aboutsummaryrefslogtreecommitdiffhomepage
path: root/tools/sk_app/VulkanWindowContext.cpp
blob: ad0e15ca7b8a26a25d6a8b45de4e7de9a234bdaf (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632

/*
 * Copyright 2015 Google Inc.
 *
 * Use of this source code is governed by a BSD-style license that can be
 * found in the LICENSE file.
 */

#include "GrBackendSurface.h"
#include "GrContext.h"
#include "SkAutoMalloc.h"
#include "SkSurface.h"
#include "VulkanWindowContext.h"

#include "vk/GrVkImage.h"
#include "vk/GrVkInterface.h"
#include "vk/GrVkUtil.h"
#include "vk/GrVkTypes.h"

#ifdef VK_USE_PLATFORM_WIN32_KHR
// windows wants to define this as CreateSemaphoreA or CreateSemaphoreW
#undef CreateSemaphore
#endif

#define GET_PROC(F) f ## F = (PFN_vk ## F) fGetInstanceProcAddr(instance, "vk" #F)
#define GET_DEV_PROC(F) f ## F = (PFN_vk ## F) fGetDeviceProcAddr(device, "vk" #F)

namespace sk_app {

VulkanWindowContext::VulkanWindowContext(const DisplayParams& params,
                                         CreateVkSurfaceFn createVkSurface,
                                         CanPresentFn canPresent,
                                         PFN_vkGetInstanceProcAddr instProc,
                                         PFN_vkGetDeviceProcAddr devProc)
    : WindowContext(params)
    , fCreateVkSurfaceFn(createVkSurface)
    , fCanPresentFn(canPresent)
    , fSurface(VK_NULL_HANDLE)
    , fSwapchain(VK_NULL_HANDLE)
    , fImages(nullptr)
    , fImageLayouts(nullptr)
    , fSurfaces(nullptr)
    , fCommandPool(VK_NULL_HANDLE)
    , fBackbuffers(nullptr) {
    fGetInstanceProcAddr = instProc;
    fGetDeviceProcAddr = devProc;
    this->initializeContext();
}

void VulkanWindowContext::initializeContext() {
    // any config code here (particularly for msaa)?
    fBackendContext.reset(GrVkBackendContext::Create(fGetInstanceProcAddr, fGetDeviceProcAddr,
                                                     &fPresentQueueIndex, fCanPresentFn));

    if (!(fBackendContext->fExtensions & kKHR_surface_GrVkExtensionFlag) ||
        !(fBackendContext->fExtensions & kKHR_swapchain_GrVkExtensionFlag)) {
        fBackendContext.reset(nullptr);
        return;
    }

    VkInstance instance = fBackendContext->fInstance;
    VkDevice device = fBackendContext->fDevice;
    GET_PROC(DestroySurfaceKHR);
    GET_PROC(GetPhysicalDeviceSurfaceSupportKHR);
    GET_PROC(GetPhysicalDeviceSurfaceCapabilitiesKHR);
    GET_PROC(GetPhysicalDeviceSurfaceFormatsKHR);
    GET_PROC(GetPhysicalDeviceSurfacePresentModesKHR);
    GET_DEV_PROC(CreateSwapchainKHR);
    GET_DEV_PROC(DestroySwapchainKHR);
    GET_DEV_PROC(GetSwapchainImagesKHR);
    GET_DEV_PROC(AcquireNextImageKHR);
    GET_DEV_PROC(QueuePresentKHR);
    GET_DEV_PROC(GetDeviceQueue);

    fContext = GrContext::MakeVulkan(fBackendContext, fDisplayParams.fGrContextOptions);

    fSurface = fCreateVkSurfaceFn(instance);
    if (VK_NULL_HANDLE == fSurface) {
        fBackendContext.reset(nullptr);
        return;
    }

    VkBool32 supported;
    VkResult res = fGetPhysicalDeviceSurfaceSupportKHR(fBackendContext->fPhysicalDevice,
                                                       fPresentQueueIndex, fSurface,
                                                       &supported);
    if (VK_SUCCESS != res) {
        this->destroyContext();
        return;
    }

    if (!this->createSwapchain(-1, -1, fDisplayParams)) {
        this->destroyContext();
        return;
    }

