageSize), createImage, loadImagePNG, saveImagePNG, image, image', blend, grab,+  -- * Text+  Font(..), textFont, textSize, text, textC, textR,+  -- * Math+  mapRange, radians, degrees,+  -- * Misc+  randomSeed, random, getTime, Time(..),+  module Graphics.Rendering.Cairo+) where++import Data.Monoid+import Control.Monad.State+import Data.Word (Word8)++import Data.Time.Clock (UTCTime(..),getCurrentTime)+import Data.Time.LocalTime (timeToTimeOfDay,TimeOfDay(..))+import Data.Time.Calendar (toGregorian)++import System.Random (mkStdGen,setStdGen,randomRIO,Random)++import Linear.V2 (V2(..))+import Linear.V4 (V4(..))+import Linear.Affine (Point(..))++import SDL (Texture,TextureInfo(..),queryTexture)+import qualified Graphics.Rendering.Cairo as C+import Graphics.Rendering.Cairo (Render,LineJoin(..),LineCap(..),Format(..),Operator(..))++import SDL.Cairo (withCairoTexture')++type Byte = Word8++-- | RGBA Color is just a byte vector. Colors can be added, subtracted, etc.+type Color = V4 Byte++data CanvasState = CanvasState{ csSize :: V2 Double, -- ^texture size+                                csSurface :: C.Surface, -- ^Cairo surface+                                csFG :: Maybe Color, -- ^stroke color+                                csBG :: Maybe Color, -- ^fill color+                                csFont :: Font,      -- ^current font+                                csActions :: Endo [Render ()], -- ^list of actions to perform+                                csImages :: [Image] -- ^keeping track of images to free later+                              }++-- |get size of the canvas (Processing: @width(), height()@)+getCanvasSize :: Canvas (V2 Double)+getCanvasSize = gets csSize++-- |wrapper around the Cairo 'Render' monad, providing a Processing-style API+newtype Canvas a = Canvas { unCanvas :: StateT CanvasState IO a }+  deriving (Functor, Applicative, Monad, MonadIO, MonadState CanvasState)++-- |draw on a SDL texture using the 'Canvas' monad+withCanvas :: Texture -> Canvas a -> IO a+withCanvas t c = withCairoTexture' t $ \s -> do+  (TextureInfo _ _ w h) <- queryTexture t+  (ret, result) <- runStateT (unCanvas $ defaults >> c)+                  CanvasState{ csSize = V2 (fromIntegral w) (fromIntegral h)+                            , csSurface = s+                            , csFG = Just $ gray 0+                            , csBG = Just $ gray 255+                            , csFont = Font "" 10 False False+                            , csActions = mempty+                            , csImages = []+                            }+  let render = appEndo (csActions result) []+  C.renderWith s $ sequence_ render+  forM_ (csImages result) $ \(Image s _ _) -> C.surfaceFinish s+  return ret+  where defaults = do+          strokeWeight 1+          strokeCap C.LineCapRound++----++-- |set current stroke color+stroke :: Color -> Canvas ()+stroke clr = get >>= \cs -> put cs{csFG=Just clr}+-- |set current fill color+fill :: Color -> Canvas ()+fill clr = get >>= \cs -> put cs{csBG=Just clr}+-- |disable stroke (-> shapes without borders!), reenabled by using 'stroke'+noStroke :: Canvas ()+noStroke = get >>= \cs -> put cs{csFG=Nothing}+-- |disable fill (-> shapes are not filled!), reenabled by using 'fill'+noFill :: Canvas ()+noFill = get >>= \cs -> put cs{csBG=Nothing}++-- |create opaque gray color+gray :: Byte -> Color+gray c = V4 c c c 255+-- |create opaque red color+red :: Byte -> Color+red c = V4 c 0 0 255+-- |create opaque green color+green :: Byte -> Color+green c = V4 0 c 0 255+-- |create opaque blue color+blue :: Byte -> Color+blue c = V4 0 0 c 255+-- |create opaque mixed color+rgb :: Byte -> Byte -> Byte -> Color+rgb r g b = V4 r g b 255+-- |set transparency of color (half red would be: @red 255 !