Difference between revisions of "Robocode/Game Physics"
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# Time is updated (time = time + 1) | # Time is updated (time = time + 1) | ||
# All bullets move and check for collisions | # All bullets move and check for collisions | ||
| − | # All robots move (heading, | + | # All robots move (heading, acceleration, velocity, distance, in that order) |
# All robots perform scans (and collect team messages) | # All robots perform scans (and collect team messages) | ||
# All robots are resumed to take new action | # All robots are resumed to take new action | ||
Revision as of 05:39, 18 August 2008
This page describes the game physics of Robocode
Robocode Game Physics
Contents
Coordinates and Direction Conventions
| Coordinates System: | Robocode is using the Cartesian Coordinate System, which means that that the (0, 0) coordinate is located in the bottom left of the battle field. |
|---|---|
| Clockwise Direction: | Robocode is using a clockwise direction convention where 0 / 360 deg is towards "North", 90 deg towards "East", 180 deg towards "South", and 270 deg towards "West". |
Figure 1:
http://www.ibm.com/developerworks/java/library/j-robocode2/fig2.gif
Time and distance measurements in Robocode
| Time (t): | Robocode time is measured in "ticks". Each robot gets one turn per tick. 1 tick = 1 turn. |
|---|---|
| Distance Measurement: | 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. |
Robot Movement Physics
| Acceleration (a): | 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. |
|---|---|
| Velocity Equation(v): | 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. |
| Distance Equation (d): | d = vt. That is, distance = velocity * time |
Robot, Gun, and Radar rotation
| Max rate of rotation of robot: | (10 - 0.75 * abs(velocity)) deg / turn. The faster you're moving, the slower you turn. |
|---|---|
| Max rate of rotation of gun: | 20 deg / turn. This is added to the current rate of rotation of the robot. |
| Max rate of rotation of radar: | 45 deg / turn. This is added to the current rate of rotation of the gun. |
Bullets
| Damage: | 4 * firepower. If firepower > 1, it does an additional damage = 2 * (power - 1). |
|---|---|
| Velocity: | 20 - 3 * firepower. |
| GunHeat generated: | 1 + firepower / 5. You cannot fire if gunHeat > 0. All guns are hot at the start of each round. |
| Power returned on hit: | 3 * firepower. |
Collisions
| With Another Robot: | Each robot takes 0.6 damage. If a robot is moving away from the collision, it will not be stopped. |
|---|---|
| With a Wall: | AdvancedRobots take abs(velocity) * 0.5 - 1; (Never < 0). |
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, acceleration, 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
