Robocode Game Physics
This page describes the game physics of Robocode
Coordinates and Direction Conventions
| Coordinates System:
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Robocode is using the Cartesian Coordinate System, which means that that the (0, 0) coordinate is located in the buttom left of the battle field.
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| Clockwise Direction:
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Robocode is using a clockwise direction convension where 0 / 360 deg is towards "North", 90 deg towards "East", 180 deg towards "South", and 270 deg towards "West".
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Figure 1:
http://www.ibm.com/developerworks/java/library/j-robocode2/fig2.gif
Time and distance measurements in Robocode
| Time (t):
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Robocode time is measured in "ticks". Each robot gets one turn per tick. 1 tick = 1 turn.
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| Distance Measurement:
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Robocode's units are basically measured in pixels, with two exceptions. First, all distances are measured with double precision, so you can actually move a fraction of a pixel. Second, Robocode automatically scales down battles to fit on the screen. In this case, the unit of distance is actually smaller than a pixel.
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Robot Movement Physics
| Acceleration (a):
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Robots accelerate at the rate of 1 pixel/turn. Robots decelerate at the rate of 2 pixels/turn. Robocode determines acceleration for you, based on the distance you are trying to move.
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| Velocity Equation(v):
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v = at. Velocity can never exceed 8 pixels/turn. Note that technically, velocity is a vector, but in Robocode we simply assume the direction of the vector to be the robot's heading.
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| Distance Equation (d):
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d = vt. That is, distance = velocity * time
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Robot, Gun, and Radar rotation
| Max rate of rotation of robot:
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(10 - 0.75 * abs(velocity)) deg / turn. The faster you're moving, the slower you turn.
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| Max rate of rotation of gun:
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20 deg / turn. This is added to the current rate of rotation of the robot.
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| Max rate of rotation of radar:
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45 deg / turn. This is added to the current rate of rotation of the gun.
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Bullets
| Damage:
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4 * firepower. If firepower > 1, it does an additional damage = 2 * (power - 1).
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| Velocity:
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20 - 3 * firepower.
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| GunHeat generated:
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1 + firepower / 5. You cannot fire if gunHeat > 0. All guns are hot at the start of each round.
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| Power returned on hit:
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3 * firepower.
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Collisions
| With Another Robot:
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Each robot takes 0.6 damage. If a robot is moving away from the collision, it will not be stopped.
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| With a Wall:
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AdvancedRobots take abs(velocity) * 0.5 - 1; (Never < 0).
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Robocode Processing Loop
The order that Robocode runs is as follows:
- Battle view is (re)painted
- All robots execute their code until they take action (and then paused)
- Time is updated (time = time + 1)
- All bullets move and check for collisions
- All robots move (heading, accelration, velocity, distance, in that order)
- All robots perform scans (and collect team messages)
- All robots are resumed to take new action
- Each robot is processing its event queue
See Also
