I recently began incorporating OpenCL into my OpenGL application that renders a basic particle system, the basic interoperation–without events–between the two works fine. However, having tried to use the clCreateEventFromGLsyncKHR function in order to improve performance instead of having to call glFinish and clFinish, I am unable to get the running program as the program complains with the following error:
error LNK2019: unresolved external symbol _clCreateEventFromGLsyncKHR
I have tried to use both of the provided functions used to obtain extension-function pointers (clGetExtensionFunctionAddressForPlatform, clGetExtensionFunctionAddress) but for reasons I cant fathom, I am not able to get it to work.
Sample code:
#include <CL/cl_gl_ext.h>
typedef cl_event (*PFNCLCREATEEVENTFROMGLSYNCKHR) (cl_context context, cl_GLsync sync, cl_int *errcode_ret);
PFNCLCREATEEVENTFROMGLSYNCKHR clCreateEventFromGLsyncKHR = (PFNCLCREATEEVENTFROMGLSYNCKHR)clGetExtensionFunctionAddressForPlatform(opencl::target::inst()->platform(), "clCreateEventFromGLsyncKHR");
GLsync sync = glFenceSync(GL_SYNC_GPU_COMMANDS_COMPLETE, 0);
cl_event gl_event = clCreateEventFromGLsyncKHR(opencl::contexts["GL_CL_context"]->_get(), sync, NULL );
Would anyone kindly assist me in understanding as to where it is I am going wrong?
For those interested:
Name: GeForce GT 740M
Vendor: NVIDIA Corporation
Device OpenCL C version: OpenCL C 1.1
Driver version: 327.23
Profile: FULL_PROFILE
Version: OpenCL 1.1 CUDA
Extensions: cl_khr_byte_addressable_store cl_khr_icd cl_khr_gl_sharing cl_nv_d3d9_sharing cl_nv_d3d10_sharing cl_khr_d3d10_sharing cl_nv_d3d11_sharing cl_nv_compiler_options
cl_nv_device_attribute_query cl_nv_pragma_unroll cl_khr_global_int32_base_atomics cl_khr_global_int32_extended_atomics
cl_khr_local_int32_base_atomics cl_khr_local_int32_extended_atomics cl_khr_fp64
Update
The above code still does not work if I use a device that supports the cl_khr_gl_event extension
Your device does not support cl_khr_gl_event extension. That extension is needed to use the clCreateEventFromGLsyncKHR method. As stated here. Typically all the methods that are part of an extension end/start have KHR/NV/AMD in their name.
Another problem with your code, is that you have not enabled the extension anyway, with you have to do by defining the following:
#include <CL/cl_gl_ext.h>
Related
I am trying to run the c++ code example from the OpenCL C++ Bindings Doc: Example.
Compilation of the c++ code works fine, but compilation of the kernel gives errors in connection with pipes:
<kernel>:10:71: error: unknown type name 'pipe'
global int *output, int val, write_only pipe int outPipe, queue_t childQueue)
^
<kernel>:10:76: error: expected ')'
global int *output, int val, write_only pipe int outPipe, queue_t childQueue)
^
<kernel>:9:30: note: to match this '('
kernel void vectorAdd(global const Foo* aNum, global const int *inputA, global const int *inputB,
^
<kernel>:10:76: error: parameter name omitted
global int *output, int val, write_only pipe int outPipe, queue_t childQueue)
^
