Strange surface plot

[FloopCZ]

Hi, on my machine, the surface plot seems to have multiple issues. If I run the following code:

#include <arrayfire.h>
int main(int argc, char *argv[])
{
    try {
        af::info();
        af::array X = af::seq(0., 0.4, 0.1);
        af::array Y = af::seq(0., 0.9, 0.1);
        af::array Z = af::constant(1., 5, 10);
        af::Window window(1500, 800, "The door.");
        do {
            window.surface(X, Y, Z, "The weird surface");
        } while(!window.close());
    } catch (af::exception& e) {
        fprintf(stderr, "%s\n", e.what());
        throw;
    }
    return 0;
}

I see the following image (without the red lines):

The image has a few problems:

1. The Y-axis labels are all the same.
2. The X-axis labels are probably all the same as well.
3. The surface is plotted in wrong position and probably scaled badly (hard to say).

System version:

ArrayFire v3.6.0 (OpenCL, 64-bit Linux, build default)
[0] INTEL: Intel(R) Core(TM) i7-7500U CPU @ 2.70GHz, 15930 MB
Linux pine 4.13.11-1-ARCH #1 SMP PREEMPT Thu Nov 2 10:25:56 CET 2017 x86_64 GNU/Linux
Both Forge from devel branch and from arrayfire behave the same, CPU backend as well.

Also when I resize the window, the program crashes with:

Failed to blit
[1]    788 segmentation fault (core dumped)  ./a.out

Thank you for your help and for a nice high-performance visualization tool!

[9prady9]

@FloopCZ We will look into it and update here as soon as we find something. Unfortunately, I can't give an ETA on this, but I will try to look into it as soon as possible.

[FloopCZ]

Thank you @9prady9. :-)

[9prady9]

@FloopCZ This seems to be an issue inside ArrayFire while auto-calculating the axes limits. I have raised an issue in the downstream(ArrayFire) project and you can follow its progress over there.

As far as the window crash upon resize, I am unable to replicate this on my end. The window seems to be resizing just fine for me.

As a work around for the render, you can use the following code to explicitly set the chart axes yourselves so that you are not effected by the auto-calculation.

        af::info();
        af::array X = af::seq(0., 0.4, 0.1);

        af::array Y = af::seq(0., 0.9, 0.1);

        af::array Z = af::constant(0., 5, 10);

        af::Window window(1500, 800, "The door.");

        window.setAxesLimits(0.0f, 0.4f, 0.0f, 0.9f, -1.0f, 1.0f, true);

[FloopCZ]

@9prady9 Thank you for the workaround, I have just tried it. Unfortunately, the image still has similar problems. This is what I see:

[9prady9]

Looks like transformation is off, I will look into it in forge.

[mlloreda]

@9prady9 Am able to reproduce window resize issue on Ubuntu 16.04. Appears to be an issue with glbinding.

Starting program: /home/arrayfire/forge/build/examples/cpu/field 
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
Failed to blit

