/*************************************************************************/
/*  animation_blend_space_1d.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 "animation_blend_space_1d.h"

void AnimationNodeBlendSpace1D::get_parameter_list(List<PropertyInfo> *r_list) const {
	r_list->push_back(PropertyInfo(Variant::FLOAT, blend_position));
}

Variant AnimationNodeBlendSpace1D::get_parameter_default_value(const StringName &p_parameter) const {
	return 0;
}

Ref<AnimationNode> AnimationNodeBlendSpace1D::get_child_by_name(const StringName &p_name) {
	return get_blend_point_node(p_name.operator String().to_int());
}

void AnimationNodeBlendSpace1D::_validate_property(PropertyInfo &property) const {
	if (property.name.begins_with("blend_point_")) {
		String left = property.name.get_slicec('/', 0);
		int idx = left.get_slicec('_', 2).to_int();
		if (idx >= blend_points_used) {
			property.usage = PROPERTY_USAGE_NONE;
		}
	}
	AnimationRootNode::_validate_property(property);
}

void AnimationNodeBlendSpace1D::_tree_changed() {
	emit_signal(SNAME("tree_changed"));
}

void AnimationNodeBlendSpace1D::_bind_methods() {
	ClassDB::bind_method(D_METHOD("add_blend_point", "node", "pos", "at_index"), &AnimationNodeBlendSpace1D::add_blend_point, DEFVAL(-1));
	ClassDB::bind_method(D_METHOD("set_blend_point_position", "point", "pos"), &AnimationNodeBlendSpace1D::set_blend_point_position);
	ClassDB::bind_method(D_METHOD("get_blend_point_position", "point"), &AnimationNodeBlendSpace1D::get_blend_point_position);
	ClassDB::bind_method(D_METHOD("set_blend_point_node", "point", "node"), &AnimationNodeBlendSpace1D::set_blend_point_node);
	ClassDB::bind_method(D_METHOD("get_blend_point_node", "point"), &AnimationNodeBlendSpace1D::get_blend_point_node);
	ClassDB::bind_method(D_METHOD("remove_blend_point", "point"), &AnimationNodeBlendSpace1D::remove_blend_point);
	ClassDB::bind_method(D_METHOD("get_blend_point_count"), &AnimationNodeBlendSpace1D::get_blend_point_count);

	ClassDB::bind_method(D_METHOD("set_min_space", "min_space"), &AnimationNodeBlendSpace1D::set_min_space);
	ClassDB::bind_method(D_METHOD("get_min_space"), &AnimationNodeBlendSpace1D::get_min_space);

	ClassDB::bind_method(D_METHOD("set_max_space", "max_space"), &AnimationNodeBlendSpace1D::set_max_space);
	ClassDB::bind_method(D_METHOD("get_max_space"), &AnimationNodeBlendSpace1D::get_max_space);

	ClassDB::bind_method(D_METHOD("set_snap", "snap"), &AnimationNodeBlendSpace1D::set_snap);
	ClassDB::bind_method(D_METHOD("get_snap"), &AnimationNodeBlendSpace1D::get_snap);

	ClassDB::bind_method(D_METHOD("set_value_label", "text"), &AnimationNodeBlendSpace1D::set_value_label);
	ClassDB::bind_method(D_METHOD("get_value_label"), &AnimationNodeBlendSpace1D::get_value_label);

	ClassDB::bind_method(D_METHOD("_add_blend_point", "index", "node"), &AnimationNodeBlendSpace1D::_add_blend_point);

	for (int i = 0; i < MAX_BLEND_POINTS; i++) {
		ADD_PROPERTYI(PropertyInfo(Variant::OBJECT, "blend_point_" + itos(i) + "/node", PROPERTY_HINT_RESOURCE_TYPE, "AnimationRootNode", PROPERTY_USAGE_NO_EDITOR | PROPERTY_USAGE_INTERNAL), "_add_blend_point", "get_blend_point_node", i);
		ADD_PROPERTYI(PropertyInfo(Variant::FLOAT, "blend_point_" + itos(i) + "/pos", PROPERTY_HINT_NONE, "", PROPERTY_USAGE_NO_EDITOR | PROPERTY_USAGE_INTERNAL), "set_blend_point_position", "get_blend_point_position", i);
	}