<kernel>:13:11: warning: implicit declaration of function 'write_pipe' is invalid in C99
write_pipe(outPipe, &val);
^
<kernel>:13:22: error: use of undeclared identifier 'outPipe'
write_pipe(outPipe, &val);
^
<kernel>:25:26: error: use of undeclared identifier 'childQueue'
enqueue_kernel(childQueue, CLK_ENQUEUE_FLAGS_WAIT_KERNEL, ndrange,
My Setup:
NVIDIA GPU
Debian
used "sudo apt install opencl-headers ocl-icd-opencl-dev -y" to install ocl stuff
clinfo output:
Number of platforms 1
Platform Name NVIDIA CUDA
Platform Vendor NVIDIA Corporation
Platform Version OpenCL 3.0 CUDA 11.4.264
Platform Profile FULL_PROFILE
Platform Extensions cl_khr_global_int32_base_atomics cl_khr_global_int32_extended_atomics cl_khr_local_int32_base_atomics cl_khr_local_int32_extended_atomics cl_khr_fp64 cl_khr_3d_image_writes cl_khr_byte_addressable_store cl_khr_icd cl_khr_gl_sharing cl_nv_compiler_options cl_nv_device_attribute_query cl_nv_pragma_unroll cl_nv_copy_opts cl_nv_create_buffer cl_khr_int64_base_atomics cl_khr_int64_extended_atomics cl_khr_device_uuid cl_khr_pci_bus_info
Platform Extensions with Version cl_khr_global_int32_base_atomics 0x400000 (1.0.0)
cl_khr_global_int32_extended_atomics 0x400000 (1.0.0)
cl_khr_local_int32_base_atomics 0x400000 (1.0.0)
cl_khr_local_int32_extended_atomics 0x400000 (1.0.0)
cl_khr_fp64 0x400000 (1.0.0)
cl_khr_3d_image_writes 0x400000 (1.0.0)
cl_khr_byte_addressable_store 0x400000 (1.0.0)
cl_khr_icd 0x400000 (1.0.0)
cl_khr_gl_sharing 0x400000 (1.0.0)
cl_nv_compiler_options 0x400000 (1.0.0)
cl_nv_device_attribute_query 0x400000 (1.0.0)
cl_nv_pragma_unroll 0x400000 (1.0.0)
cl_nv_copy_opts 0x400000 (1.0.0)
cl_nv_create_buffer 0x400000 (1.0.0)
cl_khr_int64_base_atomics 0x400000 (1.0.0)
cl_khr_int64_extended_atomics 0x400000 (1.0.0)
cl_khr_device_uuid 0x400000 (1.0.0)
cl_khr_pci_bus_info 0x400000 (1.0.0)
Platform Numeric Version 0xc00000 (3.0.0)
Platform Extensions function suffix NV
Platform Host timer resolution 0ns
Platform Name NVIDIA CUDA
Number of devices 1
Device Name NVIDIA GeForce RTX 3060 Ti
Device Vendor NVIDIA Corporation
Device Vendor ID 0x10de
Device Version OpenCL 3.0 CUDA
Device UUID c6edf95f-d769-661d-a242-e9a192a0dcb1
Driver UUID c6edf95f-d769-661d-a242-e9a192a0dcb1
Valid Device LUID No
Device LUID 6d69-637300000000
Device Node Mask 0
Device Numeric Version 0xc00000 (3.0.0)
Driver Version 470.141.03
Device OpenCL C Version OpenCL C 1.2
Device OpenCL C all versions OpenCL C 0x400000 (1.0.0)
OpenCL C 0x401000 (1.1.0)
OpenCL C 0x402000 (1.2.0)
OpenCL C 0xc00000 (3.0.0)
Device OpenCL C features __opencl_c_fp64 0xc00000 (3.0.0)
__opencl_c_images 0xc00000 (3.0.0)
__opencl_c_int64 0xc00000 (3.0.0)
__opencl_c_3d_image_writes 0xc00000 (3.0.0)
Latest comfornace test passed v2021-02-01-00
Device Type GPU
Device Topology (NV) PCI-E, 0000:02:00.0
Device Profile FULL_PROFILE
Device Available Yes
Compiler Available Yes
Linker Available Yes
Max compute units 38
Max clock frequency 1695MHz
Compute Capability (NV) 8.6
Device Partition (core)
Max number of sub-devices 1
Supported partition types None
Supported affinity domains (n/a)
Max work item dimensions 3
Max work item sizes 1024x1024x64
