import { default } from "https://deno.land/x/threejs_4_deno@v121/src/renderers/shaders/ShaderChunk/normal_fragment_maps.glsl.js";
type
`
#ifdef OBJECTSPACE_NORMALMAP
normal = texture2D( normalMap, vUv ).xyz * 2.0 - 1.0; // overrides both flatShading and attribute normals
#ifdef FLIP_SIDED
normal = - normal;
#endif
#ifdef DOUBLE_SIDED
normal = normal * ( float( gl_FrontFacing ) * 2.0 - 1.0 );
#endif
normal = normalize( normalMatrix * normal );
#elif defined( TANGENTSPACE_NORMALMAP )
vec3 mapN = texture2D( normalMap, vUv ).xyz * 2.0 - 1.0;
mapN.xy *= normalScale;
#ifdef USE_TANGENT
normal = normalize( vTBN * mapN );
#else
normal = perturbNormal2Arb( -vViewPosition, normal, mapN );
#endif
#elif defined( USE_BUMPMAP )
normal = perturbNormalArb( -vViewPosition, normal, dHdxy_fwd() );
#endif
`