 const float PRIM_TEX_WIDTH_SCALAR	= 1/float(PRIM_TEXTURE_WIDTH);
 const uint PRIMS_PER_ROW			= PRIM_TEXTURE_WIDTH/PQUAD_SIDE_WIDTH;
 const uint OVERSAMPLING				= 4u;
-
-const  vec2 PRIM_QUAD_BL 			= vec2(PRIM_TEX_WIDTH_SCALAR,PRIM_TEX_HEIGHT_SCALAR)/(2*float(OVERSAMPLING));
+const float PQUAD_DENOM				= (float(PRIM_TEXTURE_WIDTH)/2);
+
+vec2	halfScreenLocOffset = (screenLoc / 2) + (1/(float(OVERSAMPLING*4u)));
 
 float warpFog(float z){
 const float ZNEAR = 6554 * 32;

 vec4 intrinsicCodeTexel(uint textureID,vec3 norm,vec2 uv){
 if(textureID==0u)return vec4(0,1,0,1);//Green means textureID=zero
 if(textureID==DEAD_BEEF)return vec4(1,1,0,1);//Yellow means 0xDEADBEEF (unwritten) reverse[4022250974][3735928559u]
 uvec4 	tocHeader 	= texelFetch(rootBuffer,int(textureID+TOC_OFFSET_VEC4_HEADER));
 if(tocHeader[TOC_HEADER_OFFSET_QUADS_MAGIC]!=1337u)return vec4(1,0,1,1);//Magenta means invalid texture.
 
 //uint	renderFlags = tocHeader[TOC_HEADER_OFFSET_QUADS_RENDER_FLAGS];
 uv = clamp(uv-.5,0,4096);

 if(primitiveID==0u || primitiveID>65535u)
  break;
 primitiveID--; //Compensate for zero representing "unwritten."
 vec3 pQuad = pQuads[i]= getPQuad(primitiveID);
 vec4 _uvzw	= textureProjLod(primitiveUVZWTexture,pQuad,0);
 _uvzw.xyz /= _uvzw.w;
 vUVZI[i]   = vec4(_uvzw.xyz,getTextureID(primitiveID));
 _w[i]		= _uvzw.w;
