using System;
using UnityEngine;
using UnityEngine.Rendering;
using UnityEditor;

using System.Linq;

//namespace UnityEditor.Experimental.Rendering.HDPipeline
//{
    internal class LayeredPhotogrammetryGUI : ShaderGUI//LitGUI
    {

        protected const string kUVBase = "_UVBase";
        protected const string kTexWorldScale = "_TexWorldScale";
        protected const string kUVMappingMask = "_UVMappingMask";

        protected const string kBaseColor = "_BaseColor";
        protected const string kBaseColorMap = "_BaseColorMap";
        protected const string kMetallic = "_Metallic";
        protected const string kSmoothness = "_Smoothness";
        protected const string kMaskMap = "_MaskMap";
        protected const string kNormalMap = "_NormalMap";
        protected const string kNormalScale = "_NormalScale";
        protected const string kHeightMap = "_HeightMap";
        protected const string kHeightAmplitude = "_LayerHeightAmplitude";
        protected const string kHeightCenter = "_LayerHeightCenter";

        protected const string kUVDetail = "_UVDetail";
        protected const string kUVDetailsMappingMask = "_UVDetailsMappingMask";
        protected const string kDetailMap = "_DetailMap";
        protected const string kDetailMask = "_DetailMask";
        protected const string kDetailAlbedoScale = "_DetailAlbedoScale";
        protected const string kDetailNormalScale = "_DetailNormalScale";
        protected const string kDetailSmoothnessScale = "_DetailSmoothnessScale";

        protected MaterialProperty alphaCutoffEnable = null;
        protected const string kAlphaCutoffEnabled = "_AlphaCutoffEnable";
        protected MaterialProperty alphaCutoff = null;
        protected const string kAlphaCutoff = "_AlphaCutoff";

        protected MaterialEditor m_MaterialEditor;

        public enum LayerUVBaseMapping
        {
            UV0,
            UV1,
            UV2,
            UV3,
            Planar,
        }

        public enum VertexColorMode
        {
            None,
            Multiply,
            Add
        }

        public enum UVBaseMapping
        {
            UV0,
            Planar,
        }

        public enum HeightmapMode
        {
            Parallax,
            Displacement,
        }

        public enum UVDetailMapping
        {
            UV0,
            UV1,
            UV2,
            UV3
        }

        public enum EmissiveColorMode
        {
            UseEmissiveColor,
            UseEmissiveMask,
        }

        private class StylesLayer
        {
            public readonly GUIContent[] layerLabels =
            {
                new GUIContent("Main layer"),
                new GUIContent("Layer 1"),
                new GUIContent("Layer 2"),
                new GUIContent("Layer 3"),
            };

            public readonly GUIStyle[] layerLabelColors =
            {
                new GUIStyle(EditorStyles.label),
                new GUIStyle(EditorStyles.label),
                new GUIStyle(EditorStyles.label),
                new GUIStyle(EditorStyles.label)
            };

            public readonly GUIContent layersText = new GUIContent("Inputs");
            public readonly GUIContent emissiveText = new GUIContent("Emissive");
            public readonly GUIContent layerMapMaskText = new GUIContent("Layer Mask", "Layer mask");
            public readonly GUIContent vertexColorModeText = new GUIContent("Vertex Color Mode", "Mode multiply: vertex color is multiply with the mask. Mode additive: vertex color values are remapped between -1 and 1 and added to the mask (neutral at 0.5 vertex color).");
            public readonly GUIContent layerCountText = new GUIContent("Layer Count", "Number of layers.");
            public readonly GUIContent layerTilingBlendMaskText = new GUIContent("Tiling", "Tiling for the blend mask.");
            public readonly GUIContent objectScaleAffectTileText = new GUIContent("Tiling 0123 follow object Scale", "Tiling will be affected by the object scale.");
            public readonly GUIContent objectScaleAffectTileText2 = new GUIContent("Tiling 123 follow object Scale", "Tiling will be affected by the object scale.");

