Partially implement a framebuffer object for bluring shadows

src/Picture/Render.hs

@@ -49,6 +49,12 @@ renderPicture' pdata rot zoom (tranx,trany) (winx,winy) wallPoints lightPoints p
         )
 
 -- draw lightmap
+
+    bindFramebuffer Framebuffer $= (_spareFBO pdata)
+    clearColor $= Color4 0 0.5 0 1
+    clearDepth $= (200)
+    clear [ColorBuffer]
+
     nWalls <- F.foldM (pokeShader (_wallShadowShader pdata)) wallPoints
     bindShaderBuffers [_wallShadowShader pdata] [nWalls]
 
@@ -78,10 +84,24 @@ renderPicture' pdata rot zoom (tranx,trany) (winx,winy) wallPoints lightPoints p
     ticksS <- SDL.ticks
     ticksAfterL <- SDL.ticks
 
+    blend $= Disabled
+
+--    blendFunc $= (Zero,One)
+    bindFramebuffer Framebuffer $= defaultFramebufferObject
+--
+--    blendFunc $= (SrcAlpha, OneMinusSrcAlpha)
+    bindShaderBuffers [_fullscreenShader pdata] [4]
+    textureBinding Texture2D $= Just (_fboTexture pdata)
+--    blendFunc $= (One, Zero)
+    drawShader (_fullscreenShader pdata) 4
+
+    blend $= Enabled
+
 -- draw picture on top of light/shadow map
 -- set drawing for on top
     blendFuncSeparate    $= ((SrcAlphaSaturate, OneMinusSrcAlpha), (Zero,One))
     clear [DepthBuffer]
+
 -- draw background
     bindArrayBuffers 1 $ _vaoBufferTargets $ _shaderVAO $ _backgroundShader pdata
     depthFunc $= Just Less