Move examples into separate executables.

Former-commit-id: 8e5ede8a2eb27373c5a2582de65b8a832bd6261e

examples/boundingbox.hs

@@ -0,0 +1,51 @@
+#!/usr/bin/env stack
+-- stack --resolver lts-13.14 runghc --package reanimate
+{-# LANGUAGE OverloadedStrings #-}
+module Main (main) where
+
+import           Control.Lens
+
+import           Graphics.SvgTree (Number(..),Tree)
+import           Reanimate.Driver (reanimate)
+import           Reanimate.LaTeX
+import           Reanimate.Monad
+import           Reanimate.Svg
+import           Reanimate.Signal
+
+main :: IO ()
+main = reanimate bbox
+
+bbox :: Animation
+bbox = bg `sim`
+    mapA (translate (-50) 0) bbox1 `sim`
+    mapA (translate 50 0) bbox2
+  where
+    bg = mkAnimation 0 $ emit $ mkBackground "black"
+
+bbox1 :: Animation
+bbox1 = mkAnimation 5 $ do
+    s <- getSignal signalLinear
+    emit $ mkGroup
+      [ mkBoundingBox $ rotate (360*s) svg
+      , withFillColor "white" $ rotate (360*s) svg ]
+  where
+    svg = scale 3 $ center $ latexAlign "\\sum_{k=1}^\\infty"
+
+bbox2 :: Animation
+bbox2 = autoReverse $ mkAnimation 2.5 $ do
+  s <- getSignal signalLinear
+  emit $ mkGroup
+    [ mkBoundingBox $ partialSvg s heartShape
+    , withStrokeColor "white" $ withFillOpacity 0 $ partialSvg s heartShape ]
+
+mkBoundingBox :: Tree -> Tree
+mkBoundingBox svg = withStrokeColor "red" $ withFillOpacity 0 $
+    mkRect (Num x, Num y) (Num w) (Num h)
+  where
+    (x, y, w, h) = boundingBox svg
+
+heartShape =
+    center $ rotateAroundCenter 225 $ mkPathString
+      "M0.0,40.0 v-40.0 h40.0\
+      \a20.0 20.0 90.0 0 1 0.0,40.0\
+      \a20.0 20.0 90.0 0 1 -40.0,0.0 Z"