            public readonly GUIContent layerBaseColor = new GUIContent("Base Color");
            public readonly GUIContent layerMetallic = new GUIContent("Metallic");
            public readonly GUIContent layerMask = new GUIContent("Mask Map - M(R), AO(G), S(A)", "Mask map");
            public readonly GUIContent layerSmoothness = new GUIContent("Smoothness");
            public readonly GUIContent layerNormalMap = new GUIContent("Normal Map");
            public readonly GUIContent layerHeightMapText = new GUIContent("Height Map (R)", "Height Map");
            public readonly GUIContent layerHeightMapAmplitudeText = new GUIContent("Height Map Amplitude", "Height Map amplitude in world units.");
            public readonly GUIContent layerHeightMapCenterText = new GUIContent("Height Map Center", "Center of the heightmap in the texture (between 0 and 1)");
            public readonly GUIContent layerTilingText = new GUIContent("Tiling", "Tiling factor applied to UVSet.");
            public readonly GUIContent layerTexWorldScaleText = new GUIContent("World Scale", "Tiling factor applied to Planar/Trilinear mapping");
            public readonly GUIContent UVBaseText = new GUIContent("Base UV Mapping", "Base UV Mapping mode of the layer.");
            public readonly GUIContent UVBlendMaskText = new GUIContent("BlendMask UV Mapping", "Base UV Mapping mode of the layer.");
            public readonly GUIContent UVDetailText = new GUIContent("Detail UV Mapping", "Detail UV Mapping mode of the layer.");
            public readonly GUIContent mainLayerInfluenceText = new GUIContent("Main layer influence", "Main layer influence.");
            public readonly GUIContent densityOpacityInfluenceText = new GUIContent("Density / Opacity", "Density / Opacity");
            public readonly GUIContent useHeightBasedBlendText = new GUIContent("Use Height Based Blend", "Layer will be blended with the underlying layer based on the height.");
            public readonly GUIContent useDensityModeModeText = new GUIContent("Use Density Mode", "Enable density mode");
            public readonly GUIContent useMainLayerInfluenceModeText = new GUIContent("Main Layer Influence", "Switch between regular layers mode and base/layers mode");
            public readonly GUIContent heightControlText = new GUIContent("Height control");
            public readonly GUIContent layerDetailMapNormalText = new GUIContent("Detail Map A(R) Ny(G) S(B) Nx(A)", "Detail Map");
            public readonly GUIContent layerDetailMaskText = new GUIContent("Detail Mask (G)", "Mask for detailMap");
            public readonly GUIContent layerDetailAlbedoScaleText = new GUIContent("Detail AlbedoScale", "Detail Albedo Scale factor");
            public readonly GUIContent layerDetailNormalScaleText = new GUIContent("Detail NormalScale", "Normal Scale factor");
            public readonly GUIContent layerDetailSmoothnessScaleText = new GUIContent("Detail SmoothnessScale", "Smoothness Scale factor");

            public readonly GUIContent blendUsingHeight = new GUIContent("Blend Using Height", "Blend Layers using height.");
            public readonly GUIContent inheritBaseColorThresholdText = new GUIContent("Threshold", "Inherit the base color from the base layer.");
            public readonly GUIContent minimumOpacityText = new GUIContent("Minimum Opacity", "Minimum Opacity.");
            public readonly GUIContent opacityAsDensityText = new GUIContent("Use Opacity as Density", "Use Opacity as Density.");
            public readonly GUIContent inheritBaseNormalText = new GUIContent("Normal influence", "Inherit the normal from the base layer.");
            public readonly GUIContent inheritBaseHeightText = new GUIContent("Heightmap influence", "Inherit the height from the base layer.");
            public readonly GUIContent inheritBaseColorText = new GUIContent("BaseColor influence", "Inherit the base color from the base layer.");
            
            public static GUIContent alphaCutoffEnableText = new GUIContent("Alpha Cutoff Enable", "Threshold for alpha cutoff");
            public static GUIContent alphaCutoffText = new GUIContent("Alpha Cutoff", "Threshold for alpha cutoff");

            public static string advancedText = "Advanced Options";

            public StylesLayer()
            {
                layerLabelColors[0].normal.textColor = Color.white;
                layerLabelColors[1].normal.textColor = Color.red;
                layerLabelColors[2].normal.textColor = Color.green;
                layerLabelColors[3].normal.textColor = Color.blue;
            }
        }

        static StylesLayer s_Styles = null;
        private static StylesLayer styles { get { if (s_Styles == null) s_Styles = new StylesLayer(); return s_Styles; } }

        // Needed for json serialization to work
        [Serializable]
        internal struct SerializeableGUIDs
        {
            public string[] GUIDArray;
        }

        const int kMaxLayerCount = 4;

        // Layer options
        MaterialProperty layerCount = null;
        const string kLayerCount = "_LayerCount";
        MaterialProperty layerMaskMap = null;
        const string kLayerMaskMap = "_LayerMaskMap";
        MaterialProperty vertexColorMode = null;
        const string kVertexColorMode = "_VertexColorMode";
        MaterialProperty objectScaleAffectTile = null;
        const string kObjectScaleAffectTile = "_ObjectScaleAffectTile";
        MaterialProperty UVBlendMask = null;
        const string kUVBlendMask = "_UVBlendMask";
        MaterialProperty layerTilingBlendMask = null;
        const string kLayerTilingBlendMask = "_LayerTilingBlendMask";
        MaterialProperty texWorldScaleBlendMask = null;
        const string kTexWorldScaleBlendMask = "_TexWorldScaleBlendMask";
        MaterialProperty useMainLayerInfluence = null;
        const string kkUseMainLayerInfluence = "_UseMainLayerInfluence";
        MaterialProperty useHeightBasedBlend = null;
        const string kUseHeightBasedBlend = "_UseHeightBasedBlend";

