From 1a85d9d562ca7f6f003eaa63cf05fca6bd6cb083 Mon Sep 17 00:00:00 2001
From: justin <justin.g.kruger@gmail.com>
Date: Mon, 10 Nov 2025 19:15:07 +0000
Subject: [PATCH] Use vertex pulling for ceiling stencil

---
 shader/ceiling/stencil.vert | 16 ++++++++++++++--
 src/Dodge/Render.hs         | 15 +++------------
 src/Preload/Render.hs       |  6 ++++--
 3 files changed, 21 insertions(+), 16 deletions(-)

diff --git a/shader/ceiling/stencil.vert b/shader/ceiling/stencil.vert
index ffb827dbb..76812fc0c 100644
--- a/shader/ceiling/stencil.vert
+++ b/shader/ceiling/stencil.vert
@@ -1,6 +1,18 @@
 #version 450 core
-layout (location = 0) in vec4 poss;
+//layout (location = 0) in vec4 poss;
+//void main()
+//{
+//  gl_Position = poss;
+//}
+struct PosTex { vec4 pospos; vec4 texang; };
+layout (std140, binding = 0) uniform TheMat { mat4 theMat; } ;
+layout (std430, binding = 2) readonly buffer Pos { PosTex data[]; };
+int indices[6] = {0,1,3,0,3,2};
 void main()
 {
-  gl_Position = poss;
+    vec4 pp = data[gl_VertexID / 6].pospos;
+    int j = indices[gl_VertexID % 6];
+    float z = (j > 1.5 ? 5000 : 100);
+    vec2 xy = (j % 2 > 0 ? pp.xy : pp.zw);
+    gl_Position = theMat * vec4(xy,z,1);
 }
diff --git a/src/Dodge/Render.hs b/src/Dodge/Render.hs
index c7f13a87d..147ef11ba 100644
--- a/src/Dodge/Render.hs
+++ b/src/Dodge/Render.hs
@@ -136,22 +136,13 @@ doDrawing' win pdata u = do
     glCullFace GL_BACK
     unless (debugOn Remove_LOS cfig) $ do
         glUseProgram (pdata ^. ceilingStencilShader . shaderUINT)
---        glProgramUniform3f
---            (pdata ^. ceilingStencilShader . shaderUINT)
---            0
---            vfx
---            vfy
---            20
---        glProgramUniform1f
---            (pdata ^. ceilingStencilShader . shaderUINT)
---            1
---            1000 -- this should be the furthest on screen distance from the viewpoint
-        glBindVertexArray $ pdata ^. ceilingStencilShader . shaderVAO . vaoName
+--        glBindVertexArray $ pdata ^. ceilingStencilShader . shaderVAO . vaoName
+        glBindVertexArray $ pdata ^. dummyVAO . vaoName
         glEnable GL_DEPTH_CLAMP
         glDrawArrays
             (_unPrimitiveMode $ pdata ^. ceilingStencilShader . shaderPrimitive)
             0
-            (fromIntegral trueNWalls)
+            (fromIntegral (trueNWalls * 6))
         glDisable GL_DEPTH_CLAMP
     glStencilMask 127 -- to alter last seven bits
     glStencilOp GL_KEEP GL_KEEP GL_KEEP
diff --git a/src/Preload/Render.hs b/src/Preload/Render.hs
index 297a24b92..b4bbb5531 100644
--- a/src/Preload/Render.hs
+++ b/src/Preload/Render.hs
@@ -88,8 +88,10 @@ preloadRender = do
         makeShaderUsingVAO "lighting/cap" [vert, geom] pmTriangles shPosVAO
     lightingLineShadowShad <-
         makeShaderUsingVAO "lighting/lineShadow" [vert, geom] pmLinesAdjacency shedgevao
-    ceilingstencilshader <-
-        makeShaderUsingVBO "ceiling/stencil" [vert, geom] (toFloatVAs [4]) pmPoints wallvbo
+
+    ceilingstencilshader <- makeShaderUsingVAO "ceiling/stencil" [vert] pmTriangles
+        (VAO dummyvao)
+--        makeShaderUsingVBO "ceiling/stencil" [vert, geom] (toFloatVAs [4]) pmPoints wallvbo
 
     putStrLn "Setup 2D shaders"
     bslist <- makeShaderVBO "dualTwoD/basic" [vert, frag] (toFloatVAs [3, 4]) pmTriangles