import { BufferGeometry } from '../core/BufferGeometry';

import { BufferAttribute } from '../core/BufferAttribute';

/**

* @author mrdoob / http://mrdoob.com/

* based on http://papervision3d.googlecode.com/svn/trunk/as3/trunk/src/org/papervision3d/objects/primitives/Plane.as

*/

function PlaneBufferGeometry( width, height, widthSegments, heightSegments ) {

BufferGeometry.call( this );

this.type = 'PlaneBufferGeometry';

this.parameters = {

width: width,

height: height,

widthSegments: widthSegments,

heightSegments: heightSegments

};

var width_half = width / 2;

var height_half = height / 2;

var gridX = Math.floor( widthSegments ) || 1;

var gridY = Math.floor( heightSegments ) || 1;

var gridX1 = gridX + 1;

var gridY1 = gridY + 1;

var segment_width = width / gridX;

var segment_height = height / gridY;

var vertices = new Float32Array( gridX1 * gridY1 * 3 );

var normals = new Float32Array( gridX1 * gridY1 * 3 );

var uvs = new Float32Array( gridX1 * gridY1 * 2 );

var offset = 0;

var offset2 = 0;

for ( var iy = 0; iy < gridY1; iy ++ ) {

var y = iy * segment_height - height_half;

for ( var ix = 0; ix < gridX1; ix ++ ) {

var x = ix * segment_width - width_half;

vertices[ offset ] = x;

vertices[ offset + 1 ] = - y;

normals[ offset + 2 ] = 1;

uvs[ offset2 ] = ix / gridX;

uvs[ offset2 + 1 ] = 1 - ( iy / gridY );

offset += 3;

offset2 += 2;

}

}

offset = 0;

var indices = new ( ( vertices.length / 3 ) > 65535 ? Uint32Array : Uint16Array )( gridX * gridY * 6 );

for ( var iy = 0; iy < gridY; iy ++ ) {

for ( var ix = 0; ix < gridX; ix ++ ) {

var a = ix + gridX1 * iy;

var b = ix + gridX1 * ( iy + 1 );

var c = ( ix + 1 ) + gridX1 * ( iy + 1 );

var d = ( ix + 1 ) + gridX1 * iy;

indices[ offset ] = a;

indices[ offset + 1 ] = b;

indices[ offset + 2 ] = d;

indices[ offset + 3 ] = b;

indices[ offset + 4 ] = c;

indices[ offset + 5 ] = d;

offset += 6;

}

}

this.setIndex( new BufferAttribute( indices, 1 ) );

this.addAttribute( 'position', new BufferAttribute( vertices, 3 ) );

this.addAttribute( 'normal', new BufferAttribute( normals, 3 ) );

this.addAttribute( 'uv', new BufferAttribute( uvs, 2 ) );

}

PlaneBufferGeometry.prototype = Object.create( BufferGeometry.prototype );

PlaneBufferGeometry.prototype.constructor = PlaneBufferGeometry;

export { PlaneBufferGeometry };