\@ 128@)+(!@) :: Color -> Byte -> Color+(V4 r g b _) !@ a = V4 r g b a++-- |set line width for shape borders etc.+strokeWeight :: Double -> Canvas ()+strokeWeight d = renderCairo $ C.setLineWidth d++-- |set the style of connections between lines of shapes+strokeJoin :: C.LineJoin -> Canvas ()+strokeJoin l = renderCairo $ C.setLineJoin l+-- |set the style of the line caps+strokeCap :: C.LineCap -> Canvas ()+strokeCap l = renderCairo $ C.setLineCap l++----++-- | position and size representation (X Y W H)+data Dim = D Double Double Double Double deriving (Show,Eq)++-- | create dimensions from position and size vector+toD (V2 a b) (V2 c d) = D a b c d++-- | takes dimensions with centered position, returns normalized (left corner)+centered (D cx cy w h) = D (cx-w/2) (cy-h/2) w h+-- | takes dimensions with bottom-right corner instead of size, returns normalized (with size)+corners (D xl yl xh yh) = D xl yl (xh-xl) (yh-yl)++----++-- |replace current matrix with identity+resetMatrix :: Canvas ()+resetMatrix = renderCairo $ C.identityMatrix++-- |push current matrix onto the stack+pushMatrix :: Canvas ()+pushMatrix = renderCairo $ C.save++-- |pop a matrix+popMatrix :: Canvas ()+popMatrix = renderCairo $ C.restore++-- |translate coordinate system+translate :: V2 Double -> Canvas ()+translate (V2 x y) = renderCairo $ C.translate x y++-- |scale coordinate system+scale :: V2 Double -> Canvas ()+scale (V2 x y) = renderCairo $ C.scale x y++-- |rotate coordinate system+rotate :: Double -> Canvas ()+rotate a = renderCairo $ C.rotate a++----++-- |clear the canvas with given color+background :: Color -> Canvas ()+background c = do+  (V2 w h) <- gets csSize+  renderCairo $ setColor c >> C.rectangle 0 0 w h >> C.fill++-- |draw a point with stroke color (cairo emulates this with 1x1 rects!)+point :: V2 Double -> Canvas ()+point (V2 x y) = ifColor csFG $ \c -> do+      C.rectangle x y 1 1+      setColor c+      C.fill++-- |draw a line between two points with stroke color+line :: V2 Double -> V2 Double -> Canvas ()+line (V2 x1 y1) (V2 x2 y2) = ifColor csFG $ \c -> do+      C.moveTo x1 y1+      C.lineTo x2 y2+      setColor c+      C.stroke++-- |draw a triangle connecting three points+triangle :: V2 Double -> V2 Double -> V2 Double -> Canvas ()+triangle (V2 x1 y1) (V2 x2 y2) (V2 x3 y3) = drawShape $ do+    C.moveTo x1 y1+    C.lineTo x2 y2+    C.lineTo x3 y3+    C.lineTo x1 y1++-- |draw a rectangle+rect :: Dim -> Canvas ()+rect (D x y w h) = drawShape $ C.rectangle x y w h++-- |draw a polygon connecting given points (equivalent to @'shape' ('ShapeRegular' True)@)+polygon :: [V2 Double] -> Canvas ()+polygon = shape (ShapeRegular True)++-- | Shape mode to use+data ShapeMode = ShapeRegular Bool  -- ^regular path. flag decides whether the first and last point are connected+               | ShapePoints -- ^just draw the points, no lines+               | ShapeLines -- ^interpret points as pairs, draw lines+               | ShapeTriangles -- ^interpret points as triples, draw triangles+               | ShapeTriangleStrip -- ^draw triangle for every neighborhood of 3 points+               | ShapeTriangleFan -- ^fix first point, draw triangles with every neighboring pair and first point+               deriving (Show,Eq)++-- |draw shape along a given path using given @'ShapeMode'@.