Added `MeshEmitter` node for particles in visual shader

8 files changed, 352 insertions, 7 deletions

diff --git a/doc/classes/VisualShaderNodeParticleMeshEmitter.xml b/doc/classes/VisualShaderNodeParticleMeshEmitter.xml
new file mode 100644
index 0000000000..7abb330fd3
--- /dev/null
+++ b/doc/classes/VisualShaderNodeParticleMeshEmitter.xml
@@ -0,0 +1,17 @@
+<?xml version="1.0" encoding="UTF-8" ?>
+<class name="VisualShaderNodeParticleMeshEmitter" inherits="VisualShaderNodeParticleEmitter" version="4.0">
+	<brief_description>
+	</brief_description>
+	<description>
+	</description>
+	<tutorials>
+	</tutorials>
+	<members>
+		<member name="mesh" type="Mesh" setter="set_mesh" getter="get_mesh">
+		</member>
+		<member name="surface_index" type="int" setter="set_surface_index" getter="get_surface_index" default="0">
+		</member>
+		<member name="use_all_surfaces" type="bool" setter="set_use_all_surfaces" getter="is_use_all_surfaces" default="true">
+		</member>
+	</members>
+</class>
diff --git a/editor/plugins/visual_shader_editor_plugin.cpp b/editor/plugins/visual_shader_editor_plugin.cpp
index 10a9b2bb10..c7c6b9b0ee 100644
--- a/editor/plugins/visual_shader_editor_plugin.cpp
+++ b/editor/plugins/visual_shader_editor_plugin.cpp
@@ -4527,6 +4527,7 @@ VisualShaderEditor::VisualShaderEditor() {
 	add_options.push_back(AddOption("MultiplyByAxisAngle", "Particles", "Transform", "VisualShaderNodeParticleMultiplyByAxisAngle", "A node for help to multiply a position input vector by rotation using specific axis. Intended to work with emitters.", -1, VisualShaderNode::PORT_TYPE_VECTOR, TYPE_FLAGS_EMIT | TYPE_FLAGS_PROCESS | TYPE_FLAGS_COLLIDE, Shader::MODE_PARTICLES));
 
 	add_options.push_back(AddOption("BoxEmitter", "Particles", "Emitters", "VisualShaderNodeParticleBoxEmitter", "", -1, VisualShaderNode::PORT_TYPE_VECTOR, TYPE_FLAGS_EMIT, Shader::MODE_PARTICLES));
+	add_options.push_back(AddOption("MeshEmitter", "Particles", "Emitters", "VisualShaderNodeParticleMeshEmitter", "", -1, VisualShaderNode::PORT_TYPE_VECTOR, TYPE_FLAGS_EMIT, Shader::MODE_PARTICLES));
 	add_options.push_back(AddOption("RingEmitter", "Particles", "Emitters", "VisualShaderNodeParticleRingEmitter", "", -1, VisualShaderNode::PORT_TYPE_VECTOR, TYPE_FLAGS_EMIT, Shader::MODE_PARTICLES));
 	add_options.push_back(AddOption("SphereEmitter", "Particles", "Emitters", "VisualShaderNodeParticleSphereEmitter", "", -1, VisualShaderNode::PORT_TYPE_VECTOR, TYPE_FLAGS_EMIT, Shader::MODE_PARTICLES));
 
diff --git a/scene/register_scene_types.cpp b/scene/register_scene_types.cpp
index d44cd7ca63..d96126aae0 100644
--- a/scene/register_scene_types.cpp
+++ b/scene/register_scene_types.cpp
@@ -628,6 +628,7 @@ void register_scene_types() {
 	GDREGISTER_CLASS(VisualShaderNodeParticleSphereEmitter);
 	GDREGISTER_CLASS(VisualShaderNodeParticleBoxEmitter);
 	GDREGISTER_CLASS(VisualShaderNodeParticleRingEmitter);
+	GDREGISTER_CLASS(VisualShaderNodeParticleMeshEmitter);
 	GDREGISTER_CLASS(VisualShaderNodeParticleMultiplyByAxisAngle);
 	GDREGISTER_CLASS(VisualShaderNodeParticleConeVelocity);
 	GDREGISTER_CLASS(VisualShaderNodeParticleRandomness);
diff --git a/scene/resources/visual_shader.cpp b/scene/resources/visual_shader.cpp
index 0aa79b8ceb..4496feeb14 100644
--- a/scene/resources/visual_shader.cpp
+++ b/scene/resources/visual_shader.cpp
@@ -36,6 +36,11 @@
 #include "visual_shader_particle_nodes.h"
 #include "visual_shader_sdf_nodes.h"
 
