+--- Day changed Wed May 21 2014
+12:09 <@matches> PDF is a mess of a "standard"
+12:09 <@matches> As are all useful things I suppose
+12:09 <@matches> As far as I can work out
+12:09 <@matches> It is not a DOM but a graph
+12:10 <@matches> However, it is also PostScript-y
+12:10 <@matches> But they deal with "interactivity"
+12:10 <@matches> By including XHTML
+12:10 <@matches> And having an "action dictionary" which is literally just a string of javascript
+12:11 <@matches> I just
+12:11 <@matches> Can't even begin to understand how it all works
+12:12 <@matches> But yeah, not really "Crippled Postscript" so much as "Everything including the kitchen sink except for a few bits of Postscript"
+12:13 <@matches> So the Postscript part of it is no longer turing complete, but I don't think you can pretend something in which you can stick arbitrary Javascript isn't turing complete :S
+12:13 <@matches> Oh and even though they have XHTML-ish stuff their Javascript API is totally different to W3Cs
+12:13 <@matches> Hooray
+12:14 <@matches> I suppose the fact that nothing except Adobe products seem to actually use Javascript/XHTML stuff is telling us something about this approach
+12:15 <@matches> I reckon the ideal standard
+12:15 <@matches> Would probably be the DOM but with the "we actually care about efficiency" parts of PDF
+12:18 <@matches> The interactivity of web pages combined with the actually professional looking type setting of PDF
+12:18 <@matches> Or just plain text files
+12:19 <@matches> Plain text files are an underapreciated Document Format
+12:23 <@matches> Ah, I think it sort of makes sense now
+12:23 <@matches> PDF uses what is essentially PostScript to construct this graph thing
+12:24 <@matches> And the graph thing can have elements in it that are just "Make this part of the graph the equivelant DOM from this XHTML"
+12:25 <@matches> And it can also have elements that are "Execute this Javascript to dynamically change this graph"
+12:25 <@matches> But the normal elements are just like PostScript as it would be sent to a printer to show the thing statically
+12:26 <@matches> So when it's rendered it is interpreting the Postscripty bits and when its being interacted with it is updating the Postscripty bits
+12:26 <@matches> I *think*
+12:26 <@matches> This is different from the webby standards which don't really specify how things are actually drawn
+12:27 <@matches> No wait it's not
+12:27 <@matches> Argh I don't know
+12:27 <@matches> You can't classify this shit
+12:27 <@matches> Document Goes In -> Pixels Come Out
+12:28 * matches despairs
+12:49 < sulix> You will find (slightly) less despair if you relegate javascript to the footnote where it belongs. :P
+13:07 < sulix> Hmm... the HTML 2 spec looks like it almost got properly IETF standardised. Might just reference that.
+13:12 < sulix> Oh, they obsoleted it and replaced it with a "Just look at w3c" standard...
+13:17 <@matches> But PDF isn't just flattened PostScript
+13:17 <@matches> It is like, everything
+13:17 <@matches> All merged into one horrifying standard
+13:18 <@matches> Oh well
+13:18 <@matches> I made my shape example in PostScript by removing the alpha
+13:18 <@matches> I'm not sure whether there's any point in including it as a figure
+13:18 <@matches> Most of the PostScript file is taken up by the header
+13:19 < sulix> Holy balls, I just looked up the CSS spec. There are like 200 of them.
+13:19 <@matches> Yeah I just used CSS2
+13:19 <@matches> The others are like
+13:19 <@matches> Colours
+13:19 <@matches> Or something
+13:20 < sulix> That's what I'm using, too.
+13:20 < sulix> The tired and tested "what gets top result on google" method of paper selection.
+13:20 <@matches> Closer examination reveals that most of the PostScript header is defining commands to be shorter :P
+13:20 <@matches> Amazing
+13:20 <@matches> Cairo probably needs to get referenced somewhere
+13:21 <@matches> If only so I have a way out of my Javascript in PDF section by saying that Cairo doesn't support it
+13:21 <@matches> I desperately need to escape the Javascript
+13:25 < sulix> I think the secret is to use the phrase "rendering model" wherever possible.