Max work group size 1024
Preferred work group size multiple (device) 32
Preferred work group size multiple (kernel) 32
Warp size (NV) 32
Max sub-groups per work group 0
Preferred / native vector sizes
char 1 / 1
short 1 / 1
int 1 / 1
long 1 / 1
half 0 / 0 (n/a)
float 1 / 1
double 1 / 1 (cl_khr_fp64)
Half-precision Floating-point support (n/a)
Single-precision Floating-point support (core)
Denormals Yes
Infinity and NANs Yes
Round to nearest Yes
Round to zero Yes
Round to infinity Yes
IEEE754-2008 fused multiply-add Yes
Support is emulated in software No
Correctly-rounded divide and sqrt operations Yes
Double-precision Floating-point support (cl_khr_fp64)
Denormals Yes
Infinity and NANs Yes
Round to nearest Yes
Round to zero Yes
Round to infinity Yes
IEEE754-2008 fused multiply-add Yes
Support is emulated in software No
Address bits 64, Little-Endian
Global memory size 8367570944 (7.793GiB)
Error Correction support No
Max memory allocation 2091892736 (1.948GiB)
Unified memory for Host and Device No
Integrated memory (NV) No
Shared Virtual Memory (SVM) capabilities (core)
Coarse-grained buffer sharing Yes
Fine-grained buffer sharing No
Fine-grained system sharing No
Atomics No
Minimum alignment for any data type 128 bytes
Alignment of base address 4096 bits (512 bytes)
Preferred alignment for atomics
SVM 0 bytes
Global 0 bytes
Local 0 bytes
Atomic memory capabilities relaxed, work-group scope
Atomic fence capabilities relaxed, acquire/release, work-group scope
Max size for global variable 0
Preferred total size of global vars 0
Global Memory cache type Read/Write
Global Memory cache size 1089536 (1.039MiB)
Global Memory cache line size 128 bytes
Image support Yes
Max number of samplers per kernel 32
Max size for 1D images from buffer 268435456 pixels
Max 1D or 2D image array size 2048 images
Max 2D image size 32768x32768 pixels
Max 3D image size 16384x16384x16384 pixels
Max number of read image args 256
Max number of write image args 32
Max number of read/write image args 0
Pipe support No
Max number of pipe args 0
Max active pipe reservations 0
Max pipe packet size 0
Local memory type Local
Local memory size 49152 (48KiB)
Registers per block (NV) 65536
Max number of constant args 9
Max constant buffer size 65536 (64KiB)
Generic address space support No
Max size of kernel argument 4352 (4.25KiB)
Queue properties (on host)
Out-of-order execution Yes
Profiling Yes
Device enqueue capabilities (n/a)
Queue properties (on device)
Out-of-order execution No
Profiling No
Preferred size 0
Max size 0
Max queues on device 0
Max events on device 0
Prefer user sync for interop No
Profiling timer resolution 1000ns
Execution capabilities
Run OpenCL kernels Yes
Run native kernels No
Non-uniform work-groups No
Work-group collective functions No
Sub-group independent forward progress No
Kernel execution timeout (NV) Yes
Concurrent copy and kernel execution (NV) Yes
Number of async copy engines 2
IL version (n/a)
ILs with version <printDeviceInfo:186: get CL_DEVICE_ILS_WITH_VERSION : error -30>
printf() buffer size 1048576 (1024KiB)
Built-in kernels (n/a)