+String make_unique_id(VisualShader::Type p_type, int p_id, const String &p_name) {
+	static const char *typepf[VisualShader::TYPE_MAX] = { "vtx", "frg", "lgt", "start", "process", "collide", "start_custom", "process_custom", "sky", "fog" };
+	return p_name + "_" + String(typepf[p_type]) + "_" + itos(p_id);
+}
+
 bool VisualShaderNode::is_simple_decl() const {
 	return simple_decl;
 }
@@ -1829,6 +1834,7 @@ void VisualShader::_update_shader() const {
 			code += "	vec3 __vec3_buff2;\n";
 			code += "	float __scalar_buff1;\n";
 			code += "	float __scalar_buff2;\n";
+			code += "	int __scalar_ibuff;\n";
 			code += "	vec3 __ndiff = normalize(__diff);\n\n";
 		}
 		if (has_start) {
diff --git a/scene/resources/visual_shader.h b/scene/resources/visual_shader.h
index 7743affba7..09f91e54c8 100644
--- a/scene/resources/visual_shader.h
+++ b/scene/resources/visual_shader.h
@@ -697,4 +697,6 @@ public:
 	VisualShaderNodeGlobalExpression();
 };
 
+extern String make_unique_id(VisualShader::Type p_type, int p_id, const String &p_name);
+
 #endif // VISUAL_SHADER_H
diff --git a/scene/resources/visual_shader_nodes.cpp b/scene/resources/visual_shader_nodes.cpp
index c3d9ef7b04..5a61df4a03 100644
--- a/scene/resources/visual_shader_nodes.cpp
+++ b/scene/resources/visual_shader_nodes.cpp
@@ -494,11 +494,6 @@ String VisualShaderNodeTexture::get_input_port_default_hint(int p_port) const {
 	return "";
 }
 
-static String make_unique_id(VisualShader::Type p_type, int p_id, const String &p_name) {
-	static const char *typepf[VisualShader::TYPE_MAX] = { "vtx", "frg", "lgt" };
-	return p_name + "_" + String(typepf[p_type]) + "_" + itos(p_id);
-}
-
 Vector<VisualShader::DefaultTextureParam> VisualShaderNodeTexture::get_default_texture_parameters(VisualShader::Type p_type, int p_id) const {
 	VisualShader::DefaultTextureParam dtp;
 	dtp.name = make_unique_id(p_type, p_id, "tex");
diff --git a/scene/resources/visual_shader_particle_nodes.cpp b/scene/resources/visual_shader_particle_nodes.cpp
index ada91cec1e..5bdaa8b272 100644
--- a/scene/resources/visual_shader_particle_nodes.cpp
+++ b/scene/resources/visual_shader_particle_nodes.cpp
@@ -30,6 +30,8 @@
 
 #include "visual_shader_particle_nodes.h"
 
+#include "core/core_string_names.h"
+
 // VisualShaderNodeParticleEmitter
 
 int VisualShaderNodeParticleEmitter::get_output_port_count() const {
@@ -255,6 +257,283 @@ VisualShaderNodeParticleRingEmitter::VisualShaderNodeParticleRingEmitter() {
 	set_input_port_default_value(2, 0.0);
 }
 