    // create presentQueue
    fGetDeviceQueue(fBackendContext->fDevice, fPresentQueueIndex, 0, &fPresentQueue);
}

bool VulkanWindowContext::createSwapchain(int width, int height,
                                          const DisplayParams& params) {
    // check for capabilities
    VkSurfaceCapabilitiesKHR caps;
    VkResult res = fGetPhysicalDeviceSurfaceCapabilitiesKHR(fBackendContext->fPhysicalDevice,
                                                            fSurface, &caps);
    if (VK_SUCCESS != res) {
        return false;
    }

    uint32_t surfaceFormatCount;
    res = fGetPhysicalDeviceSurfaceFormatsKHR(fBackendContext->fPhysicalDevice, fSurface,
                                              &surfaceFormatCount, nullptr);
    if (VK_SUCCESS != res) {
        return false;
    }

    SkAutoMalloc surfaceFormatAlloc(surfaceFormatCount * sizeof(VkSurfaceFormatKHR));
    VkSurfaceFormatKHR* surfaceFormats = (VkSurfaceFormatKHR*)surfaceFormatAlloc.get();
    res = fGetPhysicalDeviceSurfaceFormatsKHR(fBackendContext->fPhysicalDevice, fSurface,
                                              &surfaceFormatCount, surfaceFormats);
    if (VK_SUCCESS != res) {
        return false;
    }

    uint32_t presentModeCount;
    res = fGetPhysicalDeviceSurfacePresentModesKHR(fBackendContext->fPhysicalDevice, fSurface,
                                                   &presentModeCount, nullptr);
    if (VK_SUCCESS != res) {
        return false;
    }

    SkAutoMalloc presentModeAlloc(presentModeCount * sizeof(VkPresentModeKHR));
    VkPresentModeKHR* presentModes = (VkPresentModeKHR*)presentModeAlloc.get();
    res = fGetPhysicalDeviceSurfacePresentModesKHR(fBackendContext->fPhysicalDevice, fSurface,
                                                   &presentModeCount, presentModes);
    if (VK_SUCCESS != res) {
        return false;
    }

    VkExtent2D extent = caps.currentExtent;
    // use the hints
    if (extent.width == (uint32_t)-1) {
        extent.width = width;
        extent.height = height;
    }

    // clamp width; to protect us from broken hints
    if (extent.width < caps.minImageExtent.width) {
        extent.width = caps.minImageExtent.width;
    } else if (extent.width > caps.maxImageExtent.width) {
        extent.width = caps.maxImageExtent.width;
    }
    // clamp height
    if (extent.height < caps.minImageExtent.height) {
        extent.height = caps.minImageExtent.height;
    } else if (extent.height > caps.maxImageExtent.height) {
        extent.height = caps.maxImageExtent.height;
    }

    fWidth = (int)extent.width;
    fHeight = (int)extent.height;

    uint32_t imageCount = caps.minImageCount + 2;
    if (caps.maxImageCount > 0 && imageCount > caps.maxImageCount) {
        // Application must settle for fewer images than desired:
        imageCount = caps.maxImageCount;
    }

    VkImageUsageFlags usageFlags = VK_IMAGE_USAGE_COLOR_ATTACHMENT_BIT |
                                   VK_IMAGE_USAGE_TRANSFER_SRC_BIT |
                                   VK_IMAGE_USAGE_TRANSFER_DST_BIT;
    SkASSERT((caps.supportedUsageFlags & usageFlags) == usageFlags);
    SkASSERT(caps.supportedTransforms & caps.currentTransform);
    SkASSERT(caps.supportedCompositeAlpha & (VK_COMPOSITE_ALPHA_OPAQUE_BIT_KHR |
                                             VK_COMPOSITE_ALPHA_INHERIT_BIT_KHR));
    VkCompositeAlphaFlagBitsKHR composite_alpha =
        (caps.supportedCompositeAlpha & VK_COMPOSITE_ALPHA_INHERIT_BIT_KHR) ?
                                        VK_COMPOSITE_ALPHA_INHERIT_BIT_KHR :
                                        VK_COMPOSITE_ALPHA_OPAQUE_BIT_KHR;

