Method AllocImage

vgpu/image.go:774–853

AllocImage allocates the VkImage on the device (must set first), based on the current Format info, and other flags.

()

// AllocImage allocates the VkImage on the device (must set first),
// based on the current Format info, and other flags.
func (im *Image) AllocImage() {
	im.FreeImage()
	var usage vk.ImageUsageFlagBits
	// var imgFlags vk.ImageCreateFlags
	imgType := vk.ImageType2d
	switch {
	case im.HasFlag(DepthImage):
		usage |= vk.ImageUsageDepthStencilAttachmentBit
	case im.HasFlag(FramebufferImage):
		usage |= vk.ImageUsageColorAttachmentBit
		usage |= vk.ImageUsageTransferSrcBit // todo: extra bit to qualify
	default:
		usage |= vk.ImageUsageSampledBit // default is sampled texture
		usage |= vk.ImageUsageTransferDstBit
	}
	if im.IsHostActive() && !im.HasFlag(FramebufferImage) {
		usage |= vk.ImageUsageTransferDstBit
	}
	if im.HasFlag(ImageOnHostOnly) {
		usage |= vk.ImageUsageTransferDstBit
	}

	if im.Format.Layers == 0 {
		im.Format.Layers = 1
	}

	var image vk.Image
	w, h := im.Format.Size32()
	imgcfg := &vk.ImageCreateInfo{
		SType: vk.StructureTypeImageCreateInfo,
		// Flags:     imgFlags,
		ImageType: imgType,
		Format:    im.Format.Format,
		Extent: vk.Extent3D{
			Width:  w,
			Height: h,
			Depth:  1,
		},
		MipLevels:     1,
		ArrayLayers:   uint32(im.Format.Layers),
		Samples:       im.Format.Samples,
		Tiling:        vk.ImageTilingOptimal,
		Usage:         vk.ImageUsageFlags(usage),
		InitialLayout: vk.ImageLayoutUndefined,
		SharingMode:   vk.SharingModeExclusive,
	}

	properties := vk.MemoryPropertyDeviceLocalBit
	if im.HasFlag(ImageOnHostOnly) {
		properties = vk.MemoryPropertyHostVisibleBit | vk.MemoryPropertyHostCoherentBit
		imgcfg.Tiling = vk.ImageTilingLinear // essential for grabbing
	}

	ret := vk.CreateImage(im.Dev, imgcfg, nil, &image)
	IfPanic(NewError(ret))
	im.Image = image

	var memReqs vk.MemoryRequirements