	ADD_PROPERTY(PropertyInfo(Variant::FLOAT, "min_space", PROPERTY_HINT_NONE, "", PROPERTY_USAGE_NO_EDITOR), "set_min_space", "get_min_space");
	ADD_PROPERTY(PropertyInfo(Variant::FLOAT, "max_space", PROPERTY_HINT_NONE, "", PROPERTY_USAGE_NO_EDITOR), "set_max_space", "get_max_space");
	ADD_PROPERTY(PropertyInfo(Variant::FLOAT, "snap", PROPERTY_HINT_NONE, "", PROPERTY_USAGE_NO_EDITOR), "set_snap", "get_snap");
	ADD_PROPERTY(PropertyInfo(Variant::STRING, "value_label", PROPERTY_HINT_NONE, "", PROPERTY_USAGE_NO_EDITOR), "set_value_label", "get_value_label");
}

void AnimationNodeBlendSpace1D::get_child_nodes(List<ChildNode> *r_child_nodes) {
	for (int i = 0; i < blend_points_used; i++) {
		ChildNode cn;
		cn.name = itos(i);
		cn.node = blend_points[i].node;
		r_child_nodes->push_back(cn);
	}
}

void AnimationNodeBlendSpace1D::add_blend_point(const Ref<AnimationRootNode> &p_node, float p_position, int p_at_index) {
	ERR_FAIL_COND(blend_points_used >= MAX_BLEND_POINTS);
	ERR_FAIL_COND(p_node.is_null());

	ERR_FAIL_COND(p_at_index < -1 || p_at_index > blend_points_used);

	if (p_at_index == -1 || p_at_index == blend_points_used) {
		p_at_index = blend_points_used;
	} else {
		for (int i = blend_points_used - 1; i > p_at_index; i--) {
			blend_points[i] = blend_points[i - 1];
		}
	}

	blend_points[p_at_index].node = p_node;
	blend_points[p_at_index].position = p_position;

	blend_points[p_at_index].node->connect("tree_changed", callable_mp(this, &AnimationNodeBlendSpace1D::_tree_changed), varray(), CONNECT_REFERENCE_COUNTED);

	blend_points_used++;
	emit_signal(SNAME("tree_changed"));
}

void AnimationNodeBlendSpace1D::set_blend_point_position(int p_point, float p_position) {
	ERR_FAIL_INDEX(p_point, blend_points_used);

	blend_points[p_point].position = p_position;
}

void AnimationNodeBlendSpace1D::set_blend_point_node(int p_point, const Ref<AnimationRootNode> &p_node) {
	ERR_FAIL_INDEX(p_point, blend_points_used);
	ERR_FAIL_COND(p_node.is_null());

	if (blend_points[p_point].node.is_valid()) {
		blend_points[p_point].node->disconnect("tree_changed", callable_mp(this, &AnimationNodeBlendSpace1D::_tree_changed));
	}

	blend_points[p_point].node = p_node;
	blend_points[p_point].node->connect("tree_changed", callable_mp(this, &AnimationNodeBlendSpace1D::_tree_changed), varray(), CONNECT_REFERENCE_COUNTED);

	emit_signal(SNAME("tree_changed"));
}

float AnimationNodeBlendSpace1D::get_blend_point_position(int p_point) const {
	ERR_FAIL_INDEX_V(p_point, blend_points_used, 0);
	return blend_points[p_point].position;
}

Ref<AnimationRootNode> AnimationNodeBlendSpace1D::get_blend_point_node(int p_point) const {
	ERR_FAIL_INDEX_V(p_point, blend_points_used, Ref<AnimationRootNode>());
	return blend_points[p_point].node;
}

void AnimationNodeBlendSpace1D::remove_blend_point(int p_point) {
	ERR_FAIL_INDEX(p_point, blend_points_used);

