diff --git a/shader/wallFace.frag b/shader/wallFace.frag
new file mode 100644
index 000000000..a4e0a29a7
--- /dev/null
+++ b/shader/wallFace.frag
@@ -0,0 +1,12 @@
+#version 430 core
+in vec2 tPos;
+in vec4 gColor;
+
+uniform sampler2D tex;
+
+out vec4 fColor;
+
+void main()
+{
+  fColor = gColor * texture(tex,tPos);
+}
diff --git a/shader/wallFace.geom b/shader/wallFace.geom
new file mode 100644
index 000000000..7f2cc9b7d
--- /dev/null
+++ b/shader/wallFace.geom
@@ -0,0 +1,36 @@
+#version 430 core
+layout (points) in;
+layout (triangle_strip, max_vertices = 4) out;
+
+in vec4 vColor [];
+out vec4 gColor;
+out vec2 tPos;
+
+uniform mat4 perpMat;
+
+// consider using isLHS to check if the wall is facing the center
+float isLHS (vec2 startV, vec2 testV)
+{
+    return sign( -startV.x * testV.y + startV.y * testV.x);
+}
+
+void main()
+{
+    gColor = vColor[0];
+
+vec4 p1 = vec4 (gl_in[0].gl_Position.xy,0,1);
+vec4 p2 = vec4 (gl_in[0].gl_Position.zw,0,1);
+vec4 p3 = vec4 (p1.xy,-0.5,1);
+vec4 p4 = vec4 (p2.xy,-0.5,1);
+
+vec4 a1 = perpMat * p1;
+vec4 a2 = perpMat * p2;
+vec4 a3 = perpMat * p3;
+vec4 a4 = perpMat * p4;
+
+  tPos = vec2 ( 1,-1) ; gl_Position = a1; EmitVertex();
+  tPos = vec2 ( 1, 1) ; gl_Position = a3; EmitVertex();
+  tPos = vec2 (-1,-1) ; gl_Position = a2; EmitVertex();
+  tPos = vec2 (-1, 1) ; gl_Position = a4; EmitVertex();
+  EndPrimitive();
+}
diff --git a/shader/wallFace.vert b/shader/wallFace.vert
new file mode 100644
index 000000000..0456509f9
--- /dev/null
+++ b/shader/wallFace.vert
@@ -0,0 +1,11 @@
+#version 430 core
+layout (location = 0) in vec4 poss;
+layout (location = 1) in vec4 color;
+
+out vec4 vColor;
+
+void main()
+{
+  gl_Position = poss;
+  vColor = color;
+}
diff --git a/shader/wallFace.vet b/shader/wallFace.vet
new file mode 100644
index 000000000..0456509f9
--- /dev/null
+++ b/shader/wallFace.vet
@@ -0,0 +1,11 @@
+#version 430 core
+layout (location = 0) in vec4 poss;
+layout (location = 1) in vec4 color;
+
+out vec4 vColor;
+
+void main()
+{
+  gl_Position = poss;
+  vColor = color;
+}
diff --git a/src/Picture/Render.hs b/src/Picture/Render.hs
index 106b19b9c..5fd2ea0be 100644
--- a/src/Picture/Render.hs
+++ b/src/Picture/Render.hs
@@ -31,19 +31,8 @@ import qualified Data.IntMap.Strict as IM
 
 import qualified SDL as SDL
 
-renderPicture' :: RenderData -> Float -> Float -> (Float,Float) -> (Float,Float) ->
-                    [(Point2,Point2)] -> [Point4] ->
-                    (Float,Float) -> Picture -> IO (Word32,Word32)
-renderPicture' pdata rot zoom (tranx,trany) (winx,winy) wallPoints lightPoints
-                    (viewFromx,viewFromy) pic = do
-    wallPokeStart <- SDL.ticks
-
--- setting the depth function to less, instead of lequal, 
--- seems to stop a lot of unecessary drawing
--- of wall shadows when creating the light map
-    depthFunc $= Just Less
-
--- set common uniforms
+setCommonUniforms :: RenderData -> Float -> Float -> (Float,Float) -> (Float,Float) -> IO ()
+setCommonUniforms pdata rot zoom (tranx,trany) (winx,winy) = do
     setShaderUniforms rot zoom (tranx,trany) (winx,winy) 
         ( (extractProgAndUnis $ _lightSourceShader pdata) 
         : (extractProgAndUnis $ _wallShadowShader pdata) 
@@ -52,6 +41,36 @@ renderPicture' pdata rot zoom (tranx,trany) (winx,winy) wallPoints lightPoints
         : (map extractProgAndUnis $ _listShaders pdata)
         )
 
+createLightMap :: RenderData -> Float -> Float -> (Float,Float) -> (Float,Float) ->
+                    [(Point2,Point2)] -> [Point4] ->
+                    (Float,Float) -> Picture -> IO ()
+createLightMap pdata rot zoom (tranx,trany) (winx,winy) wallPoints lightPoints
+                    (viewFromx,viewFromy) pic = do
+    return ()
+
+renderPicture' :: RenderData -> Float -> Float -> (Float,Float) -> (Float,Float) ->
+                    [(Point2,Point2)] -> [Point4] ->
+                    (Float,Float) -> Picture -> IO (Word32,Word32)
+renderPicture' pdata rot zoom trans wins wallPoints lightPoints
+                    viewFroms pic = do
+    startTicks <- SDL.ticks
+    setCommonUniforms pdata rot zoom trans wins
+    renderPicture pdata rot zoom trans wins wallPoints lightPoints viewFroms pic
+    endTicks <- SDL.ticks
+    return (startTicks, endTicks - startTicks)
+
+renderPicture :: RenderData -> Float -> Float -> (Float,Float) -> (Float,Float) ->
+                    [(Point2,Point2)] -> [Point4] ->
+                    (Float,Float) -> Picture -> IO (Word32,Word32)
+renderPicture pdata rot zoom (tranx,trany) (winx,winy) wallPoints lightPoints
+                    (viewFromx,viewFromy) pic = do
+    wallPokeStart <- SDL.ticks
+
+-- setting the depth function to less, instead of lequal, 
+-- seems to stop a lot of unecessary drawing
+-- of wall shadows when creating the light map
+    depthFunc $= Just Less
+
 -- draw lightmap
 
     bindFramebuffer Framebuffer $= (_spareFBO pdata)