Implement angle constraints in fin editor

core/src/main/resources/l10n/messages.properties

@@ -1260,9 +1260,11 @@ FreeformFinSetCfg.lbl.ttip.Fincant = The angle that the fins are canted with res
 FreeformFinSetCfg.lbl.FincrossSection = Fin cross section:
 FreeformFinSetCfg.lbl.Thickness = Thickness:
 FreeformFinSetConfig.lbl.doubleClick1 = Double-click
-FreeformFinSetConfig.lbl.doubleClick2 = to edit
+FreeformFinSetConfig.lbl.doubleClick2 = to edit table entry
-FreeformFinSetConfig.lbl.clickDrag = Click+drag: Add and move points
 FreeformFinSetConfig.lbl.ctrlClick = Ctrl+click: Delete point
+FreeformFinSetConfig.lbl.clickDrag = Click+drag: Add and move points
+FreeformFinSetConfig.lbl.shiftClickDrag = Shift+click+drag: Lock angle to previous point
+FreeformFinSetConfig.lbl.ctrlShiftClickDrag = Ctrl+shift+click+drag: Lock angle to following point
 FreeformFinSetConfig.lbl.scaleFin = Scale Fin
 FreeformFinSetConfig.lbl.exportCSV = Export CSV
 FreeformFinSetConfig.lbl.deletePoint = Delete point

swing/src/main/java/info/openrocket/swing/gui/configdialog/FreeformFinSetConfig.java

@@ -337,9 +337,11 @@ public class FreeformFinSetConfig extends FinSetConfig {
 		order.add(table);
 
 		// row of text directly below figure
-		panel.add(new StyledLabel(trans.get("lbl.doubleClick1")+" "+trans.get("FreeformFinSetConfig.lbl.doubleClick2"), -2), "spanx 3");
+		panel.add(new StyledLabel(trans.get("lbl.doubleClick1")+" "+trans.get("FreeformFinSetConfig.lbl.doubleClick2"), -2), "spanx 2");
-        panel.add(new StyledLabel(trans.get("FreeformFinSetConfig.lbl.clickDrag"), -2), "spanx 3");
+        panel.add(new StyledLabel(trans.get("FreeformFinSetConfig.lbl.ctrlClick"), -2), "spanx 2, wrap");
-        panel.add(new StyledLabel(trans.get("FreeformFinSetConfig.lbl.ctrlClick"), -2), "spanx 3, wrap");
+        panel.add(new StyledLabel(trans.get("FreeformFinSetConfig.lbl.clickDrag"), -2), "spanx 2");
+        panel.add(new StyledLabel(trans.get("FreeformFinSetConfig.lbl.shiftClickDrag"), -2), "spanx 2");
+        panel.add(new StyledLabel(trans.get("FreeformFinSetConfig.lbl.ctrlShiftClickDrag"), -2), "spanx 2, wrap");
         
         // row of controls at the bottom of the tab:
         panel.add(selector.getAsPanel(), "aligny bottom, gap unrel");
@@ -534,13 +536,58 @@ public class FreeformFinSetConfig extends FinSetConfig {
 		@Override
 		public void mouseDragged(MouseEvent event) {
 			int mods = event.getModifiersEx();
+		/*XXX
 			if (dragIndex < 0 || (mods & (ANY_MASK | MouseEvent.BUTTON1_DOWN_MASK)) != MouseEvent.BUTTON1_DOWN_MASK) {
 				super.mouseDragged(event);
 				return;
 			}
+		*/
 
