From 0f626376626a227236755dc86ac7a9c6b76ec1cc Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Simon=20L=C3=BCbe=C3=9F?= <simon.luebess@gmail.com>
Date: Thu, 25 Mar 2021 20:43:43 +0100
Subject: [PATCH] Generate fallback entries for missing block textures

---
 Sandbox/src/VoxelFun/TextureAtlas.bf | 31 ++++++++++++++++++++++++++--
 1 file changed, 29 insertions(+), 2 deletions(-)

diff --git a/Sandbox/src/VoxelFun/TextureAtlas.bf b/Sandbox/src/VoxelFun/TextureAtlas.bf
index a1d0b8a..d145ee8 100644
--- a/Sandbox/src/VoxelFun/TextureAtlas.bf
+++ b/Sandbox/src/VoxelFun/TextureAtlas.bf
@@ -8,11 +8,13 @@ namespace Sandbox.VoxelFun
 {
 	class TextureAtlas : Texture2D
 	{
+		typealias TexEntry = (Color* data, uint32 width, uint32 height, BlockTexture blockTex);
+
 		public this(GraphicsContext context, List<BlockTexture> textures) : base(context)
 		{
 			// Todo: rewrite this garbage algorithm
 
-			List<(Color* data, uint32 width, uint32 height, BlockTexture blockTex)> textureDatas = new .(textures.Count);
+			List<TexEntry> textureDatas = new .(textures.Count);
 			defer
 			{
 				for(let item in textureDatas)
@@ -26,6 +28,11 @@ namespace Sandbox.VoxelFun
 			uint32 maxWidth = 0;
 			uint32 maxHeight = 0;
 
+			Color[4] nullColors = .(.HotPink, .Black, .Black, .HotPink);
+			BlockTexture nullBT = scope .("NULL");
+			TexEntry nullTexture = (&nullColors, 2, 2, nullBT);
+			bool nullTexWriten = false;
+
 			for(let texture in textures)
 			{
 				(Color* data, uint32 width, uint32 height, BlockTexture blockTex) tex;
@@ -57,7 +64,8 @@ namespace Sandbox.VoxelFun
 			uint32 currentX = 0;
 			uint32 currentY = 0;
 
-			for(let texture in textureDatas)
+			/// Copies the data of the given texture into the atlas
+			void CopyTextureIntoAtlas(TexEntry texture)
 			{
 				texture.blockTex.[Friend]_atlasStart = .((float)currentX / (float)textureWidth, (float)currentY / (float)textureHeight);
 				texture.blockTex.[Friend]_atlasSize = .((float)texture.width / (float)textureWidth, (float)texture.height / (float)textureHeight);
@@ -76,6 +84,25 @@ namespace Sandbox.VoxelFun
 				}
 			}
 
+			for(let texture in textureDatas)
+			{
+				if(texture.data != null)
+				{
+					CopyTextureIntoAtlas(texture);
+				}
+				else
+				{
+					if(!nullTexWriten)
+					{
+						CopyTextureIntoAtlas(nullTexture);
+						nullTexWriten = true;
+					}
+					
+					texture.blockTex.[Friend]_atlasStart = nullTexture.blockTex.[Friend]_atlasStart;
+					texture.blockTex.[Friend]_atlasSize = nullTexture.blockTex.[Friend]_atlasSize;
+				}
+			}
+
 			Texture2DDesc desc;
 			desc.Width = textureWidth;
 			desc.Height = textureHeight;