Add alternate shadow volume rendering pathway (layered geo)

shader/shadow/cap.geom

@@ -1,5 +1,6 @@
 #version 450 core
 layout (triangles) in;
+layout (invocations = 20) in;
 layout (triangle_strip, max_vertices = 3) out;
 layout (std140, binding = 0) uniform TheMat { mat4 theMat; } ;
 layout (std140, binding = 1) uniform LightsBlock
@@ -7,8 +8,7 @@ layout (std140, binding = 1) uniform LightsBlock
     vec4 posBool[20];
     vec4 colRad[20];
 } ;
-uniform int lightID;
-vec3 lightPos = posBool[lightID].xyz ;
+vec3 lightPos = posBool[gl_InvocationID].xyz ;
 float theBool = posBool[gl_InvocationID].w;
 // this code is duplicated in lineShadow.geom, should not be changed on its own
 vec4 projNear (vec4 pos)
@@ -35,8 +35,11 @@ void main()
     {
         // the front cap
         vec4 v1 = vec4 (0,0,1,0) ;
+        gl_Layer = gl_InvocationID;
         gl_Position = theMat * projNear(p0); EmitVertex();
+        gl_Layer = gl_InvocationID;
         gl_Position = theMat * projNear(p1); EmitVertex();
+        gl_Layer = gl_InvocationID;
         gl_Position = theMat * projNear(p2); EmitVertex();
         EndPrimitive();
     }

shader/shadow/cap.vert

@@ -1,10 +1,6 @@
 #version 450 core
 layout (location = 0) in vec3 position;
 layout (std140, binding = 0) uniform TheMat { mat4 theMat; } ;
-uniform vec3 lightPos;
-uniform vec4 lumRad;
-out vec3 dField;
-out vec3 lum;
 void main()
 {
     gl_Position = vec4(position,1);

shader/shadow/light.frag

@@ -4,9 +4,9 @@ layout (std140, binding = 1) uniform LightsBlock
     vec4 posBool[20];
     vec4 colRad[20];
 } ;
-uniform int lightID;
-vec3 lightPos = posBool[lightID].xyz;
-vec4 lumRad = colRad[lightID];
+//uniform int lightID;
+vec3 lightPos = posBool[gl_Layer].xyz;
+vec4 lumRad = colRad[gl_Layer];
 uniform sampler2D screenTexture;
 in vec2 gTexPos;
 out vec4 fColor;
@@ -17,6 +17,6 @@ void main()
     if (dist > lumRad.a) {discard;}
     float x = 1 - dist / lumRad.a ;
     vec3 c = (x * x * x) * lumRad.rgb ;
-    //fColor = vec4(c,0);
-    fColor = vec4(1,0,0,0);
+    fColor = vec4(c,0);
+    //fColor = vec4(0.05,0,0,0);
 }

shader/shadow/light.geom

@@ -1,6 +1,6 @@
 #version 450 core
-layout (triangles) in;
-layout (triangle_strip, max_vertices = 3) out;
+layout (points) in;
+layout (triangle_strip, max_vertices = 4) out;
 layout (invocations = 20) in;
 layout (std140, binding = 1) uniform LightsBlock
 {
@@ -8,18 +8,26 @@ layout (std140, binding = 1) uniform LightsBlock
     vec4 colRad[20];
 } ;
 float theBool = posBool[gl_InvocationID].w;
-in vec2 vTexPos[];
 out vec2 gTexPos;
 void main()
 {
     if (theBool == 1){
-    for (int i = 0; i < 3; i++)
-    {
-        gTexPos = vTexPos[i];
+        gTexPos = vec2(0,1);
+        gl_Position = vec4(-1,1,0,1) ;
+        gl_Layer = gl_InvocationID;
+        EmitVertex();
+        gTexPos = vec2(0,0);
+        gl_Position = vec4(-1,-1,0,1) ;
+        gl_Layer = gl_InvocationID;
+        EmitVertex();
+        gTexPos = vec2(1,1);
+        gl_Position = vec4(1,1,0,1) ;
+        gl_Layer = gl_InvocationID;
+        EmitVertex();
+        gTexPos = vec2(1,0);
+        gl_Position = vec4(1,-1,0,1) ;
         gl_Layer = gl_InvocationID;
-        gl_Position = gl_in[i].gl_Position;
         EmitVertex();
-    }
     EndPrimitive();
     }else {}
 }

shader/shadow/light.vert

@@ -1,9 +1,4 @@
 #version 450 core
-layout (location = 0) in vec2 pos;
-layout (location = 1) in vec2 texPos;
-out vec2 vTexPos;
 void main()
 {
-  gl_Position = vec4(pos,0,1);
-  vTexPos = texPos;
 }