Draw walls using vertex pulling

shader/pull/wall.frag

@@ -0,0 +1,19 @@
+#version 450 core
+layout (location=0) out vec4 fCol;
+layout (location=1) out vec4 fPos;
+layout (location=2) out vec4 fNorm;
+in vec3 vTexCoords;
+in vec4 vPos;
+in float vAng;
+layout (binding=40) uniform sampler2DArray diffuseSampler;
+layout (binding=41) uniform sampler2DArray normalSampler;
+vec2 rotateV2 (float a, vec2 v)
+{ return vec2(v.x*cos(a) - v.y*sin(a), v.x*sin(a) + v.y*cos(a)); }
+void main()
+{
+  fCol = texture(diffuseSampler,vTexCoords);
+  fPos = vPos;
+  vec4 basenorm = texture(normalSampler,vTexCoords) - 0.5;
+  vec2 n1 = rotateV2(vAng,vec2(basenorm.x,basenorm.z));
+  fNorm = vec4(-vec3(n1,basenorm.y),0);
+}

shader/pull/wall.vert

@@ -0,0 +1,22 @@
+#version 450 core
+struct PosTex { vec4 pospos; vec4 texang; };
+layout (std140, binding = 0) uniform TheMat { mat4 theMat; } ;
+layout (std430, binding = 2) readonly buffer Pos { PosTex data[]; };
+out float vAng;
+out vec4 vPos;
+out vec3 vTexCoords;
+int indices[6] = {0,1,3,0,3,2};
+void main()
+{
+    vec4 texang = data[gl_VertexID / 6].texang;
+    vec4 pp = data[gl_VertexID / 6].pospos;
+    int j = indices[gl_VertexID % 6];
+    float z = (j > 1.5 ? 100 : 0);
+    vec2 xy = (j % 2 > 0 ? pp.xy : pp.zw);
+    vPos = vec4( xy, z, 1);
+    gl_Position = theMat * vPos;
+    vAng = texang.y;
+    float d = distance(pp.xy,pp.zw) / 50;
+    int jj = j / 2;
+    vTexCoords = vec3(d * (j % 2), 2 * jj , texang.x);
+}

shader/pull/window.vert

@@ -12,5 +12,6 @@ void main()
     int j = indices[gl_VertexID % 6];
     float z = (j > 1.5 ? 5000 : 0);
     vec2 xy = (j % 2 > 0 ? pp.xy : pp.zw);
-    gl_Position = theMat * vec4( xy, z, 1);
+    vPos = vec4( xy, z, 1);
+    gl_Position = theMat * vPos;
 }