+// VisualShaderNodeParticleMeshEmitter
+
+String VisualShaderNodeParticleMeshEmitter::get_caption() const {
+	return "MeshEmitter";
+}
+
+int VisualShaderNodeParticleMeshEmitter::get_output_port_count() const {
+	return 2;
+}
+
+VisualShaderNodeParticleBoxEmitter::PortType VisualShaderNodeParticleMeshEmitter::get_output_port_type(int p_port) const {
+	switch (p_port) {
+		case 0:
+			return PORT_TYPE_VECTOR; // position
+		case 1:
+			return PORT_TYPE_VECTOR; // normal
+	}
+	return PORT_TYPE_SCALAR;
+}
+
+String VisualShaderNodeParticleMeshEmitter::get_output_port_name(int p_port) const {
+	switch (p_port) {
+		case 0:
+			return "position";
+		case 1:
+			return "normal";
+	}
+	return String();
+}
+
+int VisualShaderNodeParticleMeshEmitter::get_input_port_count() const {
+	return 0;
+}
+
+VisualShaderNodeParticleBoxEmitter::PortType VisualShaderNodeParticleMeshEmitter::get_input_port_type(int p_port) const {
+	return PORT_TYPE_SCALAR;
+}
+
+String VisualShaderNodeParticleMeshEmitter::get_input_port_name(int p_port) const {
+	return String();
+}
+
+String VisualShaderNodeParticleMeshEmitter::generate_global_per_node(Shader::Mode p_mode, VisualShader::Type p_type, int p_id) const {
+	String code;
+
+	if (mesh.is_valid()) {
+		code += "uniform sampler2D " + make_unique_id(p_type, p_id, "mesh_vx") + ";\n";
+		code += "uniform sampler2D " + make_unique_id(p_type, p_id, "mesh_nm") + ";\n";
+	}
+
+	return code;
+}
+
+String VisualShaderNodeParticleMeshEmitter::generate_code(Shader::Mode p_mode, VisualShader::Type p_type, int p_id, const String *p_input_vars, const String *p_output_vars, bool p_for_preview) const {
+	String code;
+
+	code += "	__scalar_ibuff = int(__rand_from_seed(__seed) * 65535.0) % " + itos(position_texture->get_width()) + ";\n";
+
+	if (position_texture->get_width() == 0) {
+		code += "		" + p_output_vars[0] + " = vec3(0.0);\n";
+	} else {
+		if (mode_2d) {
+			code += "	" + p_output_vars[0] + " = vec3(";
+			code += "texelFetch(";
+			code += make_unique_id(p_type, p_id, "mesh_vx") + ", ";
+			code += "ivec2(__scalar_ibuff, 0), 0).xy, 0.0);\n";
+		} else {
+			code += "	" + p_output_vars[0] + " = texelFetch(";
+			code += make_unique_id(p_type, p_id, "mesh_vx") + ", ";
+			code += "ivec2(__scalar_ibuff, 0), 0).xyz;\n";
+		}
+	}
+
+	if (normal_texture->get_width() == 0) {
+		code += "		" + p_output_vars[1] + " = vec3(0.0);\n";
+	} else {
+		if (mode_2d) {
+			code += "	" + p_output_vars[1] + " = vec3(";
+			code += "texelFetch(";
+			code += make_unique_id(p_type, p_id, "mesh_nm") + ", ";
+			code += "ivec2(__scalar_ibuff, 0), 0).xy, 0.0);\n";
+		} else {
+			code += "	" + p_output_vars[1] + " = texelFetch(";
+			code += make_unique_id(p_type, p_id, "mesh_nm") + ", ";
+			code += "ivec2(__scalar_ibuff, 0), 0).xyz;\n";
+		}
+	}
+
+	return code;
+}
+
+Vector<VisualShader::DefaultTextureParam> VisualShaderNodeParticleMeshEmitter::get_default_texture_parameters(VisualShader::Type p_type, int p_id) const {
+	VisualShader::DefaultTextureParam dtp_vx;
+	dtp_vx.name = make_unique_id(p_type, p_id, "mesh_vx");
+	dtp_vx.param = position_texture;
+
+	VisualShader::DefaultTextureParam dtp_nm;
+	dtp_nm.name = make_unique_id(p_type, p_id, "mesh_nm");
+	dtp_nm.param = normal_texture;
+
+	Vector<VisualShader::DefaultTextureParam> ret;
+	ret.push_back(dtp_vx);
+	ret.push_back(dtp_nm);
+	return ret;
+}
+
+void VisualShaderNodeParticleMeshEmitter::update_texture() {
+	if (!mesh.is_valid()) {
+		return;
+	}
+
+	Vector<Vector3> vertices;
+	Vector<Vector3> normals;
+
+	if (use_all_surfaces) {
+		for (int i = 0; i < max_surface_index; i++) {
+			Array vertex_array = mesh->surface_get_arrays(i)[Mesh::ARRAY_VERTEX];
+			for (int j = 0; j < vertex_array.size(); j++) {
+				vertices.push_back((Vector3)vertex_array[j]);
+			}
+
+			Array normal_array = mesh->surface_get_arrays(i)[Mesh::ARRAY_NORMAL];
+			for (int j = 0; j < vertex_array.size(); j++) {
+				normals.push_back((Vector3)vertex_array[j]);
+			}
+		}
+	} else {
+		Array vertex_array = mesh->surface_get_arrays(surface_index)[Mesh::ARRAY_VERTEX];
+		for (int i = 0; i < vertex_array.size(); i++) {
+			vertices.push_back((Vector3)vertex_array[i]);
+		}
+
+		Array normal_array = mesh->surface_get_arrays(surface_index)[Mesh::ARRAY_NORMAL];
+		for (int i = 0; i < normal_array.size(); i++) {
+			normals.push_back((Vector3)normal_array[i]);
+		}
+	}
+
+	// vertices
+	{
+		Ref<Image> image;
+		image.instantiate();
+		image->create(vertices.size(), 1, false, Image::Format::FORMAT_RGBF);