+-- (Processing: @beginShape(),vertex(),endShape()@)+shape :: ShapeMode -> [V2 Double] -> Canvas ()+shape (ShapeRegular closed) ((V2 x y):ps) = drawShape $ do+  C.moveTo x y+  forM_ ps $ \(V2 x' y') -> C.lineTo x' y'+  when closed $ C.closePath+shape ShapePoints ps = forM_ ps point+shape ShapeLines (p1:p2:ps) = do+  line p1 p2+  shape ShapeLines ps+shape ShapeLines _ = return ()+shape ShapeTriangles (p1:p2:p3:ps) = do+  triangle p1 p2 p3+  shape ShapeTriangles ps+shape ShapeTriangles _ = return ()+shape ShapeTriangleStrip (p1:p2:p3:ps) = do+  triangle p1 p2 p3+  shape ShapeTriangleStrip (p2:p3:ps)+shape ShapeTriangleStrip _ = return ()+shape ShapeTriangleFan (p1:p2:p3:ps) = do+  triangle p1 p2 p3+  shape ShapeTriangleFan (p1:p3:ps)+shape ShapeTriangleFan _ = return ()++----++-- |draw arc: @arc dimensions startAngle endAngle@+arc :: Dim -> Double -> Double -> Canvas ()+arc (D x y w h) sa ea = drawShape $ do+  C.save+  C.translate x y+  C.scale (w/2) (h/2)+  C.arc 0 0 1 sa ea+  C.restore++-- |draw ellipse+ellipse :: Dim -> Canvas ()+ellipse dim = arc dim 0 (2*pi)++-- |draw circle: @circle leftCorner diameter@+circle :: V2 Double -> Double -> Canvas ()+circle (V2 x y) d = ellipse (D x y d d)++-- |draw circle: @circle centerPoint diameter@+circle' :: V2 Double -> Double -> Canvas ()+circle' (V2 x y) d = ellipse $ centered (D x y d d)++-- |draw cubic bezier spline: @bezier fstAnchor fstControl sndControl sndAnchor@+bezier :: V2 Double -> V2 Double -> V2 Double -> V2 Double -> Canvas ()+bezier (V2 x1 y1) (V2 x2 y2) (V2 x3 y3) (V2 x4 y4) = drawShape $ do+  C.moveTo x1 y1+  C.curveTo x2 y2 x3 y3 x4 y4++-- |draw quadratic bezier spline: @bezier fstAnchor control sndAnchor@+bezierQ :: V2 Double -> V2 Double -> V2 Double -> Canvas ()+bezierQ p0 p12 p3 = bezier p0 p1 p2 p3+  where p1 = p0 + 2/3*(p12-p0)+        p2 = p3 + 2/3*(p12-p3)++----++-- |map a value from one range onto another+mapRange :: Double -> (Double,Double) -> (Double,Double) -> Double+mapRange v (l1,r1) (l2,r2) = (v-l1)*fac + l2+  where fac = (r2-l2)/(r1-l1)++-- |convert degrees to radians+radians :: Double -> Double+radians d = d*pi/180+-- |convert radians to degrees+degrees :: Double -> Double+degrees r = r/pi*180+-- |force value v into given range+constrain :: Double -> (Double,Double) -> Double+constrain v (l,h) = max l $ min h v++-- |set new random seed+randomSeed :: Int -> Canvas ()+randomSeed s = liftIO $ setStdGen $ mkStdGen s++-- |get new random number+random :: (Random a) => (a,a) -> Canvas a+random = liftIO . randomRIO++-- |date and time as returned by getTime+data Time = Time { year :: Int, month :: Int, day :: Int+                 , hour :: Int, minute :: Int, second :: Int } deriving (Show,Eq)++-- |get current system time. Use the 'Time' accessors for specific components.+-- (Processing: @year(),month(),day(),hour(),minute(),second()@)+getTime :: IO Time+getTime = do+  (UTCTime day time) <- getCurrentTime+  let (y,m,d) = toGregorian day+      (TimeOfDay h mins s) = timeToTimeOfDay time+  return $ Time (fromIntegral y::Int) m d h mins (round s :: Int)++----++data Image = Image {imageSurface::C.Surface, imageSize::(V2 Int), imageFormat::Format}++-- | create a new empty image of given size+createImage :: V2 Int -> Canvas Image+createImage (V2 w h) = do+  s <- liftIO $ C.createImageSurface FormatARGB32 w h+  let img = Image s (V2 w h) FormatARGB32+  track img+  return img++--TODO: add checks (file exists, correct format, etc.)