Add static glTF support (#14557)

Co-authored-by: Lars Mueller <appgurulars@gmx.de>
Co-authored-by: jordan4ibanez <jordan4ibanez@users.noreply.github.com>
Co-authored-by: sfan5 <sfan5@live.de>
Co-authored-by: SmallJoker <SmallJoker@users.noreply.github.com>

games/devtest/mods/gltf/LICENSE.md

@@ -0,0 +1,14 @@
+glTF test model (and corresponding texture) licenses:
+
+* Spider (`gltf_spider.gltf`, `gltf_spider.png`):
+  * By [archfan7411](https://github.com/archfan7411)
+  * Licensed under CC0, public domain "wherever public domain carries fewer rights or legal protections"
+* Frog (`gltf_frog.gltf`, `gltf_frog.png`):
+  * By [Susybaka1234](https://sketchfab.com/3d-models/african-clawed-frog-v2-c81152c93948480c931c280d18957358)
+  * Licensed under CC-BY 4.0
+* Snow Man (`gltf_snow_man.gltf`, `gltf_snow_man.png`):
+  * By [jordan4ibanez](https://github.com/jordan4ibanez)
+  * Licensed under CC0
+* Minimal triangle, triangle without indices (`gltf_minimal_triangle.gltf`, `gltf_triangle_without_indices.gltf`)
+  * From [the glTF sample model collection](https://github.com/KhronosGroup/glTF-Sample-Models)
+  * Licensed under CC0 / public domain

games/devtest/mods/gltf/init.lua

@@ -0,0 +1,51 @@
+local function register_entity(name, textures, backface_culling)
+	minetest.register_entity("gltf:" .. name, {
+		initial_properties = {
+			visual = "mesh",
+			mesh = "gltf_" .. name .. ".gltf",
+			textures = textures,
+			backface_culling = backface_culling,
+		},
+	})
+end
+
+-- These do not have texture coordinates; they simple render as black surfaces.
+register_entity("minimal_triangle", {}, false)
+register_entity("triangle_with_vertex_stride", {}, false)
+register_entity("triangle_without_indices", {}, false)
+do
+	local cube_textures = {"gltf_cube.png"}
+	register_entity("blender_cube", cube_textures)
+	register_entity("blender_cube_scaled", cube_textures)
+	register_entity("blender_cube_matrix_transform", cube_textures)
+end
+register_entity("snow_man", {"gltf_snow_man.png"})
+register_entity("spider", {"gltf_spider.png"})
+-- Note: Model has an animation, but we can use it as a static test nevertheless
+-- The claws rendering incorrectly from one side is expected behavior:
+-- They use an unsupported double-sided material.
+register_entity("frog", {"gltf_frog.png"}, false)
+
+minetest.register_node("gltf:frog", {
+	description = "glTF frog, but it's a node",
+	tiles = {{name = "gltf_frog.png", backface_culling = false}},
+	drawtype = "mesh",
+	mesh = "gltf_frog.gltf",
+})
+
+minetest.register_chatcommand("show_model", {
+	params = "<model> [textures]",
+	description = "Show a model (defaults to gltf models, for example '/show_model frog').",
+	func = function(name, param)
+		local model, textures = param:match"^(.-)%s+(.+)$"
+		if not model then
+			model = "gltf_" .. param .. ".gltf"
+			textures = "gltf_" .. param .. ".png"
+		end
+		minetest.show_formspec(name, "gltf:model", table.concat{
+			"formspec_version[7]",
+			"size[10,10]",
+			"model[0,0;10,10;model;", model, ";", textures, ";0,0;true;true;0,0;0]",
+		})
+	end,
+})

games/devtest/mods/gltf/invalid/invalid_bufferview_bounds.gltf

@@ -0,0 +1 @@
+{"scene":0,"scenes":[{"nodes":[0]}],"nodes":[{"mesh":0}],"meshes":[{"primitives":[{"attributes":{"POSITION":0}}]}],"buffers":[{"uri":"data:application/octet-stream;base64,AAAAAAAAAAAAAAAAAACAPwAAAAAAAAAAAAAAAAAAgD8AAAAA","byteLength":36}],"bufferViews":[{"buffer":0,"byteOffset":1,"byteLength":36,"target":34962}],"accessors":[{"bufferView":0,"byteOffset":0,"componentType":5126,"count":3,"type":"VEC3","max":[1,1,0],"min":[0,0,0]}],"asset":{"version":"2.0"}}

