Performance Challenges in Compiling Code to JavaScript

1.cs

float elapsed = ...;
Vector3 position = object1.Position, velocity = object1.Velocity;
Vector3 nextPosition = position + (velocity * elapsed);
GraphicsContext.DrawLine(position, nextPosition);

2.js

var elapsed = ...;
var position = object1.Position, velocity = object1.Velocity;
var nextPosition = Vector3.Add(position, Vector3.Multiply(velocity, elapsed));
GraphicsContext.DrawLine(position, nextPosition);

3.js

var elapsed = ...;
var position = object1.Position, velocity = object1.Velocity;
velocity.MultiplyBy(elapsed);
position.Add(velocity);
GraphicsContext.DrawLine(// ... hey, wait a second ...

4.js

var elapsed = ...;
var position = object1.Position, velocity = object1.Velocity;
var nextPosition = object1.NextPosition;
nextPosition.CopyFrom(position);
velocity.MultiplyBy(elapsed);
nextPosition.Add(velocity);
GraphicsContext.DrawLine(position, nextPosition);

5.js

var elapsed = ...;
var position = object1.Position.Copy(), velocity = object1.Velocity.Copy();
var nextPosition = object1.NextPosition.Copy();
nextPosition.CopyFrom(position);
velocity.MultiplyBy(elapsed);
nextPosition.Add(velocity);
GraphicsContext.DrawLine(position, nextPosition);

6.js

var elapsed = ...;
var position = object1.Position, velocity = object1.Velocity.Copy();
var nextPosition = object1.NextPosition;
nextPosition.CopyFrom(position);
velocity.MultiplyBy(elapsed);
nextPosition.Add(velocity);
GraphicsContext.DrawLine(position, nextPosition);

7.js

var elapsed = ...;
var position = object1.Position, velocity = object1.Velocity.Copy();
var nextPosition = object1.NextPosition;
nextPosition.CopyFrom(position);
velocity.MultiplyBy(elapsed);
nextPosition.Add(velocity);
// jdoe: Add support for camera zooming (game's not using it yet so I'm not sure this works...)
position.MultiplyBy(Camera.ZoomFactor);
nextPosition.MultiplyBy(Camera.ZoomFactor);
GraphicsContext.DrawLine(position, nextPosition);