53 lines
2.3 KiB
Plaintext
53 lines
2.3 KiB
Plaintext
|
# haku
|
||
|
|
|
||
|
|
Haku is a little scripting language used by rakugaki for programming brushes.
|
||
|
|
Here's a brief tour of the language.
|
||
|
|
|
||
|
|
## Your brush
|
||
|
|
|
||
|
|
Your brush is a piece of code that describes what's to be drawn on the wall.
|
||
|
|
|
||
|
|
For example:
|
||
|
|
|
||
|
|
```haku
|
||
|
|
(stroke
|
||
|
|
8
|
||
|
|
(rgba 0 0 0 1)
|
||
|
|
(vec 0 0))
|
||
|
|
```
|
||
|
|
|
||
|
|
This is the simplest brush you can write.
|
||
|
|
It demonstrates a few things:
|
||
|
|
|
||
|
|
- The brush's task is to produce a description of what's to be drawn.
|
||
|
|
Brushes produce *scribbles* - commands that instruct rakugaki draw something on the wall.
|
||
|
|
|
||
|
|
- This brush produces the `(stroke)` scribble.
|
||
|
|
This scribble is composed out of three things:
|
||
|
|
|
||
|
|
- The stroke thickness - in this case `8`.
|
||
|
|
- The stroke color - in this case `(rgba 0 0 0 1)`.
|
||
|
|
Note that unlike most drawing programs, rakugaki brushes represent color channels with decimal numbers from 0 to 1, rather than integers from 0 to 255.
|
||
|
|
- The shape to draw - in this case a `(vec 0 0)`.
|
||
|
|
|
||
|
|
- Vectors are aggregations of four generic decimal numbers, most often used to represent positions in the wall's Cartesian coordinate space.
|
||
|
|
Although vectors are mathematically not the same as points, brushes always execute in a coordinate space relative to where you want to draw with the brush, so a separate `(point)` type isn't needed.
|
||
|
|
|
||
|
|
- Vectors in haku are four-dimensional, but the wall is two-dimensional, so the extra dimensions are discarded when drawing to the wall.
|
||
|
|
|
||
|
|
- haku permits constructing vectors from zero two four values - from `(vec)`, up to `(vec x y w h)`.
|
||
|
|
Any values that you leave out end up being zero.
|
||
|
|
|
||
|
|
- Note that a brush can only produce *one* scribble - this is because scribbles may be composed together using lists (described later.)
|
||
|
|
|
||
|
|
I highly recommend that you play around with the brush to get a feel for editing haku code!
|
||
|
|
|
||
|
|
## Limits
|
||
|
|
|
||
|
|
The wall is infinite, but your brush may only draw in a small area around your cursor (~500 pixels.)
|
||
|
|
Drawing outside this area may result in pixels getting dropped in ugly ways, but it can also be used to your advantage in order to produce cool glitch art.
|
||
|
|
|
||
|
|
Additionally, haku code has some pretty strong limitations on what it can do.
|
||
|
|
It cannot be too big, it cannot execute for too long, and it cannot consume too much memory.
|
||
|
|
It does not have access to the world outside the wall.
|