Add support for extending GLTF with more texture formats and support WebP

modules/gltf/doc_classes/GLTFDocumentExtension.xml

@@ -103,6 +103,17 @@
 				The return value is used to determine if this [GLTFDocumentExtension] instance should be used for importing a given GLTF file. If [constant OK], the import will use this [GLTFDocumentExtension] instance. If not overridden, [constant OK] is returned.
 			</description>
 		</method>
+		<method name="_parse_image_data" qualifiers="virtual">
+			<return type="int" enum="Error" />
+			<param index="0" name="state" type="GLTFState" />
+			<param index="1" name="image_data" type="PackedByteArray" />
+			<param index="2" name="mime_type" type="String" />
+			<param index="3" name="ret_image" type="Image" />
+			<description>
+				Part of the import process. This method is run after [method _parse_node_extensions] and before [method _parse_texture_json].
+				Runs when parsing image data from a GLTF file. The data could be sourced from a separate file, a URI, or a buffer, and then is passed as a byte array.
+			</description>
+		</method>
 		<method name="_parse_node_extensions" qualifiers="virtual">
 			<return type="int" enum="Error" />
 			<param index="0" name="state" type="GLTFState" />
@@ -113,5 +124,15 @@
 				Runs when parsing the node extensions of a GLTFNode. This method can be used to process the extension JSON data into a format that can be used by [method _generate_scene_node]. The return value should be a member of the [enum Error] enum.
 			</description>
 		</method>
+		<method name="_parse_texture_json" qualifiers="virtual">
+			<return type="int" enum="Error" />
+			<param index="0" name="state" type="GLTFState" />
+			<param index="1" name="texture_json" type="Dictionary" />
+			<param index="2" name="ret_gltf_texture" type="GLTFTexture" />
+			<description>
+				Part of the import process. This method is run after [method _parse_image_data] and before [method _generate_scene_node].
+				Runs when parsing the texture JSON from the GLTF textures array. This can be used to set the source image index to use as the texture.
+			</description>
+		</method>
 	</methods>
 </class>

modules/gltf/doc_classes/GLTFState.xml

@@ -70,6 +70,7 @@
 		<method name="get_images">
 			<return type="Texture2D[]" />
 			<description>
+				Gets the images of the GLTF file as an array of [Texture2D]s. These are the images that the [member GLTFTexture.src_image] index refers to.
 			</description>
 		</method>
 		<method name="get_lights">
@@ -182,6 +183,7 @@
 			<return type="void" />
 			<param index="0" name="images" type="Texture2D[]" />
 			<description>
+				Sets the images in the state stored as an array of [Texture2D]s. This can be used during export. These are the images that the [member GLTFTexture.src_image] index refers to.
 			</description>
 		</method>
 		<method name="set_lights">

modules/gltf/doc_classes/GLTFTexture.xml

@@ -10,7 +10,8 @@
 		<member name="sampler" type="int" setter="set_sampler" getter="get_sampler" default="-1">
 			ID of the texture sampler to use when sampling the image. If -1, then the default texture sampler is used (linear filtering, and repeat wrapping in both axes).
 		</member>
-		<member name="src_image" type="int" setter="set_src_image" getter="get_src_image" default="0">
+		<member name="src_image" type="int" setter="set_src_image" getter="get_src_image" default="-1">
+			The index of the image associated with this texture, see [method GLTFState.get_images]. If -1, then this texture does not have an image assigned.
 		</member>
 	</members>
 </class>

modules/gltf/extensions/gltf_document_extension.cpp

@@ -35,6 +35,8 @@ void GLTFDocumentExtension::_bind_methods() {
 	GDVIRTUAL_BIND(_import_preflight, "state", "extensions");
 	GDVIRTUAL_BIND(_get_supported_extensions);
 	GDVIRTUAL_BIND(_parse_node_extensions, "state", "gltf_node", "extensions");
+	GDVIRTUAL_BIND(_parse_image_data, "state", "image_data", "mime_type", "ret_image");
+	GDVIRTUAL_BIND(_parse_texture_json, "state", "texture_json", "ret_gltf_texture");
 	GDVIRTUAL_BIND(_generate_scene_node, "state", "gltf_node", "scene_parent");
 	GDVIRTUAL_BIND(_import_post_parse, "state");
 	GDVIRTUAL_BIND(_import_node, "state", "gltf_node", "json", "node");
@@ -68,6 +70,22 @@ Error GLTFDocumentExtension::parse_node_extensions(Ref<GLTFState> p_state, Ref<G
 	return err;
 }
 
