From 1582b341d339191129e2ed32cf41867f6f89974f Mon Sep 17 00:00:00 2001
From: lisyarus <lisyarus@gmail.com>
Date: Wed, 1 Feb 2023 20:35:32 +0300
Subject: [PATCH] Support child nodes & node transforms in gltf parser

---
 libs/gfx/include/psemek/gfx/gltf_parser.hpp |  9 +++++-
 libs/gfx/source/gltf_mesh.cpp               |  5 +++-
 libs/gfx/source/gltf_parser.cpp             | 33 ++++++++++++++++++++-
 3 files changed, 44 insertions(+), 3 deletions(-)

diff --git a/libs/gfx/include/psemek/gfx/gltf_parser.hpp b/libs/gfx/include/psemek/gfx/gltf_parser.hpp
index 477c6d10..35147b97 100644
--- a/libs/gfx/include/psemek/gfx/gltf_parser.hpp
+++ b/libs/gfx/include/psemek/gfx/gltf_parser.hpp
@@ -2,6 +2,8 @@
 
 #include <psemek/io/stream.hpp>
 #include <psemek/gfx/color.hpp>
+#include <psemek/geom/vector.hpp>
+#include <psemek/geom/quaternion.hpp>
 
 #include <vector>
 #include <string>
@@ -15,7 +17,12 @@ namespace psemek::gfx
 		struct node
 		{
 			std::string name;
-			std::size_t mesh;
+			std::optional<std::size_t> mesh;
+			std::vector<std::size_t> children;
+
+			geom::vector<float, 3> translation;
+			geom::quaternion<float> rotation;
+			geom::vector<float, 3> scale;
 		};
 
 		struct mesh
diff --git a/libs/gfx/source/gltf_mesh.cpp b/libs/gfx/source/gltf_mesh.cpp
index 6abfb879..b0ddf769 100644
--- a/libs/gfx/source/gltf_mesh.cpp
+++ b/libs/gfx/source/gltf_mesh.cpp
@@ -80,9 +80,12 @@ namespace psemek::gfx
 
 			for (auto const & node : asset.nodes)
 			{
+				if (!node.mesh)
+					continue;
+
 				auto & target_mesh = meshes_[node.name];
 
-				auto const & mesh = asset.meshes[node.mesh];
+				auto const & mesh = asset.meshes[*node.mesh];
 
 				for (auto const & primitive : mesh.primitives)
 				{
diff --git a/libs/gfx/source/gltf_parser.cpp b/libs/gfx/source/gltf_parser.cpp
index e41568f8..eeaa24eb 100644
--- a/libs/gfx/source/gltf_parser.cpp
+++ b/libs/gfx/source/gltf_parser.cpp
@@ -74,8 +74,39 @@ namespace psemek::gfx
 		for (auto const & node : document["nodes"].GetArray())
 		{
 			auto & target = result.nodes.emplace_back();
-			target.mesh = node["mesh"].GetUint64();
 			target.name = node["name"].GetString();
+			if (node.HasMember("mesh"))
+				target.mesh = node["mesh"].GetUint64();
+
+			target.translation = {0.f, 0.f, 0.f};
+			if (node.HasMember("translation"))
+			{
+				auto const & translation = node["translation"].GetArray();
+				for (std::size_t i = 0; i < 3; ++i)
+					target.translation[i] = translation[i].GetFloat();
+			}
+
+			target.rotation = geom::quaternion<float>::identity();
+			if (node.HasMember("rotation"))
+			{
+				auto const & rotation = node["rotation"].GetArray();
+				for (std::size_t i = 0; i < 4; ++i)
+					target.rotation[i] = rotation[i].GetFloat();
+			}
+
+			target.scale = {0.f, 0.f, 0.f};
+			if (node.HasMember("scale"))
+			{
+				auto const & scale = node["scale"].GetArray();
+				for (std::size_t i = 0; i < 3; ++i)
+					target.scale[i] = scale[i].GetFloat();
+			}
+
+			if (node.HasMember("children"))
+			{
+				for (auto const & child : node["children"].GetArray())
+					target.children.push_back(child.GetUint64());
+			}
 		}
 
 		for (auto const & mesh : document["meshes"].GetArray())