From 4a80ef547b2990a8d37d112c66b6646ae669a4f1 Mon Sep 17 00:00:00 2001
From: Jarrod Doyle <thejarroddoyle@gmail.com>
Date: Wed, 28 Aug 2024 07:44:07 +0100
Subject: [PATCH] Support toggling lightmap layers

---
 project/code/TMV/Mission.cs | 75 ++++++++++++++++++++++++++++++++++++-
 project/materials/base.tres | 31 ++++++++++-----
 2 files changed, 95 insertions(+), 11 deletions(-)

diff --git a/project/code/TMV/Mission.cs b/project/code/TMV/Mission.cs
index fb4b120..1e3802d 100644
--- a/project/code/TMV/Mission.cs
+++ b/project/code/TMV/Mission.cs
@@ -45,12 +45,16 @@ public partial class Mission : Node3D
 	DbFile _file;
 	TextureLoader _textureLoader;
 	ModelLoader _modelLoader;
+	List<ShaderMaterial> _materials;
+	Vector2I _lmLayerMask;
 
 	public override void _Ready()
 	{
 		var extractPath = ProjectSettings.GlobalizePath($"user://extracted/tmp");
 		_installPaths = new ResourcePathManager(extractPath);
 		_modelLoader = new ModelLoader(_installPaths);
+		_materials = new List<ShaderMaterial>();
+		_lmLayerMask = new Vector2I(~0, ~0);
 		var missionSelector = GetNode<Control>("%MissionSelector") as MissionSelector;
 		missionSelector.pathManager = _installPaths;
 		missionSelector.MissionSelected += (string campaign, string mission) =>
@@ -84,6 +88,10 @@ public partial class Mission : Node3D
 			{
 				Build = true;
 			}
+			if (keyEvent.Keycode == Key.O)
+			{
+				ToggleLightmap();
+			}
 		}
 	}
 
@@ -93,6 +101,8 @@ public partial class Mission : Node3D
 		{
 			node.QueueFree();
 		}
+
+		_materials.Clear();
 	}
 
 	public void RebuildMap()
@@ -111,6 +121,60 @@ public partial class Mission : Node3D
 		}
 	}
 
+	public void ToggleLightmap()
+	{
+		if (_lmLayerMask == Vector2I.Zero)
+		{
+			_lmLayerMask = new Vector2I(~0, ~0);
+		}
+		else
+		{
+			_lmLayerMask = Vector2I.Zero;
+		}
+
+		foreach (var mat in _materials)
+		{
+			mat.SetShaderParameter("lightmap_bitmask", _lmLayerMask);
+		}
+	}
+
+	public void ToggleLmLayer(uint layer)
+	{
+		if (layer >= 64)
+		{
+			throw new ArgumentOutOfRangeException(nameof(layer));
+		}
+
+		static int ToggleBit(int bitIdx, int val)
+		{
+			var mask = 1 << bitIdx;
+			var isEnabled = (val & mask) != 0;
+			if (isEnabled)
+			{
+				val &= ~mask;
+			}
+			else
+			{
+				val |= mask;
+			}
+			return val;
+		}
+
+		if (layer < 32)
+		{
+			_lmLayerMask.X = ToggleBit((int)layer, _lmLayerMask.X);
+		}
+		else
+		{
+			_lmLayerMask.Y = ToggleBit((int)layer - 32, _lmLayerMask.Y);
+		}
+
+		foreach (var mat in _materials)
+		{
+			mat.SetShaderParameter("lightmap_bitmask", _lmLayerMask);
+		}
+	}
+
 	// TODO: Make this less of a mess
 	private ObjectHierarchy BuildHierarchy()
 	{
@@ -239,10 +303,12 @@ public partial class Mission : Node3D
 			}
 
 			var albedoTexture = _textureLoader.Get(textureId);
+			var mat = BuildMaterial(albedoTexture, lightmapTexture, lmHdr, _lmLayerMask);
+			_materials.Add(mat);
 
