Method GrabDepthImage

vgpu/render.go:335–360

GrabDepthImage grabs the current render depth image, using given command buffer which must have the cmdBegin called already. Uses the GrabDepth Storage Buffer. call this after: sys.MemCmdEndSubmitWaitFree()

(dev vk.Device, cmd vk.CommandBuffer)

// which must have the cmdBegin called already.  Uses the GrabDepth Storage Buffer.
// call this after: sys.MemCmdEndSubmitWaitFree()
func (rp *Render) GrabDepthImage(dev vk.Device, cmd vk.CommandBuffer) error {
	nsamp := rp.Format.NSamples()
	if nsamp > 1 {
		err := errors.New("vgpu.Render.GrabDepthImage(): does not work if multisampling is > 1")
		if Debug {
			log.Println(err)
		}
		return err
	}
	rp.ConfigGrabDepth(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.

	reg := vk.BufferImageCopy{BufferOffset: 0, BufferRowLength: 0, BufferImageHeight: 0}
	reg.ImageSubresource.AspectMask = vk.ImageAspectFlags(vk.ImageAspectDepthBit)
	reg.ImageSubresource.MipLevel = 0
	reg.ImageSubresource.BaseArrayLayer = 0
	reg.ImageSubresource.LayerCount = 1
	reg.ImageOffset.X, reg.ImageOffset.Y, reg.ImageOffset.Z = 0, 0, 0
	reg.ImageExtent.Width = uint32(rp.Format.Size.X)
	reg.ImageExtent.Height = uint32(rp.Format.Size.Y)
	reg.ImageExtent.Depth = 1

	vk.CmdCopyImageToBuffer(cmd, rp.Depth.Image, vk.ImageLayoutTransferSrcOptimal, rp.GrabDepth.Host, 1, []vk.BufferImageCopy{reg})
	return nil
}

// DepthImageArray returns the float values from the last GrabDepthImage call
// automatically handles down-sampling from multisampling.