CODEWITHSUNDEEP
c++glfwvulkan
Mathias
Mathias

Reputation: 39

Vulkan and glfw - glfwVulkanSupported() always return false

I'm trying to run a basic Vulkan test using GLFW3.2 :

#include <vulkan/vulkan.h>
#include <GLFW/glfw3.h>

#include <iostream>

int main(int argc, char *argv[])
{
    if (glfwVulkanSupported())
    {
        std::cout << "vulkan supported !" << std::endl;

    }
    else 
    {
        std::cout << "vulkan NOT supported !" << std::endl;

    }
    return 0;
}

Which i build using the following cmake :

cmake_minimum_required(VERSION 3.5.1)
project(vktest)

set (CMAKE_CXX_STANDARD 11)
set(CMAKE_CXX_COMPILER "/usr/bin/g++-4.9")

set(CMAKE_EXPORT_COMPILE_COMMANDS ON)
set(CMAKE_INCLUDE_CURRENT_DIR ON)

find_package(Vulkan REQUIRED)
find_package(glfw3 3.2 REQUIRED)
include_directories(${Vulkan_INCLUDE_DIRS})

message("kek")
message(${Vulkan_INCLUDE_DIRS})
message(${Vulkan_LIBRARIES})
message(${Vulkan_LIBRARY})

add_executable(vktest vulkanTest.cpp)

target_link_libraries(vktest ${Vulkan_LIBRARIES})
target_link_libraries(vktest glfw)

Building this works just fine.

But when i run the program i always get in the else statement.

I installed nvidia last driver, lunarg's vulkan sdk with the following environment variables :

export VULKAN_SDK=/home/mathias/vulkan/VulkanSDK/1.0.42.2/x86_64
set PATH $VULKAN_SDK/bin $PATH
set LD_LIBRARY_PATH $VULKAN_SDK/lib $LD_LIBRARY_PATH
set VK_LAYER_PATH $VULKAN_SDK/etc/explicit_layer.d

Besides i can run the cube example.

Any idea of why it never returns true ?

Upvotes: 3

Views: 2337

Answers (2)

Benno Straub
Benno Straub

Reputation: 2577

You are probably missing a glfwInit() call.

#define GLFW_INCLUDE_VULKAN
#include <GLFW/glfw3.h>
#include <cassert>
int main(int argc, const char** argv) {
    bool success =  glfwInit();  //< Important! 
    assert(success);
    if(glfwVVulkanSupported()) {
        puts("Success!");
    }
    return 0;
}

Generally, the only glfw function you should call before glfwInit() is glfwSetErrorCallback. (There may be other exceptions, but none that I am aware of.)

Upvotes: 6

Swift - Friday Pie
Swift - Friday Pie

Reputation: 14673

Your code is missing #define GLFW_INCLUDE_VULKAN , does it not? 

#define GLFW_INCLUDE_VULKAN //as required by GLFW
#include "vulkan\vk_cpp.hpp" 
#include "GLFW\glfw3.h" 
#include <iostream>
#include <algorithm>
#include <iterator>

int main()
{
    if (!glfwInit()) //Initialize GLFW
    {
        std::cout << "GLFW not initialized.\n";
        abort();
    }
    if (!glfwVulkanSupported()) //Any Vulkan-related function requires GLFW initialized
    {
        std::cout << "Vulkan not supported.\n";
        abort();
    }
    uint32_t ext_count; // an output placeholder
    auto ext_list = glfwGetRequiredInstanceExtensions(&ext_count);

    std::copy(&ext_list[0], &ext_list[ext_count-1], std::ostream_iterator<const char *>(cout, "\n"));

    //feed extension list into InstanceCreateInfo struct in prepare for Vulkan instance creation
    vk::InstanceCreateInfo ifo{ vk::InstanceCreateFlags(), nullptr, 0, nullptr, ext_count, ext_list };
    glfwDefaultWindowHints();
    glfwWindowHint(GLFW_CLIENT_API, GLFW_NO_API); // Comment out this if you need OpenGL also
    GLFWwindow* hWnd = glfwCreateWindow(640, 480, "Foobar", NULL, NULL); // The usual window
    auto inst = vk::createInstance(ifo); // Vulkan instance creation
    vk::SurfaceKHR surf{};
    auto psurf = VkSurfaceKHR(surf); // you can cast vk::* object to Vk* using a type cast
    auto r = glfwCreateWindowSurface(VkInstance(inst), hWnd, NULL, &psurf); //VK_SUCCESS is somehow...0
    // Draw stuff here

    // Finish drawing
    vkDestroySurfaceKHR((VkInstance)inst, VkSurfaceKHR(surf), nullptr);//vkcpp seems have no destructor for surface object
    glfwDestroyWindow(hWnd); //Destroy the surface before the window
    glfwTerminate(); // Free GLFW resource
    return 0;
}

if there are typos in this code free to fix them. I have no way to compile it at current location

Upvotes: 2

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