A device seems like a kind of hardware device. But there's HAL device and reference device. So can I understand a D3D device as a system, a software driver system or a hardware and hardware driver system which is a rendering component of D3D?
Updates：I think a "virtual device" is more appropriate, they share the same physical hardware device.
And for the difference of HAL device and reference device, can I say that HAL device take advantage of GPU while reference device take advantage of CPU which is apparently slower. But reference device is useful for feature testing.
I'm not sure your question is appropriate for the Stack Overflow community, but:
The D3D device is a standard interface used to interact in a uniform way with either a physical GPU, or to use the CPU to emulate the function if a physical GPU (obviously with a performance cost).
In that respect, it is a "Virtual Device", but it is better to simply think of it as a group of functions that allow interaction with a GPU.
Related
So I want to run ARcore on hickey board, I am currently running Android 9.0 AOSP on it. Is it possible to run an AR application on hickey board with an external USB camera? do I need a specific camera or is there anything else I need in order to run AR applications on hickey board? or hickey even supports the AR core? if you could answer this it would really help me.
Thank you.
ARCore has some minimum system requirements including sensors, cameras etc.
I don't believe there is an official minimum requirements set published openly at this point but there is a list of supported devices: https://developers.google.com/ar/discover/supported-devices
Google actually test and certify these devices so I don't think you will find 'official' support for you set up - they say:
To certify each device, we check the quality of the camera, motion sensors, and the design architecture to ensure it performs as expected. Also, the device needs to have a powerful enough CPU that integrates with the hardware design to ensure good performance and effective real-time calculations.
I need to know how to get which kind of video card is using in directX, because some features in my program are not supported in amd video card and cause crash.
So, I need to get which card the computer is using(some computer may have more than one video card).
So before you throw ATI/AMD under the bus here, make sure that the problem is not actually due to your application. For Direct3D 10/11, be sure to enable the debug device and ensure you do not have any CORRUPTION or ERRORS, and look at all WARNINGS.
Next, see if there is a newer driver available for the repro case. If there is, then just tell your users to update their drivers. If not, and it seems to be a legitimate crash inside the driver then report that as a bug to ATI/AMD (or NVidia or Intel as the case may be).
Test your app on more than one video card/driver combination from each vendor. For indies this can be challenging, but it's an important part of making sure your application works on a broad set of hardware. For Direct3D 11, you need to try various Direct3D hardware feature level devices to ensure good coverage.
Real games do have some extra warnings tied to detecting specific hardware IDs when dealing with wide-spread driver bugs and unofficial vendor-specific extensions). There is an example of doing this detection here based on the vendorid/deviceid combination in DXGI_ADAPTER_DESC or D3DADAPTER_IDENTIFIER9. Locking out all cards from a specific vendor is overkill and likely to just annoy your customers.
I can't seem to find a good comprehensive list of available ioctls for netbsd.
I am looking to do some operations on harddisk (getting size, physical sector size, model). I have the code working in linux. It looks something like this, I removed errors etc to make it more compact:
ioctl(fileno(driveptr[i]),HDIO_GET_IDENTITY,&hd);
ioctl(fileno(driveptr[i]),BLKGETSIZE64,&drivesize[i]);
ioctl(fileno(driveptr[i]),BLKPBSZGET,&psztemp);
Is there an equivalent to these ioctls in netbsd?
regards
The driver source for a given type of disk interface (or any other kind of device driver) is probably the best canonical place to find device specific ioctls.
NetBSD at a systems level, like many unix-based systems, tries hard to avoid being hardware specific, even in terms of providing detailed hardware specific information to user level. The goal of unix, after all, is to provide a system that is uniform across a wide variety of hardware platorms, not to provide detailed low-level access to specific hardware. The very best you can get in terms of hardware specific details is the information printed by the drivers at boot time about the hardware as it is probed and attached.
At a more generic level you can basically only get disk and partition labels -- i.e. information pertinent to the way the system presents disk devices to userland. Unfortunately the only driver manual page that documents these is sd(4) (cd(4) has some more detail about more ioctls specific to cd-rom devices). scsi(4) documents bus-level ioctls for SCSI and ATAPI interfaces.
On x86 platforms there's "sysctl machdep.diskinfo" (and the equivalent C level interface via sysctl(3)) to get details about what the BIOS reported about the disks it knew about at boot time, but that may be incomplete.
When a manufacturer designs a hardware device, they obviously have someone who is in charge of writing a driver for that device for different platforms.
While I know that there are probably more than one "type" of driver for different types of devices, a driver for a device by it's nature must be very different from a normal application or script.
I've always wanted to pick apart a driver just to find out how it allows an OS to interface with hardware, but my programming knowledge is lacking.
Out of curiosity, I'd just like to know:
How does a device driver work, exactly?
When designing a driver for a device, what things do programmers consider?
What languages are drivers written in?
What is the overall process for designing a driver?
I suggest that you read (at lease the first chapter) "Linux Device Drivers". It will answer your basic questions and will allow you to study how to develop device drivers for Linux OS if you want to.
You can find it here: http://lwn.net/Kernel/LDD3/
When designing a device driver, programmers look at the functionalities of the device that are to be implemented and write the driver accordingly
I prefer C / C++ for writing a device driver
but have seen driver in assembly language also
overall process is dependent on device itself
My laptop has two video cards, a high powered NVIDIA one and an onboard Intel one. When I call IDirect3D9::GetAdapterCount however, it only finds the onboard Intel one, probably because the high powered one is being hidden.
I'm able to go into my laptop settings and tell it 'force choose' the NVIDIA card, and then it works, but this is not an acceptable solution for my end-users. I've also noticed that when I run Battlefield3, it's able to properly find the NVIDIA card even without 'force choose' enabled. Maybe there's a special white-list that has Battlefield listed? Or some other secret method?
Any ideas how to acquire that elusive card?
Are you sure the intel chip is enumeratable? Quite often its not. By sticking in a discrete GPU the sandybridge (and older) chipset is generally disabled. You probably want to check the Nvidia optimus test tool.
GetAdapterCount will actually returns count of the monitors in system, not videocards. And as far as I know there is no way to force choose it programmatically.
If you talking about nVidia optimus technology, it choose videochip using driver settings.