+-- | load a PNG image from given path.+loadImagePNG :: FilePath -> Canvas Image+loadImagePNG path = do+  s <- liftIO $ C.imageSurfaceCreateFromPNG path+  w <- C.imageSurfaceGetWidth s+  h <- C.imageSurfaceGetHeight s+  f <- C.imageSurfaceGetFormat s+  let img = Image s (V2 w h) f+  track img+  return img++-- | Save an image as PNG to given file path+saveImagePNG :: Image -> FilePath -> Canvas ()+saveImagePNG (Image s _ _) fp = renderCairo $ liftIO (C.surfaceWriteToPNG s fp)++-- | Render complete image on given coordinates+image :: Image -> V2 Double -> Canvas ()+image img@(Image _ (V2 w h) _) (V2 x y) =+  image' img (D x y (fromIntegral w) (fromIntegral h))++-- | Render complete image inside given dimensions+image' :: Image -> Dim -> Canvas ()+image' img@(Image s (V2 ow oh) _) =+  blend OperatorSource img (D 0 0 (fromIntegral ow) (fromIntegral oh))++-- | Copy given part of image to given part of screen, using given blending+-- operator and resizing when necessary. Use 'OperatorSource' to copy without+-- blending effects. (Processing: @copy(),blend()@)+blend :: Operator -> Image -> Dim -> Dim -> Canvas ()+blend op (Image s (V2 ow oh) _) sdim ddim = do+  surf <- gets csSurface+  renderCairo $ copyFromToSurface op s sdim surf ddim++-- | get a copy of the image from current window (Processing: @get()@)+grab :: Dim -> Canvas Image+grab dim@(D x y w h) = do+  surf <- gets csSurface+  i@(Image s _ _) <- createImage (V2 (round w) (round h))+  renderCairo $ copyFromToSurface OperatorSource surf dim s (D 0 0 w h)+  return i++----++-- | Font definition+data Font = Font{fontFace::String+                ,fontSize::Double+                ,fontBold::Bool+                ,fontItalic::Bool} deriving (Show,Eq)++-- | set current font for text rendering+textFont :: Font -> Canvas ()+textFont f = do+  get >>= \cs -> put cs{csFont=f}+  renderCairo $ setFont f++-- | get the size of the text when rendered in current font+textSize :: String -> Canvas (V2 Double)+textSize s = gets csSurface >>= \cs -> do+  font <- gets csFont+  (C.TextExtents _ _ w h _ _) <- C.renderWith cs $ setFont font >> C.textExtents s+  return $ V2 w h++-- | render text left-aligned (coordinate is top-left corner)+text :: String -> V2 Double -> Canvas ()+text str (V2 x y) = ifColor csFG $ \c -> do+  (C.TextExtents _ yb _ h _ _) <- C.textExtents str+  setColor c+  C.moveTo x (y-yb)+  C.showText str++-- | render text right-aligned (coordinate is top-right corner)+textR :: String -> V2 Double -> Canvas ()+textR str (V2 x y) = do+  (V2 w h) <- textSize str+  text str $ V2 (x-w) y++-- | render text centered (coordinate is central)+textC :: String -> V2 Double -> Canvas ()+textC str (V2 x y) = do+  (V2 w h) <- textSize str+  text str $ V2 (x-(w/2)) (y-(h/2))+++-- helpers --++-- | execute a raw Cairo Render action+renderCairo :: Render () -> Canvas ()+renderCairo m = get >>= \cs -> put cs{csActions = csActions cs <> Endo ([m]++)}++-- |draw a shape - first fill with bg color, then draw border with stroke color+drawShape :: Render a -> Canvas ()+drawShape m = do+ ifColor csBG $ \c -> m >> setColor c >> C.fill+ ifColor csFG $ \c -> m >> setColor c >> C.stroke++-- |if color (csFG/csBG) is set, perform given render block+ifColor :: (CanvasState -> Maybe Color) -> (Color -> Render ()) -> Canvas ()+ifColor cf m = get >>= \cs -> forM_ (cf cs) $ \c -> renderCairo (m c)++-- |convert from 256-value RGBA to Double representation, set color+setColor :: Color -> Render ()+setColor c@(V4 r g b a) = C.setSourceRGBA (conv r) (conv g) (conv b) (conv a)+  where conv = ((1.0/256)*).fromIntegral++-- | Add to garbage collection list+track :: Image -> Canvas ()+track img = get >>= \cs -> put cs{csImages=img:csImages cs}++-- cairo helpers --++-- | helper: returns new surface with scaled content. does NOT cleanup!