The rotation thing

[pauland]

anyone who does not understand the difference between an object orientated vector editor and a canvas orientated raster editor might miss the point completely

I think canvas rotation is not related to being vector or bitmap based software - it's a universal concept.

It's reasonable to request the feature, but ridiculous to suggest it as a necessity.

As others have said, it's an "essential" feature I've never missed in Xara and never used while using PhotoShop.

[handrawn]

there is no such thing as a canvas in xara Paul is there?

[or in illustrator, or inkscape]

sure rotation of a drawing is a universal concept, but you cannot rotate what isn't there

in vector drawing applications you have object[s] which you can already rotate - selecting them for rotation is a precise one click operation, unlike pixel selection which can be wooly

this is important to stress - the caveman will not evolve until he understands it

[pauland]

Xara has a background - you can colour it. If we were painting our background would be a physical canvas. Xara has the concept of a canvas, but not the terminology.

Rotating the canvas is not a feature I miss. Pixel selection certainly isn't wooly.

[handrawn]

ok



a xara background is an object - it exists on a background layer and you edit it exactly the same as any other object - right? - you can lock it out of rotation, or include it if you wish
and you don't paint it - xara does not paint, it creates objects, and therefore it has no canvas

pixel selection is wooly only in the sense that with tools such as a magic wand there is threshold to consider - contiguity - because you are not selecting something that is discrete [in the mathematical sense] you are trying to define an internal boundary, which can only be done to a given level of precision

[pauland]

Steve, there's a load of differrent things going on there!

All software builds analogies to the read world so that users can migrate real-world concepts to a user-interface.

Of course, Xara doesn't paint, but neither does painter or photoshop. Xara doesn't paint, but does have brushes! Xara has no explicit canvas, but does have a page, so effectively page = canvas.

Pixel based editors are entirely discrete - they don't describe images using mathematics - as per vector software, but they do describe images in terms of discrete units - pixels - that represent information as distinct blocks.

You are entirely right to say that vectors have a wide range of precision for representing images, while pixel based editors are limited by the number of pixels used in their representation. That said, the selection within a pixel based editor is entirely accurate - it selects only whole pixels, the only imprecision is due to the skill of the user and the quality of the interface. Of course, if an image is zoomed out in a pixel interface, it's not possible to pick some pixels precisely (since one screen pixel represents multiple image pixels).

Xara doesn't have the ability to rotate canvas (cough, page) and content, but it's absence has nothing to do with Xara being vector based.

Interesting discussion.

[handrawn]

yes interesting

ok - wooly was a bad choice of word, agreed - selecting precisely and quickly takes a lot of skill in a pixel-based editor, and in a vector one [usually] not anything like so much
I really only mentioned this because I think its important to realise how easy it is to rotate objects in vector as opposed to selections on a canvas

semantically you can call a page-area/art-board/canvas anything you like and interchange the labels too, also agreed

And I'll grant you that pixels themselves are discrete, but in the sense that cells in your body are discrete [which they are] - on this analogy a photoshop layer is like all the organs within the body and its interconnecting tissue, discrete in a sense but all connected up as one [hopefully ] - xara objects are like separate people, they have an existence of their own

you cannot have pixels missing from a raster matrix they are always there, whatever their visible state at a given time, so a layer is homogeneous, there are no gaps as there are in xara

[pauland]

you cannot have pixels missing from a raster matrix they are always there, whatever their visible state at a given time, so a layer is homogeneous, there are no gaps as there are in xara

Umm.. bitmap software doesn't have to have a representation for every pixel on a layer internally, so I don't really accept that they are "always there"!

It may be convenient to have a representation for every pixel, but it doesn't have to be so. Software manipulating large, mostly empty datasets will use sparse arrays, or similar. In a bitmap editor a given pixel can be absent until the user decides otherwise, or the image is exported to a particular graphics format.

[handrawn]

now we are moved to programming and I bow to your expertise regarding sparse arrays and the like for the actual donkeywork as opposed to the representation of workspace

to my non-technical mind a sparse array is a form of compression, still maintaining a 'contigual' integrity - however I am sufficiently out of my depth there to not be certain

my original point was about how the user should visualise the workspace, as a means of appreciating a fundamental difference between raster and vector, without going deeply into matrix, bezier, arrays and such, which like I say, I'm no expert at

[pauland]

Anyway, I think we both agree rotating the workspace/canvas/page is something I've never missed or even thought about - it's hardly essential.

[handrawn]

no its not essential IMO, agreed

if xara were a freehand drawing tool of the calibre of say paintool-SAI then the ability to move the canvas round with the mouse or tablet keys 'at the same time' as you draw with the tablet pen, would be useful - but xara is not that kind of a drawing tool..