three.js/src/renderers/shaders/ShaderLib/meshbasic_frag.glsl.js

export default /* glsl */`
uniform vec3 diffuse;
uniform float opacity;

#ifndef FLAT_SHADED

	varying vec3 vNormal;

#endif

#include <common>
#include <color_pars_fragment>
#include <uv_pars_fragment>
#include <uv2_pars_fragment>
#include <map_pars_fragment>
#include <alphamap_pars_fragment>
#include <aomap_pars_fragment>
#include <lightmap_pars_fragment>
#include <envmap_common_pars_fragment>
#include <envmap_pars_fragment>
#include <cube_uv_reflection_fragment>
#include <fog_pars_fragment>
#include <specularmap_pars_fragment>
#include <logdepthbuf_pars_fragment>
#include <clipping_planes_pars_fragment>

void main() {

	#include <clipping_planes_fragment>

	vec4 diffuseColor = vec4( diffuse, opacity );

	#include <logdepthbuf_fragment>
	#include <map_fragment>
	#include <color_fragment>
	#include <alphamap_fragment>
	#include <alphatest_fragment>
	#include <specularmap_fragment>

	ReflectedLight reflectedLight = ReflectedLight( vec3( 0.0 ), vec3( 0.0 ), vec3( 0.0 ), vec3( 0.0 ) );

	// accumulation (baked indirect lighting only)
	#ifdef USE_LIGHTMAP
	
		vec4 lightMapTexel= texture2D( lightMap, vUv2 );
		reflectedLight.indirectDiffuse += lightMapTexelToLinear( lightMapTexel ).rgb * lightMapIntensity;

	#else

		reflectedLight.indirectDiffuse += vec3( 1.0 );

	#endif

	// modulation
	#include <aomap_fragment>

	reflectedLight.indirectDiffuse *= diffuseColor.rgb;

	vec3 outgoingLight = reflectedLight.indirectDiffuse;

	#include <envmap_fragment>

	gl_FragColor = vec4( outgoingLight, diffuseColor.a );

	#include <tonemapping_fragment>
	#include <encodings_fragment>
	#include <fog_fragment>
	#include <premultiplied_alpha_fragment>

}
`;