        // Lit properties
        MaterialProperty[] layerBaseColor = new MaterialProperty[kMaxLayerCount];
        MaterialProperty[] layerBaseColorMap = new MaterialProperty[kMaxLayerCount];
        MaterialProperty[] layerSmoothness = new MaterialProperty[kMaxLayerCount];
        MaterialProperty[] layerMetallic = new MaterialProperty[kMaxLayerCount];
        MaterialProperty[] layerNormalMap = new MaterialProperty[kMaxLayerCount];
        MaterialProperty[] layerNormalScale = new MaterialProperty[kMaxLayerCount];
        MaterialProperty[] layerMask = new MaterialProperty[kMaxLayerCount];
        MaterialProperty[] layerHeightMap = new MaterialProperty[kMaxLayerCount];
        MaterialProperty[] layerHeightAmplitude = new MaterialProperty[kMaxLayerCount];
        MaterialProperty[] layerHeightCenter = new MaterialProperty[kMaxLayerCount];
        MaterialProperty[] layerDetailMask = new MaterialProperty[kMaxLayerCount];
        MaterialProperty[] layerDetailMap = new MaterialProperty[kMaxLayerCount];
        MaterialProperty[] layerDetailAlbedoScale = new MaterialProperty[kMaxLayerCount];
        MaterialProperty[] layerDetailNormalScale = new MaterialProperty[kMaxLayerCount];
        MaterialProperty[] layerDetailSmoothnessScale = new MaterialProperty[kMaxLayerCount];

        // Properties for multiple layers inherit from referenced lit materials
        MaterialProperty[] layerTexWorldScale = new MaterialProperty[kMaxLayerCount];
        MaterialProperty[] layerUVBase = new MaterialProperty[kMaxLayerCount];
        MaterialProperty[] layerUVMappingMask = new MaterialProperty[kMaxLayerCount];
        MaterialProperty[] layerUVDetail = new MaterialProperty[kMaxLayerCount];
        MaterialProperty[] layerUVDetailsMappingMask = new MaterialProperty[kMaxLayerCount];
        // This one is specific to layer lit
        MaterialProperty[] layerTiling = new MaterialProperty[kMaxLayerCount];
        const string kLayerTiling = "_LayerTiling";

        // Density/opacity mode
        MaterialProperty useDensityMode = null;
        const string kUseDensityMode = "_UseDensityMode";
        MaterialProperty[] opacityAsDensity = new MaterialProperty[kMaxLayerCount];
        const string kOpacityAsDensity = "_OpacityAsDensity";
        MaterialProperty[] minimumOpacity = new MaterialProperty[kMaxLayerCount];
        const string kMinimumOpacity = "_MinimumOpacity";

        // HeightmapMode control
        MaterialProperty[] blendUsingHeight = new MaterialProperty[kMaxLayerCount - 1]; // Only in case of influence mode
        const string kBlendUsingHeight = "_BlendUsingHeight";

        // Influence
        MaterialProperty[] inheritBaseNormal = new MaterialProperty[kMaxLayerCount - 1];
        const string kInheritBaseNormal = "_InheritBaseNormal";
        MaterialProperty[] inheritBaseHeight = new MaterialProperty[kMaxLayerCount - 1];
        const string kInheritBaseHeight = "_InheritBaseHeight";
        MaterialProperty[] inheritBaseColor = new MaterialProperty[kMaxLayerCount - 1];
        const string kInheritBaseColor = "_InheritBaseColor";
        MaterialProperty[] inheritBaseColorThreshold = new MaterialProperty[kMaxLayerCount - 1];
        const string kInheritBaseColorThreshold = "_InheritBaseColorThreshold";

        protected void FindMaterialProperties(MaterialProperty[] props)
        {
            // Inherit from LitUI
            layerCount = FindProperty(kLayerCount, props);
            layerMaskMap = FindProperty(kLayerMaskMap, props);
            vertexColorMode = FindProperty(kVertexColorMode, props);
            objectScaleAffectTile = FindProperty(kObjectScaleAffectTile, props);
            UVBlendMask = FindProperty(kUVBlendMask, props);
            layerTilingBlendMask = FindProperty(kLayerTilingBlendMask, props);
            texWorldScaleBlendMask = FindProperty(kTexWorldScaleBlendMask, props);

            useMainLayerInfluence = FindProperty(kkUseMainLayerInfluence, props);
            useHeightBasedBlend = FindProperty(kUseHeightBasedBlend, props);

            useDensityMode = FindProperty(kUseDensityMode, props);

