That page indicates that "legacy opengl" is deprecated, and will not work on mobile.
But "legacy opengl" has some instructional value. You need far fewer primitives with legacy opengl. While I understand that it will eventually go away, I hope that the OpenGL standards group puts some thought into the issue of teaching new programmers the core concepts of the language. Personally, I think it would be ideal if a "hello world" example program did not need more than a handful of primitives. In learning contexts, it's important for the student to get in and try things out, at each stage of progress - otherwise you wind up with a very difficult problem: where students are supposedly learning but what they have learned may have nothing to do with what you intended to teach them. (Which can be fine in some contexts, but can leave people floundering with OpenGL.) Anyways, I am working on a draft "es specific" opengl lab, and probably more work needs to be done there. But until that's ready, the legacy opengl lab is better than our other options. Thanks, -- Raul On Tue, Jun 30, 2015 at 11:02 AM, bill lam <[email protected]> wrote: > You should be careful when using glBegin and friends because > they had been removed from core profile since 3.2, however > not all graphic cards fully support compatibility profile, > OpenGL ES 2 does not support them at all. > > https://www.opengl.org/wiki/Legacy_OpenGL > > to choose compatibility profle, create the widget with the > option, > > cc g opengl compatibility > > wd reference no longer mentions this option so as to discourage > users from using it. > > Modern OpenGL requires learning from scratch, previous knowledge > of OpenGL 1.0 does not help much. eg it is quite easy to draw a > sphere using glu... , but to model a sphere in opengl 3.2 is not > that trivial. > > Вт, 30 июн 2015, Raul Miller написал(а): >> Turns out, though, that current opengl still supports the fixed >> feature pipeline introduced in OpenGL 1.0. >> >> This pipeline is no longer implemented in hardware, but the shaders >> are more than capable of supporting the needed features, so the fixed >> feature pipeline is supported by the drivers. >> >> Specifically: if you use glBegin/glColor3f/glVertex3f/glEnd, that >> overrides glUseProgram. >> >> I have not yet gone over the original opengl lab, and I am still >> learning these standards, but I expect that most of that lab should >> still be valid. >> >> FYI, >> >> -- >> Raul >> >> On Sun, Mar 8, 2015 at 1:26 AM, bill lam <[email protected]> wrote: >> > Jqt supports opengl 2 or newer. >> > On Mar 8, 2015 4:50 AM, "Raul Miller" <[email protected]> wrote: >> > >> >> For texture mapping, I think you'd need to abandon plot (at least as >> >> it is currently written) and move over to opengl. >> >> >> >> For opengl, you either need to drop back to earlier versions of J (J6 >> >> and J7 both had opengl labs - albeit with differences in the details) >> >> or you'll need to explore the webgl capabilities inherent in JHS or >> >> you'll need to temporarily abandon J while you learn the ropes >> >> (perhaps at shadertoy) and then maybe bring your knowledge back into >> >> the community. >> >> >> >> References: >> >> >> >> http://www.jsoftware.com/jwiki/OpenGL >> >> >> >> >> >> http://webglplayground.net/documentation >> >> >> >> https://www.shadertoy.com/results?query=tag%3Dtexture >> >> >> >> Or, if you are less inclined towards experimentation and prefer some >> >> heavy reading: >> >> >> >> https://www.cse.msu.edu/~cse872/tutorial4.html >> >> >> >> https://www.opengl.org/archives/resources/faq/technical/texture.htm >> >> >> >> http://www.glprogramming.com/red/chapter09.html >> >> >> >> ... >> >> >> >> Beware though that the opengl standards have drifted over the years >> >> and there will be subtle gotchas where some older things no longer >> >> work and some newer things don't quite work exactly like they are >> >> described to work. >> >> >> >> What usually works for me is some time spent finding out what the >> >> puzzling terms mean, and then some blind experiments based on some >> >> working example - go back and forth on that enough and mix in some >> >> attempts to create things from scratch (which helps identify blind >> >> spots). But I also like to stay close to working examples, as much as >> >> I can, to avoid too much time lost on blind alleys (where someone with >> >> more self importance than practical sense says something which sounds >> >> plausible but which is totally unrelated to what you want to be >> >> doing). >> >> >> >> Thanks, >> >> >> >> -- >> >> Raul >> >> >> >> On Sat, Mar 7, 2015 at 3:10 PM, Skip Cave <[email protected]> wrote: >> >> > My next challenge is to map a texture (rectangular .jpg image) onto that >> >> > ellipse and plane. Any hints as to how to do that? >> >> > >> >> > Skip Cave >> >> > Cave Consulting LLC >> >> > >> >> > On Sat, Mar 7, 2015 at 1:35 PM, Skip Cave <[email protected]> >> >> wrote: >> >> > >> >> >> Raul, Thanks for the links! That's what I needed. I didn't think about >> >> >> looking in the Studio Labs for the Plot documentation. The final secret >> >> is >> >> >> to throw away the imaginary parts of the ellipse equation so all z >> >> outside >> >> >> the ellipse is zero: >> >> >> >> >> >> a =.1 >> >> >> >> >> >> b=. 1.7 >> >> >> >> >> >> c =. 1.5 >> >> >> >> >> >> x =. 5 %~21 21 $ i:10 >> >> >> >> >> >> y =. |: x >> >> >> >> >> >> z =. {. |: +. c * ((1 - ((x^2)%(a^2)) + ((y^2)%(b^2))))^0.5 >> >> >> >> >> >> 'surface' plot z >> >> >> >> >> >> >> >> >> Here's the plot: http://bit.ly/1GbYuy1 >> >> >> >> >> >> >> >> >> The axes should be 1, 1,7 and 1.5, but they are not, so I need to look >> >> at >> >> >> that. >> >> >> >> >> >> >> >> >> Skip >> >> >> >> >> > ---------------------------------------------------------------------- >> >> > For information about J forums see http://www.jsoftware.com/forums.htm >> >> ---------------------------------------------------------------------- >> >> For information about J forums see http://www.jsoftware.com/forums.htm >> >> >> > ---------------------------------------------------------------------- >> > For information about J forums see http://www.jsoftware.com/forums.htm >> ---------------------------------------------------------------------- >> For information about J forums see http://www.jsoftware.com/forums.htm > > -- > regards, > ==================================================== > GPG key 1024D/4434BAB3 2008-08-24 > gpg --keyserver subkeys.pgp.net --recv-keys 4434BAB3 > gpg --keyserver subkeys.pgp.net --armor --export 4434BAB3 > ---------------------------------------------------------------------- > For information about J forums see http://www.jsoftware.com/forums.htm ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