games/devtest/mods/gltf/invalid/json_missing_brace.gltf

@@ -0,0 +1 @@
+{

games/devtest/mods/gltf/mod.conf

@@ -0,0 +1,2 @@
+name = gltf
+description = Hosts gltf test models, both for the C++ unit tests and for in-game viewing

games/devtest/mods/gltf/models/gltf_blender_cube.gltf

@@ -0,0 +1 @@
+{"asset":{"generator":"Khronos glTF Blender I/O v1.7.33","version":"2.0"},"scene":0,"scenes":[{"name":"Scene","nodes":[0]}],"nodes":[{"mesh":0,"name":"Cube","scale":[10,10,10]}],"meshes":[{"name":"Cube.004","primitives":[{"attributes":{"POSITION":0,"NORMAL":1,"TEXCOORD_0":2},"indices":3}]}],"accessors":[{"bufferView":0,"componentType":5126,"count":24,"max":[1,1,1],"min":[-1,-1,-1],"type":"VEC3"},{"bufferView":1,"componentType":5126,"count":24,"type":"VEC3"},{"bufferView":2,"componentType":5126,"count":24,"type":"VEC2"},{"bufferView":3,"componentType":5123,"count":36,"type":"SCALAR"}],"bufferViews":[{"buffer":0,"byteLength":288,"byteOffset":0},{"buffer":0,"byteLength":288,"byteOffset":288},{"buffer":0,"byteLength":192,"byteOffset":576},{"buffer":0,"byteLength":72,"byteOffset":768}],"buffers":[{"byteLength":840,"uri":"data:application/octet-stream;base64,AACAvwAAgL8AAIA/AACAvwAAgL8AAIA/AACAvwAAgL8AAIA/AACAvwAAgD8AAIA/AACAvwAAgD8AAIA/AACAvwAAgD8AAIA/AACAvwAAgL8AAIC/AACAvwAAgL8AAIC/AACAvwAAgL8AAIC/AACAvwAAgD8AAIC/AACAvwAAgD8AAIC/AACAvwAAgD8AAIC/AACAPwAAgL8AAIA/AACAPwAAgL8AAIA/AACAPwAAgL8AAIA/AACAPwAAgD8AAIA/AACAPwAAgD8AAIA/AACAPwAAgD8AAIA/AACAPwAAgL8AAIC/AACAPwAAgL8AAIC/AACAPwAAgL8AAIC/AACAPwAAgD8AAIC/AACAPwAAgD8AAIC/AACAPwAAgD8AAIC/AACAvwAAAAAAAACAAAAAAAAAgL8AAACAAAAAAAAAAAAAAIA/AACAvwAAAAAAAACAAAAAAAAAAAAAAIA/AAAAAAAAgD8AAACAAACAvwAAAAAAAACAAAAAAAAAgL8AAACAAAAAAAAAAAAAAIC/AACAvwAAAAAAAACAAAAAAAAAAAAAAIC/AAAAAAAAgD8AAACAAAAAAAAAgL8AAACAAAAAAAAAAAAAAIA/AACAPwAAAAAAAACAAAAAAAAAAAAAAIA/AAAAAAAAgD8AAACAAACAPwAAAAAAAACAAAAAAAAAgL8AAACAAAAAAAAAAAAAAIC/AACAPwAAAAAAAACAAAAAAAAAAAAAAIC/AAAAAAAAgD8AAACAAACAPwAAAAAAAACAAADAPgAAgD8AAAA+AACAPgAAwD4AAAAAAAAgPwAAgD8AACA/AAAAAAAAYD8AAIA+AADAPgAAQD8AAAA+AAAAPwAAwD4AAEA/AAAgPwAAQD8AACA/AABAPwAAYD8AAAA/AADAPgAAgD4AAMA+AACAPgAAwD4AAIA+AAAgPwAAgD4AACA/AACAPgAAID8AAIA+AADAPgAAAD8AAMA+AAAAPwAAwD4AAAA/AAAgPwAAAD8AACA/AAAAPwAAID8AAAA/AAADAAkAAAAJAAYACAAKABUACAAVABMAFAAXABEAFAARAA4ADQAPAAQADQAEAAIABwASAAwABwAMAAEAFgALAAUAFgAFABAA"}]}

