[Pharo-dev] Coordinates problem with Athens and Morphic while coding Hyperion

kilon alios kilon.alios at gmail.com
Thu Nov 28 10:54:02 EST 2013


absolutely, more code mean deeper understanding how to be more dangerous as
a coder

i dont see any big difficult on the horizon, except the problem I discussed
earlier in the list. I need to figure out how to make sure the mouse
touches a line. This is necessary for 2 reasons

a) when not in edit mode then the mouse by clicking on the line will be
able to drag it around

b) when in add points mode, clicking on the line will add more control
points on the parts of the lines clicked.


Another thing that troubles me is how to handle storing vector lines. I
could make each line and even each segment into a separate morph. But I am
not so sure if that is an overkill.

I see also that Roassal stores them as shapes and allows you to add them
with the + method. I like that.

I am also thinking making my own morph class which will be a lot more
lightweight and Athens friendly.

Another alternative is to use a database to store all vector information.

 But overall I think most of functionality I want to cover is already
provided by Athens, its just a matter of coding it.


On Thu, Nov 28, 2013 at 4:16 PM, Igor Stasenko <siguctua at gmail.com> wrote:

>
>
>
> On 28 November 2013 13:52, kilon alios <kilon.alios at gmail.com> wrote:
>
>> thats all I got I am afraid right now. A simple editing of a straight
>> line, but I am learning athens, roassal, morphic so it takes time. Its my
>> first with everything and my very first project with pharo. I am not aiming
>> for something super sophisticated, bezier lines, gradients, bitmaps etc
>> simple stuff but I am having so much fun with this project I wont give up
>> until I have it finished. :)
>>
>>
> btw, if you want, i got somewhere code for Bezier curve editing (in
> morphic)..
> it is not fully working, but at least something you can look at:
>  - if i remember you can add control points and move them around.
>
>
>
>>
>> On Thu, Nov 28, 2013 at 2:30 PM, Alexandre Bergel <
>> alexandre.bergel at me.com> wrote:
>>
>>> Do you have  more screenshots of Hyperion?
>>>
>>> Alexandre
>>> --
>>> _,.;:~^~:;._,.;:~^~:;._,.;:~^~:;._,.;:~^~:;._,.;:
>>> Alexandre Bergel  http://www.bergel.eu
>>> ^~:;._,.;:~^~:;._,.;:~^~:;._,.;:~^~:;._,.;:~^~:;.
>>>
>>>
>>>
>>> On Nov 28, 2013, at 7:49 AM, kilon alios <kilon.alios at gmail.com> wrote:
>>>
>>> > Ok I have verified and indeed its not an Athens problem. My bad. The
>>> position of the morph is reported at 5 at 30 and the not the correct 0 at 0.So it looks like Morphic for some strange reason it offsets it.
>>> >
>>> > I knew about translateBy but I did not know about restoreAfter. so
>>> thank you.
>>> >
>>> > I prefer my version of the code because it makes clearer what I am
>>> trying to do. However ideally because I am drawing a box inside another box
>>> the best way would be to follow your approach and scale the second box
>>> using one shape instead of two I am currently doing. But thats the price I
>>> am paying from not knowing exactly how to do this.
>>> >
>>> > Also trying to painstakingly find the correct transform and scale
>>> values requires A LOT of testing . This is why I find a vector editor for
>>> Athens and Pharo absolutely essential. No coding can beat designing via
>>> mouse.
>>> >
>>> > On the other hand I could use Inkscape and import the svg to Athens ,
>>> which what I am about to research. Designing all GUI elements by code is a
>>> very bad idea, but no less a learning experience.
>>> >
>>> > I will most probably move to Roassal too.
>>> >
>>> > As always thanks for the help.
>>> >
>>> >
>>> > On Thu, Nov 28, 2013 at 12:29 PM, Igor Stasenko <siguctua at gmail.com>
>>> wrote:
>>> > well, by default the athens canvas coordinate system matches morphic
>>> one..
