Bezier Editor - add "Apply Function on Selected Keys"

Added Apply Function on Selected Key(s) feature so you can now scale, move keys
and more easily create effects (like Bounce, Overshoot, etc)
Functions can have parameters "time" and "value", "time" is the time of the key,
"value" is the current value of the key.

editor/animation_bezier_editor.cpp

@@ -30,6 +30,7 @@
 
 #include "animation_bezier_editor.h"
 
+#include "core/math/expression.h"
 #include "editor/editor_node.h"
 
 float AnimationBezierTrackEdit::_bezier_h_to_pixel(float p_h) {
@@ -673,6 +674,9 @@ void AnimationBezierTrackEdit::_gui_input(const Ref<InputEvent> &p_event) {
 				menu->add_separator();
 				menu->add_icon_item(get_icon("Duplicate", "EditorIcons"), TTR("Duplicate Selected Key(s)"), MENU_KEY_DUPLICATE);
 				menu->add_separator();
+				//menu->add_icon_item(get_icon("Path", "EditorIcons"), TTR("Apply Function on Selected Key(s)"), MENU_KEY_APPLY_FUNCTION);
+				menu->add_item(TTR("Apply Function on Selected Key(s)"), MENU_KEY_APPLY_FUNCTION);
+				menu->add_separator();
 				menu->add_icon_item(get_icon("Remove", "EditorIcons"), TTR("Delete Selected Key(s)"), MENU_KEY_DELETE);
 			}
 
@@ -1079,6 +1083,12 @@ void AnimationBezierTrackEdit::_menu_selected(int p_index) {
 		case MENU_KEY_DELETE: {
 			delete_selection();
 		} break;
+		case MENU_KEY_APPLY_FUNCTION: {
+			apply_function_dialog->popup_centered(Size2(200, 100) * EDSCALE);
+		} break;
+		case EDIT_FUNCTION_CONFIRM: {
+			apply_function_on_selection();
+		} break;
 	}
 }
 
@@ -1140,6 +1150,87 @@ void AnimationBezierTrackEdit::duplicate_selection() {
 	update();
 }
 
+void AnimationBezierTrackEdit::apply_function_on_selection() {
+
+	String function_text = apply_function_value->get_line_edit()->get_text();
+
+	Ref<Expression> expr;
+	expr.instance();
+
+	Vector<String> params;
+	params.push_back("time");
+	params.push_back("value");
+
+	Error err = expr->parse(function_text, params);
+	if (err != OK) {
+		return;
+	}
+
+	if (selection.size() == 0)
+		return;
+
+	undo_redo->create_action(TTR("Anim Apply Function"));
+
+	List<AnimMoveRestore> to_restore;
+	// 1-remove the keys
+	for (Set<int>::Element *E = selection.back(); E; E = E->prev()) {
+
+		undo_redo->add_do_method(animation.ptr(), "track_remove_key", track, E->get());
+	}
+
+	// 2-move the keys (re insert them)
+	for (Set<int>::Element *E = selection.back(); E; E = E->prev()) {
+
+		float t = editor->snap_time(animation->track_get_key_time(track, E->get()));
+
+		Array key = animation->track_get_key_value(track, E->get());
+		float v = key[0];
+
+		Array a;
+		a.push_back(t);
+		a.push_back(v);
+
+		Variant res = expr->execute(a, NULL, false);
+		if (res.get_type() == Variant::REAL || res.get_type() == Variant::INT) {
+			v = float(res);
+		}
+
+		key[0] = v;
+		undo_redo->add_do_method(animation.ptr(), "track_insert_key", track, t, key, 1);
+	}
+
+	// 3-(undo) remove inserted keys
+	for (Set<int>::Element *E = selection.back(); E; E = E->prev()) {
+
+		float newpos = editor->snap_time(animation->track_get_key_time(track, E->get()));
+
+		undo_redo->add_undo_method(animation.ptr(), "track_remove_key_at_position", track, newpos);
+	}
+
+	// 4-(undo) reinsert keys
+	for (Set<int>::Element *E = selection.back(); E; E = E->prev()) {
+
+		float oldpos = animation->track_get_key_time(track, E->get());
+		undo_redo->add_undo_method(animation.ptr(), "track_insert_key", track, oldpos, animation->track_get_key_value(track, E->get()), 1);
+	}
+
+	undo_redo->add_do_method(this, "_clear_selection_for_anim", animation);
+	undo_redo->add_undo_method(this, "_clear_selection_for_anim", animation);
+
+	// 5-reselect
+
+	for (Set<int>::Element *E = selection.back(); E; E = E->prev()) {
+
+		float oldpos = animation->track_get_key_time(track, E->get());
+		float newpos = editor->snap_time(oldpos + moving_selection_offset.x);
+
+		undo_redo->add_do_method(this, "_select_at_anim", animation, track, newpos);
+		undo_redo->add_undo_method(this, "_select_at_anim", animation, track, oldpos);
+	}
+
+	undo_redo->commit_action();
+}
+
 void AnimationBezierTrackEdit::delete_selection() {
 	if (selection.size()) {
 		undo_redo->create_action(TTR("Anim Delete Keys"));
@@ -1221,5 +1312,17 @@ AnimationBezierTrackEdit::AnimationBezierTrackEdit() {
 	add_child(menu);
 	menu->connect("id_pressed", this, "_menu_selected");
 
+	apply_function_dialog = memnew(ConfirmationDialog);
+	VBoxContainer *vbc = memnew(VBoxContainer);
+	apply_function_dialog->add_child(vbc);
+
+	apply_function_value = memnew(SpinBox);
+	apply_function_value->set_min(-99999);
+	apply_function_value->set_max(99999);
+	apply_function_value->set_step(0.001);
+	vbc->add_margin_child(TTR("Function (time,value):"), apply_function_value);
+	apply_function_dialog->connect("confirmed", this, "_menu_selected", varray(EDIT_FUNCTION_CONFIRM));
+	add_child(apply_function_dialog);
+
 	//set_mouse_filter(MOUSE_FILTER_PASS); //scroll has to work too for selection
 }

editor/animation_bezier_editor.h

@@ -46,7 +46,9 @@ class AnimationBezierTrackEdit : public Control {
 	enum {
 		MENU_KEY_INSERT,
 		MENU_KEY_DUPLICATE,
-		MENU_KEY_DELETE
+		MENU_KEY_DELETE,
+		MENU_KEY_APPLY_FUNCTION,
+		EDIT_FUNCTION_CONFIRM
 	};
 
 	HandleMode handle_mode;
@@ -76,6 +78,9 @@ class AnimationBezierTrackEdit : public Control {
 
 	PopupMenu *menu;
 
+	ConfirmationDialog *apply_function_dialog;
+	SpinBox *apply_function_value;
+
 	void _zoom_changed();
 
 	void _gui_input(const Ref<InputEvent> &p_event);
@@ -164,6 +169,7 @@ class AnimationBezierTrackEdit : public Control {
 
 	void duplicate_selection();
 	void delete_selection();
+	void apply_function_on_selection();
 
 	AnimationBezierTrackEdit();
 };