    // Pick our surface format. For now, just make sure it matches our sRGB request:
    VkFormat surfaceFormat = VK_FORMAT_UNDEFINED;
    VkColorSpaceKHR colorSpace = VK_COLORSPACE_SRGB_NONLINEAR_KHR;
    for (uint32_t i = 0; i < surfaceFormatCount; ++i) {
        VkFormat localFormat = surfaceFormats[i].format;
        if (GrVkFormatIsSupported(localFormat)) {
            surfaceFormat = localFormat;
            colorSpace = surfaceFormats[i].colorSpace;
            break;
        }
    }
    fDisplayParams = params;
    fSampleCount = params.fMSAASampleCount;
    fStencilBits = 8;

    if (VK_FORMAT_UNDEFINED == surfaceFormat) {
        return false;
    }

    SkColorType colorType;
    switch (surfaceFormat) {
        case VK_FORMAT_R8G8B8A8_UNORM: // fall through
        case VK_FORMAT_R8G8B8A8_SRGB:
            colorType = kRGBA_8888_SkColorType;
            break;
        case VK_FORMAT_B8G8R8A8_UNORM: // fall through
        case VK_FORMAT_B8G8R8A8_SRGB:
            colorType = kBGRA_8888_SkColorType;
            break;
        default:
            return false;
    }

    // If mailbox mode is available, use it, as it is the lowest-latency non-
    // tearing mode. If not, fall back to FIFO which is always available.
    VkPresentModeKHR mode = VK_PRESENT_MODE_FIFO_KHR;
    for (uint32_t i = 0; i < presentModeCount; ++i) {
        // use mailbox
        if (VK_PRESENT_MODE_MAILBOX_KHR == presentModes[i]) {
            mode = presentModes[i];
            break;
        }
    }

    VkSwapchainCreateInfoKHR swapchainCreateInfo;
    memset(&swapchainCreateInfo, 0, sizeof(VkSwapchainCreateInfoKHR));
    swapchainCreateInfo.sType = VK_STRUCTURE_TYPE_SWAPCHAIN_CREATE_INFO_KHR;
    swapchainCreateInfo.surface = fSurface;
    swapchainCreateInfo.minImageCount = imageCount;
    swapchainCreateInfo.imageFormat = surfaceFormat;
    swapchainCreateInfo.imageColorSpace = colorSpace;
    swapchainCreateInfo.imageExtent = extent;
    swapchainCreateInfo.imageArrayLayers = 1;
    swapchainCreateInfo.imageUsage = usageFlags;

    uint32_t queueFamilies[] = { fBackendContext->fGraphicsQueueIndex, fPresentQueueIndex };
    if (fBackendContext->fGraphicsQueueIndex != fPresentQueueIndex) {
        swapchainCreateInfo.imageSharingMode = VK_SHARING_MODE_CONCURRENT;
        swapchainCreateInfo.queueFamilyIndexCount = 2;
        swapchainCreateInfo.pQueueFamilyIndices = queueFamilies;
    } else {
        swapchainCreateInfo.imageSharingMode = VK_SHARING_MODE_EXCLUSIVE;
        swapchainCreateInfo.queueFamilyIndexCount = 0;
        swapchainCreateInfo.pQueueFamilyIndices = nullptr;
    }

    swapchainCreateInfo.preTransform = VK_SURFACE_TRANSFORM_IDENTITY_BIT_KHR;
    swapchainCreateInfo.compositeAlpha = composite_alpha;
    swapchainCreateInfo.presentMode = mode;
    swapchainCreateInfo.clipped = true;
    swapchainCreateInfo.oldSwapchain = fSwapchain;

    res = fCreateSwapchainKHR(fBackendContext->fDevice, &swapchainCreateInfo, nullptr, &fSwapchain);
    if (VK_SUCCESS != res) {
        return false;
    }