            for (int i = 0; i < kMaxLayerCount; ++i)
            {
                layerBaseColor[i] = FindProperty(string.Format("{0}{1}", kBaseColor, i), props);
                layerBaseColorMap[i] = FindProperty(string.Format("{0}{1}", kBaseColorMap, i), props);
                layerSmoothness[i] = FindProperty(string.Format("{0}{1}", kSmoothness, i), props);
                layerMetallic[i] = FindProperty(string.Format("{0}{1}", kMetallic, i), props);
                layerNormalMap[i] = FindProperty(string.Format("{0}{1}", kNormalMap, i), props);
                layerNormalScale[i] = FindProperty(string.Format("{0}{1}", kNormalScale, i), props);
                layerMask[i] = FindProperty(string.Format("{0}{1}", kMaskMap, i), props);
                layerHeightMap[i] = FindProperty(string.Format("{0}{1}", kHeightMap, i), props);
                layerTexWorldScale[i] = FindProperty(string.Format("{0}{1}", kTexWorldScale, i), props);
                layerUVBase[i] = FindProperty(string.Format("{0}{1}", kUVBase, i), props);
                layerUVMappingMask[i] = FindProperty(string.Format("{0}{1}", kUVMappingMask, i), props);
                layerUVDetail[i] = FindProperty(string.Format("{0}{1}", kUVDetail, i), props);
                layerUVDetailsMappingMask[i] = FindProperty(string.Format("{0}{1}", kUVDetailsMappingMask, i), props);
                layerTiling[i] = FindProperty(string.Format("{0}{1}", kLayerTiling, i), props);
                layerDetailMap[i] = FindProperty(string.Format("{0}{1}", kDetailMap, i), props);
                layerDetailMask[i] = FindProperty(string.Format("{0}{1}", kDetailMask, i), props);
                layerDetailAlbedoScale[i] = FindProperty(string.Format("{0}{1}", kDetailAlbedoScale, i), props);
                layerDetailNormalScale[i] = FindProperty(string.Format("{0}{1}", kDetailNormalScale, i), props);
                layerDetailSmoothnessScale[i] = FindProperty(string.Format("{0}{1}", kDetailSmoothnessScale, i), props);

                // Density/opacity mode
                opacityAsDensity[i] = FindProperty(string.Format("{0}{1}", kOpacityAsDensity, i), props);
                minimumOpacity[i] = FindProperty(string.Format("{0}{1}", kMinimumOpacity, i), props);

                layerHeightAmplitude[i] = FindProperty(string.Format("{0}{1}", kHeightAmplitude, i), props);
                layerHeightCenter[i] = FindProperty(string.Format("{0}{1}", kHeightCenter, i), props);

                if (i != 0)
                {
                    blendUsingHeight[i - 1] = FindProperty(string.Format("{0}{1}", kBlendUsingHeight, i), props);
                    // Influence
                    inheritBaseNormal[i - 1] = FindProperty(string.Format("{0}{1}", kInheritBaseNormal, i), props);
                    inheritBaseHeight[i - 1] = FindProperty(string.Format("{0}{1}", kInheritBaseHeight, i), props);
                    inheritBaseColor[i - 1] = FindProperty(string.Format("{0}{1}", kInheritBaseColor, i), props);
                    inheritBaseColorThreshold[i - 1] = FindProperty(string.Format("{0}{1}", kInheritBaseColorThreshold, i), props);
                }
            }

            // Reuse property from LitUI.cs
            //emissiveColor = FindProperty(kEmissiveColor, props);
            //emissiveColorMap = FindProperty(kEmissiveColorMap, props);
            //emissiveIntensity = FindProperty(kEmissiveIntensity, props);
        }

        int numLayer
        {
            set { layerCount.floatValue = (float)value; }
            get { return (int)layerCount.floatValue; }
        }

        bool DoLayerGUI(AssetImporter materialImporter, int layerIndex)
        {
            bool result = false;

            Material material = m_MaterialEditor.target as Material;

            bool mainLayerInfluenceEnable = useMainLayerInfluence.floatValue > 0.0f;

            EditorGUILayout.LabelField(styles.layerLabels[layerIndex], styles.layerLabelColors[layerIndex]);

            m_MaterialEditor.TexturePropertySingleLine(styles.layerBaseColor, layerBaseColorMap[layerIndex], layerBaseColor[layerIndex]);
            m_MaterialEditor.ShaderProperty(layerMetallic[layerIndex], styles.layerMetallic);
            m_MaterialEditor.ShaderProperty(layerSmoothness[layerIndex], styles.layerSmoothness);

            m_MaterialEditor.TexturePropertySingleLine(styles.layerMask, layerMask[layerIndex]);
            m_MaterialEditor.TexturePropertySingleLine(styles.layerNormalMap, layerNormalMap[layerIndex], layerNormalScale[layerIndex]);

            m_MaterialEditor.TexturePropertySingleLine(styles.layerHeightMapText, layerHeightMap[layerIndex]);
            if (!layerHeightMap[layerIndex].hasMixedValue && layerHeightMap[layerIndex].textureValue != null)
            {
                EditorGUI.indentLevel++;
                m_MaterialEditor.ShaderProperty(layerHeightAmplitude[layerIndex], styles.layerHeightMapAmplitudeText);
                m_MaterialEditor.ShaderProperty(layerHeightCenter[layerIndex], styles.layerHeightMapCenterText);
                EditorGUI.showMixedValue = false;
                EditorGUI.indentLevel--;
            }

