Stencil out windows over ceilings

src/Dodge/Render.hs

@@ -132,8 +132,9 @@ doDrawing' win pdata u = do
             0
     -- draw wall occlusions from the camera's point of view
     glDisable GL_CULL_FACE
---    glEnable GL_STENCIL_TEST
---    glStencilFunc 
+    glEnable GL_STENCIL_TEST
+    glStencilFunc GL_NOTEQUAL 128 255
+    glStencilOp GL_KEEP GL_KEEP GL_REPLACE
     unless (debugOn Remove_LOS cfig) $ do
         glUseProgram (pdata ^. ceilingStencilShader . shaderUINT)
         glProgramUniform3f
@@ -151,6 +152,8 @@ doDrawing' win pdata u = do
             (_unPrimitiveMode $ pdata ^. ceilingStencilShader . shaderPrimitive)
             0
             (fromIntegral trueNWalls)
+    glStencilMask 127 -- to alter last seven bits
+    glStencilOp GL_KEEP GL_KEEP GL_KEEP
     -- clear color and normals
     withArray [0, 0, 0, 1] $
         glClearNamedFramebufferfv (pdata ^. fboBase . _1 . unFBO) GL_COLOR 0
@@ -168,8 +171,6 @@ doDrawing' win pdata u = do
         (_unPrimitiveMode $ pdata ^. wallShader . shaderPrimitive)
         0
         (fromIntegral trueNWalls)
-    --draw object pictures onto base buffer (are there any?!)
-    --    renderLayer BottomLayer shadV layerCounts
     --draw object shapes onto base buffer
     let fs = _shapeShader pdata
     glUseProgram (_shaderUINT fs)
@@ -184,8 +185,6 @@ doDrawing' win pdata u = do
     glBindVertexArray $ pdata ^. chasmShader . shaderVAO . vaoName
     glDepthMask GL_FALSE
     glDrawBuffer GL_NONE
-    glEnable GL_STENCIL_TEST
-    glStencilFunc GL_ALWAYS 0 255
     glStencilOp GL_INCR GL_INCR GL_INCR
     with 0 $
         glClearNamedFramebufferiv
@@ -210,6 +209,8 @@ doDrawing' win pdata u = do
     glDisable GL_STENCIL_TEST
     glDisable GL_CULL_FACE
     glEnable GL_BLEND
+    -- reset stencil to not draw on ceilings
+    glStencilFunc GL_NOTEQUAL 128 255
     --draw lightmap into its own buffer
     createLightMap
         cfig

src/Render.hs

@@ -158,12 +158,11 @@ renderShadows shadrendertype nWalls nSils nCaps positiontexture normaltexture li
         -- setup stencil
         glColorMask GL_FALSE GL_FALSE GL_FALSE GL_FALSE
         glStencilMask 127 -- so we only affect the last 7 bits
-        with 0 $ \ptr ->
+        with 0 $
             glClearNamedFramebufferiv
                 (pdata ^. fboLighting . _1 . unFBO)
                 GL_STENCIL
                 0
-                ptr
         glDisable GL_CULL_FACE
         -- the first bit has been used to stencil out "ceilings" under which we never draw
         glStencilFunc GL_NOTEQUAL 128 255