/*
  Simple DirectMedia Layer
  Copyright (C) 1997-2020 Sam Lantinga <slouken@libsdl.org>

  This software is provided 'as-is', without any express or implied
  warranty.  In no event will the authors be held liable for any damages
  arising from the use of this software.

  Permission is granted to anyone to use this software for any purpose,
  including commercial applications, and to alter it and redistribute it
  freely, subject to the following restrictions:

  1. The origin of this software must not be misrepresented; you must not
     claim that you wrote the original software. If you use this software
     in a product, an acknowledgment in the product documentation would be
     appreciated but is not required.
  2. Altered source versions must be plainly marked as such, and must not be
     misrepresented as being the original software.
  3. This notice may not be removed or altered from any source distribution.
*/
#include "../../SDL_internal.h"

#if SDL_VIDEO_VULKAN && SDL_VIDEO_DRIVER_X11

#include "SDL_x11video.h"

#include "SDL_loadso.h"
#include "SDL_x11vulkan.h"

#include <X11/Xlib.h>
/*#include <xcb/xcb.h>*/

#if defined(__OpenBSD__)
#define DEFAULT_VULKAN  "libvulkan.so"
#else
#define DEFAULT_VULKAN  "libvulkan.so.1"
#endif

/*
typedef uint32_t xcb_window_t;
typedef uint32_t xcb_visualid_t;
*/

int X11_Vulkan_LoadLibrary(_THIS, const char *path)
{
    SDL_VideoData *videoData = (SDL_VideoData *)_this->driverdata;
    VkExtensionProperties *extensions = NULL;
    Uint32 extensionCount = 0;
    SDL_bool hasSurfaceExtension = SDL_FALSE;
    SDL_bool hasXlibSurfaceExtension = SDL_FALSE;
    SDL_bool hasXCBSurfaceExtension = SDL_FALSE;
    PFN_vkGetInstanceProcAddr vkGetInstanceProcAddr = NULL;
    Uint32 i;
    if(_this->vulkan_config.loader_handle)
        return SDL_SetError("Vulkan already loaded");

    /* Load the Vulkan loader library */
    if(!path)
        path = SDL_getenv("SDL_VULKAN_LIBRARY");
    if(!path)
        path = DEFAULT_VULKAN;
    _this->vulkan_config.loader_handle = SDL_LoadObject(path);
    if(!_this->vulkan_config.loader_handle)
        return -1;
    SDL_strlcpy(_this->vulkan_config.loader_path, path, SDL_arraysize(_this->vulkan_config.loader_path));
    vkGetInstanceProcAddr = (PFN_vkGetInstanceProcAddr)SDL_LoadFunction(
        _this->vulkan_config.loader_handle, "vkGetInstanceProcAddr");
    if(!vkGetInstanceProcAddr)
        goto fail;
    _this->vulkan_config.vkGetInstanceProcAddr = (void *)vkGetInstanceProcAddr;
    _this->vulkan_config.vkEnumerateInstanceExtensionProperties =
        (void *)((PFN_vkGetInstanceProcAddr)_this->vulkan_config.vkGetInstanceProcAddr)(
            VK_NULL_HANDLE, "vkEnumerateInstanceExtensionProperties");
    if(!_this->vulkan_config.vkEnumerateInstanceExtensionProperties)
        goto fail;
    extensions = SDL_Vulkan_CreateInstanceExtensionsList(
        (PFN_vkEnumerateInstanceExtensionProperties)
            _this->vulkan_config.vkEnumerateInstanceExtensionProperties,
        &extensionCount);
    if(!extensions)
        goto fail;
    for(i = 0; i < extensionCount; i++)
    {
        if(SDL_strcmp(VK_KHR_SURFACE_EXTENSION_NAME, extensions[i].extensionName) == 0)
            hasSurfaceExtension = SDL_TRUE;
        else if(SDL_strcmp(VK_KHR_XCB_SURFACE_EXTENSION_NAME, extensions[i].extensionName) == 0)
            hasXCBSurfaceExtension = SDL_TRUE;
        else if(SDL_strcmp(VK_KHR_XLIB_SURFACE_EXTENSION_NAME, extensions[i].extensionName) == 0)
            hasXlibSurfaceExtension = SDL_TRUE;
    }
    SDL_free(extensions);
    if(!hasSurfaceExtension)
    {
        SDL_SetError("Installed Vulkan doesn't implement the "
                     VK_KHR_SURFACE_EXTENSION_NAME " extension");
        goto fail;
    }
    if(hasXlibSurfaceExtension)
    {
        videoData->vulkan_xlib_xcb_library = NULL;
    }
    else if(!hasXCBSurfaceExtension)
    {
        SDL_SetError("Installed Vulkan doesn't implement either the "
                     VK_KHR_XCB_SURFACE_EXTENSION_NAME "extension or the "
                     VK_KHR_XLIB_SURFACE_EXTENSION_NAME " extension");
        goto fail;
    }
    else
    {
        const char *libX11XCBLibraryName = SDL_getenv("SDL_X11_XCB_LIBRARY");
        if(!libX11XCBLibraryName)
            libX11XCBLibraryName = "libX11-xcb.so";
        videoData->vulkan_xlib_xcb_library = SDL_LoadObject(libX11XCBLibraryName);
        if(!videoData->vulkan_xlib_xcb_library)
            goto fail;
        videoData->vulkan_XGetXCBConnection =
            SDL_LoadFunction(videoData->vulkan_xlib_xcb_library, "XGetXCBConnection");
        if(!videoData->vulkan_XGetXCBConnection)
        {
            SDL_UnloadObject(videoData->vulkan_xlib_xcb_library);
            goto fail;
        }
    }
    return 0;

