Struct DrawingStream 

pub struct DrawingStream { /* private fields */ }

Byte drawing stream of GameBoy.

It simillars with crate::io::GbStream. But there are some significant differences.

1. DrawingStream uses APA mode drawing library of GBDK. this causes many side effects, For example, if you try to use DrawingStream inside a VBL interrupt, it will have unexpected result. For more detail, please refer GBDK Docs

2. Unable to change line with \n, this means, when you want to make a new line, you should use the DrawingStream::cursor function.

3. DrawingStream can also draw shapes in addition to texts.

Examples

let mut s = unsafe {DrawingStream::new()}; // prints to second line.
write!(s, "Hello, APA!");

Implementations

impl DrawingStream

pub unsafe fn new() -> Self

Creates new DrawingStream.

Enable APA mode to draw texts.

Safety

This will break crate::io::GbStream.

After this function, you cannot use GbStream dependent functions such as println!.

pub fn set_style(&self, style: DrawingStyle)

Apply drawing style.

Internally, call color function of GBDK.

pub fn cursor(&self, x: u8, y: u8)

Set cursor of DrawingStream.

Panics

Panics if coordinate parameter out of bounds.

Safety

Because of the bound check, it is guaranteed to move the cursor to a valid range.

Examples

let mut s = unsafe {DrawingStream::new()};
DrawingStream::cursor(0, 1); //prints to second line.
write!(s, "Hello, Cursor!");

pub fn draw_point(&self, (x, y): (u8, u8))

Draw a point to screen.

Panics

Panics if coordinates out of bounds.

pub fn draw_line(&self, (x1, y1): (u8, u8), (x2, y2): (u8, u8))

Draw a line to screen.

Panics

Panics if coordinates out of bounds.

pub fn draw_box(&self, (x1, y1): (u8, u8), (x2, y2): (u8, u8), fill: bool)

Draw a box to screen.

Panics

Panics if coordinates out of bounds.

pub fn draw_circle(&self, (x, y): (u8, u8), radius: u8, fill: bool)

Draw a circle to screen.

Panics

Panics if coordinates out of bounds.

pub fn write_byte(&mut self, b: u8) -> Result<(), Error>

Writes a byte into this writer, returning whether the write succeeded.

write_char assumes that the input is valid Unicode character. However, GBDK maps one byte to one character or symbol.

Therefore, write_byte is recommended when you want to print one character to the GameBoy.

Errors

This function will return an instance of Error on error.

Trait Implementations

impl Write for DrawingStream

fn write_str(&mut self, s: &str) -> Result

Writes a string slice into this writer, returning whether the write succeeded.

fn write_char(&mut self, c: char) -> Result<(), Error>

Writes a char into this writer, returning whether the write succeeded.

fn write_fmt(&mut self, args: Arguments<'_>) -> Result<(), Error>

Glue for usage of the write! macro with implementors of this trait.