/*************************************************************************/
/*  occluder_instance_3d.cpp                                             */
/*************************************************************************/
/*                       This file is part of:                           */
/*                           GODOT ENGINE                                */
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/* Copyright (c) 2007-2021 Juan Linietsky, Ariel Manzur.                 */
/* Copyright (c) 2014-2021 Godot Engine contributors (cf. AUTHORS.md).   */
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#include "occluder_instance_3d.h"
#include "core/core_string_names.h"
#include "scene/3d/mesh_instance_3d.h"

RID Occluder3D::get_rid() const {
	if (!occluder.is_valid()) {
		occluder = RS::get_singleton()->occluder_create();
		RS::get_singleton()->occluder_set_mesh(occluder, vertices, indices);
	}
	return occluder;
}

void Occluder3D::set_vertices(PackedVector3Array p_vertices) {
	vertices = p_vertices;
	if (occluder.is_valid()) {
		RS::get_singleton()->occluder_set_mesh(occluder, vertices, indices);
	}
	_update_changes();
}

PackedVector3Array Occluder3D::get_vertices() const {
	return vertices;
}

void Occluder3D::set_indices(PackedInt32Array p_indices) {
	indices = p_indices;
	if (occluder.is_valid()) {
		RS::get_singleton()->occluder_set_mesh(occluder, vertices, indices);
	}
	_update_changes();
}

PackedInt32Array Occluder3D::get_indices() const {
	return indices;
}

void Occluder3D::_update_changes() {
	aabb = AABB();

	const Vector3 *ptr = vertices.ptr();
	for (int i = 0; i < vertices.size(); i++) {
		aabb.expand_to(ptr[i]);
	}

	debug_lines.clear();
	debug_mesh.unref();

	emit_changed();
}

Vector<Vector3> Occluder3D::get_debug_lines() const {
	if (!debug_lines.is_empty()) {
		return debug_lines;
	}

	if (indices.size() % 3 != 0) {
		return Vector<Vector3>();
	}

	for (int i = 0; i < indices.size() / 3; i++) {
		for (int j = 0; j < 3; j++) {
			int a = indices[i * 3 + j];
			int b = indices[i * 3 + (j + 1) % 3];
			ERR_FAIL_INDEX_V_MSG(a, vertices.size(), Vector<Vector3>(), "Occluder indices are out of range.");
			ERR_FAIL_INDEX_V_MSG(b, vertices.size(), Vector<Vector3>(), "Occluder indices are out of range.");
			debug_lines.push_back(vertices[a]);
			debug_lines.push_back(vertices[b]);
		}
	}
	return debug_lines;
}

Ref<ArrayMesh> Occluder3D::get_debug_mesh() const {
	if (debug_mesh.is_valid()) {
		return debug_mesh;
	}

	if (indices.size() % 3 != 0) {
		return debug_mesh;
	}

	Array arrays;
	arrays.resize(Mesh::ARRAY_MAX);
	arrays[Mesh::ARRAY_VERTEX] = vertices;
	arrays[Mesh::ARRAY_INDEX] = indices;

	debug_mesh.instance();
	debug_mesh->add_surface_from_arrays(Mesh::PRIMITIVE_TRIANGLES, arrays);
	return debug_mesh;
}

AABB Occluder3D::get_aabb() const {
	return aabb;
}

void Occluder3D::_bind_methods() {
	ClassDB::bind_method(D_METHOD("set_vertices", "vertices"), &Occluder3D::set_vertices);
	ClassDB::bind_method(D_METHOD("get_vertices"), &Occluder3D::get_vertices);

	ClassDB::bind_method(D_METHOD("set_indices", "indices"), &Occluder3D::set_indices);
	ClassDB::bind_method(D_METHOD("get_indices"), &Occluder3D::get_indices);

	ADD_PROPERTY(PropertyInfo(Variant::PACKED_VECTOR3_ARRAY, "vertices", PROPERTY_HINT_NONE, "", PROPERTY_USAGE_NOEDITOR), "set_vertices", "get_vertices");
	ADD_PROPERTY(PropertyInfo(Variant::PACKED_INT32_ARRAY, "indices", PROPERTY_HINT_NONE, "", PROPERTY_USAGE_NOEDITOR), "set_indices", "get_indices");
}

Occluder3D::Occluder3D() {
}

Occluder3D::~Occluder3D() {
	if (occluder.is_valid()) {
		RS::get_singleton()->free(occluder);
	}
}
/////////////////////////////////////////////////

AABB OccluderInstance3D::get_aabb() const {
	if (occluder.is_valid()) {
		return occluder->get_aabb();
	}
	return AABB();
}

Vector<Face3> OccluderInstance3D::get_faces(uint32_t p_usage_flags) const {
	return Vector<Face3>();
}

void OccluderInstance3D::set_occluder(const Ref<Occluder3D> &p_occluder) {
	if (occluder == p_occluder) {
		return;
	}

	if (occluder.is_valid()) {
		occluder->disconnect(CoreStringNames::get_singleton()->changed, callable_mp(this, &OccluderInstance3D::_occluder_changed));
	}

	occluder = p_occluder;

	if (occluder.is_valid()) {
		set_base(occluder->get_rid());
		occluder->connect(CoreStringNames::get_singleton()->changed, callable_mp(this, &OccluderInstance3D::_occluder_changed));
	} else {
		set_base(RID());
	}

