Math and random

Angles are in degrees: 0 = right, 90 = up, 180 = left, 270 = down.

Angles and distances (inside an object)

Function	What it does	Example
`float angleTo(float targetX, float targetY) const`	Angle from this instance to a point.	`setDirection(angleTo(mouseX(), mouseY()));`
`float angleTo(const Entity& other) const`	Angle to another instance.	`angleTo(*player)`
`float distanceTo(float targetX, float targetY) const`	Distance in pixels to a point.	`if (distanceTo(160, 90) < 8) ...`
`float distanceTo(const Entity& other) const`	Distance to another instance.	`if (distanceTo(*player) < 40) ...`

Function	What it does	Example
`float lerp(float a, float b, float t)`	Blend from `a` to `b`: `t = 0` gives `a`, `t = 1` gives `b`.	`x = lerp(x, target, 0.1f);`
`float approach(float current, float target, float step)`	Moves from `current` to `target` by at most `step`, without overshooting.	`hspeed = approach(hspeed, 0, 0.2f);`
`int sign(float v)`	`-1`, `0` or `1`, according to the sign.	`if (hspeed != 0) scaleX = sign(hspeed);`
`float wrap(float v, float min, float max)`	Wraps around inside the range. `wrap(370, 0, 360)` = `10`.	`x = wrap(x, 0, roomWidth());`

A 2D vector with x and y. y grows downwards, as on screen.

Member	What it does
`Vec2{x, y}`	Creates a vector.
`+`, `-`, ``, `/` (and `+=`, `-=`, `=`, `/=`)	Arithmetic with vectors and numbers.
`float length() const`	Length of the vector.
`Vec2 normalized() const`	The same vector with length 1.
`static Vec2 fromAngle(float distance, float degrees)`	Vector with the given length and angle.

const Vec2 v = Vec2::fromAngle(4.0f, 45);  // 4 pixels diagonally up and to the right
hspeed = v.x;
vspeed = v.y;

Function	What it does	Example
`float random(float a, float b)`	Decimal number from `a` up to almost `b`.	`vspeed = random(0.8f, 1.6f);`
`int randomInt(int a, int b)`	Whole number from `a` to `b`, including both.	`int side = randomInt(0, 3);`
`bool chance(float p)`	`true` with probability `p` (0 = never, 1 = always).	`if (chance(0.25f)) ...`
`pick(a, b, ...)`	Picks one of the values at random. Mixed types become the common type.	`pick(1, 5, 9)`
`void randomSeed(unsigned seed)`	Fixes the seed: the same seed repeats the same random results.	`randomSeed(42);`

See Random numbers for examples.