Make the primitive shape tools avoid setting a negative transform scale (#1973)

* Fix transformation for primitive tools, make odd-sided polygons and stars flipped with radius instead of scale

* Extract to function and add comment

* Code review

---------

Co-authored-by: hypercube <0hypercube@gmail.com>
Co-authored-by: Keavon Chambers <keavon@keavon.com>

editor/src/messages/tool/tool_messages/ellipse_tool.rs

@@ -224,7 +224,7 @@ impl Fsm for EllipseToolFsmState {
 					if let Some(layer) = shape_data.layer {
 						responses.add(GraphOperationMessage::TransformSet {
 							layer,
-							transform: DAffine2::from_scale_angle_translation(end - start, 0., (start + end) / 2.),
+							transform: DAffine2::from_scale_angle_translation((end - start).abs(), 0., (start + end) / 2.),
 							transform_in: TransformIn::Viewport,
 							skip_rerender: false,
 						});

editor/src/messages/tool/tool_messages/polygon_tool.rs

@@ -2,9 +2,11 @@ use super::tool_prelude::*;
 use crate::messages::portfolio::document::graph_operation::utility_types::TransformIn;
 use crate::messages::portfolio::document::node_graph::document_node_definitions::resolve_document_node_type;
 use crate::messages::portfolio::document::overlays::utility_types::OverlayContext;
+use crate::messages::portfolio::document::utility_types::document_metadata::LayerNodeIdentifier;
+use crate::messages::portfolio::document::utility_types::network_interface::InputConnector;
 use crate::messages::tool::common_functionality::auto_panning::AutoPanning;
 use crate::messages::tool::common_functionality::color_selector::{ToolColorOptions, ToolColorType};
-use crate::messages::tool::common_functionality::graph_modification_utils;
+use crate::messages::tool::common_functionality::graph_modification_utils::{self, NodeGraphLayer};
 use crate::messages::tool::common_functionality::resize::Resize;
 use crate::messages::tool::common_functionality::snapping::SnapData;
 
@@ -280,9 +282,11 @@ impl Fsm for PolygonToolFsmState {
 				if let Some([start, end]) = tool_data.data.calculate_points(document, input, center, lock_ratio) {
 					if let Some(layer) = tool_data.data.layer {
 						// TODO: make the scale impact the polygon/star node - we need to determine how to allow the polygon node to make irregular shapes
+
+						update_radius_sign(end, start, layer, document, responses);
 						responses.add(GraphOperationMessage::TransformSet {
 							layer,
-							transform: DAffine2::from_scale_angle_translation(end - start, 0., (start + end) / 2.),
+							transform: DAffine2::from_scale_angle_translation((end - start).abs(), 0., (start + end) / 2.),
 							transform_in: TransformIn::Viewport,
 							skip_rerender: false,
 						});
@@ -363,3 +367,32 @@ impl Fsm for PolygonToolFsmState {
 		responses.add(FrontendMessage::UpdateMouseCursor { cursor: MouseCursorIcon::Crosshair });
 	}
 }
+
+/// In the case where the polygon/star is upside down and the number of sides is odd, we negate the radius instead of using a negative scale.
+fn update_radius_sign(end: DVec2, start: DVec2, layer: LayerNodeIdentifier, document: &mut DocumentMessageHandler, responses: &mut VecDeque<Message>) {
+	let sign_num = if end[1] > start[1] { 1. } else { -1. };
+	let new_layer = NodeGraphLayer::new(layer, &document.network_interface);
+
+	if new_layer.find_input("Regular Polygon", 1).unwrap_or(&TaggedValue::U32(0)).to_u32() % 2 == 1 {
+		let Some(polygon_node_id) = new_layer.upstream_node_id_from_name("Regular Polygon") else { return };
+
+		responses.add(NodeGraphMessage::SetInput {
+			input_connector: InputConnector::node(polygon_node_id, 2),
+			input: NodeInput::value(TaggedValue::F64(sign_num * 0.5), false),
+		});
+		return;
+	}
+
+	if new_layer.find_input("Star", 1).unwrap_or(&TaggedValue::U32(0)).to_u32() % 2 == 1 {
+		let Some(star_node_id) = new_layer.upstream_node_id_from_name("Star") else { return };
+
+		responses.add(NodeGraphMessage::SetInput {
+			input_connector: InputConnector::node(star_node_id, 2),
+			input: NodeInput::value(TaggedValue::F64(sign_num * 0.5), false),
+		});
+		responses.add(NodeGraphMessage::SetInput {
+			input_connector: InputConnector::node(star_node_id, 3),
+			input: NodeInput::value(TaggedValue::F64(sign_num * 0.25), false),
+		});
+	}
+}

editor/src/messages/tool/tool_messages/rectangle_tool.rs

@@ -231,7 +231,7 @@ impl Fsm for RectangleToolFsmState {
 						// TODO: make the scale impact the rect node
 						responses.add(GraphOperationMessage::TransformSet {
 							layer,
-							transform: DAffine2::from_scale_angle_translation(end - start, 0., (start + end) / 2.),
+							transform: DAffine2::from_scale_angle_translation((end - start).abs(), 0., (start + end) / 2.),
 							transform_in: TransformIn::Viewport,
 							skip_rerender: false,
 						});

node-graph/graph-craft/src/document/value.rs

@@ -194,6 +194,13 @@ impl TaggedValue {
 			_ => panic!("Cannot convert to primitive string"),
 		}
 	}
+
+	pub fn to_u32(&self) -> u32 {
+		match self {
+			TaggedValue::U32(x) => *x,
+			_ => panic!("Passed value is not of type u32"),
+		}
+	}
 }
 
 impl Display for TaggedValue {