games/devtest/mods/gltf/models/gltf_blender_cube_matrix_transform.gltf

@@ -0,0 +1 @@
+{"asset":{"generator":"Khronos glTF Blender I/O v1.7.33","version":"2.0"},"scene":0,"scenes":[{"name":"Scene","nodes":[0]}],"nodes":[{"mesh":0,"name":"Cube","matrix":[1,0,0,0,0,2,0,0,0,0,3,0,4,5,6,1]}],"meshes":[{"name":"Cube.004","primitives":[{"attributes":{"POSITION":0,"NORMAL":1,"TEXCOORD_0":2},"indices":3}]}],"accessors":[{"bufferView":0,"componentType":5126,"count":24,"max":[1,1,1],"min":[-1,-1,-1],"type":"VEC3"},{"bufferView":1,"componentType":5126,"count":24,"type":"VEC3"},{"bufferView":2,"componentType":5126,"count":24,"type":"VEC2"},{"bufferView":3,"componentType":5123,"count":36,"type":"SCALAR"}],"bufferViews":[{"buffer":0,"byteLength":288,"byteOffset":0},{"buffer":0,"byteLength":288,"byteOffset":288},{"buffer":0,"byteLength":192,"byteOffset":576},{"buffer":0,"byteLength":72,"byteOffset":768}],"buffers":[{"byteLength":840,"uri":"data:application/octet-stream;base64,AACAvwAAgL8AAIA/AACAvwAAgL8AAIA/AACAvwAAgL8AAIA/AACAvwAAgD8AAIA/AACAvwAAgD8AAIA/AACAvwAAgD8AAIA/AACAvwAAgL8AAIC/AACAvwAAgL8AAIC/AACAvwAAgL8AAIC/AACAvwAAgD8AAIC/AACAvwAAgD8AAIC/AACAvwAAgD8AAIC/AACAPwAAgL8AAIA/AACAPwAAgL8AAIA/AACAPwAAgL8AAIA/AACAPwAAgD8AAIA/AACAPwAAgD8AAIA/AACAPwAAgD8AAIA/AACAPwAAgL8AAIC/AACAPwAAgL8AAIC/AACAPwAAgL8AAIC/AACAPwAAgD8AAIC/AACAPwAAgD8AAIC/AACAPwAAgD8AAIC/AACAvwAAAAAAAACAAAAAAAAAgL8AAACAAAAAAAAAAAAAAIA/AACAvwAAAAAAAACAAAAAAAAAAAAAAIA/AAAAAAAAgD8AAACAAACAvwAAAAAAAACAAAAAAAAAgL8AAACAAAAAAAAAAAAAAIC/AACAvwAAAAAAAACAAAAAAAAAAAAAAIC/AAAAAAAAgD8AAACAAAAAAAAAgL8AAACAAAAAAAAAAAAAAIA/AACAPwAAAAAAAACAAAAAAAAAAAAAAIA/AAAAAAAAgD8AAACAAACAPwAAAAAAAACAAAAAAAAAgL8AAACAAAAAAAAAAAAAAIC/AACAPwAAAAAAAACAAAAAAAAAAAAAAIC/AAAAAAAAgD8AAACAAACAPwAAAAAAAACAAADAPgAAgD8AAAA+AACAPgAAwD4AAAAAAAAgPwAAgD8AACA/AAAAAAAAYD8AAIA+AADAPgAAQD8AAAA+AAAAPwAAwD4AAEA/AAAgPwAAQD8AACA/AABAPwAAYD8AAAA/AADAPgAAgD4AAMA+AACAPgAAwD4AAIA+AAAgPwAAgD4AACA/AACAPgAAID8AAIA+AADAPgAAAD8AAMA+AAAAPwAAwD4AAAA/AAAgPwAAAD8AACA/AAAAPwAAID8AAAA/AAADAAkAAAAJAAYACAAKABUACAAVABMAFAAXABEAFAARAA4ADQAPAAQADQAEAAIABwASAAwABwAMAAEAFgALAAUAFgAFABAA"}]}

