From f58530cbb12bddb63b2d508f85e3195ca5b94927 Mon Sep 17 00:00:00 2001
From: justin <justin.g.kruger@gmail.com>
Date: Tue, 31 Aug 2021 16:04:42 +0100
Subject: [PATCH] Clouds are affected by (underlying) lightmap

---
 shader/lighting/capTest.geom    | 57 +++++++++++++++++++++++++++++++++
 src/Dodge/Creature/ShadowBox.hs | 26 +++++++++++++++
 src/Dodge/Render.hs             | 36 ++++++++++++++-------
 3 files changed, 108 insertions(+), 11 deletions(-)
 create mode 100644 shader/lighting/capTest.geom
 create mode 100644 src/Dodge/Creature/ShadowBox.hs

diff --git a/shader/lighting/capTest.geom b/shader/lighting/capTest.geom
new file mode 100644
index 000000000..d14eee6b7
--- /dev/null
+++ b/shader/lighting/capTest.geom
@@ -0,0 +1,57 @@
+#version 430 core
+// an attempt to test whether a geometry surface occludes the camera from a
+// light source
+layout (triangles) in;
+layout (triangle_strip, max_vertices = 4) out;
+layout (std140, binding = 0) uniform TheMat { mat4 theMat; } ;
+uniform vec3 lightPos;
+uniform vec2 camPos;
+void main()
+{
+    vec3 p0 = gl_in[0].gl_Position.xyz ;
+    vec3 p1 = gl_in[1].gl_Position.xyz ;
+    vec3 p2 = gl_in[2].gl_Position.xyz ;
+    
+    // first determine intersection point (if any)
+
+    vec3 u = p1 - p0 ;
+    vec3 v = p2 - p0 ;
+    vec3 n = cross (u,v) ;
+    vec3 dir = vec3 (camPos, 100) - lightPos ;
+    vec3 w0 = p0 - lightPos ;
+    float a = dot(n, w0) ;
+    float b = dot(n,dir) ;
+    if (abs(b) < 0.00001) {}
+    else {
+        float r = a / b ;   
+        if (r < 0.0) {}
+        else {
+            vec3 ip = lightPos + r * dir ;
+            float uu, uv, vv, wu, wv, D;
+            uu = dot(u,u);
+            uv = dot(u,v);
+            vv = dot(v,v);
+            vec3 w = ip - p0;
+            wu = dot (w,u);
+            wv = dot (w,v);
+            D = uv * uv - uu * vv;
+            //get and test parametric coords
+            float s, t;
+            s = (uv * wv - vv * wu) / D;
+            if (s < 0.0 || s > 1.0) {}
+            else
+            {
+                t = (uv * wu - uu * wv) / D;
+                if (t < 0.0 || (s + t) > 1.0) {}
+                else
+                {
+                    gl_Position = vec4(-1,-1,50,1); EmitVertex();
+                    gl_Position = vec4(-1, 1,50,1); EmitVertex();
+                    gl_Position = vec4( 1,-1,50,1); EmitVertex();
+                    gl_Position = vec4( 1, 1,50,1); EmitVertex();
+                    EndPrimitive();
+                }
+            }
+        }
+    }
+}
diff --git a/src/Dodge/Creature/ShadowBox.hs b/src/Dodge/Creature/ShadowBox.hs
new file mode 100644
index 000000000..b88f5799c
--- /dev/null
+++ b/src/Dodge/Creature/ShadowBox.hs
@@ -0,0 +1,26 @@
+module Dodge.Creature.ShadowBox
+  where
+import Dodge.Data
+import Polyhedra
+import Geometry
+
+import qualified Data.IntMap as IM
+crToBox :: Creature -> [[Point3]]
+crToBox cr = map (map f . polyToTris) $ boxXYZ 10 10 15
+  where
+    f = (+ V3 (x-5) (y-5) 1)
+    V2 x y = _crPos cr
+youBox' :: World -> [[Point3]]
+youBox' w = crToBox' $ _creatures w IM.! 0
+
+youBox :: World -> [Point3]
+youBox = concat . youBox'
+
+crToBox' :: Creature -> [[Point3]]
+crToBox' cr = map (map f . polyToTris) $ boxXYZ 20 20 15
+  where
+    f = (+ V3 (x-10) (y-10) 1)
+    V2 x y = _crPos cr
+
+youSil :: World -> [Point3]
+youSil = constructEdgesList . youBox'
diff --git a/src/Dodge/Render.hs b/src/Dodge/Render.hs
index b1cb70ece..d978bec0e 100644
--- a/src/Dodge/Render.hs
+++ b/src/Dodge/Render.hs
@@ -122,13 +122,6 @@ doDrawing pdata w = do
     viewport $= (Position 0 0
         , divideSize (w ^. config . shadow_resolution) $ Size (round $ fstV2 wins) (round $ sndV2 wins))
 
