PLOGO/README.md

# PLOGO

Purchase LOGO

A toy language.

A kind of LOGO-like DSL built in the p5.js library.

This is a rudimentary proof of concept right now with globals and without implementing classes.  To write loops or *subroutines* one must use regular javascript.

![example program](example.jpg)  

## How to Use

Put your code inside the turtle function in turtle.js

## Reference Commands


### Movement

```
forward(n)
```
move n pixels ahead

```
back(n)
```
move n pixels back

```
left(Δ)  
```
turns Δ degrees to the left

```
right(Δ)
```
turns Δ degrees to the right

### Drawing

```
penup()
```
Going forward, Turtle will stop drawing a line with movement commands

```
pendown()
``` 
Turtle will start drawing lines tracing route.  **By default, pendown is on / true**

```
penColor('colorName')
```
penColor takes any color word: purple, grey, blue, etc. **The color name must be in quotes.**

Alternatively, a HTML color name, like #ff4d4d, may be specified in quotes. Example: ```penColor('$ff4d4d')```

Alternatively, a RGB color or RGBA color with transparency can be specified, with *color*. Example: ```penColor(color(255,0,255))```. See transparency example in examples section below.

```
penSize(n)
```
Width of pen in pixels
		       
### Randomness

```
randint(n)
```

or

```
randint()
```
Returns a random int between 0 and n. Specifying a value is optional. If no input *n*, the default is between 0 and 100. Example: ```forward(randint(30))```


## Examples

### Backwards box

```
penColor('orange');
penSize(3);

left(90);
back(100);
left(90);
back(100);
left(90);
back(100);
left(90);
back(100);
```

### Random Walk (with javascript for-loop)

```
for (let i = 0; i < 100; i++){
  right(randint());
  forward(randint());
}
 
```

### Forward, with color transparency

In this example, the last parameter inside penColor's color is the alpha transparency amount. Like the individual red, green, blue colors specified before it, this can be a number from 0 to 255. The lower the number, the more transparent.

```
penSize(20);

penColor(color(100,0,100,50));
forward(100);

penColor(color(100,0,100,150));
forward(100);

penColor(color(100,0,100,250));
forward(100);
```