 			Point2D.Double point = getCoordinates(event);
 			final FreeformFinSet finset = (FreeformFinSet) component;
+
+		// If shift is held down and a point is being dragged, constrain angle relative to previous or following point
+			int lockIndex = -1;
+			int highlightIndex = -1;
+			if (dragIndex >= 0 && (mods & MouseEvent.SHIFT_DOWN_MASK) != 0) {
+				if ((mods & MouseEvent.CTRL_DOWN_MASK) != 0) {
+					if (dragIndex < finset.getFinPoints().length-1) {
+						lockIndex = dragIndex + 1;
+						highlightIndex = dragIndex;
+					}
+				}
+				else if (dragIndex > 0) {
+					lockIndex = dragIndex - 1;
+					highlightIndex = dragIndex - 1;
+				}
+
+				if (lockIndex >= 0) {
+					// Fetch point to lock to
+					final Coordinate lockPoint = finset.getFinPoints()[lockIndex];
+					// Distances to vertical and horizontal lines
+					final double diffX = point.x - lockPoint.x;
+					final double diffY = point.y - lockPoint.y;
+					final double distanceX = Math.abs(diffX);
+					final double distanceY = Math.abs(diffY);
+					// Calculate distance to 45 or 135 degree line, as appropriate
+					final double a = 1;		// always
+					final double b = (Math.signum(diffX) == Math.signum(diffY)) ? -1 : 1;
+					final double c = -(a*lockPoint.x + b*lockPoint.y);
+					final double distanceDiag = Math.abs(a*point.x + b*point.y + c) / Math.sqrt(2);
+
+					// Snap in the appropriate direction
+					if (distanceX <= distanceY && distanceX <= distanceDiag) 		// snap horizontal
+						point.x = lockPoint.x;
+					else if (distanceY <= distanceX && distanceY <= distanceDiag)	// snap vertical
+						point.y = lockPoint.y;
+					else {															// snap diagonal
+						point.x = (b*( b*point.x - a*point.y) - a*c) / 2;
+						point.y = (a*(-b*point.x + a*point.y) - b*c) / 2;
+					}
+				}
+			}
+			figure.setHighlightIndex(highlightIndex);
+
 			try {
 				finset.setPoint(dragIndex, point.x, point.y);
 			} catch (IllegalFinPointException e) {
@@ -627,6 +674,9 @@ public class FreeformFinSetConfig extends FinSetConfig {
 		public void mouseReleased(MouseEvent event) {
 			dragIndex = -1;
 			dragPoint = null;
+			figure.setHighlightIndex(-1);
+			figure.updateFigure();
+
 			super.mouseReleased(event);
 		}
 		

swing/src/main/java/info/openrocket/swing/gui/scalefigure/FinPointFigure.java

@@ -39,6 +39,7 @@ public class FinPointFigure extends AbstractScaleFigure {
 
 	private static final int LINE_WIDTH_FIN_PIXELS = 1;
 	private static final int LINE_WIDTH_BODY_PIXELS = 2;
+	private static final int LINE_WIDTH_HIGHLIGHT_PIXELS = 3;
 
 	// the size of the boxes around each fin point vertex
 	private static final int LINE_WIDTH_BOX_PIXELS = 1;
@@ -59,6 +60,7 @@ public class FinPointFigure extends AbstractScaleFigure {
 
 	private Rectangle2D.Double[] finPointHandles = null;
 	private int selectedIndex = -1;
+	private int highlightIndex = -1;
 
 	private static Color backgroundColor;
 	private static Color finPointBodyLineColor;
@@ -124,6 +126,7 @@ public class FinPointFigure extends AbstractScaleFigure {
 		paintRocketBody(g2);
 		
 		paintFinShape(g2);
+		paintHighlight(g2);
 		paintFinHandles(g2);
 	}
 	
@@ -262,6 +265,22 @@ public class FinPointFigure extends AbstractScaleFigure {
 		g2.draw(shape);
 	}
 
+	private void paintHighlight(final Graphics2D g2) {
+		final Coordinate[] points = finset.getFinPointsWithRoot();
+
+		if (highlightIndex < 0 || highlightIndex > points.length - 1) {
+			return;
+		}
+
+		Coordinate start = points[highlightIndex];
+		Coordinate end = points[highlightIndex+1];
+
+		final float highlightWidth_m = (float) (LINE_WIDTH_HIGHLIGHT_PIXELS / scale  );
+		g2.setStroke(new BasicStroke(highlightWidth_m));
+		g2.setColor(Color.RED);
+		g2.draw(new Line2D.Double(start.x, start.y, end.x, end.y));
+	}
+	
 	private void paintFinHandles(final Graphics2D g2) {
 		// Excludes fin tab points
 		final Coordinate[] drawPoints = finset.getFinPoints();
@@ -438,4 +457,8 @@ public class FinPointFigure extends AbstractScaleFigure {
 		this.selectedIndex = newIndex;
 	}
 
+	public void setHighlightIndex(final int newIndex) {
+		this.highlightIndex = newIndex;
+	}
+
 }