See sin

The cannon method fires a missile heading a specified range and direction. cannon returns 1 (true) if a missile was fired, or 0 (false) if the cannon is reloading. Degree is forced into the range 0-359 as in scan. Range can be 0-700, with greater ranges truncated to 700.

Examples:

degree = 45             # set a direction to scan
range = scan(degree, 2) # scan for a target
if range > 0            # if there is a target in range
  cannon(degree, range) # fire a missle
end

See sin

The damage method returns the current amount of damage incurred. damage() takes no arguments, and returns the percent of damage, 0-99. (100 percent damage means the robot is completely disabled, thus no longer running!)

Examples:

d = damage # save current state

... # other instructions

if d != damage   # compare current state to prior state
  drive(90, 100) # robot has been hit, start moving
  d = damage     # get current damage again
end

The drive method activates the robot's drive mechanism, on a specified heading and speed. Degree is forced into the range 0-359 as in scan. Speed is expressed as a percent, with 100 as maximum. A speed of 0 disengages the drive. Changes in direction can be negotiated at speeds of less than 50 percent.

Examples:

drive(0, 100) # head due east, at maximum speed
drive(90, 0)  # stop motion

The loc_x method returns the robot's current x axis location. loc_x takes no arguments, and returns 0-999. The loc_y method is similar to loc_x, but returns the current y axis position.

Examples:

  drive(180,50)      # start heading for west wall
  while loc_x > 20 do
                     # do nothing until we are close
  end
  drive(180,0)       # stop drive

See loc_x

The main method provides an entry point for the crystal-robots virtual CPU for the robot.

TODO this needs a lot more description

Examples:

main("MyRobot") do
  puts("Hello World!")
end

The rand method returns a random number between 0 and limit, up to 32767.

Examples:

degree = rand(360)      # pick a random starting point
range = scan(degree, 0) # and scan

The scan method invokes the robot's scanner, at a specified degree and resolution. scan returns 0 if no robots are within the scan range or a positive integer representing the range to the closest robot. Degree should be within the range 0-359, otherwise degree is forced into 0-359 by a modulo 360 operation, and made positive if necessary. Resolution controls the scanner's sensing resolution, up to +/- 10 degrees.

Examples:

range = scan(45, 0)   # scan 45, with no variance
range = scan(365, 10) # scans the range from 355 to 15

These methods provide trigonometric values. sin, cos, and tan, take a degree argument, 0-359, and returns the trigonometric value times 100,000. The scaling is necessary since the crystal-robots CPU is an integer only machine, and trig values are between 0.0 and 1.0. atan takes a ratio argument that has been scaled up by 100,000, and returns a degree value, between -90 and +90. The resulting calculation should not be scaled to the actual value until the final operation, as not to lose accuracy. See programming examples for usage.

TODO link to programming examples

Just yield

The speed method returns the current speed of the robot. speed takes no arguments, and returns the percent of speed, 0-100. Note that speed may not always be the same as the last drive, because of acceleration and deceleration.

Examples:

drive(270, 100) # start drive, due south

... # other instructions

if speed == 0   # check current speed
  drive(90, 20) # ran into the south wall, or another robot
end

The sqrt method returns the square root of a number. Number is made positive, if necessary.

Examples:

x = x1 - x2 # compute the classical distance formula
y = y1 - y2 # between two points (x1,y1) (x2,y2)
distance = sqrt((x*x) - (y*y))

See sin