Label component

crates/bevy_asset/src/assets.rs

@@ -84,6 +84,10 @@ impl<T> Assets<T> {
         self.assets.get_mut(&handle.id)
     }
 
+    pub fn get_or_insert_with(&mut self, handle: Handle<T>, insert_fn: impl FnOnce() -> T) -> &mut T {
+        self.assets.entry(handle.id).or_insert_with(insert_fn)
+    }
+
     pub fn iter(&self) -> impl Iterator<Item = (Handle<T>, &T)> {
         self.assets.iter().map(|(k, v)| (Handle::from_id(*k), v))
     }

crates/bevy_render/src/color.rs

@@ -7,7 +7,7 @@ use std::ops::{Add, AddAssign};
 use zerocopy::AsBytes;
 
 #[repr(C)]
-#[derive(Debug, Default, Clone, Copy, PartialEq, AsBytes)]
+#[derive(Debug, Clone, Copy, PartialEq, AsBytes)]
 pub struct Color {
     pub r: f32,
     pub g: f32,
@@ -31,6 +31,12 @@ impl Color {
     }
 }
 
+impl Default for Color {
+    fn default() -> Self {
+        Color::WHITE
+    }
+}
+
 impl AddAssign<Color> for Color {
     fn add_assign(&mut self, rhs: Color) {
         *self = Color {

crates/bevy_ui/Cargo.toml

@@ -9,6 +9,7 @@ bevy_app = { path = "../bevy_app" }
 bevy_asset = { path = "../bevy_asset" }
 bevy_core = { path = "../bevy_core" }
 bevy_derive = { path = "../bevy_derive" }
+bevy_text = { path = "../bevy_text" }
 bevy_transform = { path = "../bevy_transform" }
 bevy_render = { path = "../bevy_render" }
 bevy_window = { path = "../bevy_window" }

crates/bevy_ui/src/entity.rs

@@ -1,5 +1,7 @@
 use super::Node;
-use crate::{render::UI_PIPELINE_HANDLE, sprite::Sprite, ColorMaterial, Rect, QUAD_HANDLE};
+use crate::{
+    render::UI_PIPELINE_HANDLE, sprite::Sprite, widget::Label, ColorMaterial, Rect, QUAD_HANDLE,
+};
 use bevy_asset::Handle;
 use bevy_derive::EntityArchetype;
 use bevy_render::{mesh::Mesh, Renderable};
@@ -29,6 +31,34 @@ impl Default for UiEntity {
     }
 }
 
+#[derive(EntityArchetype)]
+#[module(meta = false)]
+pub struct LabelEntity {
+    pub node: Node,
+    pub rect: Rect,
+    pub mesh: Handle<Mesh>, // TODO: maybe abstract this out
+    pub material: Handle<ColorMaterial>,
+    pub renderable: Renderable,
+    pub label: Label,
+}
+
+impl Default for LabelEntity {
+    fn default() -> Self {
+        LabelEntity {
+            node: Default::default(),
+            rect: Default::default(),
+            mesh: QUAD_HANDLE,
+            // NOTE: labels each get their own material.
+            material: Handle::new(), // TODO: maybe abstract this out
+            renderable: Renderable {
+                pipelines: vec![UI_PIPELINE_HANDLE],
+                ..Default::default()
+            },
+            label: Label::default(),
+        }
+    }
+}
+
 #[derive(EntityArchetype)]
 #[module(meta = false)]
 pub struct SpriteEntity {

crates/bevy_ui/src/lib.rs

@@ -1,6 +1,7 @@
 mod anchors;
 mod color_material;
 pub mod entity;
+pub mod widget;
 mod margins;
 mod node;
 mod rect;
@@ -27,6 +28,7 @@ use bevy_render::{
 use glam::Vec2;
 use legion::prelude::IntoSystem;
 use sprite::sprite_system;
+use widget::Label;
 
 #[derive(Default)]
 pub struct UiPlugin;
@@ -36,12 +38,13 @@ pub const QUAD_HANDLE: Handle<Mesh> = Handle::from_u128(142404619811301375266013
 impl AppPlugin for UiPlugin {
     fn build(&self, app: &mut AppBuilder) {
         app.add_asset::<ColorMaterial>()
+            .add_system_to_stage(stage::POST_UPDATE, sprite_system())
+            .add_system_to_stage(stage::POST_UPDATE, ui_update_system())
+            .add_system_to_stage(stage::POST_UPDATE, Label::label_system.system())
             .add_system_to_stage(
                 stage::POST_UPDATE,
                 asset_shader_def_system::<ColorMaterial>.system(),
-            )
+            );
-            .add_system_to_stage(stage::POST_UPDATE, sprite_system())
-            .add_system_to_stage(stage::POST_UPDATE, ui_update_system());
 
         let resources = app.resources();
         let mut render_graph = resources.get_mut::<RenderGraph>().unwrap();