            EditorGUI.BeginChangeCheck();
            m_MaterialEditor.ShaderProperty(layerUVBase[layerIndex], styles.UVBaseText);
            if (EditorGUI.EndChangeCheck())
            {
                result = true;
            }
            if (((LayerUVBaseMapping)layerUVBase[layerIndex].floatValue == LayerUVBaseMapping.Planar))
            {
                EditorGUI.indentLevel++;
                m_MaterialEditor.ShaderProperty(layerTexWorldScale[layerIndex], styles.layerTexWorldScaleText);
                EditorGUI.indentLevel--;
            }
            else
            {
                EditorGUI.indentLevel++;
                m_MaterialEditor.ShaderProperty(layerTiling[layerIndex], styles.layerTilingText);
                EditorGUI.indentLevel--;
            }
            m_MaterialEditor.TextureScaleOffsetProperty(layerBaseColorMap[layerIndex]);

            m_MaterialEditor.TexturePropertySingleLine(styles.layerDetailMaskText, layerDetailMask[layerIndex]);
            m_MaterialEditor.TexturePropertySingleLine(styles.layerDetailMapNormalText, layerDetailMap[layerIndex]);

            if (((LayerUVBaseMapping)layerUVBase[layerIndex].floatValue == LayerUVBaseMapping.Planar))
            {
                GUILayout.Label("       " + styles.UVDetailText.text + ": Planar");
            }
            else
            {
                EditorGUI.BeginChangeCheck();
                m_MaterialEditor.ShaderProperty(layerUVDetail[layerIndex], styles.UVDetailText);
                if (EditorGUI.EndChangeCheck())
                {
                    result = true;
                }
            }
            m_MaterialEditor.TextureScaleOffsetProperty(layerDetailMap[layerIndex]);
            m_MaterialEditor.ShaderProperty(layerDetailAlbedoScale[layerIndex], styles.layerDetailAlbedoScaleText);
            m_MaterialEditor.ShaderProperty(layerDetailNormalScale[layerIndex], styles.layerDetailNormalScaleText);
            m_MaterialEditor.ShaderProperty(layerDetailSmoothnessScale[layerIndex], styles.layerDetailSmoothnessScaleText);

            // We setup the masking map based on the enum for each layer.
            // using mapping mask allow to reduce the number of generated combination for a very small increase in ALU
            LayerUVBaseMapping layerUVBaseMapping = (LayerUVBaseMapping)layerUVBase[layerIndex].floatValue;

            float X, Y, Z, W;
            X = (layerUVBaseMapping == LayerUVBaseMapping.UV0) ? 1.0f : 0.0f;
            Y = (layerUVBaseMapping == LayerUVBaseMapping.UV1) ? 1.0f : 0.0f;
            Z = (layerUVBaseMapping == LayerUVBaseMapping.UV2) ? 1.0f : 0.0f;
            W = (layerUVBaseMapping == LayerUVBaseMapping.UV3) ? 1.0f : 0.0f;
            layerUVMappingMask[layerIndex].colorValue = (layerIndex == 0) ? new Color(1.0f, 0.0f, 0.0f, 0.0f) : new Color(X, Y, Z, W); // Special case for Main Layer and Blend Mask, only UV0. As Layer0 is share by both here, need to force X to 1.0 in all case

            UVDetailMapping layerUVDetailMapping = (UVDetailMapping)layerUVDetail[layerIndex].floatValue;
            X = (layerUVDetailMapping == UVDetailMapping.UV0) ? 1.0f : 0.0f;
            Y = (layerUVDetailMapping == UVDetailMapping.UV1) ? 1.0f : 0.0f;
            Z = (layerUVDetailMapping == UVDetailMapping.UV2) ? 1.0f : 0.0f;
            W = (layerUVDetailMapping == UVDetailMapping.UV3) ? 1.0f : 0.0f;
            layerUVDetailsMappingMask[layerIndex].colorValue = new Color(X, Y, Z, W);

            bool useDensityModeEnable = useDensityMode.floatValue != 0.0f;
            if (useDensityModeEnable)
            {
                EditorGUILayout.LabelField(styles.densityOpacityInfluenceText, EditorStyles.boldLabel);

                EditorGUI.indentLevel++;
                m_MaterialEditor.ShaderProperty(opacityAsDensity[layerIndex], styles.opacityAsDensityText);
                m_MaterialEditor.ShaderProperty(minimumOpacity[layerIndex], styles.minimumOpacityText);
                EditorGUI.indentLevel--;
            }

