Implement texture atlas, details on why it works unclear

src/Dodge/Data.hs

@@ -63,6 +63,7 @@ data World = World
     , _wallsZone            :: IM.IntMap (IM.IntMap (IM.IntMap Wall))
     , _forceFields          :: IM.IntMap ForceField
     , _floorItems           :: IM.IntMap FloorItem
+    , _floorTiles           :: [RenderType]
     , _randGen              :: StdGen
     , _mousePos             :: !(Float,Float)
     , _testString           :: String

src/Dodge/Default/World.hs

@@ -9,6 +9,7 @@ import Dodge.Config.KeyConfig
 import Dodge.Item.Data
 import Picture
 import Geometry
+import Picture.Texture
 
 import System.Random
 import qualified Data.IntMap.Strict as IM
@@ -36,6 +37,17 @@ defaultWorld = World
     , _wallsZone = IM.empty
     , _forceFields = IM.empty
     , _floorItems = IM.empty
+    , _floorTiles = 
+        let x = 200
+            y = 0.9
+            z = 16
+            r = 4
+        in tileToRender [(0,0,z),(r,0,z),(r,r,z),(0,r,z)]
+            [(20,100 + 20,y)
+            ,( x,100 + 20,y)
+            ,( x,100 +  x,y)
+            ,(20,100 +  x,y)
+            ]
     , _randGen = mkStdGen 2
     , _mousePos = (0,0)
     , _testString = []

src/Dodge/Render.hs

@@ -1,8 +1,7 @@
 {- |
 Contains the central drawing functions for the dodge loop. -}
 module Dodge.Render 
-    ( module Dodge.Render.Picture
-    , doDrawing
+    ( doDrawing
     )
   where
 import Dodge.Data
@@ -39,10 +38,8 @@ import Data.Tuple.Extra
 import Graphics.Rendering.OpenGL hiding (color,scale,translate,rotate)
 import qualified SDL
 
-{- |
-Central drawing function.
-Returns a 'Word32' that should give the number of ticks it took to evaluate.
- -}
+{- | Central drawing function.
+Returns a 'Word32' that should give the number of ticks it took to evaluate.  -}
 doDrawing :: RenderData -> World -> IO Word32
 doDrawing pdata w = do
     sTicks <- SDL.ticks
@@ -73,6 +70,9 @@ doDrawing pdata w = do
     -- the depth buffer is ready to be drawn on
     blendFuncSeparate    $= ((SrcAlphaSaturate, OneMinusSrcAlpha), (Zero,One))
     renderBackground pdata rot camzoom trans wins
+
+    _ <- renderShader (_textureArrayShader pdata) (_floorTiles w)
+
     -- draw the walls
     depthFunc $= Just Less
     if w ^. config . wall_textured