    // destroy the old swapchain
    if (swapchainCreateInfo.oldSwapchain != VK_NULL_HANDLE) {
        GR_VK_CALL(fBackendContext->fInterface, DeviceWaitIdle(fBackendContext->fDevice));

        this->destroyBuffers();

        fDestroySwapchainKHR(fBackendContext->fDevice, swapchainCreateInfo.oldSwapchain, nullptr);
    }

    this->createBuffers(swapchainCreateInfo.imageFormat, colorType);

    return true;
}

void VulkanWindowContext::createBuffers(VkFormat format, SkColorType colorType) {
    fGetSwapchainImagesKHR(fBackendContext->fDevice, fSwapchain, &fImageCount, nullptr);
    SkASSERT(fImageCount);
    fImages = new VkImage[fImageCount];
    fGetSwapchainImagesKHR(fBackendContext->fDevice, fSwapchain, &fImageCount, fImages);

    // set up initial image layouts and create surfaces
    fImageLayouts = new VkImageLayout[fImageCount];
    fSurfaces = new sk_sp<SkSurface>[fImageCount];
    for (uint32_t i = 0; i < fImageCount; ++i) {
        fImageLayouts[i] = VK_IMAGE_LAYOUT_UNDEFINED;

        GrVkImageInfo info;
        info.fImage = fImages[i];
        info.fAlloc = GrVkAlloc();
        info.fImageLayout = VK_IMAGE_LAYOUT_UNDEFINED;
        info.fImageTiling = VK_IMAGE_TILING_OPTIMAL;
        info.fFormat = format;
        info.fLevelCount = 1;

        GrBackendRenderTarget backendRT(fWidth, fHeight, fSampleCount, info);

        fSurfaces[i] = SkSurface::MakeFromBackendRenderTarget(fContext.get(),
                                                              backendRT,
                                                              kTopLeft_GrSurfaceOrigin,
                                                              colorType,
                                                              fDisplayParams.fColorSpace,
                                                              &fDisplayParams.fSurfaceProps);
    }

    // create the command pool for the command buffers
    if (VK_NULL_HANDLE == fCommandPool) {
        VkCommandPoolCreateInfo commandPoolInfo;
        memset(&commandPoolInfo, 0, sizeof(VkCommandPoolCreateInfo));
        commandPoolInfo.sType = VK_STRUCTURE_TYPE_COMMAND_POOL_CREATE_INFO;
        // this needs to be on the render queue
        commandPoolInfo.queueFamilyIndex = fBackendContext->fGraphicsQueueIndex;
        commandPoolInfo.flags = VK_COMMAND_POOL_CREATE_RESET_COMMAND_BUFFER_BIT;
        GR_VK_CALL_ERRCHECK(fBackendContext->fInterface,
                            CreateCommandPool(fBackendContext->fDevice, &commandPoolInfo,
                                              nullptr, &fCommandPool));
    }

    // set up the backbuffers
    VkSemaphoreCreateInfo semaphoreInfo;
    memset(&semaphoreInfo, 0, sizeof(VkSemaphoreCreateInfo));
    semaphoreInfo.sType = VK_STRUCTURE_TYPE_SEMAPHORE_CREATE_INFO;
    semaphoreInfo.pNext = nullptr;
    semaphoreInfo.flags = 0;
    VkCommandBufferAllocateInfo commandBuffersInfo;
    memset(&commandBuffersInfo, 0, sizeof(VkCommandBufferAllocateInfo));
    commandBuffersInfo.sType = VK_STRUCTURE_TYPE_COMMAND_BUFFER_ALLOCATE_INFO;
    commandBuffersInfo.pNext = nullptr;
    commandBuffersInfo.commandPool = fCommandPool;
    commandBuffersInfo.level = VK_COMMAND_BUFFER_LEVEL_PRIMARY;
    commandBuffersInfo.commandBufferCount = 2;
    VkFenceCreateInfo fenceInfo;
    memset(&fenceInfo, 0, sizeof(VkFenceCreateInfo));
    fenceInfo.sType = VK_STRUCTURE_TYPE_FENCE_CREATE_INFO;
    fenceInfo.pNext = nullptr;
    fenceInfo.flags = VK_FENCE_CREATE_SIGNALED_BIT;

