NX2navi/runtime/vk_fg.cpp

// Frame generation with AMD FSR 3.1 (NX2NAVI_FRAMEGEN = fsr3; applies after a restart): AMD's frame generation
// swapchain (amd_fidelityfx_vk.dll, vk_ffx.cpp loads it) takes the place of gfx_present.c's swapchain. Every frame
// the game presents, the swapchain presents a generated frame between it and the one before, on its own present
// queue and pacing threads, so the screen shows twice the game's frame rate.
//
// The generated frame is built from the presented picture and the scene's depth and camera motion vectors, which
// vk_dlaa.c makes for DLSS and FSR 3.1 upscaling: frame generation needs one of those on (DLAA or Native AA included).
// The HUD is interpolated with the picture (it hardly moves); the menu is not, since generation pauses while it is
// open. The device creates two more queues of the graphics family for it (vk_device.c, vk_fg_queue_count).
#ifdef _WIN32
#include <windows.h>
#endif
#include <stdbool.h>
#include <stdio.h>
#include <string.h>
#include <wchar.h>

#include "third_party/ffx_api/ffx_api.h"
#include "third_party/ffx_api/ffx_framegeneration.h"
#include "third_party/ffx_api/vk/ffx_api_vk.h"

extern "C" {
#include "cfg.h"
#include "host.h"
#include "platform/platform.h"
#include "vk.h"
#include "vk_dlaa.h"
#include "vk_ffx.h"
#include "vk_fg.h"
#include "ui/menu.h"
}

namespace {

struct {
    int wanted = -1;
    VkQueue present = VK_NULL_HANDLE, acquire = VK_NULL_HANDLE;
    ffxContext sc = nullptr;   // the swapchain context
    ffxContext fg = nullptr;   // the frame generation context
    VkExtent2D fg_ext = {0, 0};
    VkFormat fg_fmt = VK_FORMAT_UNDEFINED;
    ffxQueryDescSwapchainReplacementFunctionsVK fn = {};
    uint64_t frame = 0;
    int failed = 0;
    uint64_t generated = 0, paused = 0, no_inputs = 0;
} F;

VkResult submit_game(uint32_t n, const VkSubmitInfo *si, VkFence fence) {
    vk_queue_lock();   // the game's queue is shared with the recorder and the present path
    VkResult r = vkQueueSubmit(vk_ctx()->gfx_queue, n, si, fence);
    vk_queue_unlock();
    return r;
}

ffxReturnCode_t generate(ffxDispatchDescFrameGeneration *d, void *user) {
    F.generated++;
    return vk_ffx_dispatch((ffxContext *)user, &d->header);
}

FfxApiResource image(const VkFfxImage *i) {
    VkImageCreateInfo ci = {};
    ci.sType = VK_STRUCTURE_TYPE_IMAGE_CREATE_INFO;
    ci.imageType = VK_IMAGE_TYPE_2D;
    ci.format = i->format;
    ci.extent = {i->width, i->height, 1};
    ci.mipLevels = 1;
    ci.arrayLayers = 1;
    return ffxApiGetResourceVK((void *)i->image, ffxApiGetImageResourceDescriptionVK(i->image, ci, 0),
                               FFX_API_RESOURCE_STATE_UNORDERED_ACCESS);
}

void fail(const char *what, unsigned r) {
    rt_log("fg: %s failed (%u): frame generation off for this run", what, r);
    F.failed = 1;
}

}  // namespace

extern "C" int vk_fg_wanted(void) {
    if (F.wanted < 0) {
        F.wanted = !strcmp(cfg_value("NX2NAVI_FRAMEGEN"), "fsr3");
        if (F.wanted && !vk_dlaa_wanted()) {
            rt_log("fg: frame generation needs DLSS or FSR 3.1 upscaling (any mode): off");
            F.wanted = 0;
        }
    }
    return F.wanted;
}

extern "C" uint32_t vk_fg_queue_count(void) { return vk_fg_wanted() ? 3 : 1; }

extern "C" void vk_fg_queues(VkQueue present, VkQueue acquire) { F.present = present, F.acquire = acquire; }