+13:51 <@matches> Dammit
+13:51 <@matches> So I have that wierd shape in both SVG and PostScript now
+13:51 <@matches> The SVG version fits beautifully and is wonderfully concise and you can see how SVG works
+13:51 <@matches> The PostScript version is just like, BLARGH WALL OF TEXT
+13:51 <@matches> ALSO WE DON'T HAVE ALPHA
+13:52 <@matches> So I'm not sure whether to cut just the PostScript one or both of them now :S
+13:53 <@matches> PDF looks distinctly not like it is just PostScript the more I think about it
+13:53 <@matches> It's like "We are using the same model as PostScript in that commands go in and pixels come out"
+13:54 <@matches> By that logic SVG is also the same
+13:54 <@matches> I think what I should do is just make an appendix
+13:54 <@matches> "A Shape in 20 Document Formats"
+13:56 <@matches> SVG really is the most concise compared to PS and PDF
+14:53 <@matches> Right I can simplify the god awful mess of PS a bit
+14:54 <@matches> I'm hoping I can just say "Here is the PS reference and here is some PostScript as you can see it is interpreted-ish"
+14:54 <@matches> Cairo appeared to draw each element backwards and reverse it after drawing it
+14:54 <@matches> It is stupid
+14:57 <@matches> Like, why bother doing definitions like m == moveto etc
+14:57 <@matches> If you're just going to stick pointless crap in
+14:57 <@matches> My document is half the size without using single letter definitions
+15:31 < sulix> Welp. The wrath of Tim is upon us...
+15:41 <@matches> I'm choosing to latch onto the "quite good" rather than "some way to go"
+15:45 <@matches> It sort of sounds like "Well at least you gave me a pdf file" :P
+15:48 < sulix> One day, all anyone will use are ipdf files...
+15:50 <@matches> Right, TeX is very different from PostScript I think
+15:50 <@matches> At least, pure tex
+15:50 < sulix> Also, holy mackerel, I might have just found a paper on precision in document formats...
+15:50 <@matches> :O
+15:50 < sulix> It even quotes Kahan
+15:50 <@matches> :OOO
+15:50 < sulix> https://www.tug.org/TUGboat/tb28-3/tb90beebe.pdf
+15:50 <@matches> What is it
+15:50 <@matches> Emergency rewrite of entire lit review
+15:51 < sulix> It's a bit TeX specific, but still.
+15:51 <@matches> That's alright
+15:51 <@matches> It ties in amazingly with my decision to hamfist TeX and Metafont into the lit review
+15:52 <@matches> Although I'm not sure it is wise because it means I have to talk about fonts and things
+15:53 <@matches> I wonder if "Fonts are just bezier curves" is sufficient
+15:53 <@matches> They are always treated seperately to curved paths
+15:53 <@matches> Which is understandable because it's a bit inconvenient if you want text in a document to have to define the paths for each glyph
+15:54 <@matches> Anyway I'm glad my assertion that Beziers are the only curves we care about is proving true
+16:33 <@matches> Are you in a position to retrieve this "envelope"
+16:57 < sulix> Not tonight: I'm going to pick it up tomorrow morning.
+16:58 < sulix> And hopefully replace it with a sparkling, glorious review of literature.
+17:00 <@matches> :(
+17:00 <@matches> I cannot concentrate now
+17:00 <@matches> Because I haven't read the comments, I could be doing everything wrong!
+17:02 <@matches> Admitedly I'm technically "working" right now
+17:27 < sulix> My "Document Format Taxonomy" is almost complete... Just need to add SVG.
+17:28 < sulix> (And close my eyes and assert that Microsoft Word documents are not actually documents or something)
+17:28 <@matches> I am jealous
+17:29 <@matches> I just added PostScript it's not particularly well written
+17:29 < sulix> (I don't have any pretty pictures or code, though)
+17:29 < sulix> I've discovered that, despite having totally different numbers for "implementation limits", the PostScript and PDF specs are (a) talking about the same data types and (b) lying.