    // we create one additional backbuffer structure here, because we want to
    // give the command buffers they contain a chance to finish before we cycle back
    fBackbuffers = new BackbufferInfo[fImageCount + 1];
    for (uint32_t i = 0; i < fImageCount + 1; ++i) {
        fBackbuffers[i].fImageIndex = -1;
        GR_VK_CALL_ERRCHECK(fBackendContext->fInterface,
                            CreateSemaphore(fBackendContext->fDevice, &semaphoreInfo,
                                            nullptr, &fBackbuffers[i].fAcquireSemaphore));
        GR_VK_CALL_ERRCHECK(fBackendContext->fInterface,
                            CreateSemaphore(fBackendContext->fDevice, &semaphoreInfo,
                                            nullptr, &fBackbuffers[i].fRenderSemaphore));
        GR_VK_CALL_ERRCHECK(fBackendContext->fInterface,
                            AllocateCommandBuffers(fBackendContext->fDevice, &commandBuffersInfo,
                                                   fBackbuffers[i].fTransitionCmdBuffers));
        GR_VK_CALL_ERRCHECK(fBackendContext->fInterface,
                            CreateFence(fBackendContext->fDevice, &fenceInfo, nullptr,
                                        &fBackbuffers[i].fUsageFences[0]));
        GR_VK_CALL_ERRCHECK(fBackendContext->fInterface,
                            CreateFence(fBackendContext->fDevice, &fenceInfo, nullptr,
                                        &fBackbuffers[i].fUsageFences[1]));
    }
    fCurrentBackbufferIndex = fImageCount;
}

void VulkanWindowContext::destroyBuffers() {

    if (fBackbuffers) {
        for (uint32_t i = 0; i < fImageCount + 1; ++i) {
            GR_VK_CALL_ERRCHECK(fBackendContext->fInterface,
                                WaitForFences(fBackendContext->fDevice, 2,
                                              fBackbuffers[i].fUsageFences,
                                              true, UINT64_MAX));
            fBackbuffers[i].fImageIndex = -1;
            GR_VK_CALL(fBackendContext->fInterface,
                       DestroySemaphore(fBackendContext->fDevice,
                                        fBackbuffers[i].fAcquireSemaphore,
                                        nullptr));
            GR_VK_CALL(fBackendContext->fInterface,
                       DestroySemaphore(fBackendContext->fDevice,
                                        fBackbuffers[i].fRenderSemaphore,
                                        nullptr));
            GR_VK_CALL(fBackendContext->fInterface,
                       FreeCommandBuffers(fBackendContext->fDevice, fCommandPool, 2,
                                          fBackbuffers[i].fTransitionCmdBuffers));
            GR_VK_CALL(fBackendContext->fInterface,
                       DestroyFence(fBackendContext->fDevice, fBackbuffers[i].fUsageFences[0], 0));
            GR_VK_CALL(fBackendContext->fInterface,
                       DestroyFence(fBackendContext->fDevice, fBackbuffers[i].fUsageFences[1], 0));
        }
    }

    delete[] fBackbuffers;
    fBackbuffers = nullptr;

    // Does this actually free the surfaces?
    delete[] fSurfaces;
    fSurfaces = nullptr;
    delete[] fImageLayouts;
    fImageLayouts = nullptr;
    delete[] fImages;
    fImages = nullptr;
}

VulkanWindowContext::~VulkanWindowContext() {
    this->destroyContext();
}

void VulkanWindowContext::destroyContext() {
    if (!fBackendContext.get()) {
        return;
    }