fail:
    SDL_UnloadObject(_this->vulkan_config.loader_handle);
    _this->vulkan_config.loader_handle = NULL;
    return -1;
}

void X11_Vulkan_UnloadLibrary(_THIS)
{
    SDL_VideoData *videoData = (SDL_VideoData *)_this->driverdata;
    if(_this->vulkan_config.loader_handle)
    {
        if(videoData->vulkan_xlib_xcb_library)
            SDL_UnloadObject(videoData->vulkan_xlib_xcb_library);
        SDL_UnloadObject(_this->vulkan_config.loader_handle);
        _this->vulkan_config.loader_handle = NULL;
    }
}

SDL_bool X11_Vulkan_GetInstanceExtensions(_THIS,
                                          SDL_Window *window,
                                          unsigned *count,
                                          const char **names)
{
    SDL_VideoData *videoData = (SDL_VideoData *)_this->driverdata;
    if(!_this->vulkan_config.loader_handle)
    {
        SDL_SetError("Vulkan is not loaded");
        return SDL_FALSE;
    }
    if(videoData->vulkan_xlib_xcb_library)
    {
        static const char *const extensionsForXCB[] = {
            VK_KHR_SURFACE_EXTENSION_NAME, VK_KHR_XCB_SURFACE_EXTENSION_NAME,
        };
        return SDL_Vulkan_GetInstanceExtensions_Helper(
            count, names, SDL_arraysize(extensionsForXCB), extensionsForXCB);
    }
    else
    {
        static const char *const extensionsForXlib[] = {
            VK_KHR_SURFACE_EXTENSION_NAME, VK_KHR_XLIB_SURFACE_EXTENSION_NAME,
        };
        return SDL_Vulkan_GetInstanceExtensions_Helper(
            count, names, SDL_arraysize(extensionsForXlib), extensionsForXlib);
    }
}

SDL_bool X11_Vulkan_CreateSurface(_THIS,
                                  SDL_Window *window,
                                  VkInstance instance,
                                  VkSurfaceKHR *surface)
{
    SDL_VideoData *videoData = (SDL_VideoData *)_this->driverdata;
    SDL_WindowData *windowData = (SDL_WindowData *)window->driverdata;
    PFN_vkGetInstanceProcAddr vkGetInstanceProcAddr;
    if(!_this->vulkan_config.loader_handle)
    {
        SDL_SetError("Vulkan is not loaded");
        return SDL_FALSE;
    }
    vkGetInstanceProcAddr = (PFN_vkGetInstanceProcAddr)_this->vulkan_config.vkGetInstanceProcAddr;
    if(videoData->vulkan_xlib_xcb_library)
    {
        PFN_vkCreateXcbSurfaceKHR vkCreateXcbSurfaceKHR =
            (PFN_vkCreateXcbSurfaceKHR)vkGetInstanceProcAddr(instance,
                                                             "vkCreateXcbSurfaceKHR");
        VkXcbSurfaceCreateInfoKHR createInfo;
        VkResult result;
        if(!vkCreateXcbSurfaceKHR)
        {
            SDL_SetError(VK_KHR_XCB_SURFACE_EXTENSION_NAME
                         " extension is not enabled in the Vulkan instance.");
            return SDL_FALSE;
        }
        SDL_zero(createInfo);
        createInfo.sType = VK_STRUCTURE_TYPE_XCB_SURFACE_CREATE_INFO_KHR;
        createInfo.connection = videoData->vulkan_XGetXCBConnection(videoData->display);
        if(!createInfo.connection)
        {
            SDL_SetError("XGetXCBConnection failed");
            return SDL_FALSE;
        }
        createInfo.window = (xcb_window_t)windowData->xwindow;
        result = vkCreateXcbSurfaceKHR(instance, &createInfo,
                                       NULL, surface);
        if(result != VK_SUCCESS)
        {
            SDL_SetError("vkCreateXcbSurfaceKHR failed: %s", SDL_Vulkan_GetResultString(result));
            return SDL_FALSE;
        }
        return SDL_TRUE;
    }
    else
    {
        PFN_vkCreateXlibSurfaceKHR vkCreateXlibSurfaceKHR =
            (PFN_vkCreateXlibSurfaceKHR)vkGetInstanceProcAddr(instance,
                                                              "vkCreateXlibSurfaceKHR");
        VkXlibSurfaceCreateInfoKHR createInfo;
        VkResult result;
        if(!vkCreateXlibSurfaceKHR)
        {
            SDL_SetError(VK_KHR_XLIB_SURFACE_EXTENSION_NAME
                         " extension is not enabled in the Vulkan instance.");
            return SDL_FALSE;
        }
        SDL_zero(createInfo);
        createInfo.sType = VK_STRUCTURE_TYPE_XLIB_SURFACE_CREATE_INFO_KHR;
        createInfo.dpy = videoData->display;
        createInfo.window = (xcb_window_t)windowData->xwindow;
        result = vkCreateXlibSurfaceKHR(instance, &createInfo,
                                        NULL, surface);
        if(result != VK_SUCCESS)
        {
            SDL_SetError("vkCreateXlibSurfaceKHR failed: %s", SDL_Vulkan_GetResultString(result));
            return SDL_FALSE;
        }
        return SDL_TRUE;
    }
}

#endif

/* vim: set ts=4 sw=4 expandtab: */
