amethyst 0.9 image loader util

game.rs

struct ImageLoader {
    texture_id: u64,
}

impl ImageLoader {
    fn new() -> ImageLoader {
        ImageLoader {
            texture_id: 0,
        }
    }

    fn load(&mut self, world: &mut World, image_size: (f32, f32), image_path: &str) -> SpriteRender {
        let image_handle = {
            let loader = world.read_resource::<Loader>();
            let texture_storage = world.read_resource::<AssetStorage<Texture>>();
            loader.load(
                image_path,
                PngFormat,
                Default::default(),
                (),
                &texture_storage
            )
        };
        let mut material_texture_set = world.write_resource::<MaterialTextureSet>();
        material_texture_set.insert(self.texture_id, image_handle);
        let tex_coords = TextureCoordinates {
            left: 0.0,
            right: 1.0,
            top: 0.0,
            bottom: 1.0,
        };
        let image_sprite = Sprite {
            width: image_size.0,
            height: image_size.1,
            offsets: [image_size.0 / 2.0, image_size.1 / 2.0],
            tex_coords,
        };
        let sprite_sheet = SpriteSheet {
            texture_id: self.texture_id,
            sprites: vec![image_sprite],
        };
        let sprite_sheet_handle = {
            let loader = world.read_resource::<Loader>();
            let sprite_sheet_store = world.read_resource::<AssetStorage<SpriteSheet>>();
            loader.load_from_data(sprite_sheet, (), &sprite_sheet_store)
        };
        self.texture_id += 1;
        SpriteRender {
            sprite_sheet: sprite_sheet_handle,
            sprite_number: 0,
            flip_horizontal: false,
            flip_vertical: true,
        }
    }
}

// Example usage

fn initialise_player(world: &mut World, image_loader: &mut ImageLoader) {
    let player_image_size = (120.0, 120.0);
    let player_image = image_loader.load(world, player_image_size, "./img/player.png");

    world.create_entity()
        .with(player_image)
        .with(GlobalTransform::default())
        .build();
}

you might want to auto increase the textureID every time an image is loaded, or provide new(ID: u32),
otherwise every texture has the same ID

I think it would be better if the texture ID was a parameter IMO.

@Telzhaak It does auto-increment

@Moxinilian why does this matter? I suppose it could be useful if you used a spritesheet along with some whole images