// Modified version of stencil render pass by Alexander Ameye.
// https://alexanderameye.github.io/
// https://twitter.com/alexanderameye/status/1332286868222775298

using System.Collections.Generic;
using UnityEngine;
using UnityEngine.Rendering;
using UnityEngine.Rendering.Universal;

public class StencilPass : ScriptableRenderPass
{
    private const string ProfilerTag = "Stencil Pass";
    private const string ShaderName = "Hidden/Outline";

    private static readonly ShaderTagId _srpDefaultUnlit = new ShaderTagId("SRPDefaultUnlit");
    private static readonly ShaderTagId _universalForward = new ShaderTagId("UniversalForward");
    private static readonly ShaderTagId _lightweightForward = new ShaderTagId("LightweightForward");

    private static readonly List<ShaderTagId> _shaderTags = new List<ShaderTagId>
    {
        _srpDefaultUnlit, _universalForward, _lightweightForward,
    };

    private readonly OutlineFeature.Settings _settings;

    private readonly Material _stencilMaterial;
    private FilteringSettings _filteringSettings;

    public StencilPass(OutlineFeature.Settings settings)
    {
        profilingSampler = new ProfilingSampler(ProfilerTag);
        _settings = settings;
        renderPassEvent = settings.RenderPassEvent;

        // TODO: Try this again when render layers are working with hybrid renderer.
        // uint renderingLayerMask = 1u << settings.RenderLayer - 1;
        // _filteringSettings = new FilteringSettings(RenderQueueRange.all, settings.LayerMask.value, renderingLayerMask);
        _filteringSettings = new FilteringSettings(RenderQueueRange.all, settings.LayerMask.value);

        if (!_stencilMaterial)
        {
            _stencilMaterial = CoreUtils.CreateEngineMaterial(ShaderName);
        }
    }

    public override void Execute(ScriptableRenderContext context, ref RenderingData renderingData)
    {
        DrawingSettings drawingSettings = CreateDrawingSettings(
            _shaderTags,
            ref renderingData,
            _settings.SortingCriteria
        );
        drawingSettings.overrideMaterial = _stencilMaterial;
        drawingSettings.overrideMaterialPassIndex = 0;

        // TODO: Switch to this once mismatched markers bug is fixed.
        // CommandBuffer cmd = CommandBufferPool.Get(ProfilerTag);
        CommandBuffer cmd = CommandBufferPool.Get();
        using (new ProfilingScope(cmd, profilingSampler))
        {
            context.ExecuteCommandBuffer(cmd);
            cmd.Clear();
            context.DrawRenderers(renderingData.cullResults, ref drawingSettings, ref _filteringSettings);
        }

        context.ExecuteCommandBuffer(cmd);
        CommandBufferPool.Release(cmd);
    }
}