Built-in kernels with version <printDeviceInfo:190: get CL_DEVICE_BUILT_IN_KERNELS_WITH_VERSION : error -30>
Device Extensions cl_khr_global_int32_base_atomics cl_khr_global_int32_extended_atomics cl_khr_local_int32_base_atomics cl_khr_local_int32_extended_atomics cl_khr_fp64 cl_khr_3d_image_writes cl_khr_byte_addressable_store cl_khr_icd cl_khr_gl_sharing cl_nv_compiler_options cl_nv_device_attribute_query cl_nv_pragma_unroll cl_nv_copy_opts cl_nv_create_buffer cl_khr_int64_base_atomics cl_khr_int64_extended_atomics cl_khr_device_uuid cl_khr_pci_bus_info
Device Extensions with Version cl_khr_global_int32_base_atomics 0x400000 (1.0.0)
cl_khr_global_int32_extended_atomics 0x400000 (1.0.0)
cl_khr_local_int32_base_atomics 0x400000 (1.0.0)
cl_khr_local_int32_extended_atomics 0x400000 (1.0.0)
cl_khr_fp64 0x400000 (1.0.0)
cl_khr_3d_image_writes 0x400000 (1.0.0)
cl_khr_byte_addressable_store 0x400000 (1.0.0)
cl_khr_icd 0x400000 (1.0.0)
cl_khr_gl_sharing 0x400000 (1.0.0)
cl_nv_compiler_options 0x400000 (1.0.0)
cl_nv_device_attribute_query 0x400000 (1.0.0)
cl_nv_pragma_unroll 0x400000 (1.0.0)
cl_nv_copy_opts 0x400000 (1.0.0)
cl_nv_create_buffer 0x400000 (1.0.0)
cl_khr_int64_base_atomics 0x400000 (1.0.0)
cl_khr_int64_extended_atomics 0x400000 (1.0.0)
cl_khr_device_uuid 0x400000 (1.0.0)
cl_khr_pci_bus_info 0x400000 (1.0.0)
NULL platform behavior
clGetPlatformInfo(NULL, CL_PLATFORM_NAME, ...) NVIDIA CUDA
clGetDeviceIDs(NULL, CL_DEVICE_TYPE_ALL, ...) Success [NV]
clCreateContext(NULL, ...) [default] Success [NV]
clCreateContextFromType(NULL, CL_DEVICE_TYPE_DEFAULT) No platform
clCreateContextFromType(NULL, CL_DEVICE_TYPE_CPU) No devices found in platform
clCreateContextFromType(NULL, CL_DEVICE_TYPE_GPU) No platform
clCreateContextFromType(NULL, CL_DEVICE_TYPE_ACCELERATOR) No devices found in platform
clCreateContextFromType(NULL, CL_DEVICE_TYPE_CUSTOM) Invalid device type for platform
clCreateContextFromType(NULL, CL_DEVICE_TYPE_ALL) No platform
ICD loader properties
ICD loader Name OpenCL ICD Loader
ICD loader Vendor OCL Icd free software
ICD loader Version 2.2.14
ICD loader Profile OpenCL 3.0
I would be happy if someone could help me. I have already researched extensions and opencl versions but found nothing that fixed my problem.
Pipes are an OpenCL 2 feature. Nvidia does not implement OpenCL 2, only OpenCL 1.2. You can't run this code on an Nvidia GPU.
Clarification re/from comments:
Note how your clinfo output states:
Device OpenCL C Version OpenCL C 1.2
In other words, your kernel code must only use features supported by OpenCL 1.2 and any extensions offered by the runtime and selected in your code.
So although the implementation complies with the OpenCL 3.0 specification - which, confusingly, requires fewer features than OpenCL 2.x - you can't simply use all OpenCL 2.x features.
After further research, I came to the conclusion that NVIDIA OpenCL 3.0 does not support all OpenCL 3.0 features. Apparently it is only an OpenCL 1.2 with some new features. Information about this was hidden in the 465.89 Driver Release Notes at page 4.
I'm struggling with getting GL+CL to work together.
