Implement texture atlas, details on why it works unclear

src/Picture/Data.hs

@@ -25,6 +25,7 @@ data RenderType
     | Render22 {_unRender22 :: (Point2,Point2)}
     | Render22x4 {_unRender22x4 :: ((Point2,Point2),Point4)}
     | Render3x2 {_unRender3x2 :: (Point3,Point2)}
+    | Render3x3 {_unRender3x3 :: (Point3,Point3)}
 
 type RGBA = (Float,Float,Float,Float)
 type Color = (Float,Float,Float,Float)

src/Picture/Render.hs

@@ -198,7 +198,7 @@ renderBackground pdata rot camZoom (tranx,trany) (winx,winy) = do
     --blendFuncSeparate    $= ((SrcAlphaSaturate, OneMinusSrcAlpha), (Zero,One))
 -- draw background
     --bindArrayBuffers 1 $ _vaoBufferTargets $ _shaderVAO $ _backgroundShader pdata
-    bindArrayBuffers' 1 $ _vaoVBO $ _shaderVAO $ _backgroundShader pdata
+    bindArrayBuffers 1 $ _vaoVBO $ _shaderVAO $ _backgroundShader pdata
     currentProgram $= Just (_shaderProgram $ _backgroundShader pdata)
     bindVertexArrayObject $= Just (_vao $ _shaderVAO $ _backgroundShader pdata)
     let backPtr = _vboPointer $ _vaoVBO $ _shaderVAO $ _backgroundShader pdata
@@ -219,6 +219,7 @@ setCommonUniforms pdata rot camZoom (tranx,trany) (winx,winy) = do
         : extractProgAndUnis (_lightingOccludeShader pdata) 
         : extractProgAndUnis (_lightingWallShader pdata) 
         : extractProgAndUnis (_backgroundShader pdata) 
+        : extractProgAndUnis (_textureShader pdata) 
         : map extractProgAndUnis (_pictureShaders pdata)
         )
 
@@ -233,7 +234,8 @@ setIsoMatrixUniforms pdata rot camZoom (tranx,trany) (winx,winy) = do
     setShaderUniforms rot camZoom (tranx,trany) (winx,winy) 
         ( extractProgAndUnis (_lightingFloorShader pdata) 
         : extractProgAndUnis (_backgroundShader pdata) 
-        -- : extractProgAndUnis (_textureShader pdata)
+        : extractProgAndUnis (_textureShader pdata)
+        : extractProgAndUnis (_textureArrayShader pdata)
         : map extractProgAndUnis (_pictureShaders pdata)
         )
 
@@ -250,6 +252,12 @@ renderShader shad dat = do
     eticks <- SDL.ticks
     return $ eticks - sticks
 
+--renderPictureLayer
+--    :: PictureShaderData
+--    -> Picture
+--    -> IO Word32
+--renderPictureLayer 
+
 renderFoldable
     :: Foldable f
     => RenderData

src/Picture/Texture.hs

@@ -0,0 +1,15 @@
+module Picture.Texture
+    where
+import Geometry.Data
+import Picture.Data
+
+tileToRender :: [Point3] -> [Point3] -> [RenderType]
+tileToRender [a,b,c,d] [x,y,z,w] = 
+    [ Render3x3 (x,a)
+    , Render3x3 (y,b)
+    , Render3x3 (z,c)
+    , Render3x3 (x,a)
+    , Render3x3 (z,c)
+    , Render3x3 (w,d)
+    ]
+tileToRender _ _ = undefined

src/Picture/Tree.hs

@@ -14,7 +14,7 @@ import Data.Maybe (isNothing)
 -- consider generalising to alternative rather than using LTree
 -- | Transform a picture into a tree of renderable objects
 picToLTree 
-    :: Maybe Int -- ^ Layer filter. Draw if 'Nothing' or when value is the same as at the leaf.
+    :: Maybe Int -- ^ Layer filter. Draw 'Nothing' when value is the same as at the leaf.
     -> Picture
     -> LTree RenderType
 {-# INLINE picToLTree #-}