https://www.e-inspot.com/lib/js/threejs/MaskPass.js

1/**
2 * @author alteredq / http://alteredqualia.com/
3 */
4
5THREE.MaskPass = function ( scene, camera ) {
6
7	THREE.Pass.call( this );
8
9	this.scene = scene;
10	this.camera = camera;
11
12	this.clear = true;
13	this.needsSwap = false;
14
15	this.inverse = false;
16
17};
18
19THREE.MaskPass.prototype = Object.assign( Object.create( THREE.Pass.prototype ), {
20
21	constructor: THREE.MaskPass,
22
23	render: function ( renderer, writeBuffer, readBuffer, delta, maskActive ) {
24
25		var context = renderer.context;
26		var state = renderer.state;
27
28		// don't update color or depth
29
30		state.buffers.color.setMask( false );
31		state.buffers.depth.setMask( false );
32
33		// lock buffers
34
35		state.buffers.color.setLocked( true );
36		state.buffers.depth.setLocked( true );
37
38		// set up stencil
39
40		var writeValue, clearValue;
41
42		if ( this.inverse ) {
43
44			writeValue = 0;
45			clearValue = 1;
46
47		} else {
48
49			writeValue = 1;
50			clearValue = 0;
51
52		}
53
54		state.buffers.stencil.setTest( true );
55		state.buffers.stencil.setOp( context.REPLACE, context.REPLACE, context.REPLACE );
56		state.buffers.stencil.setFunc( context.ALWAYS, writeValue, 0xffffffff );
57		state.buffers.stencil.setClear( clearValue );
58
59		// draw into the stencil buffer
60
61		renderer.render( this.scene, this.camera, readBuffer, this.clear );
62		renderer.render( this.scene, this.camera, writeBuffer, this.clear );
63
64		// unlock color and depth buffer for subsequent rendering
65
66		state.buffers.color.setLocked( false );
67		state.buffers.depth.setLocked( false );
68
69		// only render where stencil is set to 1
70
71		state.buffers.stencil.setFunc( context.EQUAL, 1, 0xffffffff );  // draw if == 1
72		state.buffers.stencil.setOp( context.KEEP, context.KEEP, context.KEEP );
73
74	}
75
76} );
77
78
79THREE.ClearMaskPass = function () {
80
81	THREE.Pass.call( this );
82
83	this.needsSwap = false;
84
85};
86
87THREE.ClearMaskPass.prototype = Object.create( THREE.Pass.prototype );
88
89Object.assign( THREE.ClearMaskPass.prototype, {
90
91	render: function ( renderer, writeBuffer, readBuffer, delta, maskActive ) {
92
93		renderer.state.buffers.stencil.setTest( false );
94
95	}
96
97} );