    GR_VK_CALL(fBackendContext->fInterface, QueueWaitIdle(fPresentQueue));
    GR_VK_CALL(fBackendContext->fInterface, DeviceWaitIdle(fBackendContext->fDevice));

    this->destroyBuffers();

    if (VK_NULL_HANDLE != fCommandPool) {
        GR_VK_CALL(fBackendContext->fInterface, DestroyCommandPool(fBackendContext->fDevice,
                                                                   fCommandPool, nullptr));
        fCommandPool = VK_NULL_HANDLE;
    }

    if (VK_NULL_HANDLE != fSwapchain) {
        fDestroySwapchainKHR(fBackendContext->fDevice, fSwapchain, nullptr);
        fSwapchain = VK_NULL_HANDLE;
    }

    if (VK_NULL_HANDLE != fSurface) {
        fDestroySurfaceKHR(fBackendContext->fInstance, fSurface, nullptr);
        fSurface = VK_NULL_HANDLE;
    }

    fContext.reset();

    fBackendContext.reset(nullptr);
}

VulkanWindowContext::BackbufferInfo* VulkanWindowContext::getAvailableBackbuffer() {
    SkASSERT(fBackbuffers);

    ++fCurrentBackbufferIndex;
    if (fCurrentBackbufferIndex > fImageCount) {
        fCurrentBackbufferIndex = 0;
    }

    BackbufferInfo* backbuffer = fBackbuffers + fCurrentBackbufferIndex;
    GR_VK_CALL_ERRCHECK(fBackendContext->fInterface,
                        WaitForFences(fBackendContext->fDevice, 2, backbuffer->fUsageFences,
                                      true, UINT64_MAX));
    return backbuffer;
}

sk_sp<SkSurface> VulkanWindowContext::getBackbufferSurface() {
    BackbufferInfo* backbuffer = this->getAvailableBackbuffer();
    SkASSERT(backbuffer);

    // reset the fence
    GR_VK_CALL_ERRCHECK(fBackendContext->fInterface,
                        ResetFences(fBackendContext->fDevice, 2, backbuffer->fUsageFences));
    // semaphores should be in unsignaled state

    // acquire the image
    VkResult res = fAcquireNextImageKHR(fBackendContext->fDevice, fSwapchain, UINT64_MAX,
                                        backbuffer->fAcquireSemaphore, VK_NULL_HANDLE,
                                        &backbuffer->fImageIndex);
    if (VK_ERROR_SURFACE_LOST_KHR == res) {
        // need to figure out how to create a new vkSurface without the platformData*
        // maybe use attach somehow? but need a Window
        return nullptr;
    }
    if (VK_ERROR_OUT_OF_DATE_KHR == res) {
        // tear swapchain down and try again
        if (!this->createSwapchain(-1, -1, fDisplayParams)) {
            return nullptr;
        }
        backbuffer = this->getAvailableBackbuffer();
        GR_VK_CALL_ERRCHECK(fBackendContext->fInterface,
                            ResetFences(fBackendContext->fDevice, 2, backbuffer->fUsageFences));

        // acquire the image
        res = fAcquireNextImageKHR(fBackendContext->fDevice, fSwapchain, UINT64_MAX,
                                   backbuffer->fAcquireSemaphore, VK_NULL_HANDLE,
                                   &backbuffer->fImageIndex);

        if (VK_SUCCESS != res) {
            return nullptr;
        }
    }

    // set up layout transfer from initial to color attachment
    VkImageLayout layout = fImageLayouts[backbuffer->fImageIndex];
    SkASSERT(VK_IMAGE_LAYOUT_UNDEFINED == layout || VK_IMAGE_LAYOUT_PRESENT_SRC_KHR == layout);
    VkPipelineStageFlags srcStageMask = (VK_IMAGE_LAYOUT_UNDEFINED == layout) ?
                                        VK_PIPELINE_STAGE_TOP_OF_PIPE_BIT :
                                        VK_PIPELINE_STAGE_COLOR_ATTACHMENT_OUTPUT_BIT;
    VkPipelineStageFlags dstStageMask = VK_PIPELINE_STAGE_COLOR_ATTACHMENT_OUTPUT_BIT;
    VkAccessFlags srcAccessMask = (VK_IMAGE_LAYOUT_UNDEFINED == layout) ?
                                  0 : VK_ACCESS_MEMORY_READ_BIT;
    VkAccessFlags dstAccessMask = VK_ACCESS_COLOR_ATTACHMENT_WRITE_BIT;

