ProPixelizerVariantStripper

ProPixelizerVariantStripper.cs

using System.Collections.Generic;
using System.Linq;
using UnityEditor;
using UnityEditor.Build;
using UnityEditor.Rendering;
using UnityEngine;

internal sealed class ProPixelizerVariantStripper : IPreprocessShaders
{
    private static readonly HashSet<string> StrippedKeywords = new HashSet<string>
    {
        "_ADDITIONAL_LIGHTS",
        "_ADDITIONAL_LIGHTS_VERTEX",
        "_ADDITIONAL_LIGHT_SHADOWS",
        "_DBUFFER_MRT1",
        "_DBUFFER_MRT2",
        "_DBUFFER_MRT3",
        "_FORWARD_PLUS",
        "_GBUFFER_NORMALS_OCT",
        "_LIGHT_COOKIES",
        "_LIGHT_LAYERS",
        "_MIXED_LIGHTING_SUBTRACTIVE",
        "_REFLECTION_PROBE_BLENDING",
        "_REFLECTION_PROBE_BOX_PROJECTION",
        "_RENDER_PASS_ENABLED",
        "_SCREEN_SPACE_OCCLUSION",
        "_SHADOWS_SOFT",
        "_SHADOWS_SOFT_HIGH",
        "_SHADOWS_SOFT_LOW",
        "_SHADOWS_SOFT_MEDIUM",
        "EVALUATE_SH_MIXED",
        "EVALUATE_SH_VERTEX"
    };

    public int callbackOrder => 0;

    public void OnProcessShader(Shader shader, ShaderSnippetData snippet, IList<ShaderCompilerData> data)
    {
        if (!BuildPipeline.isBuildingPlayer)
        {
            return;
        }

        if (!shader.name.StartsWith("ProPixelizer/"))
        {
            return;
        }

        int initialCount = data.Count;
        for (int i = data.Count - 1; i >= 0; i--)
        {
            if (ShouldStripVariant(data[i]))
            {
                data.RemoveAt(i);
            }
        }

        int strippedCount = initialCount - data.Count;
        if (strippedCount > 0)
        {
            Debug.Log(
                $"ProPixelizerVariantStripper: stripped {strippedCount} variants from {shader.name} ({snippet.passName}).");
        }
    }

    private static bool ShouldStripVariant(ShaderCompilerData compilerData)
    {
        IEnumerable<string> keywordNames = compilerData.shaderKeywordSet
            .GetShaderKeywords()
            .Select(keyword => keyword.name);

        foreach (string keywordName in keywordNames)
        {
            if (StrippedKeywords.Contains(keywordName))
            {
                return true;
            }
        }

        return false;
    }
}