>>> > but you know, it always hard to be sure, especially if you perform any
>>> local coordinate transformations before that morph has any chance to draw
>>> itself..
>>> >
>>> > You can figure this out easily: draw something at 0 at 0 and see where
>>> it is.
>>> > then draw something at morph's x at y position and see it too.
>>> >
>>> > btw, you know you don't have to create same paths over and over.
>>> > you can easily put static parts out of regularly (and costly)
>>> evaluated code:
>>> >
>>> > shape := canvas cacheAt: self "morph" ifAbsentPut: [
>>> >                 aCanvas createPath: [:path |
>>> >               path relative.
>>> > " no move-to here ***  path moveTo: ((self position x )+5)@(self
>>> position y);"
>>> >               lineTo: 20 at 0;
>>> >               cwArcTo: 5 at 5 angle: 45;
>>> >               lineTo: 0 at 20;
>>> >               cwArcTo: (-5)@5 angle: 45;
>>> >               lineTo: (-20)@0;
>>> >               cwArcTo: (-5)@(-5) angle: 45;
>>> >               lineTo: 0@(-20);
>>> >               cwArcTo: 5@(-5) angle: 45.
>>> >                 ].
>>> > ].
>>> >
>>> > "and here we're using coordinate transform to translate origin point to
>>> > given position, so it will be the starting point (0 at 0) of our shape"
>>> >
>>> > canvas pathTransform restoreAfter: [
>>> >    canvas pathTransform translateBy:((self position x )+5)@(self
>>> position y).
>>> >    canvas drawShape: shape.
>>> > ]
>>> >
>>> > by analogy you can cache all static pieces, just do something:
>>> >
>>> > shapes := canvas cacheAt: self ifAbsentPut: [ self
>>> constructStaticShapesOn: aCanvas ]
>>> >
>>> > where #constructStaticShapesOn: must answer an array of them.
>>> >
>>> >
>>> > On 28 November 2013 11:12, kilon alios <kilon.alios at gmail.com> wrote:
>>> > wow you guys are fast at replying :)
>>> >
>>> > I did
>>> >
>>> >
>>> >       self changeProportionalLayout.
>>> >       editButton := HypEditButton new .
>>> >       editButton position: 0 at 0.
>>> >       self addMorph: editButton fullFrame: #(0 0 0 0 0 0 100 100).
>>> >
>>> > I am afraid Igor I still see no change with your code.
>>> >
>>> > I like to note here, that when I first created the editButton as morph
>>> , it indeed placed it in correct place. A 0 at 0 placed it in top left
>>> corner as expected. But I did overide its DrawOn:  with an empty method and
>>> used my own method to render it with Athens. So it looks like the problem
>>> is Athens related and not Morphic related or maybe a disagreement between
>>> Morphic and Athens.
>>> >
>>> > just for the record here is the code I use to render the HypEditButton
>>> morph
>>> >
>>> > render:aCanvas
>>> >       |shape1 shape2 shape3 editButtonColor |
>>> > shape1 := aCanvas createPath: [:path |
>>> >               path relative .
>>> >
>>> >               path moveTo: ((self position x )+5)@(self position y);
>>> >               lineTo: 20 at 0;
>>> >               cwArcTo: 5 at 5 angle: 45;
>>> >               lineTo: 0 at 20;
>>> >               cwArcTo: (-5)@5 angle: 45;
>>> >               lineTo: (-20)@0;
>>> >               cwArcTo: (-5)@(-5) angle: 45;
>>> >               lineTo: 0@(-20);
>>> >               cwArcTo: 5@(-5) angle: 45.
>>> >                 ].
>>> >
>>> >       shape2 := aCanvas createPath: [:path |
>>> >               path relative .
>>> >
>>> >               path moveTo: ((self position x +7))@((self position y
>>> +3));
>>> >               lineTo: 18 at 0;
>>> >               cwArcTo: 2 at 2 angle: 45;
>>> >               lineTo: 0 at 20;
>>> >               cwArcTo: (-2)@2 angle: 45;
>>> >          lineTo: (-20)@0;
>>> >               cwArcTo: (-2)@(-2) angle: 45;
>>> >               lineTo: 0@(-20);
>>> >               cwArcTo: 4@(-2) angle: 45.
>>> >                 ].
>>> >       shape3 := aCanvas createPath: [:path |
>>> >               path relative .