games/devtest/mods/gltf/models/gltf_blender_cube_scaled.gltf

@@ -0,0 +1 @@
+{"asset":{"generator":"Khronos glTF Blender I/O v1.7.33","version":"2.0"},"scene":0,"scenes":[{"name":"Scene","nodes":[0]}],"nodes":[{"mesh":0,"name":"Cube","scale":[150,1,21.5]}],"meshes":[{"name":"Cube.004","primitives":[{"attributes":{"POSITION":0,"NORMAL":1,"TEXCOORD_0":2},"indices":3}]}],"accessors":[{"bufferView":0,"componentType":5126,"count":24,"max":[1,1,1],"min":[-1,-1,-1],"type":"VEC3"},{"bufferView":1,"componentType":5126,"count":24,"type":"VEC3"},{"bufferView":2,"componentType":5126,"count":24,"type":"VEC2"},{"bufferView":3,"componentType":5123,"count":36,"type":"SCALAR"}],"bufferViews":[{"buffer":0,"byteLength":288,"byteOffset":0},{"buffer":0,"byteLength":288,"byteOffset":288},{"buffer":0,"byteLength":192,"byteOffset":576},{"buffer":0,"byteLength":72,"byteOffset":768}],"buffers":[{"byteLength":840,"uri":"data:application/octet-stream;base64,AACAvwAAgL8AAIA/AACAvwAAgL8AAIA/AACAvwAAgL8AAIA/AACAvwAAgD8AAIA/AACAvwAAgD8AAIA/AACAvwAAgD8AAIA/AACAvwAAgL8AAIC/AACAvwAAgL8AAIC/AACAvwAAgL8AAIC/AACAvwAAgD8AAIC/AACAvwAAgD8AAIC/AACAvwAAgD8AAIC/AACAPwAAgL8AAIA/AACAPwAAgL8AAIA/AACAPwAAgL8AAIA/AACAPwAAgD8AAIA/AACAPwAAgD8AAIA/AACAPwAAgD8AAIA/AACAPwAAgL8AAIC/AACAPwAAgL8AAIC/AACAPwAAgL8AAIC/AACAPwAAgD8AAIC/AACAPwAAgD8AAIC/AACAPwAAgD8AAIC/AACAvwAAAAAAAACAAAAAAAAAgL8AAACAAAAAAAAAAAAAAIA/AACAvwAAAAAAAACAAAAAAAAAAAAAAIA/AAAAAAAAgD8AAACAAACAvwAAAAAAAACAAAAAAAAAgL8AAACAAAAAAAAAAAAAAIC/AACAvwAAAAAAAACAAAAAAAAAAAAAAIC/AAAAAAAAgD8AAACAAAAAAAAAgL8AAACAAAAAAAAAAAAAAIA/AACAPwAAAAAAAACAAAAAAAAAAAAAAIA/AAAAAAAAgD8AAACAAACAPwAAAAAAAACAAAAAAAAAgL8AAACAAAAAAAAAAAAAAIC/AACAPwAAAAAAAACAAAAAAAAAAAAAAIC/AAAAAAAAgD8AAACAAACAPwAAAAAAAACAAADAPgAAgD8AAAA+AACAPgAAwD4AAAAAAAAgPwAAgD8AACA/AAAAAAAAYD8AAIA+AADAPgAAQD8AAAA+AAAAPwAAwD4AAEA/AAAgPwAAQD8AACA/AABAPwAAYD8AAAA/AADAPgAAgD4AAMA+AACAPgAAwD4AAIA+AAAgPwAAgD4AACA/AACAPgAAID8AAIA+AADAPgAAAD8AAMA+AAAAPwAAwD4AAAA/AAAgPwAAAD8AACA/AAAAPwAAID8AAAA/AAADAAkAAAAJAAYACAAKABUACAAVABMAFAAXABEAFAARAA4ADQAPAAQADQAEAAIABwASAAwABwAMAAEAFgALAAUAFgAFABAA"}]}

games/devtest/mods/gltf/models/gltf_minimal_triangle.gltf

@@ -0,0 +1 @@
+{"scene":0,"scenes":[{"nodes":[0]}],"nodes":[{"mesh":0}],"meshes":[{"primitives":[{"attributes":{"POSITION":1},"indices":0}]}],"buffers":[{"uri":"data:application/octet-stream;base64,AAABAAIAAAAAAAAAAAAAAAAAAAAAAIA/AAAAAAAAAAAAAAAAAACAPwAAAAA=","byteLength":44}],"bufferViews":[{"buffer":0,"byteOffset":0,"byteLength":6,"target":34963},{"buffer":0,"byteOffset":8,"byteLength":36,"target":34962}],"accessors":[{"bufferView":0,"byteOffset":0,"componentType":5123,"count":3,"type":"SCALAR","max":[2],"min":[0]},{"bufferView":1,"byteOffset":0,"componentType":5126,"count":3,"type":"VEC3","max":[1,1,0],"min":[0,0,0]}],"asset":{"version":"2.0"}}

