Merge branch 'master' of github.com:Lemmih/reanimate

examples/fe_morph.hs

@@ -0,0 +1,83 @@
+#!/usr/bin/env stack
+-- stack runghc --package reanimate
+{-# LANGUAGE ApplicativeDo     #-}
+{-# LANGUAGE OverloadedStrings #-}
+{-# LANGUAGE ParallelListComp  #-}
+module Main(main) where
+
+import           Text.Printf
+
+{- FE articles/demos
+scatter: https://codepen.io/mullany/pen/JmgbRB
+distortion: https://codepen.io/mullany/pen/BWKePz
+variable stroke width: https://codepen.io/mullany/pen/qaONQm
+variable stroke gradient: https://codepen.io/mullany/pen/XXBMJd
+heart: https://codepen.io/yoksel/pen/MLVjoB
+elastic stroke: https://codepen.io/yoksel/pen/XJbzrO
+-}
+
+import           Codec.Picture.Types
+import           Control.Lens                    hiding (magma)
+import           Graphics.SvgTree
+import           Reanimate
+
+main :: IO ()
+main = reanimate $ sceneAnimation $ do
+    newSpriteSVG_ $ mkBackground "white"
+    let circles =
+          [ (900, 0.3)
+          , (760, 0.5)
+          , (670, 0.4)
+          , (600, 0.6)
+          , (450, 0.7) ]
+    play $ pauseAtEnd 2 $ mkAnimation 10 $ \t ->
+      mkGroup
+      [ mkGooeyFilter 0.2 -- fromToS 0.1 0.2 $ oscillateS t
+      , mkGroup
+        [ lowerTransformations $ center $ withFillColor "black" $ latex "Text"
+        , mkGroup
+          [rotate (t*rot) $ translate (fromToS 0 3.5 $ bellS 2 $ t) 0 $
+            withFillColorPixel (promotePixel c) $ mkCircle (size*1.5)
+          | (n,(rot, size)) <- zip [0..] circles
+          , let c = turbo (n/fromIntegral (length circles-1))
+          ]
+        ] & filterRef .~ pure (Ref "gooey")
+
+      ]
+    -- wait 1
+
+mkGooeyFilter :: Double -> SVG
+mkGooeyFilter blur =
+  FilterTree $ mkFilter ("gooey")
+      [ FEGaussianBlur $ defaultSvg
+        & gaussianBlurStdDeviationX .~ Num blur
+        & gaussianBlurEdgeMode      .~ EdgeNone
+        & filterResult              .~ Just "blur"
+      , FEColorMatrix $ defaultSvg
+        & colorMatrixType           .~ Matrix
+        & colorMatrixValues         .~ printf
+          "1 0 0 0 0 \
+          \0 1 0 0 0 \
+          \0 0 1 0 0 \
+          \0 0 0 %f %f" mul sub
+        & colorMatrixIn             .~ pure (SourceRef "blur")
+        & filterResult              .~ Just "colormatrix"
+      ]
+  where
+    -- Increase alpha contrast. Turns alphaMin to 0x00 and alphaMax to 0xFF.
+    -- Increasing alphaDiff makes the shapes softer. Decreasing it gives more
+    -- contrast.
+    -- alphaMin*mul + sub*255 = 0
+    -- alphaMax*mul + sub*255 = 255
+    -- alphaDiff*mul = 255
+    -- mul = 255/alphaDiff
+    -- sub = -alphaMin*mul/255
+    mul = 255/alphaDiff
+    sub = -alphaMin*mul/255
+    alphaCenter = 255/2 :: Double
+    alphaDiff   = 20 :: Double
+    alphaMin = alphaCenter - alphaDiff/2
+    -- alphaMax = alphaCenter + alphaDiff/2
+
+mkFilter :: String -> [FilterElement] -> Filter
+mkFilter ident fe = defaultSvg & filterChildren .~ fe & attrId ?~ ident