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diff --git a/glfw-3.2.1/docs/vulkan.dox b/glfw-3.2.1/docs/vulkan.dox new file mode 100644 index 0000000..e704222 --- /dev/null +++ b/glfw-3.2.1/docs/vulkan.dox @@ -0,0 +1,211 @@ +/*! + +@page vulkan_guide Vulkan guide + +@tableofcontents + +This guide is intended to fill the gaps between the [Vulkan +documentation](https://www.khronos.org/vulkan/) and the rest of the GLFW +documentation and is not a replacement for either. It assumes some familiarity +with Vulkan concepts like loaders, devices, queues and surfaces and leaves it to +the Vulkan documentation to explain the details of Vulkan functions. + +To develop for Vulkan you should install an SDK for your platform, for example +the [LunarG Vulkan SDK](https://vulkan.lunarg.com/). Apart from the headers and +libraries, it also provides the validation layers necessary for development. + +The GLFW library does not need the Vulkan SDK to enable support for Vulkan. +However, any Vulkan-specific test and example programs are built only if the +CMake files find a Vulkan SDK. + +For details on a specific function in this category, see the @ref vulkan. There +are also guides for the other areas of the GLFW API. + + - @ref intro_guide + - @ref window_guide + - @ref context_guide + - @ref monitor_guide + - @ref input_guide + + +@section vulkan_include Including the Vulkan and GLFW header files + +To include the Vulkan header, define [GLFW_INCLUDE_VULKAN](@ref build_macros) +before including the GLFW header. + +@code +#define GLFW_INCLUDE_VULKAN +#include <GLFW/glfw3.h> +@endcode + +If you instead want to include the Vulkan header from a custom location or use +your own custom Vulkan header then do this before the GLFW header. + +@code +#include <path/to/vulkan.h> +#include <GLFW/glfw3.h> +@endcode + +Unless a Vulkan header is included, either by the GLFW header or above it, any +GLFW functions that take or return Vulkan types will not be declared. + +The `VK_USE_PLATFORM_*_KHR` macros do not need to be defined for the Vulkan part +of GLFW to work. Define them only if you are using these extensions directly. + + +@section vulkan_support Querying for Vulkan support + +If you are linking directly against the Vulkan loader then you can skip this +section. The canonical desktop loader library exports all Vulkan core and +Khronos extension functions, allowing them to be called directly. + +If you are loading the Vulkan loader dynamically instead of linking directly +against it, you can check for the availability of a loader with @ref +glfwVulkanSupported. + +@code +if (glfwVulkanSupported()) +{ + // Vulkan is available, at least for compute +} +@endcode + +This function returns `GLFW_TRUE` if the Vulkan loader was found. This check is +performed by @ref glfwInit. + +If no loader was found, calling any other Vulkan related GLFW function will +generate a @ref GLFW_API_UNAVAILABLE error. + + +@subsection vulkan_proc Querying Vulkan function pointers + +To load any Vulkan core or extension function from the found loader, call @ref +glfwGetInstanceProcAddress. To load functions needed for instance creation, +pass `NULL` as the instance. + +@code +PFN_vkCreateInstance pfnCreateInstance = (PFN_vkCreateInstance) + glfwGetInstanceProcAddress(NULL, "vkCreateInstance"); +@endcode + +Once you have created an instance, you can load from it all other Vulkan core +functions and functions from any instance extensions you enabled. + +@code +PFN_vkCreateDevice pfnCreateDevice = (PFN_vkCreateDevice) + glfwGetInstanceProcAddress(instance, "vkCreateDevice"); +@endcode + +This function in turn calls `vkGetInstanceProcAddr`. If that fails, the +function falls back to a platform-specific query of the Vulkan loader (i.e. +`dlsym` or `GetProcAddress`). If that also fails, the function returns `NULL`. +For more information about `vkGetInstanceProcAddr`, see the Vulkan +documentation. + +Vulkan also provides `vkGetDeviceProcAddr` for loading device-specific versions +of Vulkan function. This function can be retrieved from an instance with @ref +glfwGetInstanceProcAddress. + +@code +PFN_vkGetDeviceProcAddr pfnGetDeviceProcAddr = (PFN_vkGetDeviceProcAddr) + glfwGetInstanceProcAddress(instance, "vkGetDeviceProcAddr"); +@endcode + +Device-specific functions may execute a little bit faster, due to not having to +dispatch internally based on the device passed to them. For more information +about `vkGetDeviceProcAddr`, see the Vulkan documentation. + + +@section vulkan_ext Querying required Vulkan extensions + +To do anything useful with Vulkan you need to create an instance. If you want +to use Vulkan to render to a window, you must enable the instance extensions +GLFW requires to create Vulkan surfaces. + +To query the instance extensions required, call @ref +glfwGetRequiredInstanceExtensions. + +@code +uint32_t count; +const char** extensions = glfwGetRequiredInstanceExtensions(&count); +@endcode + +These extensions must all be enabled when creating instances that are going to +be passed to @ref glfwGetPhysicalDevicePresentationSupport and @ref +glfwCreateWindowSurface. The set of extensions will vary depending on platform +and may also vary depending on graphics drivers and other factors. + +If it fails it will return `NULL` and GLFW will not be able to create Vulkan +window surfaces. You can still use Vulkan for off-screen rendering and compute +work. + +The returned array will always contain `VK_KHR_surface`, so if you don't +require any additional extensions you can pass this list directly to the +`VkInstanceCreateInfo` struct. + +@code +VkInstanceCreateInfo ici; + +memset(&ici, 0, sizeof(ici)); +ici.enabledExtensionCount = count; +ici.ppEnabledExtensionNames = extensions; +... +@endcode + +Additional extensions may be required by future versions of GLFW. You should +check whether any extensions you wish to enable are already in the returned +array, as it is an error to specify an extension more than once in the +`VkInstanceCreateInfo` struct. + + +@section vulkan_present Querying for Vulkan presentation support + +Not every queue family of every Vulkan device can present images to surfaces. +To check whether a specific queue family of a physical device supports image +presentation without first having to create a window and surface, call @ref +glfwGetPhysicalDevicePresentationSupport. + +@code +if (glfwGetPhysicalDevicePresentationSupport(instance, physical_device, queue_family_index)) +{ + // Queue family supports image presentation +} +@endcode + +The `VK_KHR_surface` extension additionally provides the +`vkGetPhysicalDeviceSurfaceSupportKHR` function, which performs the same test on +an existing Vulkan surface. + + +@section vulkan_window Creating the window + +Unless you will be using OpenGL or OpenGL ES with the same window as Vulkan, +there is no need to create a context. You can disable context creation with the +[GLFW_CLIENT_API](@ref window_hints_ctx) hint. + +@code +glfwWindowHint(GLFW_CLIENT_API, GLFW_NO_API); +GLFWwindow* window = glfwCreateWindow(640, 480, "Window Title", NULL, NULL); +@endcode + +See @ref context_less for more information. + + +@section vulkan_surface Creating a Vulkan window surface + +You can create a Vulkan surface (as defined by the `VK_KHR_surface` extension) +for a GLFW window with @ref glfwCreateWindowSurface. + +@code +VkSurfaceKHR surface; +VkResult err = glfwCreateWindowSurface(instance, window, NULL, &surface); +if (err) +{ + // Window surface creation failed +} +@endcode + +It is your responsibility to destroy the surface. GLFW does not destroy it for +you. Call `vkDestroySurfaceKHR` function from the same extension to destroy it. + +*/ |