uniform float rotation;
uniform vec2 center;

#include <common>
#include <uv_pars_vertex>
#include <fog_pars_vertex>
#include <logdepthbuf_pars_vertex>
#include <clipping_planes_pars_vertex>

void main() {

	#include <uv_vertex>

	vec4 mvPosition = modelViewMatrix * vec4( 0.0, 0.0, 0.0, 1.0 );

	vec2 scale;
	scale.x = length( vec3( modelMatrix[ 0 ].x, modelMatrix[ 0 ].y, modelMatrix[ 0 ].z ) );
	scale.y = length( vec3( modelMatrix[ 1 ].x, modelMatrix[ 1 ].y, modelMatrix[ 1 ].z ) );

	#ifndef USE_SIZEATTENUATION

		bool isPerspective = ( projectionMatrix[ 2 ][ 3 ] == - 1.0 );

		if ( isPerspective ) scale *= - mvPosition.z;

	#endif

	vec2 alignedPosition = ( position.xy - ( center - vec2( 0.5 ) ) ) * scale;

	vec2 rotatedPosition;
	rotatedPosition.x = cos( rotation ) * alignedPosition.x - sin( rotation ) * alignedPosition.y;
	rotatedPosition.y = sin( rotation ) * alignedPosition.x + cos( rotation ) * alignedPosition.y;

	mvPosition.xy += rotatedPosition;

	gl_Position = projectionMatrix * mvPosition;

	#include <logdepthbuf_vertex>
	#include <clipping_planes_vertex>
	#include <fog_vertex>

}