+17:32 <@matches> Bahaha
+17:32 < sulix> Do you know where the SVG spec mentions precision?
+17:33 <@matches> Ah, I regret not noting the page number
+17:33 <@matches> But a text search should find it
+17:33 <@matches> It specifically says things
+17:33 <@matches> I am interested in whether or not Javascript is subject to the same requirements
+17:34 < sulix> All I've found is "must be correct within 1px at 1:1 zoom", and "It is suggested that viewers attempt to keep a high degree of accuracy when zooming".
+17:35 <@matches> There's something that is about IEEE floats
+17:35 < sulix> Aaah... and a "High-Quality Viewer" must support at least double precision on coordinate system transforms.
+17:35 < sulix> But "IEEE" does not show up in a search of the spec.
+17:36 <@matches> Ah right
+17:36 <@matches> My brain just inserts IEEE whenever I hear "single" or "double" now
+17:36 <@matches> "An IEEE Double Episode of MasterChef!"
+17:36 <@matches> (Which would probably be infinitely more exciting)
+17:37 < sulix> (Or would it be NaNly more exciting...? :P)
+17:38 <@matches> Speaking of "where things are" are we meant to reference page numbers in standards?
+17:38 <@matches> I guess I'll find out when I read Tim's comments
+17:39 <@matches> Excellent my lab finished 20 minutes early
+17:39 <@matches> And also 40 minutes later than the other demonstrators :S
+17:40 <@matches> Do you want me to pick up your comments and scan them and email them to you? :P
+17:40 < sulix> That'd be great.
+17:40 < sulix> Also probably depressing.
+17:41 < sulix> But great.
+17:41 <@matches> Alright, ETA Transperth + Scanner is probably broken O'clock
+17:42 < sulix> I'll savour the blissful ignorance.
+19:50 <@matches> I don't think scanning is worth it, I'll just spam the feedback into this channel
+19:50 <@matches> First up, David's Lit Review
+19:50 <@matches> There is either "Gool" or "Cool" or possibly "Good" written and underlined on the first page
+19:51 <@matches> The opening paragraph is "A little overdramatic?"
+19:51 <@matches> (Since it's a question, I'd like to voice a "No" opinion here)
+19:51 <@matches> The DOM in a footnote is not defined
+19:52 <@matches> Page 2
+19:52 <@matches> There is a tick
+19:52 <@matches> A question mark in regards to the hyphenated bit in the rendering paragraph
+19:53 <@matches> Say "avoid" instead of lack
+19:53 <@matches> Add what the "basic primitives" actually are
+19:53 <@matches> There appears to be an issue with hyphenated phrases the hyphens are circled
+19:53 <@matches> Another tick!
+19:54 <@matches> Oh, you have a $2^64 - 1$\footnote{} which is unfortunate because it looks like $2^64 - 1^2$
+19:54 <@matches> That footnote (probably others?) would work in the paragraph without being footnote
+19:54 <@matches> Fullstops go after \cite{}
+19:55 <@matches> A tick (in regards to the quadtree diagram)
+19:55 <@matches> The concluding comment
+19:56 <@matches> "OK, Much to do (underline) There doesn't seem to be much scholarly references used. You have enough, but you seem to cite them in the context of their contributions to standards as opposed to how they addressed a research question or open problem"
+19:57 <@matches> And (not even our references lists are safe!)
+19:57 < sulix> Oh dear.
+19:57 <@matches> Where referencing web pages, include the date retrieved
+19:57 <@matches> That's it
+19:57 <@matches> I shall move on to my own for completeness although you might not need to care
+19:58 < sulix> Phew, that's not quite as horrible as it could have been, I guess.
+19:58 <@matches> I also have "Good"
+19:58 <@matches> There are some "I didn't read this bit but it had words that seemed vaguely relevant" ticks in Chapter 1 (Introduction) and 2 (Proposal)
+19:59 <@matches> Sorry Tim if you read this
+19:59 <@matches> But when I mark lab reports for Physics that's usually where I put the ticks :P
+19:59 < sulix> (The secret comes out)
+20:00 <@matches> (In my defence I did spend two hours marking the reports this morning and I am paid for none of them, so...)
