## Time, angles & units

Read the following sections carefully to fully understand how certain values are handled in the Danmaku Engine.

### Angles & rotations

All angles and rotations are measured in degrees from zero (up) to 360 (clock-wise).

### Units

All position-related values are internally handled as `float`s which are directly translated to Unity's world units.

### How time is handled

Everything which is time-based is calculated in seconds - therefore, every time-step is based on Unity's `Time.deltaTime` by default, because many Unity-projects are built frame-rate independent.

However, if you want the calculations to be frame-dependent you can enable the checkbox **"Use Frame Based Time"** in the inspector of the DanmakuController in your scene. This will internally set the time-delta for each frame to `1.0`, which mathematically turns all calculations to "per-frame" instead of "per-second".

Keep in mind that many numerical values you are using in your bullet-patterns depend on the used time-calculation, so you should decide beforehand which one you want to use. For example, if you define a bullet with a speed of 5 and you are using time-based calculations, this bullet will travel 5 distance-units per second - if you set the timing to frame-based, it will travel 5 distance-units **per frame** which is a significant difference.