crates/bevy_ui/src/widget/label.rs

@@ -0,0 +1,51 @@
+use crate::{ColorMaterial, Rect, Res, ResMut};
+use bevy_asset::{Assets, Handle};
+use bevy_render::{texture::Texture, Color};
+use bevy_text::Font;
+use legion::prelude::Com;
+
+pub struct Label {
+    pub text: String,
+    pub color: Color,
+    pub font_size: f32,
+    pub font: Handle<Font>,
+}
+
+impl Default for Label {
+    fn default() -> Self {
+        Label {
+            text: String::new(),
+            color: Color::WHITE,
+            font_size: 12.0,
+            font: Handle::default(),
+        }
+    }
+}
+
+impl Label {
+    // PERF: this is horrendously inefficient. (1) new texture every frame (2) no atlas (3) new texture for every label
+    pub fn label_system(
+        mut color_materials: ResMut<Assets<ColorMaterial>>,
+        mut textures: ResMut<Assets<Texture>>,
+        fonts: Res<Assets<Font>>,
+        label: Com<Label>,
+        rect: Com<Rect>,
+        color_material_handle: Com<Handle<ColorMaterial>>,
+    ) {
+        if let Some(font) = fonts.get(&label.font) {
+            let texture = font.render_text(
+                &label.text,
+                label.color,
+                rect.size.x() as usize,
+                rect.size.y() as usize,
+            );
+
+            let material = color_materials.get_or_insert_with(*color_material_handle, || ColorMaterial::from(Handle::<Texture>::new()));
+            if let Some(texture) = material.texture {
+                // TODO: remove texture
+            }
+
+            material.texture = Some(textures.add(texture));
+        }
+    }
+}

crates/bevy_ui/src/widget/mod.rs

@@ -0,0 +1,3 @@
+mod label;
+
+pub use label::*;

crates/glsl-to-spirv/readme.md

@@ -1,4 +1,4 @@
 This crate is deprecated please use [shaderc-rs](https://github.com/google/shaderc-rs) instead.
 
 
-BEVY NOTE: This crate is a temporary measure unit native rust shader compilation like https://github.com/gfx-rs/naga lands
+BEVY NOTE: This crate is a temporary measure until native rust shader compilation like https://github.com/gfx-rs/naga lands

examples/3d/load_model.rs

@@ -1,5 +1,4 @@
 use bevy::prelude::*;
-use bevy_asset::AssetServer;
 
 fn main() {
     App::build()
@@ -10,7 +9,7 @@ fn main() {
 
 fn setup(
     command_buffer: &mut CommandBuffer,
-    asset_server: ResMut<AssetServer>,
+    asset_server: Res<AssetServer>,
     mut materials: ResMut<Assets<StandardMaterial>>,
 ) {
     // load the mesh

examples/asset/asset_loading.rs

@@ -1,5 +1,4 @@
 use bevy::prelude::*;
-use bevy_asset::AssetServer;
 
 fn main() {
     App::build()

examples/asset/hot_asset_reloading.rs

@@ -1,5 +1,4 @@
 use bevy::prelude::*;
-use bevy_asset::AssetServer;
 
 /// Hot reloading allows you to modify assets on disk and they will be "live reloaded" while your game is running.
 /// This lets you immediately see the results of your changes without restarting the game.

examples/ui/text.rs

@@ -1,40 +1,42 @@
-use bevy::prelude::*;
+use bevy::{
+    diagnostic::{Diagnostics, FrameTimeDiagnosticsPlugin},
+    prelude::*,
+};
 
 fn main() {
     App::build()
         .add_default_plugins()
+        .add_plugin(FrameTimeDiagnosticsPlugin::default())
         .add_startup_system(setup.system())
+        .add_system(text_update_system.system())
         .run();
 }
 
-fn setup(
+fn text_update_system(diagnostics: Res<Diagnostics>, mut label: ComMut<Label>) {
-    command_buffer: &mut CommandBuffer,
+    if let Some(fps) = diagnostics.get_measurement(FrameTimeDiagnosticsPlugin::FPS) {
-    asset_server: Res<AssetServer>,
+        label.text = format!("FPS: {}", fps.value.round());
-    mut fonts: ResMut<Assets<Font>>,
+    }
-    mut textures: ResMut<Assets<Texture>>,
+}
-    mut materials: ResMut<Assets<ColorMaterial>>,
-) {
-    let font_handle = asset_server
-        .load_sync(&mut fonts, "assets/fonts/FiraSans-Bold.ttf")
-        .unwrap();
-    let font = fonts.get(&font_handle).unwrap();
 
-    let texture = font.render_text("Hello from Bevy!", Color::rgba(0.9, 0.9, 0.9, 1.0), 500, 60);
+fn setup(command_buffer: &mut CommandBuffer, asset_server: Res<AssetServer>) {
-    let half_width = texture.width as f32 / 2.0;
+    let font_handle = asset_server.load("assets/fonts/FiraSans-Bold.ttf").unwrap();
-    let half_height = texture.height as f32 / 2.0;
-    let texture_handle = textures.add(texture);
     command_buffer
         .build()
         // 2d camera
         .add_entity(Camera2dEntity::default())
         // texture
-        .add_entity(UiEntity {
+        .add_entity(LabelEntity {
             node: Node::new(
                 math::vec2(0.0, 0.0),
-                Anchors::CENTER,
+                Anchors::TOP_LEFT,
-                Margins::new(-half_width, half_width, -half_height, half_height),
+                Margins::new(0.0, 250.0, 0.0, 60.0),
             ),
-            material: materials.add(ColorMaterial::texture(texture_handle)),
+            label: Label {
+                text: "FPS:".to_string(),
+                font: font_handle,
+                font_size: 60.0,
+                color: Color::WHITE,
+            },
             ..Default::default()
         });
 }

src/prelude.rs

@@ -34,7 +34,7 @@ pub use crate::text::Font;
 #[cfg(feature = "transform")]
 pub use crate::transform::prelude::*;
 #[cfg(feature = "ui")]
-pub use crate::ui::{entity::*, Anchors, ColorMaterial, Margins, Node, Rect, Sprite};
+pub use crate::ui::{entity::*, Anchors, ColorMaterial, Margins, Node, Rect, Sprite, widget::Label};
 #[cfg(feature = "window")]
 pub use crate::window::{Window, WindowDescriptor, WindowPlugin, Windows};
 pub use crate::{