+20:01 <@matches> (It's the bits that I scribble all over that are where the marking gets done)
+20:01 <@matches> (I think I've covered myself in case the lawyers of any of my students read this channel now, so I will resume my story...)
+20:02 <@matches> Attention is called to the many glaring instances of [?] and "Refer to Section ?"
+20:02 <@matches> :S
+20:02 <@matches> I should probably define a vector image before comparing it to a raster image
+20:02 <@matches> Incidentally my Fox looks amazing
+20:02 <@matches> On printed paper
+20:03 <@matches> (Tim didn't say that, that's just my modest opinion)
+20:03 <@matches> Ahem.
+20:03 < sulix> Can you see the difference between the vector and bitmap versions easily?
+20:04 <@matches> At the original scale there is, alas, a very slight fuzziness
+20:04 <@matches> But I reckon the markers will be old and blind
+20:04 <@matches> Hmm, I should either be more careful about what I say here or stop logging this channel...
+20:04 * sulix hopes they don't read that.
+20:04 <@matches> Sorry markers
+20:04 <@matches> I worship your power
+20:04 <@matches> Please do not smite me
+20:05 <@matches> The scaled up version is interesting
+20:06 <@matches> It looks a bit like your circle with the blocky non-anti-aliased bit but actually anti-aliased by the pdf viewer
+20:06 < sulix> I guess the scaling would be done by the printer's postscript RIP.
+20:06 <@matches> Yeah I guess
+20:07 < sulix> (Side note: I find the whole idea of Postscript interpreters being called RIPs somewhat fitting)
+20:07 <@matches> The PDF decides not to antialias it and converts it to Postscript and then the postscript interpreter adds its own antialiasing?
+20:07 <@matches> I don't know
+20:07 * sulix joins the "SVG is the least broken format" club.
+20:07 <@matches> It's very tempting to descend into footnote madness with this lit review
+20:07 <@matches> "By the way, this very document is an example of this thing!"
+20:07 <@matches> Etc
+20:08 <@matches> Moving on
+20:08 <@matches> The point of talking about vector displays at all is questioned (at least I think that's what the "Why?" refers to here)
+20:08 <@matches> Or it could be "Why is there yet another ?? in this paragraph" I guess
+20:09 <@matches> But probably the former
+20:09 <@matches> I do not have space to include Bresenham's algorithm
+20:09 <@matches> Oh boy, he's going to love what I did with the SVG and Postscript images...
+20:09 <@matches> But I am glad I do not have to actually explain Bresenham's algorithm because it's actually annoyingly detailed
+20:11 < sulix> All sane descriptions of Bresenham's algorithm end up being cascades of "By symmetry" anyway.
+20:11 <@matches> I need to actually find a reference that applied Wu/Bresenham directly to a non-straight line
+20:11 <@matches> You said Bresenham adapted his algorithm to circles but I don't think I'll bother unless someone adapted them to beziers
+20:12 <@matches> Bresenham's paper on rasterisation techniques basically says "Compute some points close enough together and then just connect them with straight lines"
+20:12 <@matches> But I think things might have advanced since the 1980s
+20:12 < sulix> Well, we can compute points that are closer together and draw more lines, I guess.
+20:13 <@matches> Next, Tim wants an example of a spline
+20:13 <@matches> (Oh boy have I got that covered)
+20:13 <@matches> My mathematics terminology on Beziers is not really great
+20:14 <@matches> Well it's right but confusing maybe
+20:14 <@matches> Or I just need to say "t is a trajectory parameter"
+20:14 <@matches> Haha
+20:15 <@matches> He found one of my "????" that is actually just me typing question marks and not a broken reference
+20:15 <@matches> The *entire* section on shading and compositing has a big question mark
+20:15 <@matches> Oh dear
+20:15 <@matches> I just finished writing the compositing bit
+20:16 <@matches> I hope the question mark means "Why isn't this written" and not "Why is this in here"
+20:16 <@matches> Because it is quite useful for an excuse to say PostScript can't do alpha
+20:17 <@matches> I need to refer to the IM (I really don't think that's a thing) and DOM when citing Hayes
+20:17 <@matches> "I don't think Turing Completeness is essential" (Big cross through the Crippled Interpreted Model)
+20:17 <@matches> Fair enough
+20:17 <@matches> A tick appears
+20:18 <@matches> Predictably in the web based documents part
+20:18 <@matches> I need to explain why Ipython is cool if I want to talk about it
+20:18 <@matches> My entire section on Precision as defined in the various formats is ?