---    bindFramebuffer Framebuffer $= fst (_fboColor pdata)
---    clear [ColorBuffer]
---    depthMask $= Disabled
---    blendEquation $= FuncAdd
---    renderLayer 3 shadV layerCounts
---    renderLayer 4 shadV layerCounts
---    renderLayer 5 shadV layerCounts
 --
 --    depthMask $= Enabled
     -- this is not ideal if the original is not divisible by 2
@@ -138,6 +131,27 @@ doDrawing pdata w = do
     colorMask $= Color4 Enabled Enabled Enabled Enabled
     clearColor $= Color4 0 0 0 0
 
+    bindFramebuffer Framebuffer $= fst (_fboColor pdata)
+    clearColor $= Color4 0 0 0 0
+    clear [ColorBuffer]
+    depthFunc $= Just Lequal
+    depthMask $= Disabled
+    blendFuncSeparate $= ((SrcAlpha,OneMinusSrcAlpha),(SrcAlpha,One))
+    --blendFunc $= (SrcAlpha,One)
+    renderLayer 2 shadV layerCounts
+    clearColor $= Color4 0 0 0 0
+    depthMask $= Enabled
+    depthMask $= Disabled
+    depthFunc $= Just Always
+    textureBinding Texture2D $= Just (snd $ _fboLighting pdata)
+    blend $= Enabled
+    --blendFunc $= (Zero, OneMinusSrcAlpha)
+    blendFuncSeparate $= ((Zero, OneMinusSrcColor),(Zero, One))
+    drawShader (_fullscreenShader pdata) 4
+    blendFunc $= (SrcAlpha, OneMinusSrcAlpha)
+--    renderLayer 4 shadV layerCounts
+--    renderLayer 5 shadV layerCounts
+
     --blend $= Disabled
     depthMask $= Disabled
     depthFunc $= Just Always
@@ -152,7 +166,6 @@ doDrawing pdata w = do
     drawShader (_fullscreenShader pdata) 4
     blendFunc $= (SrcAlpha, OneMinusSrcAlpha)
 
-    --textureBinding Texture2D $= Just (snd $ _fboColor pdata)
     --drawShader (_colorBlurShader pdata) 4
     blendFunc $= (SrcAlpha, One)
     textureBinding Texture2D $= Just (snd $ _fboFourth1 pdata)
@@ -161,10 +174,11 @@ doDrawing pdata w = do
 --    textureBinding Texture2D $= Just (snd $ _fboBloom pdata)
 --    drawShader (_fullscreenShader pdata) 4
 
-    depthFunc $= Just Lequal
-    --mapM_ (uncurry $ drawShaderLay 2) (vnums IM.! 2)
-    renderLayer 2 shadV layerCounts
+    textureBinding Texture2D $= Just (snd $ _fboColor pdata)
+    drawShader (_fullscreenShader pdata) 4
+    --renderLayer 2 shadV layerCounts
     renderWindows pdata windowPoints
+    depthFunc $= Just Lequal
 
     viewport $= (Position 0 0, Size (round $ fstV2 wins) (round $ sndV2 wins))
     depthFunc $= Just Always