1 (edited by Lyx 2015-06-07 13:57:16)

Topic: Remember format, Triangular Arrowtips, other things

Diagram designer at this point does nearly anything i could ask for. The rotated text feature has greatly cut down on my needs of degrading mutable objects to mutable metaobjects. Only a few concerns remain for me, and a buddy of mine who uses DD a lot, despite him being on linux. Some of those concerns i imagine to be easy to code, others might be difficult:


1. Remember last choosen export file format


It always defaults back to EMF i think, to which neither of us ever export. I can understand other export settings being reset, but for fileformat, it IMO makes little sense.


2. Polygon-style arrowtips


This is an old one, which i might have mentioned on the forums years ago, i'm not sure. To be honest: The current arrowtips are ugly. They only might look okay for technical drawings with thin lines and small arrows. So basically: Traditional diagrams. But diagram designer lends itself to much more than this - we basically use it as a featherweight powerpoint: It just gets the job done simple and quick, whenever one just wants to arrange elements on a grid.


What's the problem exactly? Well, for thicker lines and hence larger arrowtips... they just look bad. I'm not suggesting anything fancy - on the contrary, all i'm missing are plain simple triangles! A triangle as an arrowtip - sharp and clean, like a polygon. Of course i could do that manually, by making the line and arrowtip seperate objects - i did so in the past, and dropped the practice, because it is a mess and too much trouble.


3. Filled objects/metaobjects with curved segments


I fully understand this might be a nightmare or near-impossible to implement, but it's a repeating weakness of the application, since there are no feasible workarounds: One can create a filled shape from straight line segments, but it is impossible to have a filled object with curved segments. One would have to create those objects in another application, then export into a format that DD can import.


4. (Bug) Gradient algo uses integer-interpolation


How to reproduce: Make a rectangle. Set a gradient from black to white. What one would expect as a result, is a gradient of greyscale colors. Yet, what actually seems to happen is this: 1,0,0 - 1,1,0 - 1,1,1 - 2,1,1 - 2,2,1 - and so on. As a result, those gradients have a red/orange tint.


5. Preferences option to limit grid to powers of two


To keep everything neatly synced, i always work with gridsizes that are powers of two: 1, 2, 4, 8, 16, and so on. While creating a diagram, i constantly switch between those values as needed. The addition of this being changeable in the toolbar was a great time saver, but i still all the time have to click through all the intermediate grid values (those that are not powers of two).


6. (Exotic feature) Fractal lines


I have little hope of this being implemented, but heck worth a shot. Recently i wanted to create a geographic map of a fictional country. As you know, the outline of landmasses aren't straight lines or curves. Instead, they look 'jagged'. For this reason, there are specialized applications to design such landmasses. But in fact, all that is needed IS what DD already does, plus so called "fractal lines". Fractal lines are the only feature those apps have, that DD has not.


I went through all such applications currently on the market, and every single one was a PITA, for they either are buggy, and/or fail at what DD does right. Yet if DD had fractal lines, i could just use it for such tasks. Here's an example of what a fractal line is:


http://www.spatial-effects.com/images/fractal-s.gif


So, like a line the user defines a startpoint and endpoint, but the line doesn't go straight from A to B - it does so approximatelly, but deviates pseudorandomly (a seed is used to make it persistent). I'm not too familiar with the relevant maths or code, but the following might or might not be useful for implementation:

https://icpcarchive.ecs.baylor.edu/inde … oblem=2613

Re: Remember format, Triangular Arrowtips, other things

> 2. Polygon-style arrowtips

Something like the "UML is a" arrow?
You can set it in the toolbar but the setting of these default styles is not saved...

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3 (edited by Lyx 2015-06-08 14:41:21)

Re: Remember format, Triangular Arrowtips, other things

> 2. Polygon-style arrowtips

Something like the "UML is a" arrow?
You can set it in the toolbar but the setting of these default styles is not saved...

Change the tip size to 12, and you can see that the "corners" are rounded, just as with all the other arrowtips.

I'm unsure about the technical implementation, but here is a guess:
I suspect that internally, the tips already are objects just like user objects. When increasing the tip size, the "line width" of those tips is probably scaled up as well, instead of just the object. As a result, at large sizes the corners of the tips become rounded, just as with a user object that has a large border width.

This is needed/makes sense for some arrowtips, but for the following three, it does not:
arrow2
doublearrow
UML is a

The problem is, to maintain compatibility with existing diagrams, the scale ratio would have to be changed. See, if you for the above tips stop scaling linewidth, they would become smaller... so, this has to be compensated with size, so they keep about the same dimension in existing diagrams. This also would be useful, for keeping their sizes similiar to the other tips.

4

Re: Remember format, Triangular Arrowtips, other things

1.
You don't need to choose a specific export format in the dropdown - if you want e.g. PNG you can just add the extension .png to the file name. But yes, it might be more userfriendly to remember it.

2.
Basically DD just uses Windows line drawing to draw the arrow tips and that makes them rounded when the line width is big and I'm not really sure how to avoid that in a simple way. You can also see that thick lines gets a rounded end when no arrow is selected. To make them look better you can increase the size of the line ending - you can do that by scrolling the mouse wheel over the arrow style in the toolbar or in the object's properties dialog.

4.
I can't reproduce that. When I made a black to white gradient I only see gray colors in between.

Michael Vinther

> software developer <

Re: Remember format, Triangular Arrowtips, other things

4.
I sincerely apologize. While i can reproduce it, the fault is not with DD - when i check it in an image editing application, the values are indeed greyscale. Probably it is my monitor or gamma settings. Again, sorry for the false report.

2.
Well, for user objects one can set the line-width idependently of the object size. So, i suppose this can be done for arrowtips too? That is, for arrow2, doublearrow and

6

Re: Remember format, Triangular Arrowtips, other things

I just noticed that if you change the line style to outline (====) and set the fill color to the same as the line color then the Arrow 2 head becomes less rounded and more sharp.

1 is a standard solid line with Arrorw 2 head
2 is an outline style line with Arrorw 2 head
3 is a standard solid line with a filled polygon

http://logicnet.dk/DiagramDesigner/Help/Arrow.png

Michael Vinther

> software developer <

Re: Remember format, Triangular Arrowtips, other things

Thank you!