            // Display height control if they have a meaning
            //if ((tessellationMode != null && ((TessellationMode)tessellationMode.floatValue == TessellationMode.Displacement || (TessellationMode)tessellationMode.floatValue == TessellationMode.DisplacementPhong))
            //    || (enablePerPixelDisplacement.floatValue > 0.0f)
            //    || (useHeightBasedBlend.floatValue > 0.0f)
            //    )
            //if (useHeightBasedBlend.floatValue > 0.0f)
            //{
            //    EditorGUILayout.LabelField(styles.heightControlText, EditorStyles.boldLabel);

            //    EditorGUI.indentLevel++;
            //    m_MaterialEditor.ShaderProperty(heightFactor[layerIndex], styles.heightFactorText);
            //    layerHeightAmplitude[layerIndex].floatValue = material.GetFloat(kHeightAmplitude + layerIndex) * heightFactor[layerIndex].floatValue;
            //    m_MaterialEditor.ShaderProperty(heightCenterOffset[layerIndex], styles.heightCenterOffsetText);
            //    layerCenterOffset[layerIndex].floatValue = material.GetFloat(kHeightCenter + layerIndex) + heightCenterOffset[layerIndex].floatValue;
            //    EditorGUI.indentLevel--;
            //}


            // influence
            if (layerIndex > 0)
            {
                int paramIndex = layerIndex - 1;

                bool heightBasedBlendEnable = useHeightBasedBlend.floatValue > 0.0f;
                if (heightBasedBlendEnable)
                {
                    EditorGUI.indentLevel++;
                    m_MaterialEditor.ShaderProperty(blendUsingHeight[paramIndex], styles.blendUsingHeight);
                    EditorGUI.indentLevel--;
                }

                if (mainLayerInfluenceEnable)
                {
                    EditorGUILayout.LabelField(styles.mainLayerInfluenceText, EditorStyles.boldLabel);

                    EditorGUI.indentLevel++;

                    m_MaterialEditor.ShaderProperty(inheritBaseColor[paramIndex], styles.inheritBaseColorText);
                    EditorGUI.indentLevel++;
                    m_MaterialEditor.ShaderProperty(inheritBaseColorThreshold[paramIndex], styles.inheritBaseColorThresholdText);
                    EditorGUI.indentLevel--;
                    m_MaterialEditor.ShaderProperty(inheritBaseNormal[paramIndex], styles.inheritBaseNormalText);
                    // Main height influence is only available if the shader use the heightmap for displacement (per vertex or per level)
                    // We always display it as it can be tricky to know when per pixel displacement is enabled or not
                    m_MaterialEditor.ShaderProperty(inheritBaseHeight[paramIndex], styles.inheritBaseHeightText);

                    EditorGUI.indentLevel--;
                }
            }

            if (layerIndex == 0)
                EditorGUILayout.Space();

            return result;
        }

        bool DoLayersGUI(AssetImporter materialImporter)
        {
            Material material = m_MaterialEditor.target as Material;

            bool layerChanged = false;

            GUI.changed = false;

            GUILayout.Label(styles.layersText, EditorStyles.boldLabel);

            EditorGUI.showMixedValue = layerCount.hasMixedValue;
            EditorGUI.BeginChangeCheck();
            int newLayerCount = EditorGUILayout.IntSlider(styles.layerCountText, (int)layerCount.floatValue, 2, 4);
            if (EditorGUI.EndChangeCheck())
            {
                Undo.RecordObject(material, "Change layer count");
                layerCount.floatValue = (float)newLayerCount;
                layerChanged = true;
            }

            m_MaterialEditor.TexturePropertySingleLine(styles.layerMapMaskText, layerMaskMap);

            m_MaterialEditor.ShaderProperty(UVBlendMask, styles.UVBlendMaskText);

            if (((LayerUVBaseMapping)UVBlendMask.floatValue == LayerUVBaseMapping.Planar))
            {
                m_MaterialEditor.ShaderProperty(texWorldScaleBlendMask, styles.layerTexWorldScaleText);
            }
            else
            {
                m_MaterialEditor.ShaderProperty(layerTilingBlendMask, styles.layerTilingBlendMaskText);
            }

            m_MaterialEditor.ShaderProperty(vertexColorMode, styles.vertexColorModeText);

            EditorGUI.BeginChangeCheck();
            EditorGUI.showMixedValue = useMainLayerInfluence.hasMixedValue;
            bool mainLayerModeInfluenceEnable = EditorGUILayout.Toggle(styles.useMainLayerInfluenceModeText, useMainLayerInfluence.floatValue > 0.0f);
            if (EditorGUI.EndChangeCheck())
            {
                useMainLayerInfluence.floatValue = mainLayerModeInfluenceEnable ? 1.0f : 0.0f;
            }

