psydack · psydack · Jul 17, 2021 · Jul 10, 2021 · Jul 10, 2021 · Jul 10, 2021
diff --git a/Editor/Editors/UImGuiEditor.cs b/Editor/Editors/UImGuiEditor.cs
@@ -1,6 +1,7 @@
 using ImGuiNET;
 using System.Text;
 using UImGui.Platform;
+using UImGui.Renderer;
 using UnityEditor;
 using UnityEngine;
 
@@ -114,6 +115,13 @@ private void CheckRequirements()
 				_messages.AppendLine("Must assign a RenderFeature when using the URP.");
 			}
 
+#if !UNITY_2020_1_OR_NEWER
+			if ((RenderType)_renderer.enumValueIndex == RenderType.Mesh)
+			{
+				_messages.AppendLine("Use procedural.");
+			}
+#endif
+
 			SerializedProperty configFlags = _initialConfiguration.FindPropertyRelative("ImGuiConfig");
 			if (!PlatformUtility.IsAvailable((InputType)_platform.enumValueIndex))
 			{

diff --git a/Resources/Shaders/PassesUniversal.hlsl b/Resources/Shaders/PassesUniversal.hlsl
@@ -5,6 +5,7 @@
 #ifndef UNITY_COLORSPACE_GAMMA
 #include "Packages/com.unity.render-pipelines.core/ShaderLibrary/Color.hlsl"
 #endif
+
 #include "./Common.hlsl"
 
 TEXTURE2D(_Texture);

diff --git a/Source/Renderer/RendererMesh.cs b/Source/Renderer/RendererMesh.cs
@@ -1,4 +1,5 @@
-using ImGuiNET;
+#if UNITY_2020_1_OR_NEWER
+using ImGuiNET;
 using System;
 using System.Collections.Generic;
 using System.Runtime.InteropServices;
@@ -222,4 +223,5 @@ private void CreateDrawCommands(CommandBuffer commandBuffer, ImDrawDataPtr drawD
 			commandBuffer.DisableScissorRect();
 		}
 	}
-}
+}
+#endif
diff --git a/Source/Renderer/RendererProcedural.cs b/Source/Renderer/RendererProcedural.cs
@@ -30,7 +30,6 @@ internal sealed class RendererProcedural : IRenderer
 		private readonly TextureManager _textureManager;
 
 		private readonly MaterialPropertyBlock _materialProperties = new MaterialPropertyBlock();
-		private readonly int[] _drawArgs = new int[] { 0, 1, 0, 0, 0 }; // Used to build argument buffer.
 
 		private Material _material;
 
@@ -171,14 +170,18 @@ private unsafe void UpdateBuffers(ImDrawDataPtr drawData)
 				_indexBuffer.SetData(idxArray, 0, idxOf, idxArray.Length);
 
 				// Arguments for indexed draw.
-				_drawArgs[3] = vtxOf; // Base vertex location.
-				for (int i = 0, iMax = drawList.CmdBuffer.Size; i < iMax; ++i)
+				for (int meshIndex = 0, iMax = drawList.CmdBuffer.Size; meshIndex < iMax; ++meshIndex)
 				{
-					ImDrawCmdPtr cmd = drawList.CmdBuffer[i];
-					_drawArgs[0] = (int)cmd.ElemCount; // Index count per instance.
-					_drawArgs[2] = idxOf + (int)cmd.IdxOffset; // Start index location.
-					_argumentsBuffer.SetData(_drawArgs, 0, argOf, 5);
-
+					ImDrawCmdPtr cmd = drawList.CmdBuffer[meshIndex];
+					var drawArgs = new int[]
+					{
+						(int)cmd.ElemCount,
+						1,
+						idxOf + (int)cmd.IdxOffset,
+						vtxOf,
+						0
+					};
+					_argumentsBuffer.SetData(drawArgs, 0, argOf, 5);
 					argOf += 5; // 5 int for each command.
 				}
 				vtxOf += vtxArray.Length;

diff --git a/Source/Utils/RenderUtility.cs b/Source/Utils/RenderUtility.cs
@@ -19,8 +19,10 @@ public static IRenderer Create(RenderType type, ShaderResourcesAsset shaders, Te
 
 			switch (type)
 			{
+#if UNITY_2020_1_OR_NEWER
 				case RenderType.Mesh:
 					return new RendererMesh(shaders, textures);
+#endif
 				case RenderType.Procedural:
 					return new RendererProcedural(shaders, textures);
 				default:

diff --git a/package.json b/package.json
@@ -3,9 +3,8 @@
   "displayName": "UImGui",
   "version": "4.0.0",
   "description": "A Unity wrapper for ImGui",
-  "unity": "2020.3",
+  "unity": "2019.4",
   "dependencies": {
-    "com.unity.collections": "0.15.0-preview.21"
   },
   "keywords": [
     "dear",