Method GrabImage

vgpu/framebuffer.go:120–130

RenderFrame functionality https://stackoverflow.com/questions/51477954/vulkan-off-screen-rendering-tiling-optimal-or-linear https://github.com/SaschaWillems/Vulkan/tree/b9f0ac91d2adccc3055a904d3a8f6553b10ff6cd/examples/renderheadless/renderheadless.cpp GrabImage grabs the current framebuffer image,

(dev vk.Device, cmd vk.CommandBuffer)

// which must have the cmdBegin called already.
// call this after: sys.MemCmdEndSubmitWaitFree()
func (fb *Framebuffer) GrabImage(dev vk.Device, cmd vk.CommandBuffer) {
	fb.Render.ConfigGrab(dev) // ensure image grab setup
	// first, prepare ImageGrab to receive copy from render image.
	// apparently, the color attachment, with src flag already set, does not need this.

	// todo: for Surface frame, transition src image

	fb.Render.Grab.TransitionForDst(cmd, vk.PipelineStageTransferBit) // no idea why, but SaschaWillems does
	vk.CmdCopyImage(cmd, fb.Image.Image, vk.ImageLayoutTransferSrcOptimal, fb.Render.Grab.Image, vk.ImageLayoutTransferDstOptimal, 1, []vk.ImageCopy{fb.Render.Grab.CopyImageRec()})
	fb.Render.Grab.TransitionDstToGeneral(cmd)
}

// CopyToImage copies the current framebuffer image to given image dest
// using given command buffer which must have the cmdBegin called already.