I've been following this tutorial. In my code I first call clGetPlatformIDs and retrieve the first (and only) platform. I also get my gl_context from SDL2. Then I want to query the device used by OpenGL with help of clGetGLContextInfoKHR. I successfully obtain this function with clGetExtensionFunctionAddressForPlatform(platform_id, "clGetGLContextInfoKHR") but unfortunately when I call it, I get a segmentation fault. My code is written in Rust but I use low level OpenCL binding, so it looks almost like its C counterpart.
pub fn new(gl_context: &GLContext) -> Result<Self, ClGlError> {
println!("Initialising OpenCL context");
let raw = unsafe { gl_context.raw() };
println!("Getting default opencl platform");
let platform_id = Self::default_platform()?; // this is valid and not null
let mut props:[cl_sys::cl_context_properties;5] = [
//OpenCL platform
cl_sys::CL_CONTEXT_PLATFORM as cl_sys::cl_context_properties, platform_id as cl_sys::cl_context_properties,
//OpenGL context
cl_sys::CL_GL_CONTEXT_KHR, raw as cl_sys::cl_context_properties,
0
];
let mut device: cl_device_id = std::ptr::null_mut();
let p: *mut cl_device_id = (&mut device) as *mut cl_device_id;
let fn_name = b"clGetGLContextInfoKHR\0" as *const u8 as *const i8;
println!("Getting clGetGLContextInfoKHR");
let clGetGLContextInfoKHR = unsafe{clGetExtensionFunctionAddressForPlatform(platform_id, fn_name ) as cl_sys::clGetGLContextInfoKHR_fn};
if clGetGLContextInfoKHR.is_null(){
// error handling here
}
println!("Getting device"); // this is the last thing I see before segfault
unsafe{
(*clGetGLContextInfoKHR)(props.as_mut_ptr(),cl_sys::CL_CURRENT_DEVICE_FOR_GL_CONTEXT_KHR,std::mem::size_of::<cl_device_id>(),device as *mut c_void,std::ptr::null_mut());
}
panic!("All good") // this is never reached
}
I have a fairly new Graphics card which supports cl_khr_gl_sharing.
Here is clinfo
Number of platforms 1
Platform Name NVIDIA CUDA
Platform Vendor NVIDIA Corporation
Platform Version OpenCL 1.2 CUDA 11.2.162
Platform Profile FULL_PROFILE
Platform Extensions cl_khr_global_int32_base_atomics cl_khr_global_int32_extended_atomics cl_khr_local_int32_base_atomics cl_khr_local_int32_extended_atomics cl_khr_fp64 cl_khr_byte_addressable_store cl_khr_icd cl_khr_gl_sharing cl_nv_compiler_options cl_nv_device_attribute_query cl_nv_pragma_unroll cl_nv_copy_opts cl_nv_create_buffer cl_khr_int64_base_atomics cl_khr_int64_extended_atomics cl_khr_device_uuid
Platform Extensions function suffix NV
Platform Name NVIDIA CUDA
Number of devices 1
Device Name GeForce GTX 960
Device Vendor NVIDIA Corporation
Device Vendor ID 0x10de
Device Version OpenCL 1.2 CUDA
Driver Version 460.80
Device OpenCL C Version OpenCL C 1.2
Device Type GPU
Device Extensions cl_khr_global_int32_base_atomics cl_khr_global_int32_extended_atomics cl_khr_local_int32_base_atomics cl_khr_local_int32_extended_atomics cl_khr_fp64 cl_khr_byte_addressable_store cl_khr_icd cl_khr_gl_sharing cl_nv_compiler_options cl_nv_device_attribute_query cl_nv_pragma_unroll cl_nv_copy_opts cl_nv_create_buffer cl_khr_int64_base_atomics cl_khr_int64_extended_atomics cl_khr_device_uuid
Perhaps the most important clue might be that I tried a bunch of other libraries that build on top of opencl and in all of them, whenever I called clGetGLContextInfoKHR (wrapped in safer and higher-level API) it crashed. I think it's very unlikely that all those libraries had bugs in their code, so probably it's some problem in my environment. However, as you can see, my graphics card clearly supports all necessary extensions.
I am not sure why clGetGLContextInfoKHR is failing but I figured out that it's not really necesary to call it.