            EditorGUI.BeginChangeCheck();
            EditorGUI.showMixedValue = useDensityMode.hasMixedValue;
            bool useDensityModeEnable = EditorGUILayout.Toggle(styles.useDensityModeModeText, useDensityMode.floatValue > 0.0f);
            if (EditorGUI.EndChangeCheck())
            {
                useDensityMode.floatValue = useDensityModeEnable ? 1.0f : 0.0f;
            }

            EditorGUI.BeginChangeCheck();
            EditorGUI.showMixedValue = useHeightBasedBlend.hasMixedValue;
            bool enabled = EditorGUILayout.Toggle(styles.useHeightBasedBlendText, useHeightBasedBlend.floatValue > 0.0f);
            if (EditorGUI.EndChangeCheck())
            {
                useHeightBasedBlend.floatValue = enabled ? 1.0f : 0.0f;
            }

            m_MaterialEditor.ShaderProperty(objectScaleAffectTile, mainLayerModeInfluenceEnable ? styles.objectScaleAffectTileText2 : styles.objectScaleAffectTileText);

            EditorGUILayout.Space();

            for (int i = 0; i < numLayer; i++)
            {
                layerChanged |= DoLayerGUI(materialImporter, i);
            }

            layerChanged |= GUI.changed;
            GUI.changed = false;

            return layerChanged;
        }


        protected void SetupMaterialKeywordsAndPassInternal(Material material)
        {
            SetupMaterialKeywordsAndPass(material);
        }

        static public void SetKeyword(Material m, string keyword, bool state)
        {
            if (state)
                m.EnableKeyword(keyword);
            else
                m.DisableKeyword(keyword);
        }

        static public void SetupLayersMappingKeywords(Material material)
        {
            // object scale affect tile
            SetKeyword(material, "_LAYER_TILING_COUPLED_WITH_UNIFORM_OBJECT_SCALE", material.GetFloat(kObjectScaleAffectTile) > 0.0f);

            // Blend mask
            LayerUVBaseMapping UVBlendMaskMapping = (LayerUVBaseMapping)material.GetFloat(kUVBlendMask);
            SetKeyword(material, "_LAYER_MAPPING_PLANAR_BLENDMASK", UVBlendMaskMapping == LayerUVBaseMapping.Planar);

            int numLayer = (int)material.GetFloat(kLayerCount);

            // Layer
            if (numLayer == 4)
            {
                SetKeyword(material, "_LAYEREDLIT_4_LAYERS", true);
                SetKeyword(material, "_LAYEREDLIT_3_LAYERS", false);
            }
            else if (numLayer == 3)
            {
                SetKeyword(material, "_LAYEREDLIT_4_LAYERS", false);
                SetKeyword(material, "_LAYEREDLIT_3_LAYERS", true);
            }
            else
            {
                SetKeyword(material, "_LAYEREDLIT_4_LAYERS", false);
                SetKeyword(material, "_LAYEREDLIT_3_LAYERS", false);
            }

            const string kLayerMappingPlanar = "_LAYER_MAPPING_PLANAR";

            // We have to check for each layer if the UV2 or UV3 is needed.
            bool needUV3 = false;
            bool needUV2 = false;

            for (int i = 0; i < numLayer; ++i)
            {
                string layerUVBaseParam = string.Format("{0}{1}", kUVBase, i);
                LayerUVBaseMapping layerUVBaseMapping = (LayerUVBaseMapping)material.GetFloat(layerUVBaseParam);
                string currentLayerMappingPlanar = string.Format("{0}{1}", kLayerMappingPlanar, i);
                SetKeyword(material, currentLayerMappingPlanar, layerUVBaseMapping == LayerUVBaseMapping.Planar);

                string uvBase = string.Format("{0}{1}", kUVBase, i);
                string uvDetail = string.Format("{0}{1}", kUVDetail, i);

                if (((UVDetailMapping)material.GetFloat(uvDetail) == UVDetailMapping.UV2) ||
                    ((LayerUVBaseMapping)material.GetFloat(uvBase) == LayerUVBaseMapping.UV2))
                {
                    needUV2 = true;
                }

                if (((UVDetailMapping)material.GetFloat(uvDetail) == UVDetailMapping.UV3) ||
                    ((LayerUVBaseMapping)material.GetFloat(uvBase) == LayerUVBaseMapping.UV3))
                {
                    needUV3 = true;
                    break; // If we find it UV3 let's early out
                }
            }

            if (needUV3)
            {
                material.DisableKeyword("_REQUIRE_UV2");
                material.EnableKeyword("_REQUIRE_UV3");
            }
            else if (needUV2)
            {
                material.EnableKeyword("_REQUIRE_UV2");
                material.DisableKeyword("_REQUIRE_UV3");
            }
            else
            {
                material.DisableKeyword("_REQUIRE_UV2");
                material.DisableKeyword("_REQUIRE_UV3");
            }
        }

        static public void SetupBaseUnlitKeywords(Material material)
        {
            bool alphaTestEnable = material.GetFloat(kAlphaCutoffEnabled) > 0.0f;

            material.SetOverrideTag("RenderType", alphaTestEnable ? "TransparentCutout" : "");
            material.SetInt("_SrcBlend", (int)UnityEngine.Rendering.BlendMode.One);
            material.SetInt("_DstBlend", (int)UnityEngine.Rendering.BlendMode.Zero);
            material.SetInt("_ZWrite", 1);
            material.renderQueue = alphaTestEnable ? (int)UnityEngine.Rendering.RenderQueue.AlphaTest : -1;
            material.SetInt("_CullMode", (int)UnityEngine.Rendering.CullMode.Back);

