IMO,this should hold:
rva = raw - imagebase
which is not the case in the graph,why?
The entry point RVA, entry point raw address, and image base address are not related in that way.
The image base is the "preferred address of the first byte of the image when it is loaded in memory". In other words, it's the virtual address of the image when it gets loaded assuming there's not a conflict. If there is an address conflict when the image is loaded (e.g. another image is already loaded in an overlapping range), then a new base address will be chosen for the image.
An RVA is a relative virtual address. It is "relative" in the sense that it is changed when the image is actually loaded. It's the address when the base address is not known (e.g. when the image isn't loaded). Once the image is loaded, the RVA becomes a virtual address (VA), an actual address in virtual memory.
The raw vs. RVA distinction is due to alignment. There is section alignment (the alignment of the sections when they get loaded into memory) as well as file alignment (the alignment of the raw data in the sections). The section alignment here is 0x1000 while the file alignment is 0x200.
The entry point RVA is used to determine the VA of the entry point when the image is loaded (i.e. the entry point will be located at virtual address EntryPoint (rva) + ImageBase). The entry point raw address is the offset into the file where the entry point is located.
This document has a good explanation of alignment.
Related
I have two point clouds on which I want to build one model.
I loaded them into various chunks, built a model for each. Then they need to be aligned using align on chunks. But this button is inactive for me.
What have I done wrong?
enter image description here
error: enter image description here
Chunk alignment works if you have at least a couple of aligned images in each chunk selected for the alignment.
If you do not have any aligned images and have only polygonal models in the chunks, you can try to use Align_model_to_model script from official repository:
https://github.com/agisoft-llc/metashape-scripts/blob/master/src/align_model_to_model.py
I'm currently getting started with Win32 and Direct2D and reached the chapter on DPI and DIP. At the very bottom it says ID2D1RenderTarget::GetSize returns size as DIP and ID2D1RenderTarget::GetPixelSize as physical pixels. Their individual documentation confirms that.
However I cannot observe that ID2D1RenderTarget::GetSize actually returns DIP.
I tested it by
setting the scale of one of my two otherwise identical displays to 175%,
adding <dpiAwareness xmlns="http://schemas.microsoft.com/SMI/2016/WindowsSettings">PerMonitorV2</dpiAwareness> to my application manifest,
obtaining
D2D1_SIZE_U sizeP = pRenderTarget->GetPixelSize();
D2D1_SIZE_F size = pRenderTarget->GetSize();
in method MainWindow::CalculateLayout from this example (and printing the values),
and moving the window from one screen to the other, and arbitrarily resizing it.
I can see the window-border changing size when moving from one display to another. However, the values in both sizeP and size (besides being int and float) are always identical and correspond to the physical size of the ID2D1HwndRenderTarget.
Since I do not expect the documentation to be flawed, I wonder what I am missing to actually get the DIP of the window of the ID2D1HwndRenderTarget pRenderTarget.
The size is only relative to the DPI of the render target, set using ID2D1RenderTarget::SetDpi. This value is not automatically connected to the value provided by the display system, which can be queried using ID2D1Factory::GetDesktopDpi or GetDpiForMonitor.
In HEIF, or generally any ISO-BMFF file, does any know how to use pitm box in root meta box to parse the main image?
For example, the documents say the ID of the main image is stored in the pitm box, but when I obtain that ID and find the appropriate one in iloc box, it did not point to a valid offset and length.
Or should I search for other boxes for where to find the main image's media stream? Does anyone know what I've done incorrectly?
I've known that framebuffer is the final destination of the rendering pipeline and swapchain contains many image. So what is the relation between those two things? Which one is the actual render target? And does the framebuffer later attach the final picture of the current frame on the image view? If so, how will it transfer?
Describing this via paint or diagram would be pleased.
VkFramebuffer + VkRenderPass defines the render target.
Render pass defines which attachment will be written with colors.
VkFramebuffer defines which VkImageView is to be which attachment.
VkImageView defines which part of VkImage to use.
VkImage defines which VkDeviceMemory is used and a format of the texel.
Or maybe in opposite sequence:
VkDeviceMemory is just a sequence of N bytes in memory.
VkImage object adds to it e.g. information about the format (so you can address by texels, not bytes).
VkImageView object helps select only part (array or mip) of the VkImage (like stringView, arrayView or whathaveyou does). Also can help to match to some incompatible interface (by type casting format).
VkFramebuffer binds a VkImageView with an attachment.
VkRenderpass defines which attachment will be drawn into
So it's not like you do not use an image. You do, through the Vulkan Framebuffer.
Swapchain image is no different from any other image. Except that the driver is the owner of the image. You can't destroy it directly or allocate it yourself. You just borrow it from the driver for the duration between acquire and present operation.
There's (usually) more of the swapchain images for the purposes of buffering and advance rendering. AFAIK you would need a separate VkFramebuffer for each image (which is annoying, but more in tune with what actually happens underneath).
Probably the best single sentence from the Vulkan spec that describes framebuffers is:
The specific image views that will be used for the attachments, and
their dimensions, are specified in VkFramebuffer objects.
Yes, you would need a VkFramebuffer object for each image in a swapchain, but you generally would need to allocate only one VkMemory for a depth buffer VkImage and then add the VkImageView for that single depth buffer VkImage to all of your framebuffers.
Now I am learning about virtual memory. I checked the size of each page by use SYSTEM_INFO structure in C and I known each page have 4096 byte. Have anyway to set page size to other value?
The page size is fixed by the OS and hardware.