Custom Blend Mode Tester

class Example extends Phaser.Scene
{
    constructor ()
    {
        super();
    }

    preload ()
    {
        this.load.setBaseURL('https://cdn.phaserfiles.com/v410');
        this.load.image('turkey', 'assets/pics/turkey-1985086.jpg');
        this.load.image('logo', 'assets/sprites/phaser-large.png');
    }

    create ()
    {
        const gl = this.sys.game.renderer.gl;

        const consts = [
            gl.ZERO,
            gl.ONE,
            gl.SRC_COLOR,
            gl.ONE_MINUS_SRC_COLOR,
            gl.DST_COLOR,
            gl.ONE_MINUS_DST_COLOR,
            gl.SRC_ALPHA,
            gl.ONE_MINUS_SRC_ALPHA,
            gl.DST_ALPHA,
            gl.ONE_MINUS_DST_ALPHA,
            gl.CONSTANT_COLOR,
            gl.ONE_MINUS_CONSTANT_COLOR,
            gl.CONSTANT_ALPHA,
            gl.ONE_MINUS_CONSTANT_ALPHA,
            gl.SRC_ALPHA_SATURATE
        ];

        const equations = [
            gl.FUNC_ADD,
            gl.FUNC_SUBTRACT,
            gl.FUNC_REVERSE_SUBTRACT
        ];

        const list = [
            'ZERO',
            'ONE',
            'SRC_COLOR',
            'ONE_MINUS_SRC_COLOR',
            'DST_COLOR',
            'ONE_MINUS_DST_COLOR',
            'SRC_ALPHA',
            'ONE_MINUS_SRC_ALPHA',
            'DST_ALPHA',
            'ONE_MINUS_DST_ALPHA',
            'CONSTANT_COLOR',
            'ONE_MINUS_CONSTANT_COLOR',
            'CONSTANT_ALPHA',
            'ONE_MINUS_CONSTANT_ALPHA',
            'SRC_ALPHA_SATURATE'
        ];

        const list2 = [
            'FUNC_ADD',
            'FUNC_SUBTRACT',
            'FUNC_REVERSE_SUBTRACT'
        ];

        let srcRGBIndex = 1;
        let dstRGBIndex = 7;
        let srcAlphaIndex = 1;
        let dstAlphaIndex = 1;
        let equationIndex = 0;

        let srcRGB = consts[srcRGBIndex];
        let dstRGB = consts[dstRGBIndex];
        let srcAlpha = consts[srcAlphaIndex];
        let dstAlpha = consts[dstAlphaIndex];

        let newMode = [ srcRGB, dstRGB, srcAlpha, dstAlpha ];

        let equation = equations[equationIndex];

        let renderer = this.sys.game.renderer;

        let modeIndex = renderer.addBlendMode(newMode, equation);

        this.add.image(400, 300, 'turkey');

        this.add.rectangle(200, 300, 1, 600, 0xefefef);
        this.add.rectangle(400, 300, 1, 600, 0xefefef);
        this.add.rectangle(600, 300, 1, 600, 0xefefef);
        this.add.rectangle(400, 300, 800, 1, 0xefefef);

        // this.add.image(400, 300, 'logo');
        this.add.image(400, 300, 'logo').setBlendMode(modeIndex);

        var text = this.add.text(0, 0, 'Blend Mode', { color: '#ffffff' });

        text.setText([
            srcRGBIndex + ' = ' + list[srcRGBIndex],
            dstRGBIndex + ' = ' + list[dstRGBIndex],
            srcAlphaIndex + ' = ' + list[srcAlphaIndex],
            dstAlphaIndex + ' = ' + list[dstAlphaIndex],
            '',
            equationIndex + ' = ' + list2[equationIndex] + ' - ASR'
        ]);

        this.input.keyboard.on('keydown_A', function (event) {

            equationIndex = 0;
            equation = equations[equationIndex];

            renderer.updateBlendMode(modeIndex, newMode, equation);

            text.setText([
                srcRGBIndex + ' = ' + list[srcRGBIndex],
                dstRGBIndex + ' = ' + list[dstRGBIndex],
                srcAlphaIndex + ' = ' + list[srcAlphaIndex],
                dstAlphaIndex + ' = ' + list[dstAlphaIndex],
                '',
                equationIndex + ' = ' + list2[equationIndex] + ' - ASR'
            ]);

