135 lines
2.9 KiB
JavaScript
135 lines
2.9 KiB
JavaScript
GameLib.D3.Vector3 = function(x, y, z) {
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this.x = 0;
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this.y = 0;
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this.z = 0;
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if (x) {
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this.x = x;
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}
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if (y) {
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this.y = y;
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}
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if (z) {
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this.z = z;
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}
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};
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GameLib.D3.Vector3.prototype.subtract = function (v) {
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if (v instanceof GameLib.D3.Vector3) {
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this.x -= v.x;
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this.y -= v.y;
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this.z -= v.z;
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}
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if (v instanceof GameLib.D3.Vector4) {
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console.warn("trying to subtract vector of bigger length (4 vs 3))");
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}
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return this;
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};
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GameLib.D3.Vector3.prototype.cross = function (v) {
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return new GameLib.D3.Vector3(
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this.y * v.z - this.z * v.y,
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this.z * v.x - this.x * v.z,
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this.x * v.y - this.y * v.x
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);
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};
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GameLib.D3.Vector3.prototype.negative = function () {
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this.x *= -1;
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this.y *= -1;
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this.z *= -1;
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return this;
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};
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GameLib.D3.Vector3.clockwise = function (u, v, w, viewPoint) {
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var normal = GameLib.D3.Vector3.normal(u, v, w);
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var uv = u.copy();
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var winding = normal.dot(uv.subtract(viewPoint));
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return (winding > 0);
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};
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GameLib.D3.Vector3.normal = function (u, v, w) {
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var vv = v.copy();
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var wv = w.copy();
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return vv.subtract(u).cross(wv.subtract(u));
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};
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GameLib.D3.Vector3.prototype.lookAt = function (at, up) {
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var lookAtMatrix = GameLib.D3.Matrix4.lookAt(this, at, up);
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this.multiply(lookAtMatrix);
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};
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GameLib.D3.Vector3.prototype.translate = function (v) {
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this.x += v.x;
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this.y += v.y;
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this.z += v.z;
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return this;
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};
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GameLib.D3.Vector3.prototype.squared = function () {
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return this.x * this.x + this.y * this.y + this.z * this.z;
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};
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GameLib.D3.Vector3.prototype.copy = function () {
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return new GameLib.D3.Vector3(
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this.x,
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this.y,
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this.z
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);
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};
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GameLib.D3.Vector3.prototype.multiply = function (s) {
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if (s instanceof GameLib.D3.Vector3) {
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this.x *= s.x;
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this.y *= s.y;
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this.z *= s.z;
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} else if (s instanceof GameLib.D3.Matrix4) {
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var x = s.rows[0].x * this.x + s.rows[0].y * this.y + s.rows[0].z * this.z;
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var y = s.rows[1].x * this.x + s.rows[1].y * this.y + s.rows[1].z * this.z;
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var z = s.rows[2].x * this.x + s.rows[2].y * this.y + s.rows[2].z * this.z;
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this.x = x;
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this.y = y;
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this.z = z;
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} else {
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console.log("functionality not implemented - please do this");
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throw new Error("not implemented");
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}
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return this;
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};
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GameLib.D3.Vector3.prototype.dot = function (v) {
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return (this.x * v.x) + (this.y * v.y) + (this.z * v.z);
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};
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GameLib.D3.Vector3.prototype.normalize = function () {
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var EPSILON = 0.000001;
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var v2 = this.squared();
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if (v2 < EPSILON) {
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return this; //do nothing for zero vector
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}
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var invLength = 1 / Math.sqrt(v2);
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this.x *= invLength;
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this.y *= invLength;
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this.z *= invLength;
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return this;
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};
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