games/devtest/mods/gltf/models/gltf_simple_sparse_accessor.gltf

@@ -0,0 +1 @@
+{"scene":0,"scenes":[{"nodes":[0]}],"nodes":[{"mesh":0}],"meshes":[{"primitives":[{"attributes":{"POSITION":1},"indices":0}]}],"buffers":[{"uri":"data:application/gltf-buffer;base64,AAAIAAcAAAABAAgAAQAJAAgAAQACAAkAAgAKAAkAAgADAAoAAwALAAoAAwAEAAsABAAMAAsABAAFAAwABQANAAwABQAGAA0AAAAAAAAAAAAAAAAAAACAPwAAAAAAAAAAAAAAQAAAAAAAAAAAAABAQAAAAAAAAAAAAACAQAAAAAAAAAAAAACgQAAAAAAAAAAAAADAQAAAAAAAAAAAAAAAAAAAgD8AAAAAAACAPwAAgD8AAAAAAAAAQAAAgD8AAAAAAABAQAAAgD8AAAAAAACAQAAAgD8AAAAAAACgQAAAgD8AAAAAAADAQAAAgD8AAAAACAAKAAwAAAAAAIA/AAAAQAAAAAAAAEBAAABAQAAAAAAAAKBAAACAQAAAAAA=","byteLength":284}],"bufferViews":[{"buffer":0,"byteOffset":0,"byteLength":72,"target":34963},{"buffer":0,"byteOffset":72,"byteLength":168},{"buffer":0,"byteOffset":240,"byteLength":6},{"buffer":0,"byteOffset":248,"byteLength":36}],"accessors":[{"bufferView":0,"byteOffset":0,"componentType":5123,"count":36,"type":"SCALAR","max":[13],"min":[0]},{"bufferView":1,"byteOffset":0,"componentType":5126,"count":14,"type":"VEC3","max":[6,4,0],"min":[0,0,0],"sparse":{"count":3,"indices":{"bufferView":2,"byteOffset":0,"componentType":5123},"values":{"bufferView":3,"byteOffset":0}}}],"asset":{"version":"2.0"}}

games/devtest/mods/gltf/models/gltf_triangle_with_vertex_stride.gltf

@@ -0,0 +1 @@
+{"scene":0,"scenes":[{"nodes":[0]}],"nodes":[{"mesh":0}],"meshes":[{"primitives":[{"attributes":{"POSITION":1},"indices":0}]}],"buffers":[{"uri":"data:application/octet-stream;base64,AAABAAIAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAIA/AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAACAPwAAAAAAAAAAAAAAAAAAAAA=","byteLength":80}],"bufferViews":[{"buffer":0,"byteOffset":0,"byteLength":6,"target":34963},{"buffer":0,"byteOffset":8,"byteLength":72,"byteStride":24,"target":34962}],"accessors":[{"bufferView":0,"byteOffset":0,"componentType":5123,"count":3,"type":"SCALAR","max":[2],"min":[0]},{"bufferView":1,"byteOffset":0,"componentType":5126,"count":3,"type":"VEC3","max":[1,1,0],"min":[0,0,0]}],"asset":{"version":"2.0"}}

games/devtest/mods/gltf/models/gltf_triangle_without_indices.gltf

@@ -0,0 +1 @@
+{"scene":0,"scenes":[{"nodes":[0]}],"nodes":[{"mesh":0}],"meshes":[{"primitives":[{"attributes":{"POSITION":0}}]}],"buffers":[{"uri":"data:application/octet-stream;base64,AAAAAAAAAAAAAAAAAACAPwAAAAAAAAAAAAAAAAAAgD8AAAAA","byteLength":36}],"bufferViews":[{"buffer":0,"byteOffset":0,"byteLength":36,"target":34962}],"accessors":[{"bufferView":0,"byteOffset":0,"componentType":5126,"count":3,"type":"VEC3","max":[1,1,0],"min":[0,0,0]}],"asset":{"version":"2.0"}}