bevy/examples/shader
UkoeHB c2c19e5ae4
Text rework (#15591)
**Ready for review. Examples migration progress: 100%.**

# Objective

- Implement https://github.com/bevyengine/bevy/discussions/15014

## Solution

This implements [cart's
proposal](https://github.com/bevyengine/bevy/discussions/15014#discussioncomment-10574459)
faithfully except for one change. I separated `TextSpan` from
`TextSpan2d` because `TextSpan` needs to require the `GhostNode`
component, which is a `bevy_ui` component only usable by UI.

Extra changes:
- Added `EntityCommands::commands_mut` that returns a mutable reference.
This is a blocker for extension methods that return something other than
`self`. Note that `sickle_ui`'s `UiBuilder::commands` returns a mutable
reference for this reason.

## Testing

- [x] Text examples all work.

---

## Showcase

TODO: showcase-worthy

## Migration Guide

TODO: very breaking

### Accessing text spans by index

Text sections are now text sections on different entities in a
hierarchy, Use the new `TextReader` and `TextWriter` system parameters
to access spans by index.

Before:
```rust
fn refresh_text(mut query: Query<&mut Text, With<TimeText>>, time: Res<Time>) {
    let text = query.single_mut();
    text.sections[1].value = format_time(time.elapsed());
}
```

After:
```rust
fn refresh_text(
    query: Query<Entity, With<TimeText>>,
    mut writer: UiTextWriter,
    time: Res<Time>
) {
    let entity = query.single();
    *writer.text(entity, 1) = format_time(time.elapsed());
}
```

### Iterating text spans

Text spans are now entities in a hierarchy, so the new `UiTextReader`
and `UiTextWriter` system parameters provide ways to iterate that
hierarchy. The `UiTextReader::iter` method will give you a normal
iterator over spans, and `UiTextWriter::for_each` lets you visit each of
the spans.

---------

Co-authored-by: ickshonpe <david.curthoys@googlemail.com>
Co-authored-by: Carter Anderson <mcanders1@gmail.com>
2024-10-09 18:35:36 +00:00
..
animate_shader.rs Migrate cameras to required components (#15641) 2024-10-05 01:59:52 +00:00
array_texture.rs Migrate cameras to required components (#15641) 2024-10-05 01:59:52 +00:00
automatic_instancing.rs Migrate cameras to required components (#15641) 2024-10-05 01:59:52 +00:00
compute_shader_game_of_life.rs Migrate bevy_sprite to required components (#15489) 2024-10-09 16:17:26 +00:00
custom_phase_item.rs Migrate cameras to required components (#15641) 2024-10-05 01:59:52 +00:00
custom_post_processing.rs Migrate cameras to required components (#15641) 2024-10-05 01:59:52 +00:00
custom_shader_instancing.rs Migrate cameras to required components (#15641) 2024-10-05 01:59:52 +00:00
custom_vertex_attribute.rs Migrate cameras to required components (#15641) 2024-10-05 01:59:52 +00:00
extended_material.rs Migrate cameras to required components (#15641) 2024-10-05 01:59:52 +00:00
fallback_image.rs Migrate cameras to required components (#15641) 2024-10-05 01:59:52 +00:00
gpu_readback.rs Gpu readback (#15419) 2024-09-30 17:28:55 +00:00
shader_defs.rs Migrate cameras to required components (#15641) 2024-10-05 01:59:52 +00:00
shader_material.rs Migrate cameras to required components (#15641) 2024-10-05 01:59:52 +00:00
shader_material_2d.rs Migrate cameras to required components (#15641) 2024-10-05 01:59:52 +00:00
shader_material_glsl.rs Migrate cameras to required components (#15641) 2024-10-05 01:59:52 +00:00
shader_material_screenspace_texture.rs Migrate cameras to required components (#15641) 2024-10-05 01:59:52 +00:00
shader_prepass.rs Text rework (#15591) 2024-10-09 18:35:36 +00:00
specialized_mesh_pipeline.rs Migrate cameras to required components (#15641) 2024-10-05 01:59:52 +00:00
storage_buffer.rs Migrate cameras to required components (#15641) 2024-10-05 01:59:52 +00:00
texture_binding_array.rs Migrate cameras to required components (#15641) 2024-10-05 01:59:52 +00:00