From 40e419edaefc7616a08f9c307a07424ade30cd09 Mon Sep 17 00:00:00 2001 From: C R Onjob Date: Fri, 23 May 2014 01:00:04 +0800 Subject: [PATCH] Automatic commit of irc logs You can create your own opportunities this week. Blackmail a senior executive. --- irc/#ipdf.log | 169 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 169 insertions(+) diff --git a/irc/#ipdf.log b/irc/#ipdf.log index 70a40a6..4df7d54 100644 --- a/irc/#ipdf.log +++ b/irc/#ipdf.log @@ -1547,3 +1547,172 @@ 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 +01:43 <@matches> Heh, converting SVG to PS in Inkscape appears to introduce rounding errors of up to 0.1 of whatever unit PS is using +01:44 <@matches> 1.25*56 +01:45 <@matches> Disregard I appear to have mistaken this terminal for a calculator +01:45 <@matches> They do look similar at this hour in the morning +01:49 < sulix> I'm seriously doubting whether starting to write stuff about how all of the rasterizing algorithms work was a good idea. +01:49 <@matches> Haha +01:49 <@matches> I don't really have much rasterising as such +01:49 <@matches> Straight lines +01:50 <@matches> Beziers aren't really "rasterising" so much as defining curves +01:50 <@matches> Then I mention fonts and how they are all bezier-ish +01:50 < sulix> I've just spent about an hour trying to prove that bresenham's algorithm can be made to not depend on any coordinates outside the screen. +01:50 <@matches> Then I have a bit on shading that I can't do +01:50 <@matches> :S +01:50 <@matches> That's probably not important +01:50 <@matches> To quote Tim in my thesis regards to actually explaining algorithms +01:50 < sulix> It turns out that if you clip the endpoints (even correctly), you adjust the slope of the lines slightly. +01:51 <@matches> "No you don't have space. [...] details should be left to where they are useful" +01:51 <@matches> Having said that absolutely none of this is "useful" +01:51 < sulix> To fix it you have to initialize bresenham's "accumulated error" properly. +01:51 <@matches> That sounds sort of relevant +01:52 <@matches> Well I just copied some SVG into PostScript and discovered that the coordinates are all reflected :S +01:52 < sulix> My choices for referencing this is either a textbook I don't have that "apparently mentions this" or a blog post which rants about it a bit. +01:52 <@matches> Bahaha +01:53 <@matches> That sounds like work for the final lit review rather than this one +01:53 < sulix> Still need to work out how to actually work in how my references solved problems rather than contributed to standards or whatever. +02:05 <@matches> minipage for latex is great by the way +02:06 <@matches> Like
but not awful +02:40 <@matches> Oh year +02:40 <@matches> The best spline curve example ever +02:41 <@matches> Fuck it took about 3 hours to do that +02:41 <@matches> Dear god +02:41 <@matches> Ergh remind me to go censor the log before Friday 1am +02:50 <@matches> I pushed my references changes by the way +02:51 < sulix> Yay merging! +02:51 <@matches> Oh I forgot the actual pdfs but whatever +02:51 <@matches> I am jealous of your actual concise and to the point lit review +02:51 <@matches> Mine suddenly exploded into figures +02:51 <@matches> I should stop +02:51 <@matches> I think I will delete the Shading section +02:52 <@matches> No wait it would be a gap to take it out now +02:52 <@matches> Argh +02:53 <@matches> I will just have to resist the urge to put a diagram in showing how shading works +02:53 <@matches> All these diagrams will probably kill me +02:53 < sulix> I'm thinking of scrapping chunks of the Rendering section of mine just so I don't have to finish them and can go to sleep. +02:54 <@matches> Tim did seem strongly in favour of covering the rendering stuff +02:54 <@matches> At least referencing the papers and giving the definitions of things if not actually how to render them +02:55 <@matches> Anyway I think Beziers at least are important +02:55 <@matches> I'm discovering a few interesting things about SVG +02:56 <@matches> The path definitions are basically exactly the same as postscript's commands except less stack-y +02:56 <@matches> But it has relative commands as well +02:56 <@matches> Which is interesting because if you have a really really long curve defined with relative commands +02:56 <@matches> Maybe, just maybe, it will actually cause