        });

        this.input.keyboard.on('keydown_S', function (event) {

            equationIndex = 1;
            equation = equations[equationIndex];

            renderer.updateBlendMode(modeIndex, newMode, equation);

            text.setText([
                srcRGBIndex + ' = ' + list[srcRGBIndex],
                dstRGBIndex + ' = ' + list[dstRGBIndex],
                srcAlphaIndex + ' = ' + list[srcAlphaIndex],
                dstAlphaIndex + ' = ' + list[dstAlphaIndex],
                '',
                equationIndex + ' = ' + list2[equationIndex] + ' - ASR'
            ]);

        });

        this.input.keyboard.on('keydown_R', function (event) {

            equationIndex = 2;
            equation = equations[equationIndex];

            renderer.updateBlendMode(modeIndex, newMode, equation);

            text.setText([
                srcRGBIndex + ' = ' + list[srcRGBIndex],
                dstRGBIndex + ' = ' + list[dstRGBIndex],
                srcAlphaIndex + ' = ' + list[srcAlphaIndex],
                dstAlphaIndex + ' = ' + list[dstAlphaIndex],
                '',
                equationIndex + ' = ' + list2[equationIndex] + ' - ASR'
            ]);

        });

        this.input.on('pointerup', function (pointer)
        {
            var x = Phaser.Math.Snap.Floor(pointer.x, 200, 0, true);
            var y = pointer.y;

            if (y > 300)
            {
                if (x === 0)
                {
                    srcRGBIndex = Phaser.Math.Wrap(srcRGBIndex + 1, 0, 15);
                }
                else if (x === 1)
                {
                    dstRGBIndex = Phaser.Math.Wrap(dstRGBIndex + 1, 0, 15);
                }
                else if (x === 2)
                {
                    srcAlphaIndex = Phaser.Math.Wrap(srcAlphaIndex + 1, 0, 15);
                }
                else if (x === 3)
                {
                    dstAlphaIndex = Phaser.Math.Wrap(dstAlphaIndex + 1, 0, 15);
                }
            }
            else
            {
                if (x === 0)
                {
                    srcRGBIndex = Phaser.Math.Wrap(srcRGBIndex - 1, 0, 15);
                }
                else if (x === 1)
                {
                    dstRGBIndex = Phaser.Math.Wrap(dstRGBIndex - 1, 0, 15);
                }
                else if (x === 2)
                {
                    srcAlphaIndex = Phaser.Math.Wrap(srcAlphaIndex - 1, 0, 15);
                }
                else if (x === 3)
                {
                    dstAlphaIndex = Phaser.Math.Wrap(dstAlphaIndex - 1, 0, 15);
                }
            }

            srcRGB = consts[srcRGBIndex];
            dstRGB = consts[dstRGBIndex];
            srcAlpha = consts[srcAlphaIndex];
            dstAlpha = consts[dstAlphaIndex];

            newMode = [ srcRGB, dstRGB, srcAlpha, dstAlpha ];

            renderer.updateBlendMode(modeIndex, newMode, equation);

            text.setText([
                srcRGBIndex + ' = ' + list[srcRGBIndex],
                dstRGBIndex + ' = ' + list[dstRGBIndex],
                srcAlphaIndex + ' = ' + list[srcAlphaIndex],
                dstAlphaIndex + ' = ' + list[dstAlphaIndex],
                '',
                equationIndex + ' = ' + list2[equationIndex] + ' - ASR'
            ]);
        });
    }

}

const config = {
    scale: { mode: Phaser.Scale.FIT },
    type: Phaser.WEBGL,
    width: 800,
    height: 600,
    parent: 'game-container',
    scene: Example
};

const game = new Phaser.Game(config);