using Unity.Entities;
using UnityEngine;
using Unity.Rendering;
using UnityEngine.Rendering;

[DisallowMultipleComponent]
[RequiresEntityConversion]
public class RenderSpriteAuthoring : MonoBehaviour, IConvertGameObjectToEntity
{
    private SpriteRenderer myspriteRenderer;
    private Sprite sprite;
    private Mesh mesh;
    private Material material;
    private GameObject myGameObject;

    public void Convert(Entity entity, EntityManager dstManager, GameObjectConversionSystem conversionSystem)
    {
        // Get the gameobject this script is attached to
        myGameObject = gameObject;

        // Get the sprite renderer component of this game object
        myspriteRenderer = myGameObject.GetComponent<SpriteRenderer>();

        // Get the sprite the sprite renderer is using
        sprite = myspriteRenderer.sprite;

        // Build the rendermesh
        Vector3[] verts = new Vector3[sprite.vertices.Length];
        for (int i = 0; i < sprite.vertices.Length; i++)
        {
            verts[i] = sprite.vertices[i];
        }

        int[] tris = new int[sprite.triangles.Length];
        for (int i = 0; i < sprite.triangles.Length; i++)
        {
            tris[i] = sprite.triangles[i];
        }

        // Assemble the rendermesh
        mesh = new Mesh();
        mesh.vertices = verts;
        mesh.triangles = tris;
        mesh.uv = sprite.uv;

        material = new Material(Shader.Find("Sprites/Default"));
        material.mainTexture = sprite.texture;

        // Construct the rendermesh
        var rendermesh = new RenderMesh
        {
            castShadows = ShadowCastingMode.On,
            layer = 0,
            material = material,
            mesh = mesh,
            receiveShadows = true,
            subMesh = -1
        };

        // Add the constructed rendermesh to the entity as a shared component
        dstManager.AddSharedComponentData(entity,rendermesh);
    }
}