r3-legacy/src/game-lib-matrix-4.js

GameLib.D3.Matrix4 = function(
    row0,
    row1,
    row2,
    row3
) {

    this.identity();

    if (row0) {
        this.rows[0] = row0;
    }

    if (row1) {
        this.rows[1] = row1;
    }

    if (row2) {
        this.rows[2] = row2;
    }

    if (row3) {
        this.rows[3] = row3;
    }
};

GameLib.D3.Matrix4.prototype.rotationMatrixX = function (radians) {
    this.identity();
    this.rows[1] = new GameLib.D3.API.Vector4(0, Math.cos(radians), -1 * Math.sin(radians), 0);
    this.rows[2] = new GameLib.D3.API.Vector4(0, Math.sin(radians), Math.cos(radians), 0);
    return this;
};

GameLib.D3.Matrix4.prototype.rotationMatrixY = function (radians) {
    this.identity();
    this.rows[0] = new GameLib.D3.API.Vector4(
        Math.cos(radians),
        0,
        Math.sin(radians),
        0
    );
    this.rows[2] = new GameLib.D3.API.Vector4(
        -1 * Math.sin(radians),
        0,
        Math.cos(radians),
        0
    );
    return this;
};

GameLib.D3.Matrix4.prototype.rotationMatrixZ = function (radians) {
    this.identity();
    this.rows[0] = new GameLib.D3.API.Vector4(Math.cos(radians), -1 * Math.sin(radians), 0, 0);
    this.rows[1] = new GameLib.D3.API.Vector4(Math.sin(radians), Math.cos(radians), 0, 0);
    return this;
};

GameLib.D3.Matrix4.prototype.rotateX = function (radians, point) {
    this.identity();
    this.rotationMatrixX(radians);
    return this.multiply(point);
};

GameLib.D3.Matrix4.prototype.rotateY = function (radians, point) {
    this.identity();
    this.rotationMatrixY(radians);
    return this.multiply(point);
};

GameLib.D3.Matrix4.prototype.rotateZ = function (radians, point) {
    this.identity();
    this.rotationMatrixZ(radians);
    return this.multiply(point);
};

GameLib.D3.Matrix4.prototype.multiply = function (mvp) {
    if (mvp instanceof GameLib.D3.API.Vector4) {
        return new GameLib.D3.API.Vector4(
            this.rows[0].x * mvp.x + this.rows[0].y * mvp.y + this.rows[0].z * mvp.z + this.rows[0].w * mvp.w,
            this.rows[1].x * mvp.x + this.rows[1].y * mvp.y + this.rows[1].z * mvp.z + this.rows[1].w * mvp.w,
            this.rows[2].x * mvp.x + this.rows[2].y * mvp.y + this.rows[2].z * mvp.z + this.rows[2].w * mvp.w,
            this.rows[3].x * mvp.x + this.rows[3].y * mvp.y + this.rows[3].z * mvp.z + this.rows[3].w * mvp.w
        );
    } else if (mvp instanceof GameLib.D3.API.Vector3) {
        return new GameLib.D3.API.Vector3(
            this.rows[0].x * mvp.x + this.rows[0].y * mvp.y + this.rows[0].z * mvp.z,
            this.rows[1].x * mvp.x + this.rows[1].y * mvp.y + this.rows[1].z * mvp.z,
            this.rows[2].x * mvp.x + this.rows[2].y * mvp.y + this.rows[2].z * mvp.z
        );
    }
};

GameLib.D3.Matrix4.prototype.identity = function () {
    this.rows = [
        new GameLib.D3.API.Vector4(1, 0, 0, 0),
        new GameLib.D3.API.Vector4(0, 1, 0, 0),
        new GameLib.D3.API.Vector4(0, 0, 1, 0),
        new GameLib.D3.API.Vector4(0, 0, 0, 1)
    ];
};

GameLib.D3.Matrix4.prototype.lookAt = function (position, target, up) {

    var pv = new GameLib.D3.API.Vector3(position.x, position.y, position.z);

    var z = pv.subtract(target).normalize();

    if (z.squared() === 0) {
        z.z = 1;
    }

    var x = up.cross(z).normalize();

    if (x.squared() === 0) {
        z.x += 0.0001;
        x = up.cross(z).normalize();
    }

    var y = z.cross(x);

    this.rows[0].x = x.x;
    this.rows[0].y = x.y;
    this.rows[0].z = x.z;

    this.rows[1].x = y.x;
    this.rows[1].y = y.y;
    this.rows[1].z = y.z;

    this.rows[2].x = z.x;
    this.rows[2].y = z.y;
    this.rows[2].z = z.z;

    return this;
};