+
+		for (int i = 0; i < vertices.size(); i++) {
+			Vector3 v = vertices[i];
+			image->set_pixel(i, 0, Color(v.x, v.y, v.z));
+		}
+		if (position_texture->get_width() != vertices.size()) {
+			position_texture->create_from_image(image);
+		} else {
+			position_texture->update(image);
+		}
+	}
+
+	// normals
+	{
+		Ref<Image> image;
+		image.instantiate();
+		image->create(normals.size(), 1, false, Image::Format::FORMAT_RGBF);
+
+		for (int i = 0; i < normals.size(); i++) {
+			Vector3 v = normals[i];
+			image->set_pixel(i, 0, Color(v.x, v.y, v.z));
+		}
+		if (normal_texture->get_width() != normals.size()) {
+			normal_texture->create_from_image(image);
+		} else {
+			normal_texture->update(image);
+		}
+	}
+}
+
+void VisualShaderNodeParticleMeshEmitter::set_mesh(Ref<Mesh> p_mesh) {
+	if (mesh == p_mesh) {
+		return;
+	}
+
+	if (p_mesh.is_valid()) {
+		max_surface_index = p_mesh->get_surface_count();
+	} else {
+		max_surface_index = 0;
+	}
+
+	if (mesh.is_valid()) {
+		Callable callable = callable_mp(this, &VisualShaderNodeParticleMeshEmitter::update_texture);
+
+		if (mesh->is_connected(CoreStringNames::get_singleton()->changed, callable)) {
+			mesh->disconnect(CoreStringNames::get_singleton()->changed, callable);
+		}
+	}
+
+	mesh = p_mesh;
+
+	if (mesh.is_valid()) {
+		Callable callable = callable_mp(this, &VisualShaderNodeParticleMeshEmitter::update_texture);
+
+		if (!mesh->is_connected(CoreStringNames::get_singleton()->changed, callable)) {
+			mesh->connect(CoreStringNames::get_singleton()->changed, callable);
+		}
+	}
+
+	emit_changed();
+}
+
+Ref<Mesh> VisualShaderNodeParticleMeshEmitter::get_mesh() const {
+	return mesh;
+}
+
+void VisualShaderNodeParticleMeshEmitter::set_use_all_surfaces(bool p_enabled) {
+	if (use_all_surfaces == p_enabled) {
+		return;
+	}
+	use_all_surfaces = p_enabled;
+	emit_changed();
+}
+
+bool VisualShaderNodeParticleMeshEmitter::is_use_all_surfaces() const {
+	return use_all_surfaces;
+}
+
+void VisualShaderNodeParticleMeshEmitter::set_surface_index(int p_surface_index) {
+	if (p_surface_index == surface_index || p_surface_index < 0 || p_surface_index >= max_surface_index) {
+		return;
+	}
+	surface_index = p_surface_index;
+	emit_changed();
+}
+
+int VisualShaderNodeParticleMeshEmitter::get_surface_index() const {
+	return surface_index;
+}
+
+Vector<StringName> VisualShaderNodeParticleMeshEmitter::get_editable_properties() const {
+	Vector<StringName> props = VisualShaderNodeParticleEmitter::get_editable_properties();
+
+	props.push_back("mesh");
+	props.push_back("use_all_surfaces");
+	if (!use_all_surfaces) {
+		props.push_back("surface_index");
+	}
+
+	return props;
+}
+
+Map<StringName, String> VisualShaderNodeParticleMeshEmitter::get_editable_properties_names() const {
+	Map<StringName, String> names = VisualShaderNodeParticleEmitter::get_editable_properties_names();
+
+	names.insert("mesh", TTR("Mesh"));
+	names.insert("use_all_surfaces", TTR("Use All Surfaces"));
+	if (!use_all_surfaces) {
+		names.insert("surface_index", TTR("Surface Index"));
+	}
+
+	return names;
+}
+
+void VisualShaderNodeParticleMeshEmitter::_bind_methods() {
+	ClassDB::bind_method(D_METHOD("set_mesh", "mesh"), &VisualShaderNodeParticleMeshEmitter::set_mesh);
+	ClassDB::bind_method(D_METHOD("get_mesh"), &VisualShaderNodeParticleMeshEmitter::get_mesh);
+	ClassDB::bind_method(D_METHOD("set_use_all_surfaces", "enabled"), &VisualShaderNodeParticleMeshEmitter::set_use_all_surfaces);
+	ClassDB::bind_method(D_METHOD("is_use_all_surfaces"), &VisualShaderNodeParticleMeshEmitter::is_use_all_surfaces);
+	ClassDB::bind_method(D_METHOD("set_surface_index", "surface_index"), &VisualShaderNodeParticleMeshEmitter::set_surface_index);
+	ClassDB::bind_method(D_METHOD("get_surface_index"), &VisualShaderNodeParticleMeshEmitter::get_surface_index);
+
+	ADD_PROPERTY(PropertyInfo(Variant::OBJECT, "mesh", PROPERTY_HINT_RESOURCE_TYPE, "Mesh"), "set_mesh", "get_mesh");
+	ADD_PROPERTY(PropertyInfo(Variant::BOOL, "use_all_surfaces"), "set_use_all_surfaces", "is_use_all_surfaces");
+	ADD_PROPERTY(PropertyInfo(Variant::INT, "surface_index"), "set_surface_index", "get_surface_index");
+}
+
+VisualShaderNodeParticleMeshEmitter::VisualShaderNodeParticleMeshEmitter() {
+	connect(CoreStringNames::get_singleton()->changed, callable_mp(this, &VisualShaderNodeParticleMeshEmitter::update_texture));
+
+	position_texture.instantiate();
+	normal_texture.instantiate();
+}
+
 // VisualShaderNodeParticleMultiplyByAxisAngle
 
