This page contains descriptions of general purpose utility commands and functions available in Kojo.
Environment
| Command/Function | Description |
|---|---|
size(w, h) |
sets the size of the canvas to the given width and height. |
cwidth |
returns the current width of the canvas. |
cheight |
returns the current height of the canvas. |
originBottomLeft() |
situates the origin at the bottom left of the canvas. |
setup { drawing code } |
calls the drawing code once at the beginning of your program. |
drawLoop { drawing code } |
calls the drawing code at the default refresh rate, which is 50 times a second. |
setRefreshRate(n) |
sets the refresh rate to n times per second. The next time a clear() is done, the refresh rate is reset to its default value of 50. |
erasePictures() |
erases all the pictures in the canvas. |
Random numbers
| Command/Function | Description |
|---|---|
random(upperBound) |
Returns a random integer between 0 (inclusive) and upperBound (exclusive). |
random(lowerBound, upperBound) |
Returns a random integer between lowerBound (inclusive) and upperBound (exclusive). |
randomDouble(upperBound) |
Returns a random decimal fraction between 0 (inclusive) and upperBound (exclusive). |
randomDouble(lowerBound, upperBound) |
Returns a random decimal fraction between lowerBound (inclusive) and upperBound (exclusive). |
randomNormalDouble |
Returns a normally distributed number with mean 0 and standard deviation 1. |
randomBoolean |
Returns a random boolean value. This is like a coin toss. |
randomFrom(seq) |
Returns a random value from the given sequence. |
randomFrom(seq, weights) |
Returns a random value from the given sequence as per the given distribution of weights. |
randomColor |
Returns a random color. |
initRandomGenerator() |
Initializes the Kojo random number generater with a random seed, and prints out the seed for future reference. |
initRandomGenerator(seed) |
Initializes the Kojo random number generater with the given seed (potentially obtained via the previous command) to enable the reproducing of random patterns. |
Math
| Function | Description |
mathx.map(value, low1, high1, low2, high2) |
Maps the given value from the range (low1, high1) to the range (low2, high2). |
mathx.lerp(value1, value2, amt) |
Returns the interpolation as per the given fraction amt in the range (value1, value2). |
mathx.constrain(value, min, max) |
Constrains the given value between min and max. |
mathx.distance(x1, y1, x2, y2) |
Calculates the distance between (x1, y1) and (x2, y2). |
mathx.distance(point1, point2) |
Calculates the distance between point1 and point2. |
mathx.angle(x1, y1, x2, y2) |
calculates the angle in degrees between the line from (x1, y1) to (x2, y2) and the horizontal. |
mathx.angle(point1, point2) |
calculates the angle in degrees between the line from point1 to point2 and the horizontal. |
rangeTill(from, untill, step) |
returns a range that starts from from, goes until (but excluding) until, and steps up by step. See example. |
Examples
rangeTill
rangeTill(4, 10, 2).toArray //> res16: Array[Int] = Array(4, 6, 8)
rangeTill(4, 11.5, 2.5).toArray //> res17: Array[BigDecimal] = Array(4.0, 6.5, 9.0)