Texturehandle replacement in 0.4.0

texture.rs

use bevy::{
    prelude::*,
    render::texture::{Extent3d, Texture, TextureDimension, TextureFormat},
};

struct MyTimer {
    timer: Timer,
}

struct LogoHandle(Option<Handle<StandardMaterial>>);

/// This example shows various ways to configure texture materials in 3D
fn main() {
    App::build()
        .add_plugins(DefaultPlugins)
        .add_startup_system(setup.system())
        .add_resource(MyTimer {
            // a five second non-repeating timer
            timer: Timer::from_seconds(1.0, false),
        })
        .add_resource(LogoHandle(None))
        .add_system(timer_system.system())
        .run();
}

fn timer_system(
    material_handle: Res<LogoHandle>,
    time: Res<Time>,
    mut my_timer: ResMut<MyTimer>,
    mut materials: ResMut<Assets<StandardMaterial>>,
    mut textures: ResMut<Assets<Texture>>,
) {
    if my_timer.timer.tick(time.delta_seconds()).just_finished() {
        let material_handle = material_handle.0.as_ref().unwrap();
        let old_m = materials.get_mut(material_handle).unwrap();
        let tex_h = textures.add(white_texture());
        old_m.albedo_texture = Some(tex_h);
        println!("Replaced texture with white");
    }
}

fn white_texture() -> Texture {
    let mut rvec = vec![];
    rvec.resize((200 * 200 * 4) as usize, 255);
    Texture::new(
        Extent3d::new(200, 200, 1),
        TextureDimension::D2,
        rvec,
        TextureFormat::Rgba8UnormSrgb,
    )
}

/// sets up a scene with textured entities
fn setup(
    commands: &mut Commands,
    asset_server: Res<AssetServer>,
    mut meshes: ResMut<Assets<Mesh>>,
    mut materials: ResMut<Assets<StandardMaterial>>,
    mut logohandle: ResMut<LogoHandle>,
) {
    // load a texture and retrieve its aspect ratio
    let texture_handle = asset_server.load("branding/bevy_logo_dark_big.png");
    // let texture_handle = textures.add(white_texture());

    let aspect = 0.25;

    // create a new quad mesh. this is what we will apply the texture to
    let quad_width = 8.0;
    let quad_handle = meshes.add(Mesh::from(shape::Quad::new(Vec2::new(
        quad_width,
        quad_width * aspect,
    ))));

    // this material renders the texture normally
    let material_handle = materials.add(StandardMaterial {
        albedo_texture: Some(texture_handle.clone()),
        shaded: false,
        ..Default::default()
    });
    *logohandle = LogoHandle(Some(material_handle.clone()));

    // add entities to the world
    commands
        // textured quad - normal
        .spawn(PbrBundle {
            mesh: quad_handle.clone(),
            material: material_handle.clone(),
            transform: Transform {
                translation: Vec3::new(0.0, 0.0, 1.5),
                rotation: Quat::from_rotation_x(-std::f32::consts::PI / 5.0),
                ..Default::default()
            },
            visible: Visible {
                is_transparent: true,
                ..Default::default()
            },
            ..Default::default()
        })
        // textured quad - modulated
        .spawn(PbrBundle {
            mesh: quad_handle.clone(),
            material: material_handle.clone(),
            transform: Transform {
                translation: Vec3::new(0.0, 0.0, 0.0),
                rotation: Quat::from_rotation_x(-std::f32::consts::PI / 5.0),
                ..Default::default()
            },
            visible: Visible {
                is_transparent: true,
                ..Default::default()
            },
            ..Default::default()
        })
        // textured quad - modulated
        .spawn(PbrBundle {
            mesh: quad_handle,
            material: material_handle,
            transform: Transform {
                translation: Vec3::new(0.0, 0.0, -1.5),
                rotation: Quat::from_rotation_x(-std::f32::consts::PI / 5.0),
                ..Default::default()
            },
            visible: Visible {
                is_transparent: true,
                ..Default::default()
            },
            ..Default::default()
        })
        // camera
        .spawn(Camera3dBundle {
            transform: Transform::from_translation(Vec3::new(3.0, 5.0, 8.0))
                .looking_at(Vec3::default(), Vec3::unit_y()),
            ..Default::default()
        });
}