Instead you may just use this on Linux
cl_context_properties properties[] = {
CL_GL_CONTEXT_KHR, (cl_context_properties) glXGetCurrentContext(),
CL_GLX_DISPLAY_KHR, (cl_context_properties) glXGetCurrentDisplay(),
CL_CONTEXT_PLATFORM, (cl_context_properties) platform,
0
};
this on Windows
cl_context_properties properties[] = {
CL_GL_CONTEXT_KHR, (cl_context_properties) wglGetCurrentContext(),
CL_WGL_HDC_KHR, (cl_context_properties) wglGetCurrentDC(),
CL_CONTEXT_PLATFORM, (cl_context_properties) platform,
0
};
or this on OS X
CGLContextObj glContext = CGLGetCurrentContext();
CGLShareGroupObj shareGroup = CGLGetShareGroup(glContext);
cl_context_properties properties[] = {
CL_CONTEXT_PROPERTY_USE_CGL_SHAREGROUP_APPLE,
(cl_context_properties)shareGroup,
0
};
More info can be found in the book
OpenCL in Action: How to Accelerate Graphics and Computations
I am using mayavi to do some visualization task on my remote server with GPUs.When my code run mlab.show(),the following error occurred
qt.glx: qglx_findConfig: Failed to finding matching FBConfig (8 8 8 0)
...
qt.glx: qglx_findConfig: Failed to finding matching FBConfig (1 1 1 0)
ERROR: In /work/standalone-x64-build/VTK-source/Rendering/OpenGL2/vtkOpenGLRenderWindow.cxx, line 797
vtkXOpenGLRenderWindow (0x559c336fd4e0): GL version 2.1 with the gpu_shader4 extension is not supported by your graphics driver but is required for the new OpenGL rendering backend. Please update your OpenGL driver. If you are using Mesa please make sure you have version 10.6.5 or later and make sure your driver in Mesa supports OpenGL 3.2.
I am using Ubuntu16.04 and here is some info about my remote server.
(base) zz#SYS-4028GR-TR:~$ glxinfo | grep OpenGL
OpenGL vendor string: Mesa project: www.mesa3d.org
OpenGL renderer string: Mesa GLX Indirect
OpenGL version string: 1.3 Mesa 4.0.4
OpenGL extensions:
(base) zz#SYS-4028GR-TR:~$ glxinfo | grep render
direct rendering: No (If you want to find out why, try setting LIBGL_DEBUG=verbose)
GLX_MESA_multithread_makecurrent, GLX_MESA_query_renderer,
OpenGL renderer string: Mesa GLX Indirect
Does anyone have some ideas about this situation?I try to found some ways to update Mesa in Ubuntu but failed.If there is any way to deal with this kind of problem, it would be very helpful.
I am using mayavi to do some visualization task on my remote server with GPUs.
"Remote Server", that's your problem right there. If you log in via SSH forwarding the X11 connection, all OpenGL commands are serialized as GLX commands and tunneled through the X11 connection over the network to your computer to be executed on your local graphics system.
If you have a GPU on the remote system, your best option these days is to use Xpra, configuring so that it launches its backing X server on the GPU and not with a virtual framebuffer device.
What this comes down to is to install the regular Xorg server. Modify /etc/X11/Xwrapper to allow start by a regular user. You can then start the X server with Xpra being the first client with the command line
startx /usr/bin/Xpra start :100 --use-display --daemon=no -- :100
If you don't want to fix your display, then create a executable file /usr/local/bin/xpra_display
#!/bin/sh
exec xpra start $DISPLAY --use-display --daemon=no
which you can then launch with
startx /usr/local/bin/xpra_display
without further arguments
I am trying to run this OpenCL Example in Ubuntu 10.04.
My graphics card is an NVIDIA GeForce GTX 480. I have installed the latest NVIDIA driver and CUDA toolkit manually.
The program compiles without any errors. Thus linking with libOpenCL works. The application also runs but the output is very strange (mostly zeros and some random numbers). Debugging shows that
clGetPlatformIDs(1, &platform_id, &ret_num_platforms);
returns -1001.
google and stack told me that the reason may be a missing nvidia.icd in /etc/OpenCL/vendors. It was not there so I've added /etc/OpenCL/vendors/nvidia.icd with the following line
libnvidia-opencl.so.1
I have also tried some variants (absolute paths etc). But nothing solved the problem. Right now I have no idea what else I can try. Any suggestions?