+createScaledSurface :: C.Surface -> (V2 Double) -> Render C.Surface+createScaledSurface s (V2 w h) = do+  ow <- C.imageSurfaceGetWidth s+  oh <- C.imageSurfaceGetHeight s+  s' <- liftIO $ C.createSimilarSurface s C.ContentColorAlpha (round w) (round h)+  C.renderWith s' $ do+    C.scale (w/fromIntegral ow) (h/fromIntegral oh)+    C.setSourceSurface s 0 0+    pat <- C.getSource+    C.patternSetExtend pat C.ExtendPad+    C.setOperator C.OperatorSource+    C.paint+  return s'++-- | helper: returns new surface with only part of original content. does NOT cleanup!+createTrimmedSurface :: C.Surface -> Dim -> Render C.Surface+createTrimmedSurface s (D x y w h) = do+  ow <- C.imageSurfaceGetWidth s+  oh <- C.imageSurfaceGetHeight s+  s' <- liftIO $ C.createSimilarSurface s C.ContentColorAlpha (round w) (round h)+  C.renderWith s' $ do+    C.setSourceSurface s (-x) (-y)+    C.setOperator C.OperatorSource+    C.rectangle 0 0 w h+    C.fill+  return s'++copyFromToSurface :: Operator -> C.Surface -> Dim -> C.Surface -> Dim -> Render ()+copyFromToSurface op src sdim@(D sx sy sw sh) dest (D x y w h) = do+  ow <- C.imageSurfaceGetWidth src+  oh <- C.imageSurfaceGetHeight src+  let needsTrim = sx/=0 || sy/=0 || round sw/=oh || round sh/=oh+      needsRescale = round sw/=round w || round sh/=round h+  s' <- if needsTrim then createTrimmedSurface src sdim else return src+  s'' <- if needsRescale then createScaledSurface s' (V2 w h) else return s'+  C.renderWith dest $ do+    C.save+    C.setSourceSurface s'' x y+    C.setOperator op+    C.rectangle x y w h+    C.fill+    C.restore+  when needsTrim $ C.surfaceFinish s'+  when needsRescale $ C.surfaceFinish s''++-- | Set the current font+setFont :: Font -> Render ()+setFont (Font face sz bold italic) = do+  C.selectFontFace face+                   (if italic then C.FontSlantItalic else C.FontSlantNormal)+                   (if bold then C.FontWeightBold else C.FontWeightNormal)+  C.setFontSize sz+
+ src/SDL/Cairo/Canvas/Interactive.hs view
@@ -0,0 +1,36 @@+{-# LANGUAGE OverloadedStrings #-}+{-|+Module      : SDL.Cairo+Copyright   : Copyright (c) 2015 Anton Pirogov+License     : MIT+Maintainer  : anton.pirogov@gmail.com++This module provides convenience functions for interactive development with ghci.+-}+module SDL.Cairo.Canvas.Interactive where++import Control.Monad (forever)+import Control.Concurrent (forkIO)++import SDL++import SDL.Cairo (createCairoTexture')+import SDL.Cairo.Canvas (Canvas, withCanvas)++-- |for testing and debugging usage with ghci. Starts up an SDL window,+-- forks a rendering loop and returns a function to draw in this window.+getInteractive :: IO (Canvas () -> IO ())+getInteractive = do+  initialize [InitEverything]+  w <- createWindow "SDL2 Cairo Canvas Interactive" defaultWindow+  r <- createRenderer w (-1) defaultRenderer+  t <- createCairoTexture' r w+  forkIO $ forever $ do+    lockTexture t Nothing+    copy r t Nothing Nothing+    unlockTexture t+    present r+  return $ draw t+  where draw :: Texture -> Canvas () -> IO ()+        draw = withCanvas+