+Error GLTFDocumentExtension::parse_image_data(Ref<GLTFState> p_state, const PackedByteArray &p_image_data, const String &p_mime_type, Ref<Image> r_image) {
+	ERR_FAIL_NULL_V(p_state, ERR_INVALID_PARAMETER);
+	ERR_FAIL_NULL_V(r_image, ERR_INVALID_PARAMETER);
+	Error err = OK;
+	GDVIRTUAL_CALL(_parse_image_data, p_state, p_image_data, p_mime_type, r_image, err);
+	return err;
+}
+
+Error GLTFDocumentExtension::parse_texture_json(Ref<GLTFState> p_state, const Dictionary &p_texture_json, Ref<GLTFTexture> r_gltf_texture) {
+	ERR_FAIL_NULL_V(p_state, ERR_INVALID_PARAMETER);
+	ERR_FAIL_NULL_V(r_gltf_texture, ERR_INVALID_PARAMETER);
+	Error err = OK;
+	GDVIRTUAL_CALL(_parse_texture_json, p_state, p_texture_json, r_gltf_texture, err);
+	return err;
+}
+
 Node3D *GLTFDocumentExtension::generate_scene_node(Ref<GLTFState> p_state, Ref<GLTFNode> p_gltf_node, Node *p_scene_parent) {
 	ERR_FAIL_NULL_V(p_state, nullptr);
 	ERR_FAIL_NULL_V(p_gltf_node, nullptr);

modules/gltf/extensions/gltf_document_extension.h

@@ -44,6 +44,8 @@ class GLTFDocumentExtension : public Resource {
 	virtual Error import_preflight(Ref<GLTFState> p_state, Vector<String> p_extensions);
 	virtual Vector<String> get_supported_extensions();
 	virtual Error parse_node_extensions(Ref<GLTFState> p_state, Ref<GLTFNode> p_gltf_node, Dictionary &p_extensions);
+	virtual Error parse_image_data(Ref<GLTFState> p_state, const PackedByteArray &p_image_data, const String &p_mime_type, Ref<Image> r_image);
+	virtual Error parse_texture_json(Ref<GLTFState> p_state, const Dictionary &p_texture_json, Ref<GLTFTexture> r_gltf_texture);
 	virtual Node3D *generate_scene_node(Ref<GLTFState> p_state, Ref<GLTFNode> p_gltf_node, Node *p_scene_parent);
 	virtual Error import_post_parse(Ref<GLTFState> p_state);
 	virtual Error import_node(Ref<GLTFState> p_state, Ref<GLTFNode> p_gltf_node, Dictionary &r_json, Node *p_node);
@@ -58,6 +60,8 @@ class GLTFDocumentExtension : public Resource {
 	GDVIRTUAL2R(Error, _import_preflight, Ref<GLTFState>, Vector<String>);
 	GDVIRTUAL0R(Vector<String>, _get_supported_extensions);
 	GDVIRTUAL3R(Error, _parse_node_extensions, Ref<GLTFState>, Ref<GLTFNode>, Dictionary);
+	GDVIRTUAL4R(Error, _parse_image_data, Ref<GLTFState>, PackedByteArray, String, Ref<Image>);
+	GDVIRTUAL3R(Error, _parse_texture_json, Ref<GLTFState>, Dictionary, Ref<GLTFTexture>);
 	GDVIRTUAL3R(Node3D *, _generate_scene_node, Ref<GLTFState>, Ref<GLTFNode>, Node *);
 	GDVIRTUAL1R(Error, _import_post_parse, Ref<GLTFState>);
 	GDVIRTUAL4R(Error, _import_node, Ref<GLTFState>, Ref<GLTFNode>, Dictionary, Node *);