EDIT: I have installed the Intel OpenCL SDK and I have copied its icd into /etc/OpenCL/vendors and the application works fine for
clGetDeviceIDs( platform_id, CL_DEVICE_TYPE_DEFAULT, 1,
&device_id, &ret_num_devices);
For
clGetDeviceIDs( platform_id, CL_DEVICE_TYPE_GPU, 1,
&device_id, &ret_num_devices);
I get the error -1.
EDIT:
I have noticed one thing in the console when executing the application. After execution of line
cl_int ret = clGetPlatformIDs(1, &platform_id, &ret_num_platforms);
the application gives me the output
modprobe: ERROR: ../libkmod/libkmod-module.c:809 kmod_module_insert_module() could not find module by name='nvidia_331_uvm'
modprobe: ERROR: could not insert 'nvidia_331_uvm': Function not implemented
There seems to be a conflict with an older driver version since I am using 340.
cat /proc/driver/nvidia/version
NVRM version: NVIDIA UNIX x86_64 Kernel Module 340.32 Tue Aug 5 20:58:26 PDT 2014
Maybe I should try to remove Ubuntu's own NVIDIA drivers one more time and reinstall the latest manually one more time?
EDIT:
The old driver was the problem. Somehow it wasn't removed properly thus I have done it one more time with
apt-get remove nvidia-331 nvidia-opencl-icd-331 nvidia-libopencl1-331
and now it works. I hope this helps someone who has similar problems.
The above mentioned problems occurred due to a driver conflict. If you have a similar problem then read the above edits to get the solution.
I am developing an OpenGL application and need to use the glew library. I am using Visual Studio C++ 2008 Express.
I compiled a program using gl.h, glu.h, and glut.h just fine and it does what it's supposed to do. But after including glew.h it still compiles just fine, but when I try:
glewInit();
if (glewIsSupported("GL_VERSION_2_0"))
printf("Ready for OpenGL 2.0\n");
else {
printf("OpenGL 2.0 not supported\n");
}
It keeps printing:
"OpenGL 2.0 not supported".
I tried to change it to glewIsSupported("GL_VERSION_1_3") or even glewIsSupported("GL_VERSION_1_0") and it still returns false meaning that it does not support OpenGL version whatever.
I have a Radeon HD 5750 so, it should support OpenGL 3.1 and some of the features of 3.2. I know that all the device drivers are installed properly since I was able to run all the programs in the Radeon sdk provided by ATI.
I also installed Opengl Extensions Viewer 3.15 and it says OpenGL Version 3.1 Ati Driver 6.14.10.9116. I tired all of them GLEW_VERSION_1_1, GLEW_VERSION_1_2, GLEW_VERSION_1_3, GLEW_VERSION_2_0, GLEW_VERSION_2_1, GLEW_VERSION_3_0 and all of these return false.
Any other suggestioms? I even tried GLEW_ARB_vertex_shader && GLEW_ARB_fragment_shader and this is returning false as well.
glewIsSupported is meant to check and see if the specific features are supported. You want something more like...
if (GLEW_VERSION_1_3)
{
/* Yay! OpenGL 1.3 is supported! */
}
there may be some lack of necessary initialization. I encounter the same question. And here is how I solve the question: you need to include the glCreateWindow() ahead. Include this function and try again.
Firstly, you should check whether glew has initialized properly:
if(glewInit() != GLEW_OK)
{ // something is wrong };
Secondly, you need to create the context before calling glewInit()
Thirdly, you can also try:
glewExperimental=true;
Before calling glewInit()
I encountered the same problem when running a program through windows RDP, then I noticed that my video card may not working properly when using RDP, so I tried teamviewer instead, both glewinfo.exe and my program start to work normally then.
The OP's problem may be solved for a long time, just for others' infomation.