extern "C" int vk_fg_active(void) { return F.sc != nullptr && !F.failed; }

extern "C" VkResult vk_fg_create_swapchain(const VkSwapchainCreateInfoKHR *ci, VkSwapchainKHR *sc) {
    if (F.sc) return F.fn.pOutCreateSwapchainFFXAPI(vk_ctx()->device, ci, nullptr, sc, F.sc);
    if (!vk_fg_wanted() || F.failed || !F.present || !vk_ffx_load()) return VK_ERROR_FEATURE_NOT_PRESENT;
    const VkCtx *c = vk_ctx();
    ffxCreateContextDescFrameGenerationSwapChainVK d = {};
    d.header.type = FFX_API_CREATE_CONTEXT_DESC_TYPE_FGSWAPCHAIN_VK;
    d.physicalDevice = c->phys;
    d.device = c->device;
    VkSwapchainKHR none = VK_NULL_HANDLE;
    d.swapchain = &none;
    d.createInfo = *ci;
    d.createInfo.oldSwapchain = VK_NULL_HANDLE;
    d.gameQueue = {c->gfx_queue, c->gfx_family, submit_game};
    d.asyncComputeQueue = {VK_NULL_HANDLE, c->gfx_family, nullptr};
    d.presentQueue = {F.present, c->gfx_family, nullptr};
    d.imageAcquireQueue = {F.acquire, c->gfx_family, nullptr};
    ffxReturnCode_t r = vk_ffx_create(&F.sc, &d.header);
    if (r != FFX_API_RETURN_OK) {
        F.sc = nullptr;
        fail("the frame generation swapchain", r);
        return VK_ERROR_INITIALIZATION_FAILED;
    }
    F.fn.header.type = FFX_API_QUERY_DESC_TYPE_FGSWAPCHAIN_FUNCTIONS_VK;
    if (vk_ffx_query(&F.sc, &F.fn.header) != FFX_API_RETURN_OK || !F.fn.pOutQueuePresentKHR) {
        fail("the swapchain functions", 0);
        return VK_ERROR_INITIALIZATION_FAILED;
    }
    *sc = none;
    rt_log("fg: AMD FSR 3.1 frame generation swapchain, %ux%u", ci->imageExtent.width, ci->imageExtent.height);
    return VK_SUCCESS;
}

extern "C" void vk_fg_destroy_swapchain(VkSwapchainKHR sc) {
    if (F.sc && sc) F.fn.pOutDestroySwapchainFFXAPI(vk_ctx()->device, sc, nullptr, F.sc);
}

extern "C" VkResult vk_fg_get_images(VkSwapchainKHR sc, uint32_t *n, VkImage *img) {
    return F.fn.pOutGetSwapchainImagesKHR(vk_ctx()->device, sc, n, img);
}

extern "C" VkResult vk_fg_acquire(VkSwapchainKHR sc, uint64_t timeout, VkSemaphore sem, uint32_t *idx) {
    return F.fn.pOutAcquireNextImageKHR(vk_ctx()->device, sc, timeout, sem, VK_NULL_HANDLE, idx);
}

extern "C" VkResult vk_fg_present(const VkPresentInfoKHR *pi) {
    return F.fn.pOutQueuePresentKHR(vk_ctx()->gfx_queue, pi);
}