	update_gizmo();
}

void OccluderInstance3D::_occluder_changed() {
	update_gizmo();
}

Ref<Occluder3D> OccluderInstance3D::get_occluder() const {
	return occluder;
}

void OccluderInstance3D::set_bake_mask(uint32_t p_mask) {
	bake_mask = p_mask;
}

uint32_t OccluderInstance3D::get_bake_mask() const {
	return bake_mask;
}

void OccluderInstance3D::set_bake_mask_bit(int p_layer, bool p_enable) {
	ERR_FAIL_INDEX(p_layer, 32);
	if (p_enable) {
		set_bake_mask(bake_mask | (1 << p_layer));
	} else {
		set_bake_mask(bake_mask & (~(1 << p_layer)));
	}
}

bool OccluderInstance3D::get_bake_mask_bit(int p_layer) const {
	ERR_FAIL_INDEX_V(p_layer, 32, false);
	return (bake_mask & (1 << p_layer));
}

bool OccluderInstance3D::_bake_material_check(Ref<Material> p_material) {
	StandardMaterial3D *standard_mat = Object::cast_to<StandardMaterial3D>(p_material.ptr());
	if (standard_mat && standard_mat->get_transparency() != StandardMaterial3D::TRANSPARENCY_DISABLED) {
		return false;
	}
	return true;
}

void OccluderInstance3D::_bake_node(Node *p_node, PackedVector3Array &r_vertices, PackedInt32Array &r_indices) {
	MeshInstance3D *mi = Object::cast_to<MeshInstance3D>(p_node);
	if (mi && mi->is_visible_in_tree()) {
		Ref<Mesh> mesh = mi->get_mesh();
		bool valid = true;

		if (mesh.is_null()) {
			valid = false;
		}

		if (valid && !_bake_material_check(mi->get_material_override())) {
			valid = false;
		}

		if ((mi->get_layer_mask() & bake_mask) == 0) {
			valid = false;
		}

		if (valid) {
			Transform global_to_local = get_global_transform().affine_inverse() * mi->get_global_transform();

			for (int i = 0; i < mesh->get_surface_count(); i++) {
				if (mesh->surface_get_primitive_type(i) != Mesh::PRIMITIVE_TRIANGLES) {
					continue;
				}

				if (mi->get_surface_override_material(i).is_valid()) {
					if (!_bake_material_check(mi->get_surface_override_material(i))) {
						continue;
					}
				} else {
					if (!_bake_material_check(mesh->surface_get_material(i))) {
						continue;
					}
				}

				Array arrays = mesh->surface_get_arrays(i);

				int vertex_offset = r_vertices.size();
				PackedVector3Array vertices = arrays[Mesh::ARRAY_VERTEX];
				r_vertices.resize(r_vertices.size() + vertices.size());

				Vector3 *vtx_ptr = r_vertices.ptrw();
				for (int j = 0; j < vertices.size(); j++) {
					vtx_ptr[vertex_offset + j] = global_to_local.xform(vertices[j]);
				}

				int index_offset = r_indices.size();
				PackedInt32Array indices = arrays[Mesh::ARRAY_INDEX];
				r_indices.resize(r_indices.size() + indices.size());

				int *idx_ptr = r_indices.ptrw();
				for (int j = 0; j < indices.size(); j++) {
					idx_ptr[index_offset + j] = vertex_offset + indices[j];
				}
			}
		}
	}

	for (int i = 0; i < p_node->get_child_count(); i++) {
		Node *child = p_node->get_child(i);
		if (!child->get_owner()) {
			continue; //maybe a helper
		}

		_bake_node(child, r_vertices, r_indices);
	}
}

OccluderInstance3D::BakeError OccluderInstance3D::bake(Node *p_from_node, String p_occluder_path) {
	if (p_occluder_path == "") {
		if (get_occluder().is_null()) {
			return BAKE_ERROR_NO_SAVE_PATH;
		}
	}

	PackedVector3Array vertices;
	PackedInt32Array indices;

	_bake_node(p_from_node, vertices, indices);

	if (vertices.is_empty() || indices.is_empty()) {
		return BAKE_ERROR_NO_MESHES;
	}

	Ref<Occluder3D> occ;
	if (get_occluder().is_valid()) {
		occ = get_occluder();
	} else {
		occ.instance();
		occ->set_path(p_occluder_path);
	}

	occ->set_vertices(vertices);
	occ->set_indices(indices);
	set_occluder(occ);

	return BAKE_ERROR_OK;
}

void OccluderInstance3D::_bind_methods() {
	ClassDB::bind_method(D_METHOD("set_bake_mask", "mask"), &OccluderInstance3D::set_bake_mask);
	ClassDB::bind_method(D_METHOD("get_bake_mask"), &OccluderInstance3D::get_bake_mask);
	ClassDB::bind_method(D_METHOD("set_bake_mask_bit", "layer", "enabled"), &OccluderInstance3D::set_bake_mask_bit);
	ClassDB::bind_method(D_METHOD("get_bake_mask_bit", "layer"), &OccluderInstance3D::get_bake_mask_bit);

	ClassDB::bind_method(D_METHOD("set_occluder", "occluder"), &OccluderInstance3D::set_occluder);
	ClassDB::bind_method(D_METHOD("get_occluder"), &OccluderInstance3D::get_occluder);

	ADD_PROPERTY(PropertyInfo(Variant::OBJECT, "occluder", PROPERTY_HINT_RESOURCE_TYPE, "Occluder3D"), "set_occluder", "get_occluder");
	ADD_GROUP("Bake", "bake_");
	ADD_PROPERTY(PropertyInfo(Variant::INT, "bake_mask", PROPERTY_HINT_LAYERS_3D_RENDER), "set_bake_mask", "get_bake_mask");
}

OccluderInstance3D::OccluderInstance3D() {
}

OccluderInstance3D::~OccluderInstance3D() {
}