class VTUtils {
    static random(min, max) {
        let rand = Math.random();
        if (typeof min === 'undefined') {
            return rand;
        } else if (typeof max === 'undefined') {
            if (min instanceof Array) {
                return min[Math.floor(rand * min.length)];
            } else {
                return rand * min;
            }
        } else {
            if (min > max) {
                let tmp = min;
                min = max;
                max = tmp;
            }
            return rand * (max - min) + min;
        }
    };

    static randomInt(min, max) {
        return Math.floor(VTUtils.random(min, max));
    }

    static normalize(val, max, min) {
        return (val - min) / (max - min);
    };

    static distance(x, y, x2, y2) {
        let a = x - x2;
        let b = y - y2;

        return Math.sqrt(a * a + b * b);
    }

    static map(n, start1, stop1, start2, stop2, withinBounds) {
        let newVal = (n - start1) / (stop1 - start1) * (stop2 - start2) + start2;
        if (!withinBounds) {
            return newVal;
        }
        if (start2 < stop2) {
            return this.constrain(newVal, start2, stop2);
        } else {
            return this.constrain(newVal, stop2, start2);
        }
    };

    static constrain(n, low, high) {
        return Math.max(Math.min(n, high), low);
    }

    static hsvToRgb(h, s, v) {
        var r, g, b;

        var i = Math.floor(h * 6);
        var f = h * 6 - i;
        var p = v * (1 - s);
        var q = v * (1 - f * s);
        var t = v * (1 - (1 - f) * s);

        switch (i % 6) {
            case 0:
                r = v, g = t, b = p;
                break;
            case 1:
                r = q, g = v, b = p;
                break;
            case 2:
                r = p, g = v, b = t;
                break;
            case 3:
                r = p, g = q, b = v;
                break;
            case 4:
                r = t, g = p, b = v;
                break;
            case 5:
                r = v, g = p, b = q;
                break;
        }

        return {r: r, g: g, b: b};
    }

    static peakRGB(peak) {
        return {
            r: peak,
            g: 1 - peak,
            b: 0
        };
    }
}

class VTVector {
    constructor(x, y, z) {
        this.x = x || 0;
        this.y = y || 0;
        this.z = z || 0;
    }

    //helper
    static createRandom(x, y, z) {
        x = x || 1;
        y = y || 1;
        z = z || 0;
        return new VTVector(VTUtils.random(-x, x), VTUtils.random(-y, y), VTUtils.random(-z, z));
    }

    mult(times) {
        this.x *= times;
        this.y *= times;
        this.z *= times;
    }

    set(vector) {
        this.x = vector.x;
        this.y = vector.y;
        this.z = vector.z;
    }

    add(vector) {
        this.x = this.x + vector.x;
        this.y = this.y + vector.y;
        this.z = this.z + vector.z;
    }

    addXYZ(x, y, z) {
        this.x += x;
        this.y += y;
        this.z += z;
    }

    setXYZ(x,y,z) {
        this.x = x || 0;
        this.y = y || 0;
        this.z = z || 0;
    }

    clone() {
        return new VTVector(this.x, this.y, this.z);
    }
}

class TDUtils {
    static multiply(a, b) {
        let b00 = b[0 * 4 + 0];
        let b01 = b[0 * 4 + 1];
        let b02 = b[0 * 4 + 2];
        let b03 = b[0 * 4 + 3];
        let b10 = b[1 * 4 + 0];
        let b11 = b[1 * 4 + 1];
        let b12 = b[1 * 4 + 2];
        let b13 = b[1 * 4 + 3];
        let b20 = b[2 * 4 + 0];
        let b21 = b[2 * 4 + 1];
        let b22 = b[2 * 4 + 2];
        let b23 = b[2 * 4 + 3];
        let b30 = b[3 * 4 + 0];
        let b31 = b[3 * 4 + 1];
        let b32 = b[3 * 4 + 2];
        let b33 = b[3 * 4 + 3];
        let a00 = a[0 * 4 + 0];
        let a01 = a[0 * 4 + 1];
        let a02 = a[0 * 4 + 2];
        let a03 = a[0 * 4 + 3];
        let a10 = a[1 * 4 + 0];
        let a11 = a[1 * 4 + 1];
        let a12 = a[1 * 4 + 2];
        let a13 = a[1 * 4 + 3];
        let a20 = a[2 * 4 + 0];
        let a21 = a[2 * 4 + 1];
        let a22 = a[2 * 4 + 2];
        let a23 = a[2 * 4 + 3];
        let a30 = a[3 * 4 + 0];
        let a31 = a[3 * 4 + 1];
        let a32 = a[3 * 4 + 2];
        let a33 = a[3 * 4 + 3];
        let dst = [];
        dst[0] = b00 * a00 + b01 * a10 + b02 * a20 + b03 * a30;
        dst[1] = b00 * a01 + b01 * a11 + b02 * a21 + b03 * a31;
        dst[2] = b00 * a02 + b01 * a12 + b02 * a22 + b03 * a32;
        dst[3] = b00 * a03 + b01 * a13 + b02 * a23 + b03 * a33;
        dst[4] = b10 * a00 + b11 * a10 + b12 * a20 + b13 * a30;
        dst[5] = b10 * a01 + b11 * a11 + b12 * a21 + b13 * a31;
        dst[6] = b10 * a02 + b11 * a12 + b12 * a22 + b13 * a32;
        dst[7] = b10 * a03 + b11 * a13 + b12 * a23 + b13 * a33;
        dst[8] = b20 * a00 + b21 * a10 + b22 * a20 + b23 * a30;
        dst[9] = b20 * a01 + b21 * a11 + b22 * a21 + b23 * a31;
        dst[10] = b20 * a02 + b21 * a12 + b22 * a22 + b23 * a32;
        dst[11] = b20 * a03 + b21 * a13 + b22 * a23 + b23 * a33;
        dst[12] = b30 * a00 + b31 * a10 + b32 * a20 + b33 * a30;
        dst[13] = b30 * a01 + b31 * a11 + b32 * a21 + b33 * a31;
        dst[14] = b30 * a02 + b31 * a12 + b32 * a22 + b33 * a32;
        dst[15] = b30 * a03 + b31 * a13 + b32 * a23 + b33 * a33;
        return dst;
    }

    static xRotation(angleInRadians) {
        let c = Math.cos(angleInRadians);
        let s = Math.sin(angleInRadians);

        return [
            1, 0, 0, 0,
            0, c, s, 0,
            0, -s, c, 0,
            0, 0, 0, 1,
        ];
    }

    static yRotation(angleInRadians) {
        let c = Math.cos(angleInRadians);
        let s = Math.sin(angleInRadians);

        return [
            c, 0, -s, 0,
            0, 1, 0, 0,
            s, 0, c, 0,
            0, 0, 0, 1,
        ];
    }

    static zRotation(angleInRadians) {
        let c = Math.cos(angleInRadians);
        let s = Math.sin(angleInRadians);

        return [
            c, s, 0, 0,
            -s, c, 0, 0,
            0, 0, 1, 0,
            0, 0, 0, 1,
        ];
    }

    static degToRad(d) {
        return d * Math.PI / 180;
    }
}