+20:20 <@matches> My still to be completed/started section on Graphics APIs, GPUs and Arbitrary Precision is three question marks and "How's all this going"
+20:20 <@matches> The progress report gets a single tick
+20:20 <@matches> And the references have similar issues
+20:20 <@matches> Well
+20:21 <@matches> I'll take a few minutes to quiver in terror
+20:21 <@matches> But I think if I can just find a way to not sleep and still maintain productivity, I might be able to pull this off
+20:22 <@matches> Interestingly he didn't call me out for just talking about standards
+20:22 <@matches> But now I realise that's because I didn't have all the crap I've just written on standards in there
+20:23 < sulix> It's going to be a long night, but I think we'll manage it.
+20:23 <@matches> Mine will be too long but I don't care
+20:24 <@matches> I'll ask for an extension to prepare a condensed version if I must :P
+20:28 <@matches> It's kind of funny I've been spending more time making my vector image in SVG and PostScript nice than actually writing about either of those standards
+20:50 <@matches> Argh the idea of making my koch snowflake example for PS just got in my head
+20:50 <@matches> Which would be brilliant I guess if the topic was still "Fractal Document Formats"
+20:50 <@matches> It probably would be useful if I could demonstrate precision issues..
+20:50 <@matches> NO
+20:50 <@matches> MUST WRITE
+20:50 <@matches> WORDS
+20:50 <@matches> NOT PICTURES
+20:51 <@matches> But still it would make the PostScript and SVG sections consistent with each other...
+20:51 <@matches> NO
+20:51 <@matches> Must control urge to put pointless pictures in
+20:51 <@matches> No matter how much it seems like a good idea
+20:51 <@matches> And not pointless
+20:52 <@matches> Help I'm losing this battle
+20:53 <@matches> It is probably actually a better way of making a Koch curve than the hideous Javascript parsing of strings version
+22:50 <@matches> By the way, you can totally have "pre layout" stages in PostScript since you can define your own operators
+22:50 <@matches> Or do I misunderstand your sentence
+22:50 <@matches> Oh well it sounds smart anyway
+22:51 <@matches> In fact it's a lot more concise than my DOM-y section
+22:52 <@matches> I should sign my Lit Review as Captain Obvious
+22:57 < sulix> My current version does have a "PostScript programs typically embody documents which have been type-
+22:57 < sulix> set, though as a turing-complete language, some layout can be performed
+22:57 < sulix> " sentence.
+22:57 < sulix> by the document.
+23:01 * sulix is still a little bit concerned about how he should reference things for their solutions to open problems rather than their contributions to standards.
+23:03 <@matches> I think I am managing to do it
+23:03 <@matches> I will commit something at some point
+23:03 < sulix> I'm hoping that rewriting most of the rendering section with painful discussions of algorithms will do it.
+23:03 <@matches> An example is Porter and Duff Compositing
+23:04 <@matches> Because PostScript doesn't have alpha and I am really hoping that's just because Adobe had moved on to PDF by the time alpha was a thing
+23:04 <@matches> And not because they thought alpha was dumb :P
+23:05 <@matches> So I can relate Porter and Duff's model to the standards that do use it and say how it solves a problem that the standards that don't use it still have
+23:05 <@matches> And then I can sit back in satisfaction
+23:05 <@matches> And realise this says fuck all about precision
+23:06 <@matches> But at least by talking about it, I have eliminated it from the set of things we need to worry about when talking about precision :P
+23:06 < sulix> I've got a section which basically goes through all of the different document formats and looks at what their specs say about precision now.
