// Get the rect coords of the effect region in -1..1 range, i.e. circle centred around the center of the rect
// Done in the vertex shader itself to make use of gl interpolation for varying.
" vCentredCoord = vec2( ( (vTexCoord.x - uEffectRegion.x)/(uEffectRegion.z - uEffectRegion.x) * 2.0 - 1.0 ), ( (vTexCoord.y - uEffectRegion.y)/(uEffectRegion.w - uEffectRegion.y) * 2.0 - 1.0 ) );\n"
// Get the rect coords of the effect region in -1..1 range, i.e. circle centred around the center of the rect
// Done in the vertex shader itself to make use of gl interpolation for varying.
" vCentredCoord = vec2( ( (vTexCoord.x - uEffectRegion.x)/(uEffectRegion.z - uEffectRegion.x) * 2.0 - 1.0 ), ( (vTexCoord.y - uEffectRegion.y)/(uEffectRegion.w - uEffectRegion.y) * 2.0 - 1.0 ) );\n"