bevy/crates/bevy_sprite/src/sprite.rs
Paweł Grabarz 07ed1d053e Implement and require #[derive(Component)] on all component structs (#2254)
This implements the most minimal variant of #1843 - a derive for marker trait. This is a prerequisite to more complicated features like statically defined storage type or opt-out component reflection.

In order to make component struct's purpose explicit and avoid misuse, it must be annotated with `#[derive(Component)]` (manual impl is discouraged for compatibility). Right now this is just a marker trait, but in the future it might be expanded. Making this change early allows us to make further changes later without breaking backward compatibility for derive macro users.

This already prevents a lot of issues, like using bundles in `insert` calls. Primitive types are no longer valid components as well. This can be easily worked around by adding newtype wrappers and deriving `Component` for them.

One funny example of prevented bad code (from our own tests) is when an newtype struct or enum variant is used. Previously, it was possible to write `insert(Newtype)` instead of `insert(Newtype(value))`. That code compiled, because function pointers (in this case newtype struct constructor) implement `Send + Sync + 'static`, so we allowed them to be used as components. This is no longer the case and such invalid code will trigger a compile error.


Co-authored-by: = <=>
Co-authored-by: TheRawMeatball <therawmeatball@gmail.com>
Co-authored-by: Carter Anderson <mcanders1@gmail.com>
2021-10-03 19:23:44 +00:00

107 lines
3.4 KiB
Rust

use crate::ColorMaterial;
use bevy_asset::{Assets, Handle};
use bevy_core::Bytes;
use bevy_ecs::{
component::Component,
query::Without,
system::{Query, Res},
};
use bevy_math::Vec2;
use bevy_reflect::{Reflect, ReflectDeserialize, TypeUuid};
use bevy_render::{
draw::OutsideFrustum,
renderer::{RenderResource, RenderResourceType, RenderResources},
texture::Texture,
};
use serde::{Deserialize, Serialize};
/// General Sprite Examples: [Link](https://github.com/bevyengine/bevy/tree/latest/examples/2d)
#[derive(Component, Debug, Default, Clone, TypeUuid, Reflect, RenderResources)]
#[render_resources(from_self)]
#[uuid = "7233c597-ccfa-411f-bd59-9af349432ada"]
#[repr(C)]
pub struct Sprite {
pub size: Vec2,
/// When true flips sprite to left. [Example](https://github.com/bevyengine/bevy/blob/latest/examples/2d/sprite_flipping.rs)
pub flip_x: bool,
/// When true flips sprite upside down. [Example](https://github.com/bevyengine/bevy/blob/latest/examples/2d/sprite_flipping.rs)
pub flip_y: bool,
pub resize_mode: SpriteResizeMode,
}
impl RenderResource for Sprite {
fn resource_type(&self) -> Option<RenderResourceType> {
Some(RenderResourceType::Buffer)
}
fn buffer_byte_len(&self) -> Option<usize> {
Some(12)
}
fn write_buffer_bytes(&self, buffer: &mut [u8]) {
// Write the size buffer
let (size_buf, flip_buf) = buffer.split_at_mut(8);
self.size.write_bytes(size_buf);
// First bit means flip x, second bit means flip y
flip_buf[0] = if self.flip_x { 0b01 } else { 0 } | if self.flip_y { 0b10 } else { 0 };
flip_buf[1] = 0;
flip_buf[2] = 0;
flip_buf[3] = 0;
}
fn texture(&self) -> Option<&Handle<Texture>> {
None
}
}
/// Determines how `Sprite` resize should be handled
#[derive(Debug, Clone, Copy, PartialEq, Serialize, Deserialize, Reflect)]
#[reflect_value(PartialEq, Serialize, Deserialize)]
pub enum SpriteResizeMode {
Manual,
Automatic,
}
impl Default for SpriteResizeMode {
fn default() -> Self {
SpriteResizeMode::Automatic
}
}
impl Sprite {
/// Creates new `Sprite` with `SpriteResizeMode::Manual` value for `resize_mode`
pub fn new(size: Vec2) -> Self {
Self {
size,
resize_mode: SpriteResizeMode::Manual,
flip_x: false,
flip_y: false,
}
}
}
pub fn sprite_system(
materials: Res<Assets<ColorMaterial>>,
textures: Res<Assets<Texture>>,
mut query: Query<(&mut Sprite, &Handle<ColorMaterial>), Without<OutsideFrustum>>,
) {
for (mut sprite, handle) in query.iter_mut() {
match sprite.resize_mode {
SpriteResizeMode::Manual => continue,
SpriteResizeMode::Automatic => {
let material = materials.get(handle).unwrap();
if let Some(ref texture_handle) = material.texture {
if let Some(texture) = textures.get(texture_handle) {
let texture_size = texture.size.as_vec3().truncate();
// only set sprite size if it has changed (this check prevents change
// detection from triggering)
if sprite.size != texture_size {
sprite.size = texture_size;
}
}
}
}
}
}
}