sbox-public/engine/Sandbox.Engine/Scene/Components/Render/ModelRenderer.Materials.cs

namespace Sandbox;

using Sandbox.Engine;

//
// TODO
//
// 1. Move MaterialOverride to Materials, somehow.
// 2. Make SetMaterialOverride with attribute targets obsolete (need to fix avatar/skin stuff)
// 

public partial class ModelRenderer : MaterialAccessor.ITarget
{

	[Property, MakeDirty]
	public Material MaterialOverride { get; set; }

	Dictionary<string, Material> taggedMaterialOverrides;

	/// <summary>
	/// Completely stop overriding materials
	/// </summary>
	public void ClearMaterialOverrides()
	{
		taggedMaterialOverrides = null;
		MaterialOverride = null;
		_sceneObject?.ClearMaterialOverride();
	}

	/// <summary>
	/// Set a material override for a material with a specific attribute set. For example, if you have a model with lots of different materials, but one of them has an attribute "skin" set to "1", then 
	/// calling this with a material and "skin" will override only that material.
	/// </summary>
	public void SetMaterialOverride( Material material, string target )
	{
		if ( material is null && taggedMaterialOverrides is null )
			return;

		taggedMaterialOverrides ??= new Dictionary<string, Material>();

		if ( material is null )
		{
			taggedMaterialOverrides.Remove( target );
			_sceneObject?.SetMaterialOverride( null, target );
		}
		else
		{
			taggedMaterialOverrides[target] = material;
		}

		ApplyMaterialOverrides();
	}

	/// <summary>
	/// Apply any saved material overrides to the scene object.
	/// </summary>
	void ApplyMaterialOverrides()
	{
		if ( !_sceneObject.IsValid() ) return;

		if ( taggedMaterialOverrides is not null )
		{
			foreach ( var o in taggedMaterialOverrides )
			{
				_sceneObject.SetMaterialOverride( o.Value, o.Key );
			}
		}

		_materialAccessor?.Apply();
	}

	MaterialAccessor _materialAccessor;

	/// <summary>
	/// Access to the materials 
	/// </summary>
	[Property, Group( "Materials", StartFolded = true )]
	public MaterialAccessor Materials => _materialAccessor ??= new MaterialAccessor( this );

	int MaterialAccessor.ITarget.GetMaterialCount()
	{
		if ( !Model.IsValid() ) return 0;
		return Model.Materials.Length;
	}

	Material MaterialAccessor.ITarget.Get( int index )
	{
		if ( !Model.IsValid() ) return default;
		if ( index < 0 ) return default;
		if ( index >= Model.Materials.Length ) return default;

		return Model.Materials[index];
	}

	void MaterialAccessor.ITarget.SetOverride( int index, Material material )
	{
		if ( !_sceneObject.IsValid() ) return;

		_sceneObject.native.SetMaterialOverrideByIndex( index, material?.native ?? default );
	}

	void MaterialAccessor.ITarget.ClearOverrides()
	{
		if ( !_sceneObject.IsValid() ) return;

		_sceneObject.native.ClearMaterialOverrideList();
	}

}