# populate_world_system.rs - source
Source of the Rust file `maplibre/src/raster/populate_world_system.rs`.

    1
    2
    3
    4
    5
    6
    7
    8
    9
    10
    11
    12
    13
    14
    15
    16
    17
    18
    19
    20
    21
    22
    23
    24
    25
    26
    27
    28
    29
    30
    31
    32
    33
    34
    35
    36
    37
    38
    39
    40
    41
    42
    43
    44
    45
    46
    47
    48
    49
    50
    51
    52
    53
    54
    55
    56
    57
    58
    59
    60
    61
    62
    63
    64
    65
    66
    67

    use std::{borrow::Cow, marker::PhantomData, rc::Rc};

    use crate::{
        context::MapContext,
        environment::Environment,
        io::apc::{AsyncProcedureCall, Message},
        kernel::Kernel,
        raster::{
            transferables::{LayerRaster, LayerRasterMissing, RasterTransferables},
            RasterLayerData, RasterLayersDataComponent,
        },
        tcs::system::System,
    };

    pub struct PopulateWorldSystem<E: Environment, T> {
        kernel: Rc<Kernel<E>>,
        phantom_t: PhantomData<T>,
    }

    impl<E: Environment, T> PopulateWorldSystem<E, T> {
        pub fn new(kernel: &Rc<Kernel<E>>) -> Self {
            Self {
                kernel: kernel.clone(),
                phantom_t: Default::default(),
            }
        }
    }

    impl<E: Environment, T: RasterTransferables> System for PopulateWorldSystem<E, T> {
        fn name(&self) -> Cow<'static, str> {
            "populate_world_system".into()
        }

        fn run(&mut self, MapContext { world, .. }: &mut MapContext) {
            for message in self.kernel.apc().receive(|message| {
                message.has_tag(T::LayerRaster::message_tag())
                    || message.has_tag(T::LayerRasterMissing::message_tag())
            }) {
                let message: Message = message;
                if message.has_tag(T::LayerRaster::message_tag()) {
                    let message = message.into_transferable::<T::LayerRaster>();
                    let Some(component) = world
                        .tiles
                        .query_mut::<&mut RasterLayersDataComponent>(message.coords())
                    else {
                        continue;
                    };

                    component
                        .layers
                        .push(RasterLayerData::Available(message.to_layer()));
                } else if message.has_tag(T::LayerRaster::message_tag()) {
                    let message = message.into_transferable::<T::LayerRasterMissing>();
                    let Some(component) = world
                        .tiles
                        .query_mut::<&mut RasterLayersDataComponent>(message.coords())
                    else {
                        continue;
                    };

                    component
                        .layers
                        .push(RasterLayerData::Missing(message.to_layer()));
                }
            }
        }
    }