From 71006e24fd7059e0cdb25c8339b9c1ed375ab121 Mon Sep 17 00:00:00 2001
From: justin <justin.g.kruger@gmail.com>
Date: Thu, 30 Oct 2025 11:17:06 +0000
Subject: [PATCH] Simplify wall lighting shader

---
 shader/lighting/wallShadow.geom | 35 ++++++++++++++++++++-------------
 src/Dodge/Render.hs             |  3 ++-
 2 files changed, 23 insertions(+), 15 deletions(-)

diff --git a/shader/lighting/wallShadow.geom b/shader/lighting/wallShadow.geom
index a5151d145..4df12a823 100644
--- a/shader/lighting/wallShadow.geom
+++ b/shader/lighting/wallShadow.geom
@@ -1,6 +1,7 @@
 #version 450 core
 layout(points) in;
-layout(triangle_strip, max_vertices = 18) out;
+//layout(triangle_strip, max_vertices = 18) out;
+layout(triangle_strip, max_vertices = 9) out;
 layout(std140, binding = 0) uniform TheMat { mat4 theMat; };
 layout(location=0) uniform vec3 lightPos;
 layout(location=1) uniform float rad;
@@ -24,13 +25,17 @@ vec2 shift(vec2 p) {
 float isLHS(vec2 startV, vec2 testV) {
   return sign(-startV.x * testV.y + startV.y * testV.x);
 }
-// construct a box with openings on bottom face and face away from wall
+// constructs a "bridge" shape
 void main() {
   vec2 p1 = gl_in[0].gl_Position.xy;
   vec2 p2 = gl_in[0].gl_Position.zw;
   vec2 closepoint = closestPointOnSeg(p1,p2,lightPos.xy);
   if (isLHS(p1 - lightPos.xy, p2 - lightPos.xy) < 0 && distance(closepoint,lightPos.xy) < rad) {
+      // this is a point far along the ray from the light source to the midpoint
+      // of the wall. Necessary in case the light source is very close to the
+      // wall
     vec2 closeshift = (rad * normalize(closepoint - lightPos.xy)) + lightPos.xy - closepoint;
+    vec2 shifto = (rad * normalize(closepoint - lightPos.xy)) + closepoint;
     vec2 p1cs = p1 + closeshift;
     vec2 p1o = vec2( distance(p1,lightPos.xy) > rad ? p1cs : shift(p1) );
     vec2 p2cs = p2 + closeshift;
@@ -40,27 +45,29 @@ void main() {
     gl_Position = theMat * vec4(p1,-500,1); EmitVertex();
     gl_Position = theMat * vec4(p1o,100,1); EmitVertex();
     gl_Position = theMat * vec4(p1,100,1); EmitVertex();
-    gl_Position = theMat * vec4(p1cs,100,1); EmitVertex();
+    gl_Position = theMat * vec4(shifto,100,1); EmitVertex();
     gl_Position = theMat * vec4(p2,100,1); EmitVertex();
-    gl_Position = theMat * vec4(p2cs,100,1); EmitVertex();
     gl_Position = theMat * vec4(p2o,100,1); EmitVertex();
+    gl_Position = theMat * vec4(p2,-500,1); EmitVertex();
+    gl_Position = theMat * vec4(p2o,-500,1); EmitVertex();
     EndPrimitive();
+    // be carefull with the winding...
 
 //    gl_Position = theMat * vec4(p2o,100,1); EmitVertex();
 //    gl_Position = theMat * vec4(p2,100,1); EmitVertex();
 //    gl_Position = theMat * vec4(p2o,0,1); EmitVertex();
 //    gl_Position = theMat * vec4(p2,0,1); EmitVertex();
     
-    gl_Position = theMat * vec4(p2,100,1); EmitVertex();
-    gl_Position = theMat * vec4(p2,-500,1); EmitVertex();
-    gl_Position = theMat * vec4(p2o,100,1); EmitVertex();
-    gl_Position = theMat * vec4(p2o,-500,1); EmitVertex();
-    gl_Position = theMat * vec4(p2cs,100,1); EmitVertex();
-    gl_Position = theMat * vec4(p2cs,-500,1); EmitVertex();
-    gl_Position = theMat * vec4(p1cs,100,1); EmitVertex();
-    gl_Position = theMat * vec4(p1cs,-500,1); EmitVertex();
-    gl_Position = theMat * vec4(p1o,100,1); EmitVertex();
-    gl_Position = theMat * vec4(p1o,-500,1); EmitVertex();
+///    gl_Position = theMat * vec4(p2,100,1); EmitVertex();
+///    gl_Position = theMat * vec4(p2,-500,1); EmitVertex();
+///    gl_Position = theMat * vec4(p2o,100,1); EmitVertex();
+///    gl_Position = theMat * vec4(p2o,-500,1); EmitVertex();
+///    gl_Position = theMat * vec4(p2cs,100,1); EmitVertex();
+///    gl_Position = theMat * vec4(p2cs,-500,1); EmitVertex();
+///    gl_Position = theMat * vec4(p1cs,100,1); EmitVertex();
+///    gl_Position = theMat * vec4(p1cs,-500,1); EmitVertex();
+///    gl_Position = theMat * vec4(p1o,100,1); EmitVertex();
+///    gl_Position = theMat * vec4(p1o,-500,1); EmitVertex();
     
     EndPrimitive();
   } else {
diff --git a/src/Dodge/Render.hs b/src/Dodge/Render.hs
index e80261151..0501acb89 100644
--- a/src/Dodge/Render.hs
+++ b/src/Dodge/Render.hs
@@ -128,6 +128,7 @@ doDrawing' win pdata u = do
             GL_DEPTH
             0
     -- draw wall occlusions from the camera's point of view
+    glDisable GL_CULL_FACE
     unless (debugOn Remove_LOS cfig) $ do
         glUseProgram (pdata ^. lightingWallShadShader . shaderUINT)
         glProgramUniform3f
@@ -139,7 +140,7 @@ doDrawing' win pdata u = do
         glProgramUniform1f
             (pdata ^. lightingWallShadShader . shaderUINT)
             1
-            1000
+            1000 -- this should be the furthest on screen distance from the viewpoint
         glBindVertexArray $ pdata ^. lightingWallShadShader . shaderVAO . vaoName
         glDrawArrays
             (_unPrimitiveMode $ pdata ^. lightingWallShadShader . shaderPrimitive)