extern "C" void vk_fg_frame(VkCommandBuffer cb, VkSwapchainKHR sc, VkFormat fmt, VkExtent2D ext) {
    if (!vk_fg_active()) return;
    const VkCtx *c = vk_ctx();
    if (F.fg && (F.fg_ext.width != ext.width || F.fg_ext.height != ext.height || F.fg_fmt != fmt)) {
        vkDeviceWaitIdle(c->device);   // a new window size: the context is made for its display size
        vk_ffx_destroy(&F.fg);
        F.fg = nullptr;
    }
    if (!F.fg) {
        ffxCreateBackendVKDesc be = {};
        be.header.type = FFX_API_CREATE_CONTEXT_DESC_TYPE_BACKEND_VK;
        be.vkDevice = c->device;
        be.vkPhysicalDevice = c->phys;
        be.vkDeviceProcAddr = vkGetDeviceProcAddr;
        ffxCreateContextDescFrameGeneration d = {};
        d.header.type = FFX_API_CREATE_CONTEXT_DESC_TYPE_FRAMEGENERATION;
        d.header.pNext = &be.header;
        d.flags = FFX_FRAMEGENERATION_ENABLE_DEPTH_INFINITE;
        d.displaySize = {ext.width, ext.height};
        d.maxRenderSize = {ext.width, ext.height};
        d.backBufferFormat = ffxApiGetSurfaceFormatVK(fmt);
        ffxReturnCode_t r = vk_ffx_create(&F.fg, &d.header);
        if (r != FFX_API_RETURN_OK) return F.fg = nullptr, fail("the frame generation context", r);
        F.fg_ext = ext, F.fg_fmt = fmt;
        rt_log("fg: frame generation context for %ux%u", ext.width, ext.height);
    }
    VkFfxImage depth, mv;
    float jx = 0, jy = 0;
    int reset = 0;
    int have = vk_dlaa_fg_inputs(&depth, &mv, &jx, &jy, &reset);
    int on = have && !menu_is_open();
    if (!have) F.no_inputs++;
    else if (!on) F.paused++;
    F.frame++;
    ffxConfigureDescFrameGeneration cfg = {};
    cfg.header.type = FFX_API_CONFIGURE_DESC_TYPE_FRAMEGENERATION;
    cfg.swapChain = (void *)sc;
    cfg.frameGenerationCallback = generate;
    cfg.frameGenerationCallbackUserContext = &F.fg;
    cfg.frameGenerationEnabled = on != 0;
    cfg.allowAsyncWorkloads = false;
    cfg.generationRect = {0, 0, (int32_t)ext.width, (int32_t)ext.height};
    cfg.frameID = F.frame;
    ffxReturnCode_t r = vk_ffx_configure(&F.fg, &cfg.header);
    if (r != FFX_API_RETURN_OK) return fail("frame generation configuration", r);
    if (!on) return;
    ffxDispatchDescFrameGenerationPrepare p = {};
    p.header.type = FFX_API_DISPATCH_DESC_TYPE_FRAMEGENERATION_PREPARE;
    p.frameID = F.frame;
    p.commandList = cb;
    p.renderSize = {depth.width, depth.height};
    p.jitterOffset = {jx, jy};
    p.motionVectorScale = {1.0f, 1.0f};   // render pixels, current to previous (vk_dlaa.c mv_pass), as FSR takes them
    static uint64_t last_ns;
    uint64_t now = plat_now_ns();
    double dt = last_ns ? (now - last_ns) / 1e6 : 16.67;
    last_ns = now;
    p.frameTimeDelta = dt > 0 && dt < 100 ? (float)dt : 16.67f;
    p.cameraNear = 0.1f;   // Ocarina's projection: near 0.1, far at infinity (vk_ffx.cpp)
    p.cameraFar = 1e8f;
    p.cameraFovAngleVertical = 1.0f;
    p.viewSpaceToMetersFactor = 0.01f;
    p.depth = image(&depth);
    p.motionVectors = image(&mv);
    r = vk_ffx_dispatch(&F.fg, &p.header);
    if (r != FFX_API_RETURN_OK) return fail("frame generation preparation", r);
    if (F.frame == 2 || F.frame % 3600 == 0)
        rt_log("fg: %llu frames presented, %llu generated; paused %llu (menu), %llu without depth and motion",
               (unsigned long long)F.frame, (unsigned long long)F.generated, (unsigned long long)F.paused,
               (unsigned long long)F.no_inputs);
}

extern "C" void vk_fg_release(void) {
    if (F.fg) vk_ffx_destroy(&F.fg), F.fg = nullptr;
    if (F.sc) vk_ffx_destroy(&F.sc), F.sc = nullptr;
}