 void VisualShaderNodeParticleMultiplyByAxisAngle::_bind_methods() {
@@ -334,7 +613,6 @@ bool VisualShaderNodeParticleMultiplyByAxisAngle::is_degrees_mode() const {
 Vector<StringName> VisualShaderNodeParticleMultiplyByAxisAngle::get_editable_properties() const {
 	Vector<StringName> props;
 	props.push_back("degrees_mode");
-	props.push_back("axis_amount");
 	return props;
 }
 
diff --git a/scene/resources/visual_shader_particle_nodes.h b/scene/resources/visual_shader_particle_nodes.h
index 0b1fa277de..0d0f21e4bf 100644
--- a/scene/resources/visual_shader_particle_nodes.h
+++ b/scene/resources/visual_shader_particle_nodes.h
@@ -52,7 +52,7 @@ public:
 	bool is_mode_2d() const;
 
 	Vector<StringName> get_editable_properties() const override;
-	Map<StringName, String> get_editable_properties_names() const override;
+	virtual Map<StringName, String> get_editable_properties_names() const override;
 	bool is_show_prop_names() const override;
 
 	VisualShaderNodeParticleEmitter();
@@ -106,6 +106,51 @@ public:
 	VisualShaderNodeParticleRingEmitter();
 };
 
+class VisualShaderNodeParticleMeshEmitter : public VisualShaderNodeParticleEmitter {
+	GDCLASS(VisualShaderNodeParticleMeshEmitter, VisualShaderNodeParticleEmitter);
+	Ref<Mesh> mesh;
+	bool use_all_surfaces = true;
+	int surface_index = 0;
+	int max_surface_index = 0;
+
+	Ref<ImageTexture> position_texture;
+	Ref<ImageTexture> normal_texture;
+
+protected:
+	static void _bind_methods();
+
+public:
+	virtual String get_caption() const override;
+
+	virtual int get_output_port_count() const override;
+	virtual PortType get_output_port_type(int p_port) const override;
+	virtual String get_output_port_name(int p_port) const override;
+
+	virtual int get_input_port_count() const override;
+	virtual PortType get_input_port_type(int p_port) const override;
+	virtual String get_input_port_name(int p_port) const override;
+
+	virtual String generate_global_per_node(Shader::Mode p_mode, VisualShader::Type p_type, int p_id) const override;
+	virtual String generate_code(Shader::Mode p_mode, VisualShader::Type p_type, int p_id, const String *p_input_vars, const String *p_output_vars, bool p_for_preview = false) const override;
+
+	void update_texture();
+
+	void set_mesh(Ref<Mesh> p_mesh);
+	Ref<Mesh> get_mesh() const;
+
+	void set_use_all_surfaces(bool p_enabled);
+	bool is_use_all_surfaces() const;
+
+	void set_surface_index(int p_surface_index);
+	int get_surface_index() const;
+
+	Vector<StringName> get_editable_properties() const override;
+	Map<StringName, String> get_editable_properties_names() const override;
+	Vector<VisualShader::DefaultTextureParam> get_default_texture_parameters(VisualShader::Type p_type, int p_id) const override;
+
+	VisualShaderNodeParticleMeshEmitter();
+};
+
 class VisualShaderNodeParticleMultiplyByAxisAngle : public VisualShaderNode {
 	GDCLASS(VisualShaderNodeParticleMultiplyByAxisAngle, VisualShaderNode);
 	bool degrees_mode = true;