modules/gltf/extensions/gltf_document_extension_texture_webp.cpp

@@ -0,0 +1,68 @@
+/**************************************************************************/
+/*  gltf_document_extension_texture_webp.cpp                              */
+/**************************************************************************/
+/*                         This file is part of:                          */
+/*                             GODOT ENGINE                               */
+/*                        https://godotengine.org                         */
+/**************************************************************************/
+/* Copyright (c) 2014-present Godot Engine contributors (see AUTHORS.md). */
+/* Copyright (c) 2007-2014 Juan Linietsky, Ariel Manzur.                  */
+/*                                                                        */
+/* Permission is hereby granted, free of charge, to any person obtaining  */
+/* a copy of this software and associated documentation files (the        */
+/* "Software"), to deal in the Software without restriction, including    */
+/* without limitation the rights to use, copy, modify, merge, publish,    */
+/* distribute, sublicense, and/or sell copies of the Software, and to     */
+/* permit persons to whom the Software is furnished to do so, subject to  */
+/* the following conditions:                                              */
+/*                                                                        */
+/* The above copyright notice and this permission notice shall be         */
+/* included in all copies or substantial portions of the Software.        */
+/*                                                                        */
+/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,        */
+/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF     */
+/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. */
+/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY   */
+/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,   */
+/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE      */
+/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.                 */
+/**************************************************************************/
+
+#include "gltf_document_extension_texture_webp.h"
+
+#include "scene/3d/area_3d.h"
+
+// Import process.
+Error GLTFDocumentExtensionTextureWebP::import_preflight(Ref<GLTFState> p_state, Vector<String> p_extensions) {
+	if (!p_extensions.has("EXT_texture_webp")) {
+		return ERR_SKIP;
+	}
+	return OK;
+}
+
+Vector<String> GLTFDocumentExtensionTextureWebP::get_supported_extensions() {
+	Vector<String> ret;
+	ret.push_back("EXT_texture_webp");
+	return ret;
+}
+
+Error GLTFDocumentExtensionTextureWebP::parse_image_data(Ref<GLTFState> p_state, const PackedByteArray &p_image_data, const String &p_mime_type, Ref<Image> r_image) {
+	if (p_mime_type == "image/webp") {
+		return r_image->load_webp_from_buffer(p_image_data);
+	}
+	return OK;
+}
+
+Error GLTFDocumentExtensionTextureWebP::parse_texture_json(Ref<GLTFState> p_state, const Dictionary &p_texture_json, Ref<GLTFTexture> r_gltf_texture) {
+	if (!p_texture_json.has("extensions")) {
+		return OK;
+	}
+	const Dictionary &extensions = p_texture_json["extensions"];
+	if (!extensions.has("EXT_texture_webp")) {
+		return OK;
+	}
+	const Dictionary &texture_webp = extensions["EXT_texture_webp"];
+	ERR_FAIL_COND_V(!texture_webp.has("source"), ERR_PARSE_ERROR);
+	r_gltf_texture->set_src_image(texture_webp["source"]);
+	return OK;
+}

modules/gltf/extensions/gltf_document_extension_texture_webp.h

@@ -0,0 +1,47 @@
+/**************************************************************************/
+/*  gltf_document_extension_texture_webp.h                                */
+/**************************************************************************/
+/*                         This file is part of:                          */
+/*                             GODOT ENGINE                               */
+/*                        https://godotengine.org                         */
+/**************************************************************************/
+/* Copyright (c) 2014-present Godot Engine contributors (see AUTHORS.md). */
+/* Copyright (c) 2007-2014 Juan Linietsky, Ariel Manzur.                  */
+/*                                                                        */
+/* Permission is hereby granted, free of charge, to any person obtaining  */
+/* a copy of this software and associated documentation files (the        */
+/* "Software"), to deal in the Software without restriction, including    */
+/* without limitation the rights to use, copy, modify, merge, publish,    */
+/* distribute, sublicense, and/or sell copies of the Software, and to     */
+/* permit persons to whom the Software is furnished to do so, subject to  */
+/* the following conditions:                                              */
+/*                                                                        */
+/* The above copyright notice and this permission notice shall be         */
+/* included in all copies or substantial portions of the Software.        */
+/*                                                                        */
+/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,        */
+/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF     */
+/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. */
+/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY   */
+/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,   */
+/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE      */
+/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.                 */
+/**************************************************************************/
+
+#ifndef GLTF_DOCUMENT_EXTENSION_TEXTURE_WEBP_H
+#define GLTF_DOCUMENT_EXTENSION_TEXTURE_WEBP_H
+
+#include "gltf_document_extension.h"
+
+class GLTFDocumentExtensionTextureWebP : public GLTFDocumentExtension {
+	GDCLASS(GLTFDocumentExtensionTextureWebP, GLTFDocumentExtension);
+
+public:
+	// Import process.
+	Error import_preflight(Ref<GLTFState> p_state, Vector<String> p_extensions) override;
+	Vector<String> get_supported_extensions() override;
+	Error parse_image_data(Ref<GLTFState> p_state, const PackedByteArray &p_image_data, const String &p_mime_type, Ref<Image> r_image) override;
+	Error parse_texture_json(Ref<GLTFState> p_state, const Dictionary &p_texture_json, Ref<GLTFTexture> r_gltf_texture) override;
+};
+
+#endif // GLTF_DOCUMENT_EXTENSION_TEXTURE_WEBP_H