>>> >
>>> >               path moveTo: ((self position x +15))@((self position y
>>> +10));
>>> >
>>> >               cwArcTo: 5 at 5 angle: 90;
>>> >               cwArcTo: (-5)@5 angle: 90;
>>> >               cwArcTo: (-5)@(-5) angle: 90;
>>> >               cwArcTo: 5@(-5) angle: 90.
>>> >
>>> >
>>> >                 ].
>>> >
>>> > ( editMode = true) ifTrue: [ editButtonColor := Color green] ifFalse:
>>> [ editButtonColor := Color red ].
>>> > (aCanvas setStrokePaint: editButtonColor) width: 1.
>>> >
>>> > aCanvas drawShape: shape1 .
>>> > aCanvas drawShape: shape2.
>>> > aCanvas setPaint: (editButtonColor alpha: 0.3 ).
>>> > aCanvas drawShape: shape3.
>>> >
>>> >
>>> >
>>> >
>>> >
>>> >
>>> > On Thu, Nov 28, 2013 at 12:03 PM, Igor Stasenko <siguctua at gmail.com>
>>> wrote:
>>> >
>>> >
>>> >
>>> > On 28 November 2013 10:59, kilon alios <kilon.alios at gmail.com> wrote:
>>> > just tried it, I see no change
>>> >
>>> > try:
>>> >  self changeProportionalLayout
>>> >
>>> > editButton := HypEditButton new .
>>> >       self addMorph: editButton fullFrame: #(0 0 0 0 0 0 100 100).
>>> >
>>> >
>>> > On Thu, Nov 28, 2013 at 11:54 AM, Benjamin <
>>> Benjamin.VanRyseghem.Pharo at gmail.com> wrote:
>>> > Can you try to do something like
>>> >
>>> > self changeProportionalLayout
>>> > before adding the morph ?
>>> >
>>> > Ben
>>> >
>>> > On 28 Nov 2013, at 10:51, kilon alios <kilon.alios at gmail.com> wrote:
>>> >
>>> >> So I have found some strange problems with my vector editor ,
>>> Hyperion.
>>> >>
>>> >> Hyperion is a Morph openInWindow. Code can be found in the class side
>>> of Hyperion>>open.
>>> >>
>>> >>  The coordinate system when detecting events (mouseOver, mouseUp and
>>> mouseDown events of the Hyperion instance) looks like it takes to account
>>> also beyond the morph as coordinates as a result events happening at the
>>> top right edge of the morph where Hyperion is rendered is 6 at 30( which
>>> is the size of the window's title bar plus its borders). Thats ok, I have
>>> taken these offsets to account when computing the position of the mouse. I
>>> guess it uses the global coordinated and not the local coordinates of the
>>> morph.
>>> >>
>>> >> I am adding a button to control the edit mode of a line, when in edit
>>> mode handles for line's control points are shown and those handles can be
>>> dragged around to control the shape of the line , when off edit mode, the
>>> line will be able to be drag around (not implemented yet).
>>> >>
>>> >> My problem is that when I add that button as morph to the existing
>>> morph of Hyperion in 0 at 0 , it actually appears in 0 at 30 in local
>>> coordinated of the Hyperion moprh which in global coordinates it 6 at 60 (
>>> 0 at 0 + 6 at 30 + 0 at 30 = 6 at 60). Why is that ?
>>> >>
>>> >> I have no clue why I am getting an offset of 0 at 30 in local
>>> coordinates of the Hyperion morph.
>>> >>
>>> >> here is the picture showing a) how it looks like b) the code that set
>>> the position c) transcript showing mouse coordinates when clicked in the
>>> top left corner of Hyperion morph
>>> >>  Hyperion coordinates problem.JPG
>>> >>
>>> >> if anyone wants to try the code himself the repo is here
>>> >>
>>> >> http://www.smalltalkhub.com/#!/~kilon/Hyperion
>>> >>
>>> >> To sum up, to place that button on top left, I will have to position
>>> it 0@(-30) which for me makes no sense at all.
>>> >>
>>> >> Please note that everything is rendered with Athens.
>>> >>
>>> >> Maybe I have messed up the code myself somewhere but I have looked it
>>> again and again I cant find a problem with my code.
>>> >
>>> >
>>> >
>>> >
>>> >
>>> > --
>>> > Best regards,
>>> > Igor Stasenko.
>>> >
>>> >
>>> >
>>> >
>>> > --
>>> > Best regards,
>>> > Igor Stasenko.
>>> >
>>>
>>>
>>>
>>
>
>
> --
> Best regards,
> Igor Stasenko.
>
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