+23:06 <@matches> Yeah I have that, but it was dot-pointed
+23:06 <@matches> I thought that would be OK actually but it has a question mark here... :S
+23:06 < sulix> Basically most of them say "implementation-defined" anyway.
+23:06 <@matches> Oh right because I was saying random stuff about how Postscript *used* to not have IEEE
+23:07 <@matches> Yeah it is odd that the standards don't actually reference IEEE
+23:07 <@matches> You'd think, since it's a standard...
+23:07 <@matches> Instead they just say "single" or "double" or "it might be single if you're lucky but we don't care really"
+23:08 <@matches> I assume "single" is widely accepted to mean IEEE single
+23:08 < sulix> From my reading of the Postscript spec, it says basically "We've put IEEE here, but ask your printer manufacturer because they could be using anything for all we care."
+23:08 <@matches> Ah I will check that more carefully
+23:08 <@matches> But it sounds about right
+23:08 < sulix> They give "typical limits" for their data types, but specifically do not specify what they are to be implemented as.
+23:08 <@matches> I don't think I have the time to look at what PostScript did historically before IEEE-754 although it would be kind of interesting to know
+23:09 <@matches> PostScript also does a bunch of silly maths because of units
+23:09 < sulix> The idea being that each postscript interpreter could do whatever they liked.
+23:09 <@matches> Cool
+23:09 <@matches> I should know this already :S
+23:09 <@matches> I just included a single character as a figure
+23:10 <@matches> But I want to actually work out how to do it in LaTeX by setting the size of the font appropriately
+23:10 < sulix> The PDF spec says pretty much the same thing, but notes that Adobe's implementation uses "Mostly IEEE singles" but "used to use 16.16 fixed point" and "still uses it for some things"
+23:10 <@matches> I did see that
+23:10 < sulix> TeX using 14.16 fixed point.
+23:10 < sulix> DVI uses "up-to 32bit" signed integers.
+23:11 <@matches> So basically no one actually uses IEEE for anything :P
+23:11 <@matches> Good work
+23:11 <@matches> I shall panic a bit and then try and actually do that work myself
+23:11 < sulix> SVG uses "implementation defined" or "double-precision floating point" "for coordinate transforms" if you want to be certified "High Quality"
+23:12 <@matches> I saw that one
+23:12 <@matches> But I'm skeptical about how this plays with Javascript
+23:12 <@matches> Not for High Quality even, just in general
+23:12 < sulix> Javascript numbers are always IEEE 754 doubles.
+23:13 <@matches> Ah thanks
+23:13 < sulix> (Even their integers are IEEE 754 doubles, which just happen to be integers)
+23:13 <@matches> Yes I have heard this before
+23:13 <@matches> From you probably :P
+23:14 < sulix> I don't have a source for that, and I'm not going to read the ECMAscript spec to find one, though.
+23:16 <@matches> Oh right, Javascript is actually ECMAscript
+23:16 <@matches> I forgot that
+23:17 <@matches> Dammit I am struggling to stay awake here
+23:17 <@matches> I'm not sure whether it's healthier to try to not sleep and give Tim a draft tomorrow and demand he read it in enough time to make last minute changes
+23:18 <@matches> Or sleep and then be more coherant tomorrow
+23:18 <@matches> I guess I'll try and finish a couple more sections
+23:19 < sulix> I'm going to try to finish this tonight.
+23:20 * sulix has another assignment due Friday that needs significant work.
+--- Day changed Thu May 22 2014
+00:47 <@matches> So X just managed to totally shit itself
+00:47 <@matches> Time to see when I last pressed Ctrl-S
+00:48 <@matches> Oh good (I typically press it once per sentence)
+00:48 <@matches> I hope it wasn't one of my SVGs that broke everything
+00:49 <@matches> Making all my figures in SVG
+00:49 <@matches> Lovingly hand written
+00:49 <@matches> I'm not sure that was a good idea
git.ucc.asn.au / ipdf / documents.git / commitdiff
UCC git Repository :: git.ucc.asn.au