    VkImageMemoryBarrier imageMemoryBarrier = {
        VK_STRUCTURE_TYPE_IMAGE_MEMORY_BARRIER,   // sType
        NULL,                                     // pNext
        srcAccessMask,                            // outputMask
        dstAccessMask,                            // inputMask
        layout,                                   // oldLayout
        VK_IMAGE_LAYOUT_COLOR_ATTACHMENT_OPTIMAL, // newLayout
        fPresentQueueIndex,                       // srcQueueFamilyIndex
        fBackendContext->fGraphicsQueueIndex,     // dstQueueFamilyIndex
        fImages[backbuffer->fImageIndex],         // image
        { VK_IMAGE_ASPECT_COLOR_BIT, 0, 1, 0, 1 } // subresourceRange
    };
    GR_VK_CALL_ERRCHECK(fBackendContext->fInterface,
                        ResetCommandBuffer(backbuffer->fTransitionCmdBuffers[0], 0));
    VkCommandBufferBeginInfo info;
    memset(&info, 0, sizeof(VkCommandBufferBeginInfo));
    info.sType = VK_STRUCTURE_TYPE_COMMAND_BUFFER_BEGIN_INFO;
    info.flags = 0;
    GR_VK_CALL_ERRCHECK(fBackendContext->fInterface,
                        BeginCommandBuffer(backbuffer->fTransitionCmdBuffers[0], &info));

    GR_VK_CALL(fBackendContext->fInterface,
               CmdPipelineBarrier(backbuffer->fTransitionCmdBuffers[0],
                                  srcStageMask, dstStageMask, 0,
                                  0, nullptr,
                                  0, nullptr,
                                  1, &imageMemoryBarrier));

    GR_VK_CALL_ERRCHECK(fBackendContext->fInterface,
                        EndCommandBuffer(backbuffer->fTransitionCmdBuffers[0]));

    VkPipelineStageFlags waitDstStageFlags = VK_PIPELINE_STAGE_COLOR_ATTACHMENT_OUTPUT_BIT;
    // insert the layout transfer into the queue and wait on the acquire
    VkSubmitInfo submitInfo;
    memset(&submitInfo, 0, sizeof(VkSubmitInfo));
    submitInfo.sType = VK_STRUCTURE_TYPE_SUBMIT_INFO;
    submitInfo.waitSemaphoreCount = 1;
    submitInfo.pWaitSemaphores = &backbuffer->fAcquireSemaphore;
    submitInfo.pWaitDstStageMask = &waitDstStageFlags;
    submitInfo.commandBufferCount = 1;
    submitInfo.pCommandBuffers = &backbuffer->fTransitionCmdBuffers[0];
    submitInfo.signalSemaphoreCount = 0;

    GR_VK_CALL_ERRCHECK(fBackendContext->fInterface,
                        QueueSubmit(fBackendContext->fQueue, 1, &submitInfo,
                                    backbuffer->fUsageFences[0]));

    SkSurface* surface = fSurfaces[backbuffer->fImageIndex].get();
    GrBackendRenderTarget backendRT = surface->getBackendRenderTarget(
                                                        SkSurface::kFlushRead_BackendHandleAccess);
    backendRT.setVkImageLayout(VK_IMAGE_LAYOUT_COLOR_ATTACHMENT_OPTIMAL);


    return sk_ref_sp(surface);
}

void VulkanWindowContext::swapBuffers() {

    BackbufferInfo* backbuffer = fBackbuffers + fCurrentBackbufferIndex;
    SkSurface* surface = fSurfaces[backbuffer->fImageIndex].get();

    GrBackendRenderTarget backendRT = surface->getBackendRenderTarget(
                                                        SkSurface::kFlushRead_BackendHandleAccess);
    GrVkImageInfo imageInfo;
    SkAssertResult(backendRT.getVkImageInfo(&imageInfo));
    // Check to make sure we never change the actually wrapped image
    SkASSERT(imageInfo.fImage == fImages[backbuffer->fImageIndex]);

