parallax!!!!!!

assets/world.txt

@@ -1,4 +1,26 @@
 header
+ parallax.size = 2000x1000
+ parallax.tiles = 2
+ parallax.factor.y = 100000
+ parallax.tex = BG0_himmel_blau.png
+ parallax.factor = 30
+ parallax.depth = 10
+ parallax.offset = -200
+ parallax.enable = true
+ parallax.tex = BG1_Berge_blau.png
+ parallax.factor = 10
+ parallax.depth = 9
+ parallax.enable = true
+ parallax.tex = BG2_Berge_gau.png
+ parallax.factor = 8
+ parallax.depth = 8
+ parallax.offset = -350
+ parallax.enable = true
+ parallax.tex = BG3_Berge_gruen.png
+ parallax.factor = 6
+ parallax.depth = 7
+ parallax.offset = 100
+ parallax.enable = true
  block-size = 60
  .P = [player]
  .S = [spawn]

src/game/scene.rs

@@ -9,6 +9,7 @@ use bevy_rapier2d::prelude::{Collider, *};
 use readformat::{readf, readf1};
 
 use crate::game::WORLD_DEPTH;
+use crate::parallax::{parallax, Parallax};
 use crate::AppState;
 
 use super::player::PlayerSpawnOneshot;
@@ -77,6 +78,7 @@ pub(super) fn import_text_world(
     };
 
     let mut wi = WorldInfo::default();
+    let mut parallax_info = Parallax::default();
     for line in info_string.lines() {
         let [name, val] = &readf(" {} = {}", line).expect("invalid line in info section")[..]
         else {
@@ -85,6 +87,29 @@ pub(super) fn import_text_world(
 
         match name.as_str() {
             "block-size" => wi.block_size = val.parse().unwrap(),
+            "parallax.offset" => parallax_info.offset = val.parse().unwrap(),
+            "parallax.size" => {
+                parallax_info.size = {
+                    let x = readf("{}x{}", val).unwrap();
+                    Vec2::new(x[0].parse().unwrap(), x[1].parse().unwrap())
+                }
+            }
+            "parallax.tiles" => parallax_info.tiles = val.parse().unwrap(),
+            "parallax.tex" => parallax_info.tex = val.clone(),
+            "parallax.factor" => parallax_info.factor = val.parse().unwrap(),
+            "parallax.factor.y" => parallax_info.y_factor = val.parse().unwrap(),
+            "parallax.depth" => parallax_info.depth = val.parse().unwrap(),
+            "parallax.enable" => {
+                if val == "true" {
+                    parallax(
+                        &mut commands,
+                        &mut materials,
+                        &mut meshes,
+                        &assets,
+                        parallax_info.clone(),
+                    )
+                }
+            }
             x if x.starts_with(".") => {
                 let x = readf1(".{}", x).unwrap();
                 wi.blocks.push((x, val.to_owned()));

src/main.rs

@@ -2,6 +2,7 @@
 use bevy::prelude::*;
 use bevy_rapier2d::prelude::*;
 use game::game_plugin;
+use parallax::parallax_plugin;
 
 mod game;
 mod parallax;
@@ -42,6 +43,7 @@ fn main() {
         //.add_plugins(RapierDebugRenderPlugin::default())
         .add_systems(Startup, setup_camera)
         .add_plugins(game_plugin)
+        .add_plugins(parallax_plugin)
         .init_state::<AppState>()
         .init_state::<PausedState>()
         .insert_state(AppState::InGame) // TODO dont

src/parallax.rs

@@ -1 +1,87 @@
-use bevy::prelude::*;
+use bevy::{
+    prelude::*,
+    render::{
+        primitives::Aabb,
+        view::{NoFrustumCulling, VisibilitySystems},
+    },
+    sprite::MaterialMesh2dBundle,
+};
+use bevy_rapier2d::parry::simba::scalar::SupersetOf;
+
+#[derive(Component)]
+pub struct ParallaxTile(usize);
+
+#[derive(Component, Clone)]
+pub struct Parallax {
+    pub offset: f32,
+    pub factor: f32,
+    pub y_factor: f32,
+    pub size: Vec2,
+    pub depth: f32,
+    pub tiles: usize,
+    pub tex: String,
+}
+
+impl Default for Parallax {
+    fn default() -> Self {
+        Self {
+            offset: 0.,
+            factor: 10.,
+            y_factor: 10.,
+            size: Vec2::new(2000., 1000.),
+            depth: 100.,
+            tiles: 4,
+            tex: "".to_owned(),
+        }
+    }
+}
+
+pub fn parallax_plugin(app: &mut App) {
+    app.add_systems(Update, (update_parallax,));
+}
+
+pub fn parallax(
+    commands: &mut Commands,
+    materials: &mut ResMut<Assets<ColorMaterial>>,
+    meshes: &mut ResMut<Assets<Mesh>>,
+    assets: &Res<AssetServer>,
+    parallax_info: Parallax,
+) {
+    for i in 0..parallax_info.tiles {
+        commands.spawn((
+            ParallaxTile(i),
+            parallax_info.clone(),
+            MaterialMesh2dBundle {
+                mesh: meshes.add(Rectangle::from_size(parallax_info.size)).into(),
+                material: materials.add(assets.load(parallax_info.tex.clone())),
+                transform: Transform::from_xyz(0.0, 0.0, -parallax_info.depth),
+                visibility: Visibility::Visible,
+                ..Default::default()
+            },
+            NoFrustumCulling,
+        ));
+    }
+}
+
+fn update_parallax(
+    mut commands: Commands,
+    mut query: Query<(Entity, &Parallax, &ParallaxTile, &mut Transform)>,
+    camera_query: Query<(&Camera2d, &Transform), (Without<Parallax>)>,
+) {
+    let (_, cam_transform) = camera_query.single();
+    let cam_transform = cam_transform.translation;
+    for (entity, parallax_info, ParallaxTile(tile), mut transform) in query.iter_mut() {
+        let position_on_parallax = cam_transform.xy()
+            - Vec2::new(
+                cam_transform.x / parallax_info.factor,
+                cam_transform.y / parallax_info.y_factor,
+            );
+        let first_parallax_on_cam =
+            (position_on_parallax / parallax_info.size).floor() * parallax_info.size;
+        let position = first_parallax_on_cam
+            + Vec2::new(*tile as f32, 0.) * parallax_info.size
+            + position_on_parallax % parallax_info.size;
+        transform.translation =
+            position.extend(-parallax_info.depth) + Vec3::new(0., parallax_info.offset, 0.);
+    }
+}