a precision issue +02:57 <@matches> I doubt it though +03:00 <@matches> Well good luck, I am going to sleep +03:01 < sulix> Thanks. I will see what I can say about Béziers. +03:38 * sulix collapses. +08:07 <@matches> Nice work +08:07 <@matches> Mine is too detailed I think +08:07 <@matches> It's horrible because now I'm committed to following through on that level of detail everywhere +08:09 <@matches> Removing detail feels like murder +08:12 <@matches> Would you be offended if I cited your lit review as a "more concise" overview for the bored reader? :P +14:28 < sulix> So apparently the entire internet is talking about Bézier curves today. +14:28 < sulix> This would have been really useful, say, yesterday. +14:30 < sulix> Also this page looks amazing... http://pomax.github.io/bezierinfo/ +14:39 <@matches> Haha +14:39 <@matches> I think I've got the Beziers covered +14:39 <@matches> If you could just hop over to ratemylitreview and check me on that... +14:39 <@matches> :P +14:42 < sulix> Ratemylitreview has broken some of the equations... +14:46 <@matches> If I had time I would include a "rate ratemylitreview" field +14:46 <@matches> I sent an email +14:46 <@matches> Now to fear the wrath +14:47 <@matches> Half time +14:48 <@matches> Haha I'm somewhat regretting choosing such condescending ratings +14:49 < sulix> I got terrified seeing that email before I realised it was from you. +14:49 <@matches> Bahaha +14:49 <@matches> Well I have to give him something +14:50 < sulix> You should clearly make the ratings be all amazing, like: "Good, Great, Amazing, Truly Spiffing, Superlative and \"Everything in creation has been leading up to this page of my Lit review\"" +14:51 <@matches> You can POST your own ratings but expecting that might be a bit much +14:51 <@matches> They are emailed to me as text and they are also stored in the database as text +14:51 <@matches> Not the most objective of systems :S +14:51 <@matches> I thought the ratings covered all the bases though +14:52 < sulix> You could always do what the Shakespeare proramming lanugage does. Positive adjectives +1, negative adjectives -1. +20:18 <@matches> I haven't said half of what I thought I should about floats +20:18 <@matches> Tim has been scarily silent :P +20:19 <@matches> I guess I will assume that means everything is FINE +20:19 <@matches> I finally got my Table of Contents and things to not take up 6 pages +20:20 <@matches> I have to resist the urge to add some snarky comments to my section on LaTeX +20:22 <@matches> About how in theory you don't have to worry about where things go but in practice you spend hours doing horrible things like arbitrarily adding vertical space to force something into position because the anchor position doesn't take into account your line spacing and thus isn't where you expect and the next element overlaps things as a result +20:22 <@matches> Blargh +20:22 < sulix> Just stumbled upon a mention of numerical precision causing issues with Wu's algorithm in a book. +20:22 <@matches> Cite it +20:23 <@matches> Also give it to me to cite if I can stay awake long enough to read it +20:23 <@matches> You have contributed some good last minute references +20:23 <@matches> I seem to have contributed Javascript +20:23 <@matches> I should be ashamed +20:24 < sulix> It's in Abrash's Black Book, end of Chapter 42 ("Wu'ed in Haste; Fried, Stewed at leasure"( +20:24 <@matches> Haha +20:24 <@matches> My venerable graphics book doesn't even have Wu in it :S +20:25 <@matches> It also doesn't really properly reference people's papers, or I guess you don't need to in a textbook? +20:26 <@matches> It gives De Casteljau's method without crediting him for example. It does credit Bezier with things though. +20:26 <@matches> But they clearly didn't have to worry about putting \cite{} after every single statement +20:27 <@matches> I'm not sure how well my "I couldn't find a reference, have a look at my website" footnotes are going to go down +20:27 < sulix> Casey from the Jeff & Casey show did a video blog on Bézier curves and interpolation this morning. +20:28 <@matches> I really should start reading blogs more, but I was in no position to be watching blogs this morning +20:28 < sulix> He claims that Bézier did not invent the Bézier curve, so why the hell are they named after him. +20:28 <@matches> Had I known +20:28 <@matches> Oh he didn't +20:28 <@matches> I know that +20:28 <@matches> That's in Metafont +20:28 < sulix> I should read Metafont. +20:28 <@matches> They were named after him because he was the first guy that said "These look useful for things" +20:28 <@matches> However +20:28 <@matches> I can't find the paper in a peer reviewed journal +20:29 <@matches> I think it was for Industry (TM) +20:29 <@matches> And also in French +20:29 <@matches> I just cited a paper he did write in English about his experiences with Computer Aided Design +20:29 <@matches> He doesn't define anything, just shows pictures of nice bezier curvey car bodies +20:30 < sulix> I saw a bunch of french papers by him, but couldn't be bothered trying to work out which ones were useful. +20:30 <@matches> De Casteljau's paper is also hard to find +20:30 <@matches> The order of events was +20:30 <@matches> 1912 - Bernshtein comes up with the basis polynomials for some sort of mathematical fitting +20:31 <@matches> 1959 - De Casteljau decides to approximate the curves using his algorithm +20:31 <@matches> (De Casteljau is only an approximation by the way, but it would converge to the true bezier curve) +20:31 <@matches> 196? - Bezier does stuff +20:31 <@matches> 1983/4 - Knuth decides to use them for fonts +20:32 <@matches> Somehow they ended up in PostScript around that time as well +20:32 <@matches> Now we're stuck with them +20:34 <@matches> Hmm I hope my Tensor Equation is right there +20:34 < sulix> Here's that Wu thing, btw: http://www.jagregory.com/abrash-black-book/#notes-on-wu-antialiasing +20:36 <@matches> I'm struggling to make my floating point section sound sane +20:36 <@matches> Too many little details +20:37 <@matches> Like that you can choose different bases +20:37 <@matches> What even is a number anyway +20:38 <@matches> I think the proper way to approach it is talking about a number represented by digits and some numbers take infinitely many digits etc +20:39 <@matches> Then computers can only fit X binary digits in their registers +20:39 <@matches> A floating point is basically where you have a fixed point mantissa and then shift the location of the fixed point +20:39 <@matches> Let's try and ignore the implicit leading one... +20:40 <@matches> It sort of all falls apart when trying to fit IEEE in there +20:40 <@matches> This thing is too big as well :( +20:41 <@matches> Page limits are stupid +20:42 <@matches> I can't remember what it even is but it's definitely less than what I have +21:06 <@matches> Ah I see, the aliasing of Wu's line isn't perfect +21:06 <@matches> I think Wu admits that +21:06 <@matches> Hmm, that is interesting +21:11 <@matches> Argh that blog is all like "We should use web based documents instead of PDF" +21:11 <@matches> Pixels or Perish detected +21:11 <@matches> To be fair it does actually look nice +21:14 <@matches> The table of contents in the black book are quite amusing +21:14 <@matches> No! I finished writing about graphics stuff I need to do floating stuff +21:15 < sulix> It's a brilliant book, but possibly for another day. +21:16 <@matches> Dammit I guess I do need to produce more figures +21:16 <@matches> Sigh +21:17 <@matches> A picture is worth a thousand words and all that +21:17 <@matches> And therefore takes at least as long as writing a thousand words to make +21:27 <@matches> The more I look at SVG files the more convinced I am that they are actually the write way to do things +21:27 <@matches> right +21:28 <@matches> Despite all that philosophical guff, you can do the same things as postscript in similar ways, but you also have a DOM that isn't terrifying like whatever PDF supposely does +21:28 <@matches> I guess PDF would be more efficient though +21:29 < sulix> That's pretty much the conclusion I've come to. +21:31 <@matches> Unfortunately now I know more about SVG I keep hand editing my figures +21:32 <@matches> I don't need to use gnuplot's terrible data point markers anymore! +21:32 <@matches> I am free! +21:40 <@matches> I particularly like +21:40 <@matches> That I can make the points have alpha now +21:40 <@matches> So if you plot overlapping points it is no longer impossible to see them +21:40 <@matches> Of course we are restricted by the zoom in the pdf viewer... +21:41 <@matches> This project is too meta +21:41 <@matches> It is doing my head in -- 2.20.1