From fac591fb5134aada58a1ec06ebcb1913c817b233 Mon Sep 17 00:00:00 2001
From: Dimitri Lozeve <dimitri.lozeve@gmail.com>
Date: Tue, 14 Nov 2017 00:03:16 +0000
Subject: [PATCH] Use Gloss for real-time visualization

---
 app/Main.hs | 36 +++++++++++++++++++++++++++++++++---
 orbit.cabal |  1 +
 2 files changed, 34 insertions(+), 3 deletions(-)

diff --git a/app/Main.hs b/app/Main.hs
index db98868..5577a57 100644
--- a/app/Main.hs
+++ b/app/Main.hs
@@ -8,6 +8,8 @@ import Linear.V3
 import System.Random
 import Control.Monad (replicateM)
 
+import Graphics.Gloss hiding (Point)
+
 
 --------------------------------------------------------------------------------
 -- Random body generation
@@ -76,8 +78,36 @@ csvFromInit :: Int -- ^ The number of time steps to keep
   -> String -- ^ CSV data
 csvFromInit n dt theta b = concat $ map (uncurry csvFromBodies) (take n $ steps dt theta b)
 
+
+--------------------------------------------------------------------------------
+-- Gloss
+--------------------------------------------------------------------------------
+
+width, height, offset :: Int
+width = 1000
+height = 750
+offset = 100
+
+window :: Display
+window = InWindow "Orbit" (width, height) (offset, offset)
+
+displayBody :: Body -> Picture
+displayBody b = translate (realToFrac x) (realToFrac y) $ circle (realToFrac (_bodyRadius b))
+  where P (V3 x y _) = _bodyPosition b
+
+displayBodies :: [Body] -> Picture
+displayBodies = color white . Pictures . map displayBody
+
+drawing :: Picture
+drawing = color white $ circle 80
+
 main :: IO ()
 main = do
-  bodies <- replicateM 100 randomBody
-  putStrLn $ csvFromInit 10000 (60*20) 0.5 bodies
-
+  bodies <- replicateM 300 randomBody
+  simulate
+    window
+    black
+    25
+    bodies
+    displayBodies
+    (\_ dt bs -> updateAll (realToFrac dt*1e6) 0.5 bs)
diff --git a/orbit.cabal b/orbit.cabal
index cbde683..f45e4f3 100644
--- a/orbit.cabal
+++ b/orbit.cabal
@@ -31,6 +31,7 @@ executable orbit-exe
                      , orbit
                      , linear
                      , random
+                     , gloss
   default-language:    Haskell2010
 
 test-suite orbit-test