Program received signal SIGSEGV, Segmentation fault.
__memcpy_sse2_unaligned () at ../sysdeps/x86_64/multiarch/memcpy-sse2-unaligned.S:35
35        ../sysdeps/x86_64/multiarch/memcpy-sse2-unaligned.S: No such file or directory.
(gdb) bt
#0  __memcpy_sse2_unaligned () at ../sysdeps/x86_64/multiarch/memcpy-sse2-unaligned.S:35
#1  0x00007fffeea35064 in ?? () from /usr/lib/x86_64-linux-gnu/dri/i965_dri.so
#2  0x00007fffeea35275 in ?? () from /usr/lib/x86_64-linux-gnu/dri/i965_dri.so
#3  0x00007fffeea35612 in ?? () from /usr/lib/x86_64-linux-gnu/dri/i965_dri.so
#4  0x00007fffeea3d7f4 in ?? () from /usr/lib/x86_64-linux-gnu/dri/i965_dri.so
#5  0x00007fffeea3da29 in ?? () from /usr/lib/x86_64-linux-gnu/dri/i965_dri.so
#6  0x00007fffeea0e1db in ?? () from /usr/lib/x86_64-linux-gnu/dri/i965_dri.so
#7  0x00007fffee7d6cb8 in ?? () from /usr/lib/x86_64-linux-gnu/dri/i965_dri.so
#8  0x00007fffee7d6f18 in ?? () from /usr/lib/x86_64-linux-gnu/dri/i965_dri.so
#9  0x00007fffee84b405 in ?? () from /usr/lib/x86_64-linux-gnu/dri/i965_dri.so
#10 0x00007fffee84c4d8 in ?? () from /usr/lib/x86_64-linux-gnu/dri/i965_dri.so
#11 0x00007fffee84dbe5 in ?? () from /usr/lib/x86_64-linux-gnu/dri/i965_dri.so
#12 0x00007fffeea37ce5 in ?? () from /usr/lib/x86_64-linux-gnu/dri/i965_dri.so
#13 0x00007fffee7662e7 in ?? () from /usr/lib/x86_64-linux-gnu/dri/i965_dri.so
#14 0x00007fffee766462 in ?? () from /usr/lib/x86_64-linux-gnu/dri/i965_dri.so
#15 0x00007ffff629f8aa in (anonymous namespace)::BasicCallHelper<void, int, int, int, int, gl::GLenum, gl::GLenum, void*>::call(const glbinding::Function<void, int, int, int, int, gl::GLenum, gl::GLenum, void*> *, <unknown type in /usr/lib/libglbindingd.so.2, CU 0xa21538, DIE 0xa3f887>, <unknown type in /usr/lib/libglbindingd.so.2, CU 0xa21538, DIE 0xa3f88c>, <unknown type in /usr/lib/libglbindingd.so.2, CU 0xa21538, DIE 0xa3f891>, <unknown type in /usr/lib/libglbindingd.so.2, CU 0xa21538, DIE 0xa3f896>, <unknown type in /usr/lib/libglbindingd.so.2, CU 0xa21538, DIE 0xa3f89b>, <unknown type in /usr/lib/libglbindingd.so.2, CU 0xa21538, DIE 0xa3f8a0>, <unknown type in /usr/lib/libglbindingd.so.2, CU 0xa21538, DIE 0xa3f8a5>) (function=0x7ffff67fd1a0 <glbinding::Binding::ReadPixels>, 
    arguments#0=<unknown type in /usr/lib/libglbindingd.so.2, CU 0xa21538, DIE 0xa3f887>, arguments#1=<unknown type in /usr/lib/libglbindingd.so.2, CU 0xa21538, DIE 0xa3f88c>, 
    arguments#2=<unknown type in /usr/lib/libglbindingd.so.2, CU 0xa21538, DIE 0xa3f891>, arguments#3=<unknown type in /usr/lib/libglbindingd.so.2, CU 0xa21538, DIE 0xa3f896>, 
    arguments#4=<unknown type in /usr/lib/libglbindingd.so.2, CU 0xa21538, DIE 0xa3f89b>, arguments#5=<unknown type in /usr/lib/libglbindingd.so.2, CU 0xa21538, DIE 0xa3f8a0>, 
    arguments#6=<unknown type in /usr/lib/libglbindingd.so.2, CU 0xa21538, DIE 0xa3f8a5>) at /build/libglbinding-K9IIU3/libglbinding-2.1.3+519~ubuntu16.04.1/source/glbinding/include/glbinding/Function.inl:21
#16 0x00007ffff62aea7e in glbinding::Function<void, int, int, int, int, gl::GLenum, gl::GLenum, void*>::call (this=0x7ffff67fd1a0 <glbinding::Binding::ReadPixels>, arguments#0=@0x7fffffffd54c: 0, 
    arguments#1=@0x7fffffffd548: 0, arguments#2=@0x7fffffffd544: 640, arguments#3=@0x7fffffffd540: 480, arguments#4=@0x7fffffffd53c: <incomplete type>, arguments#5=@0x7fffffffd538: <incomplete type>, 
    arguments#6=@0x7fffffffd560: 0x0) at /build/libglbinding-K9IIU3/libglbinding-2.1.3+519~ubuntu16.04.1/source/glbinding/include/glbinding/Function.inl:171
#17 0x00007ffff62ae2da in glbinding::Function<void, int, int, int, int, gl::GLenum, gl::GLenum, void*>::operator() (this=0x7ffff67fd1a0 <glbinding::Binding::ReadPixels>, arguments#0=@0x7fffffffd54c: 0, 
    arguments#1=@0x7fffffffd548: 0, arguments#2=@0x7fffffffd544: 640, arguments#3=@0x7fffffffd540: 480, arguments#4=@0x7fffffffd53c: <incomplete type>, arguments#5=@0x7fffffffd538: <incomplete type>, 
    arguments#6=@0x7fffffffd560: 0x0) at /build/libglbinding-K9IIU3/libglbinding-2.1.3+519~ubuntu16.04.1/source/glbinding/include/glbinding/Function.inl:147
#18 0x00007ffff62996c2 in gl::glReadPixels (x=0, y=0, width=640, height=480, format=<incomplete type>, type=<incomplete type>, pixels=0x0)
    at /build/libglbinding-K9IIU3/libglbinding-2.1.3+519~ubuntu16.04.1/source/glbinding/source/gl/functions_r.cpp:181
#19 0x00007ffff7ada8ea in forge::wtk::Widget::swapBuffers (this=0x93bb10) at /home/arrayfire/forge/src/backend/opengl/glfw/window.cpp:244
#20 0x00007ffff7ad5913 in forge::opengl::window_impl::draw (this=0x9209d0, pRenderable=std::shared_ptr (count 2, weak 0) 0xf1f7a0) at /home/arrayfire/forge/src/backend/opengl/window_impl.cpp:272
#21 0x00007ffff7afe758 in forge::common::Window::draw (this=0x820cc0, pChart=0xf66830) at /home/arrayfire/forge/src/backend/common/window.hpp:116
#22 0x00007ffff7afc8c4 in fg_draw_chart (pWindow=0x820cc0, pChart=0xf66830) at /home/arrayfire/forge/src/api/c/window.cpp:239
#23 0x00007ffff7b11b69 in forge::Window::draw (this=0x7fffffffdca0, pChart=...) at /home/arrayfire/forge/src/api/cpp/window.cpp:130
#24 0x0000000000402a79 in main () at /home/arrayfire/forge/examples/cpu/field.cpp:82

[9prady9]

Updates related to fix for auto-calculation of surface limits will be provided on arrayfire/arrayfire#2006 as it is related to arrayfire code base.

Surface transformation issue will be bug handled in this issue.