	ERR_FAIL_COND(blend_points[p_point].node.is_null());
	blend_points[p_point].node->disconnect("tree_changed", callable_mp(this, &AnimationNodeBlendSpace1D::_tree_changed));

	for (int i = p_point; i < blend_points_used - 1; i++) {
		blend_points[i] = blend_points[i + 1];
	}

	blend_points_used--;
	emit_signal(SNAME("tree_changed"));
}

int AnimationNodeBlendSpace1D::get_blend_point_count() const {
	return blend_points_used;
}

void AnimationNodeBlendSpace1D::set_min_space(float p_min) {
	min_space = p_min;

	if (min_space >= max_space) {
		min_space = max_space - 1;
	}
}

float AnimationNodeBlendSpace1D::get_min_space() const {
	return min_space;
}

void AnimationNodeBlendSpace1D::set_max_space(float p_max) {
	max_space = p_max;

	if (max_space <= min_space) {
		max_space = min_space + 1;
	}
}

float AnimationNodeBlendSpace1D::get_max_space() const {
	return max_space;
}

void AnimationNodeBlendSpace1D::set_snap(float p_snap) {
	snap = p_snap;
}

float AnimationNodeBlendSpace1D::get_snap() const {
	return snap;
}

void AnimationNodeBlendSpace1D::set_value_label(const String &p_label) {
	value_label = p_label;
}

String AnimationNodeBlendSpace1D::get_value_label() const {
	return value_label;
}

void AnimationNodeBlendSpace1D::_add_blend_point(int p_index, const Ref<AnimationRootNode> &p_node) {
	if (p_index == blend_points_used) {
		add_blend_point(p_node, 0);
	} else {
		set_blend_point_node(p_index, p_node);
	}
}

double AnimationNodeBlendSpace1D::process(double p_time, bool p_seek) {
	if (blend_points_used == 0) {
		return 0.0;
	}

	if (blend_points_used == 1) {
		// only one point available, just play that animation
		return blend_node(blend_points[0].name, blend_points[0].node, p_time, p_seek, 1.0, FILTER_IGNORE, false);
	}

	double blend_pos = get_parameter(blend_position);

	float weights[MAX_BLEND_POINTS] = {};

	int point_lower = -1;
	float pos_lower = 0.0;
	int point_higher = -1;
	float pos_higher = 0.0;

	// find the closest two points to blend between
	for (int i = 0; i < blend_points_used; i++) {
		float pos = blend_points[i].position;

		if (pos <= blend_pos) {
			if (point_lower == -1) {
				point_lower = i;
				pos_lower = pos;
			} else if ((blend_pos - pos) < (blend_pos - pos_lower)) {
				point_lower = i;
				pos_lower = pos;
			}
		} else {
			if (point_higher == -1) {
				point_higher = i;
				pos_higher = pos;
			} else if ((pos - blend_pos) < (pos_higher - blend_pos)) {
				point_higher = i;
				pos_higher = pos;
			}
		}
	}

	// fill in weights

	if (point_lower == -1 && point_higher != -1) {
		// we are on the left side, no other point to the left
		// we just play the next point.

		weights[point_higher] = 1.0;
	} else if (point_higher == -1) {
		// we are on the right side, no other point to the right
		// we just play the previous point

		weights[point_lower] = 1.0;
	} else {
		// we are between two points.
		// figure out weights, then blend the animations

		float distance_between_points = pos_higher - pos_lower;

		float current_pos_inbetween = blend_pos - pos_lower;

		float blend_percentage = current_pos_inbetween / distance_between_points;

		float blend_lower = 1.0 - blend_percentage;
		float blend_higher = blend_percentage;

		weights[point_lower] = blend_lower;
		weights[point_higher] = blend_higher;
	}

	// actually blend the animations now

	float max_time_remaining = 0.0;

	for (int i = 0; i < blend_points_used; i++) {
		float remaining = blend_node(blend_points[i].name, blend_points[i].node, p_time, p_seek, weights[i], FILTER_IGNORE, false);

		max_time_remaining = MAX(max_time_remaining, remaining);
	}

	return max_time_remaining;
}

String AnimationNodeBlendSpace1D::get_caption() const {
	return "BlendSpace1D";
}

AnimationNodeBlendSpace1D::AnimationNodeBlendSpace1D() {
	for (int i = 0; i < MAX_BLEND_POINTS; i++) {
		blend_points[i].name = itos(i);
	}
}

AnimationNodeBlendSpace1D::~AnimationNodeBlendSpace1D() {
}