XDA Precision

Dear Xara...

There has been a hot discussion around the accuracy of Xara dimensioning: https://www.talkgraphics.com/showthr...-more-accurate.
One resulting Bug, re-identified, is the number of significant figures available when working in mm Units. A new Unit with a 1:1 mapping has no such limitation.

I have tried to summarise the issues/bugs in the following design: Attachment 130171.

• A Line should have a Perimeter when it has a Line width (LW). That perimeter would be twice its Length plus twice the Line Width, not just its Length.
  
  • If it has LW None or 0, then you could argue its Length is correct.
  
  
• A line should have an Area when LW is not None or 0.It should be its Length time the LW, not 0.
• The SmartShape for a Rectangle (Shift+R) should return a Perimeter and an Area not not 0 for both.
  
  • If you Ungroup, the Perimeter should be 2(W + H) not 2W + H, where H is the Height.
  
  
• The SmartShape for a Text Panel (Shift+C) suffers from an incorrect Perimeter as above.
  
  • The Text Area of the default extends beyond the Panel so inputting W: 200pt returns a wildly larger value.
  • Further, after the SmartShape is Ungrouped, it is not possible to input 200pt. When the page Units are mp, the result is always off, e.g., H: 200pt --> 199,998mp; H: 200,000mp --> 200,002mp.
  
  
• For a Rectangle (M), you cannot input 200pt and get 200,000mp in either the rectangle input or the Selector input.
• If instead I create a Circle (L) and Make Line of its nodes, I can fully control its W & H but its P & A never match to the exact value.

I can instead of the above complication readily create a shaped rectangle from four constrained nodes using F4.

The best, however, seems to be to use the QuickShape Tool with 4 sides.
The resultant is fully accurate and can be handles as a Rectangle or a QuickShape so one can still include rounded corners.
Accuracy for P & A is maintained all the way down to rounding for a circle.
The bonus, for me, is your HTML Filter still renders this as a SPAN with a Fill colour.

In summary for fullest accuracy, use the QuickShape Tool (Shift+F2).
It may seem counter-intuitive but it all but replaces all the other object creation tools with better accuracy.

I look forward to your improvements to the conventional tools you present.

Acorn

Quote:

---

The best, however, seems to be to use the QuickShape Tool with 4 sides.

---

is this correct, do you mean quickshape tool here?

thanks for the xar file :)

Quote:

---

Originally Posted by handrawn

is this correct, do you mean quickshape tool here?
thanks for the xar file :)

---

I did, the Star one.
Set it to be 4-sided and away you go.

Acorn

thanks for the clarification I'll give it a go :)

see that - it surprises me greatly, but it is good

Thank you Acorn, yes I concur with all that you say.

Let me give a simple example. If I create a new blank A4 page and set the page units to Millipoints, if I set the Major Spacing of the grid to "1000mp", and set Snap to Grid on, then:

A) when I use the Rectangle Tool (M), it won't create a "1000" x "2000mp" rectangle, the nearest that the snapping will only allow me to create is a rectangle of size "999.8mp" x "1999.7mp" (and not "1000mp" x "2000mp").

B) Likewise, if I try to use the Quick Shape Tool (Shift+F2) the snapping create a square that is "1001mp x 1001mp", and not 1000 x 1000mp.

Interestingly, if I draw my shape line by line (again with snapping on), I can create the precisely size of shape that I require e.g. "1000" x "2000mp".


Worse, it seems that using either the Quick Shape Tool or the Rectangle Tool is injecting some kind of ongoing inaccuracy.
For example if (having turned off Lock Aspect Ratio), I now edit the width of my Rectangle that I created in A) [see above] to be "10000" it now goes in as "9999.9mp" (instead of "10000").

And sometimes theres errors are somewhate larger. For example I do the same thing to the shape produced by B) and edit the width by typing in "10000mp", the new width is "9989mp" not "10000".

But if I edit a shape that I had DRAWN that is 1000x2000mp in size, if I type in a width of "10000" then I do GET a width of "10000" mp.

Trying to help.

J


PS If you want accuracy, the workaround to avoid the above flaws seems to be to convert all shapes to Editable Shapes (i.e. using Shift+Control+S). Although obviously having changed a Rectangle to an Editable Shape you can no longer do things like ad Curved Corners or change the number of sides etc.