 			var mesh = new ArrayMesh();
 			mesh.AddSurfaceFromArrays(Mesh.PrimitiveType.Triangles, surface.BuildSurfaceArray());
-			mesh.SurfaceSetMaterial(0, BuildMaterial(albedoTexture, lightmapTexture, lmHdr));
+			mesh.SurfaceSetMaterial(0, mat);
 
 			var meshInstance = new MeshInstance3D { Mesh = mesh };
 			AddChild(meshInstance);
@@ -472,12 +538,17 @@ public partial class Mission : Node3D
 	}
 
 	const string MATERIAL_PATH = "res://project/materials/base.tres";
-	private static Material BuildMaterial(Texture2D albedoTexture, Texture2DArray lightmapTexture, bool lmHdr)
+	private static ShaderMaterial BuildMaterial(
+		Texture2D albedoTexture,
+		Texture2DArray lightmapTexture,
+		bool lmHdr,
+		Vector2I layerMask)
 	{
 		var material = ResourceLoader.Load<ShaderMaterial>(MATERIAL_PATH).Duplicate() as ShaderMaterial;
 		material.SetShaderParameter("texture_albedo", albedoTexture);
 		material.SetShaderParameter("lightmap_albedo", lightmapTexture);
 		material.SetShaderParameter("lightmap_2x", lmHdr);
+		material.SetShaderParameter("lightmap_bitmask", layerMask);
 		return material;
 	}
 }
\ No newline at end of file
diff --git a/project/materials/base.tres b/project/materials/base.tres
index 8854037..1a0121a 100644
--- a/project/materials/base.tres
+++ b/project/materials/base.tres
@@ -6,6 +6,7 @@ render_mode blend_mix,depth_draw_opaque,cull_back,unshaded;
 uniform sampler2D texture_albedo : filter_linear_mipmap_anisotropic,repeat_enable;
 uniform sampler2DArray lightmap_albedo : filter_linear_mipmap_anisotropic,repeat_enable;
 uniform bool lightmap_2x;
+uniform ivec2 lightmap_bitmask;
 
 float srgb_to_linear_e(float input) {
 	float output;
@@ -28,16 +29,27 @@ vec3 srgb_to_linear(vec3 input) {
 
 void fragment() {
 	vec4 albedo_tex = texture(texture_albedo,UV);
-	vec4 lightmap_tex = vec4(0.0);
-	for (int i = 0; i < 33; i++) {
-		lightmap_tex += texture(lightmap_albedo, vec3(UV2, float(i)));
+	if (lightmap_bitmask.x == 0 && lightmap_bitmask.y == 0) {
+		ALBEDO = srgb_to_linear(albedo_tex.rgb);
+	} else {
+		vec4 lightmap_tex = vec4(0.0);
+		int mask = lightmap_bitmask.x;
+		for (int i = 0; i < 33; i++) {
+			if (i == 32) {
+				mask = lightmap_bitmask.y;
+			}
+			bool layer_enabled = (mask & (1 << (i % 32))) != 0;
+			if (layer_enabled) {
+				lightmap_tex += texture(lightmap_albedo, vec3(UV2, float(i)));
+			}
+		}
+		lightmap_tex = min(vec4(1.0), lightmap_tex);
+		
+		if (lightmap_2x) {
+			lightmap_tex *= 2.0f;
+		}
+		ALBEDO = srgb_to_linear((albedo_tex * lightmap_tex).rgb);
 	}
-	lightmap_tex = min(vec4(1.0), lightmap_tex);
-	
-	if (lightmap_2x) {
-		lightmap_tex *= 2.0f;
-	}
-	ALBEDO = srgb_to_linear((albedo_tex * lightmap_tex).rgb);
 }
 "
 
@@ -45,3 +57,4 @@ void fragment() {
 render_priority = 0
 shader = SubResource("Shader_eumy4")
 shader_parameter/lightmap_2x = null
+shader_parameter/lightmap_bitmask = null