            SetKeyword(material, "_ALPHATEST_ON", alphaTestEnable);
        }

        // All Setup Keyword functions must be static. It allow to create script to automatically update the shaders with a script if code change
        static public void SetupMaterialKeywordsAndPass(Material material)
        {
            SetupBaseUnlitKeywords(material);
            SetupLayersMappingKeywords(material);

            for (int i = 0; i < kMaxLayerCount; ++i)
            {
                SetKeyword(material, "_NORMALMAP" + i, material.GetTexture(kNormalMap + i) || material.GetTexture(kDetailMap + i));

                SetKeyword(material, "_MASKMAP" + i, material.GetTexture(kMaskMap + i));

                SetKeyword(material, "_DETAIL_MAP" + i, material.GetTexture(kDetailMap + i));

                SetKeyword(material, "_HEIGHTMAP" + i, material.GetTexture(kHeightMap + i));
            }

            SetKeyword(material, "_MAIN_LAYER_INFLUENCE_MODE", material.GetFloat(kkUseMainLayerInfluence) != 0.0f);

            VertexColorMode VCMode = (VertexColorMode)material.GetFloat(kVertexColorMode);
            if (VCMode == VertexColorMode.Multiply)
            {
                SetKeyword(material, "_LAYER_MASK_VERTEX_COLOR_MUL", true);
                SetKeyword(material, "_LAYER_MASK_VERTEX_COLOR_ADD", false);
            }
            else if (VCMode == VertexColorMode.Add)
            {
                SetKeyword(material, "_LAYER_MASK_VERTEX_COLOR_MUL", false);
                SetKeyword(material, "_LAYER_MASK_VERTEX_COLOR_ADD", true);
            }
            else
            {
                SetKeyword(material, "_LAYER_MASK_VERTEX_COLOR_MUL", false);
                SetKeyword(material, "_LAYER_MASK_VERTEX_COLOR_ADD", false);
            }

            bool useHeightBasedBlend = material.GetFloat(kUseHeightBasedBlend) != 0.0f;
            SetKeyword(material, "_HEIGHT_BASED_BLEND", useHeightBasedBlend);

            bool useDensityModeEnable = material.GetFloat(kUseDensityMode) != 0.0f;
            SetKeyword(material, "_DENSITY_MODE", useDensityModeEnable);
        }
        protected void FindBaseMaterialProperties(MaterialProperty[] props)
        {
            alphaCutoffEnable = FindProperty(kAlphaCutoffEnabled, props);
            alphaCutoff = FindProperty(kAlphaCutoff, props);
        }

        protected void BaseMaterialPropertiesGUI()
        {
            EditorGUI.indentLevel++;
            m_MaterialEditor.ShaderProperty(alphaCutoffEnable, StylesLayer.alphaCutoffEnableText);
            if (alphaCutoffEnable.floatValue == 1.0f)
            {
                m_MaterialEditor.ShaderProperty(alphaCutoff, StylesLayer.alphaCutoffText);
            }
        }

        public override void OnGUI(MaterialEditor materialEditor, MaterialProperty[] props)
        {
            FindBaseMaterialProperties(props);
            FindMaterialProperties(props);

            m_MaterialEditor = materialEditor;
            // We should always do this call at the beginning
            m_MaterialEditor.serializedObject.Update();

            Material material = m_MaterialEditor.target as Material;
            AssetImporter materialImporter = AssetImporter.GetAtPath(AssetDatabase.GetAssetPath(material.GetInstanceID()));

            bool optionsChanged = false;
            EditorGUI.BeginChangeCheck();
            {
                BaseMaterialPropertiesGUI();
                EditorGUILayout.Space();
            }
            if (EditorGUI.EndChangeCheck())
            {
                optionsChanged = true;
            }

            bool layerChanged = DoLayersGUI(materialImporter);

            EditorGUI.indentLevel--;
            m_MaterialEditor.EnableInstancingField();

            if (layerChanged || optionsChanged)
            {
                foreach (var obj in m_MaterialEditor.targets)
                {
                    SetupMaterialKeywordsAndPassInternal((Material)obj);
                }
            }

            // We should always do this call at the end
            m_MaterialEditor.serializedObject.ApplyModifiedProperties();
        }
    }
//} // namespace UnityEditor