    VkImageLayout layout = imageInfo.fImageLayout;
    VkPipelineStageFlags srcStageMask = GrVkImage::LayoutToPipelineStageFlags(layout);
    VkPipelineStageFlags dstStageMask = VK_PIPELINE_STAGE_BOTTOM_OF_PIPE_BIT;
    VkAccessFlags srcAccessMask = GrVkImage::LayoutToSrcAccessMask(layout);
    VkAccessFlags dstAccessMask = VK_ACCESS_MEMORY_READ_BIT;

    VkImageMemoryBarrier imageMemoryBarrier = {
        VK_STRUCTURE_TYPE_IMAGE_MEMORY_BARRIER,   // sType
        NULL,                                     // pNext
        srcAccessMask,                            // outputMask
        dstAccessMask,                            // inputMask
        layout,                                   // oldLayout
        VK_IMAGE_LAYOUT_PRESENT_SRC_KHR,          // newLayout
        fBackendContext->fGraphicsQueueIndex,     // srcQueueFamilyIndex
        fPresentQueueIndex,                       // dstQueueFamilyIndex
        fImages[backbuffer->fImageIndex],         // image
        { VK_IMAGE_ASPECT_COLOR_BIT, 0, 1, 0, 1 } // subresourceRange
    };
    GR_VK_CALL_ERRCHECK(fBackendContext->fInterface,
                        ResetCommandBuffer(backbuffer->fTransitionCmdBuffers[1], 0));
    VkCommandBufferBeginInfo info;
    memset(&info, 0, sizeof(VkCommandBufferBeginInfo));
    info.sType = VK_STRUCTURE_TYPE_COMMAND_BUFFER_BEGIN_INFO;
    info.flags = 0;
    GR_VK_CALL_ERRCHECK(fBackendContext->fInterface,
                        BeginCommandBuffer(backbuffer->fTransitionCmdBuffers[1], &info));
    GR_VK_CALL(fBackendContext->fInterface,
               CmdPipelineBarrier(backbuffer->fTransitionCmdBuffers[1],
                                  srcStageMask, dstStageMask, 0,
                                  0, nullptr,
                                  0, nullptr,
                                  1, &imageMemoryBarrier));
    GR_VK_CALL_ERRCHECK(fBackendContext->fInterface,
                        EndCommandBuffer(backbuffer->fTransitionCmdBuffers[1]));

    fImageLayouts[backbuffer->fImageIndex] = VK_IMAGE_LAYOUT_PRESENT_SRC_KHR;

    // insert the layout transfer into the queue and wait on the acquire
    VkSubmitInfo submitInfo;
    memset(&submitInfo, 0, sizeof(VkSubmitInfo));
    submitInfo.sType = VK_STRUCTURE_TYPE_SUBMIT_INFO;
    submitInfo.waitSemaphoreCount = 0;
    submitInfo.pWaitDstStageMask = 0;
    submitInfo.commandBufferCount = 1;
    submitInfo.pCommandBuffers = &backbuffer->fTransitionCmdBuffers[1];
    submitInfo.signalSemaphoreCount = 1;
    submitInfo.pSignalSemaphores = &backbuffer->fRenderSemaphore;

    GR_VK_CALL_ERRCHECK(fBackendContext->fInterface,
                        QueueSubmit(fBackendContext->fQueue, 1, &submitInfo,
                                    backbuffer->fUsageFences[1]));

    // Submit present operation to present queue
    const VkPresentInfoKHR presentInfo =
    {
        VK_STRUCTURE_TYPE_PRESENT_INFO_KHR, // sType
        NULL, // pNext
        1, // waitSemaphoreCount
        &backbuffer->fRenderSemaphore, // pWaitSemaphores
        1, // swapchainCount
        &fSwapchain, // pSwapchains
        &backbuffer->fImageIndex, // pImageIndices
        NULL // pResults
    };

    fQueuePresentKHR(fPresentQueue, &presentInfo);
}

}   //namespace sk_app