mirror of
https://github.com/bevyengine/bevy
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b3aff9a7b1
# Objective
- Improve documentation.
- Provide helper functions for common uses of `Windows` relating to getting the primary `Window`.
- Reduce repeated `Window` code.
# Solution
- Adds infallible `primary()` and `primary_mut()` functions with standard error text. This replaces the commonly used `get_primary().unwrap()` seen throughout bevy which has inconsistent or nonexistent error messages.
- Adds `scale_factor(WindowId)` to replace repeated code blocks throughout.
# Considerations
- The added functions can panic if the primary window does not exist.
- It is very uncommon for the primary window to not exist, as seen by the regular use of `get_primary().unwrap()`. Most users will have a single window and will need to reference the primary window in their code multiple times.
- The panic provides a consistent error message to make this class of error easy to spot from the panic text.
- This follows the established standard of short names for infallible-but-unlikely-to-panic functions in bevy.
- Removes line noise for common usage of `Windows`.
63 lines
1.9 KiB
Rust
63 lines
1.9 KiB
Rust
use bevy::{prelude::*, window::PresentMode};
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/// This example illustrates how to customize the default window settings
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fn main() {
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App::new()
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.insert_resource(WindowDescriptor {
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title: "I am a window!".to_string(),
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width: 500.,
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height: 300.,
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present_mode: PresentMode::Fifo,
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..default()
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})
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.add_plugins(DefaultPlugins)
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.add_system(change_title)
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.add_system(toggle_cursor)
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.add_system(cycle_cursor_icon)
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.run();
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}
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/// This system will then change the title during execution
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fn change_title(time: Res<Time>, mut windows: ResMut<Windows>) {
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let window = windows.primary_mut();
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window.set_title(format!(
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"Seconds since startup: {}",
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time.seconds_since_startup().round()
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));
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}
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/// This system toggles the cursor's visibility when the space bar is pressed
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fn toggle_cursor(input: Res<Input<KeyCode>>, mut windows: ResMut<Windows>) {
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let window = windows.primary_mut();
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if input.just_pressed(KeyCode::Space) {
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window.set_cursor_lock_mode(!window.cursor_locked());
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window.set_cursor_visibility(!window.cursor_visible());
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}
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}
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/// This system cycles the cursor's icon through a small set of icons when clicking
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fn cycle_cursor_icon(
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input: Res<Input<MouseButton>>,
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mut windows: ResMut<Windows>,
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mut index: Local<usize>,
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) {
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const ICONS: &[CursorIcon] = &[
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CursorIcon::Default,
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CursorIcon::Hand,
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CursorIcon::Wait,
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CursorIcon::Text,
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CursorIcon::Copy,
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];
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let window = windows.primary_mut();
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if input.just_pressed(MouseButton::Left) {
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*index = (*index + 1) % ICONS.len();
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window.set_cursor_icon(ICONS[*index]);
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} else if input.just_pressed(MouseButton::Right) {
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*index = if *index == 0 {
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ICONS.len() - 1
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} else {
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*index - 1
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};
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window.set_cursor_icon(ICONS[*index]);
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}
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}
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