Merge multiple Textures

[tguichaoua]

I followed the example of shader/array_texture that require a Texture that contains the differents textures.

Is there a way to load the texture from several files, to create the texture at runtime ?

[MrGVSV]

You may want to check out the TextureAtlasBuilder.

Specifically, the merging happens here:

bevy/examples/2d/texture_atlas.rs

Lines 51 to 57 in 3de391b

	let mut texture_atlas_builder = TextureAtlasBuilder::default();
	for handle in rpg_sprite_handles.handles.iter() {
	let texture = textures.get(handle).unwrap();
	texture_atlas_builder.add_texture(handle.clone_weak().typed::<Texture>(), texture);
	}
	let texture_atlas = texture_atlas_builder.finish(&mut textures).unwrap();

And it can be used to create a texture of textures, so to speak

[tguichaoua]

I just tried it, but TextureAtlasBuilder arange texture in a square and texture array required the textures to be aranged vertically.
In the texture_atlas example, I tried to load tiles from assets/rpg/tiles (each tile is 16x16) and set the max_size of the TextureAtlasBuilder to Vec2::new(16.0, f32::INFINITY). But I got the NotEnoughSpace error.
It's possible to force texture to be arranged vertically ?

[MrGVSV]

In that case (where every texture is a tile of the exact same size), you can check out a crate I made specifically for tilesets called bevy_tile_atlas. It has a similar API as TextureAtlasBuilder but it auto-resizes indefinitely and you can set a maximum number of columns.

use bevy::prelude::*;
use bevy_tile_atlas::TileAtlasBuilder;

/// Creates a tile-based, ordered `TextureAtlas`
///
/// Assumes that the given handles are all loaded and in their desired order
fn build_tileset(handles: Vec<Handle<Texture>>, textures: &mut Assets<Texture>) -> TextureAtlas {
  let mut builder = TileAtlasBuilder::default().max_columns(1usize);
  
  for handle in handles {
    let texture = textures.get(&handle).unwrap();
    builder.add_texture(handle, texture);
  }
  
  builder.finish(textures).unwrap()
}