/**
 * Simple fake tilt-shift effect, modulating two pass Gaussian blur (see above) by vertical position
 *
 * - 9 samples per pass
 * - standard deviation 2.7
 * - "h" and "v" parameters should be set to "1 / width" and "1 / height"
 * - "r" parameter control where "focused" horizontal line lies
 */

var HorizontalTiltShiftShader = {

	uniforms: {

		'tDiffuse': { value: null },
		'h': { value: 1.0 / 512.0 },
		'r': { value: 0.35 }

	},

	vertexShader: [

		'varying vec2 vUv;',

		'void main() {',

		'	vUv = uv;',
		'	gl_Position = projectionMatrix * modelViewMatrix * vec4( position, 1.0 );',

		'}'

	].join( '\n' ),

	fragmentShader: [

		'uniform sampler2D tDiffuse;',
		'uniform float h;',
		'uniform float r;',

		'varying vec2 vUv;',

		'void main() {',

		'	vec4 sum = vec4( 0.0 );',

		'	float hh = h * abs( r - vUv.y );',

		'	sum += texture2D( tDiffuse, vec2( vUv.x - 4.0 * hh, vUv.y ) ) * 0.051;',
		'	sum += texture2D( tDiffuse, vec2( vUv.x - 3.0 * hh, vUv.y ) ) * 0.0918;',
		'	sum += texture2D( tDiffuse, vec2( vUv.x - 2.0 * hh, vUv.y ) ) * 0.12245;',
		'	sum += texture2D( tDiffuse, vec2( vUv.x - 1.0 * hh, vUv.y ) ) * 0.1531;',
		'	sum += texture2D( tDiffuse, vec2( vUv.x, vUv.y ) ) * 0.1633;',
		'	sum += texture2D( tDiffuse, vec2( vUv.x + 1.0 * hh, vUv.y ) ) * 0.1531;',
		'	sum += texture2D( tDiffuse, vec2( vUv.x + 2.0 * hh, vUv.y ) ) * 0.12245;',
		'	sum += texture2D( tDiffuse, vec2( vUv.x + 3.0 * hh, vUv.y ) ) * 0.0918;',
		'	sum += texture2D( tDiffuse, vec2( vUv.x + 4.0 * hh, vUv.y ) ) * 0.051;',

		'	gl_FragColor = sum;',

		'}'

	].join( '\n' )

};

export { HorizontalTiltShiftShader };
