pixsy/src/lib.rs

use bitsy_parser::game::Game;
use bitsy_parser::image::Image;
use bitsy_parser::tile::Tile;
use image::{GenericImageView, Pixel};
use wasm_bindgen::prelude::*;

const SD: u32 = 8;

#[wasm_bindgen]
pub fn load_default_game_data() -> String {
    bitsy_parser::mock::game_default().to_string()
}

fn tile_name(prefix: &str, index: &u32) -> Option<String> {
    if prefix.len() > 0 {
        Some(format!("{} {}", prefix, index))
    } else {
        None
    }
}

/// image is a base64-encoded string
/// prefix will be ignored if empty
#[wasm_bindgen]
pub fn add_tiles(
    game_data: String,
    image: String,
    prefix: String,
    invert: bool,
    flip: bool,
    mirror: bool,
    rotate: bool
) -> String {
    let game = Game::from(game_data);
    if game.is_err() {
        return format!("Couldn't parse game data");
    }
    let mut game = game.unwrap();

    let image: Vec<&str> = image.split("base64,").collect();
    let image = image[1];

    let image = base64::decode(image);
    if image.is_err() {
        return format!("Couldn't decode image");
    }
    let image = image.unwrap();
    let image = image::load_from_memory(image.as_ref());
    if image.is_err() {
        return format!("Couldn't load image");
    }
    let image = image.unwrap();

    let width   = image.width();
    let height  = image.height();
    let columns = (width  as f64 / SD as f64).floor() as u32;
    let rows    = (height as f64 / SD as f64).floor() as u32;

    let mut tile_index = 1;

    for column in 0..columns {
        for row in 0..rows {
            let mut pixels = Vec::with_capacity(64);

            for y in (row * SD)..((row + 1) * SD) {
                for x in (column * SD)..((column + 1) * SD) {
                    let pixel = image.get_pixel(x, y).to_rgb();
                    let total = pixel[0] as u32 + pixel[1] as u32 + pixel[2] as u32;
                    // is each channel brighter than 128/255 on average?
                    pixels.push(if total >= 384 {1} else {0});
                }
            }

            let tile = Tile {
                /// "0" will get overwritten to a new, safe tile ID
                id: "0".to_string(),
                name: tile_name(&prefix, &tile_index),
                wall: None,
                animation_frames: vec![Image { pixels }],
                colour_id: None
            };

            if !game.tiles.contains(&tile) {
                game.add_tile(tile.clone());

                tile_index += 1;
            }

            if invert {
                let mut inverted = tile.clone();
                inverted.invert();

                if inverted.name.is_some() {
                    inverted.name = Some(format!("{} inverted", inverted.name.unwrap()));
                }

                if !game.tiles.contains(&inverted) {
                    game.add_tile(inverted);
                }
            }

            if flip {
                let mut flipped = tile.clone();
                flipped.flip();

                if flipped.name.is_some() {
                    flipped.name = Some(format!("{} flipped", flipped.name.unwrap()));
                }

                if !game.tiles.contains(&flipped) {
                    game.add_tile(flipped);
                }
            }

            if mirror {
                let mut mirrored = tile.clone();
                mirrored.mirror();

                if mirrored.name.is_some() {
                    mirrored.name = Some(format!("{} mirrored", mirrored.name.unwrap()));
                }

                if !game.tiles.contains(&mirrored) {
                    game.add_tile(mirrored);
                }
            }

            if rotate {
                for i in 1..4 {
                    let mut rotated = tile.clone();

                    for _ in 0..i {
                        rotated.rotate();
                    }

                    if rotated.name.is_some() {
                        rotated.name = Some(format!("{} {}°", rotated.name.unwrap(), i * 90));
                    }

                    if !game.tiles.contains(&rotated) {
                        game.add_tile(rotated);
                    }
                }
            }
        }
    }

    game.dedupe_tiles();
    game.to_string()
}

#[cfg(test)]
mod test {
    use crate::add_tiles;

    #[test]
    fn example() {
        let game_data = bitsy_parser::mock::game_default().to_string();
        let image = include_str!("test-resources/test.png.base64").to_string();

        let output = add_tiles(
            game_data,
            image,
            "".to_string(),
            false,
            false,
            false,
            false
        );

        let expected = include_str!("test-resources/expected.bitsy");
        assert_eq!(output, expected);
    }
}