public IMgLogicalDevice CreateLogicalDevice(
IMgSurfaceKHR presentationSurface,
MgDeviceExtensionOptions option,
MgQueueAllocation allocationUsage,
MgQueueFlagBits deviceUsage)
{
string[] extensions = null;
IMgPhysicalDevice[] physicalDevices;
var errorCode = mInstance.EnumeratePhysicalDevices(out physicalDevices);
Debug.Assert(errorCode == Result.SUCCESS, errorCode + " != Result.SUCCESS");
IMgPhysicalDevice firstPhysicalDevice = physicalDevices[0];
if (option == MgDeviceExtensionOptions.ALL)
{
MgExtensionProperties[] extensionProperties;
var err = firstPhysicalDevice.EnumerateDeviceExtensionProperties(null, out extensionProperties);
Debug.Assert(err == Result.SUCCESS, err + " != Result.SUCCESS");
var enabledExtensions = new List <string>();
if (extensionProperties != null)
{
foreach (var ext in extensionProperties)
{
enabledExtensions.Add(ext.ExtensionName);
}
}
extensions = enabledExtensions.ToArray();
}
return(CreateDevice(firstPhysicalDevice, presentationSurface, allocationUsage, deviceUsage, extensions));
}
static uint FindAppropriateQueueFamily(MgQueueFamilyProperties[] queueProps, MgQueueFlagBits requestedQueueType)
{
for (uint i = 0; i < queueProps.Length; ++i)
{
// Find a queue that supports gfx
if ((queueProps [i].QueueFlags & requestedQueueType) == requestedQueueType)
{
return(i);
}
}
throw new Exception("Could not find a queue");
}
public IMgLogicalDevice CreateDevice(IMgPhysicalDevice gpu, IMgSurfaceKHR presentationSurface, MgQueueAllocation requestCount, MgQueueFlagBits requestedQueueType, string[] enabledExtensions)
{
// Find a queue that supports graphics operations
MgQueueFamilyProperties[] queueProps;
gpu.GetPhysicalDeviceQueueFamilyProperties(out queueProps);
Debug.Assert(queueProps != null);
Debug.Assert(queueProps.Length >= 1);
uint queueFamilyIndex = 0;
queueFamilyIndex = presentationSurface != null
? FindAppropriateQueueFamilyForSurface(gpu, presentationSurface, queueProps, requestedQueueType)
: FindAppropriateQueueFamily(queueProps, requestedQueueType);
uint noOfQueues = (requestCount == MgQueueAllocation.One) ? 1 : queueProps [queueFamilyIndex].QueueCount;
var queuePriorities = new float[noOfQueues];
for (uint i = 0; i < noOfQueues; ++i)
{
queuePriorities [i] = 0f;
}
var queueCreateInfo = new MgDeviceQueueCreateInfo {
QueueFamilyIndex = queueFamilyIndex,
QueueCount = noOfQueues,
QueuePriorities = queuePriorities,
};
return(CreateDevice(gpu, queueCreateInfo, enabledExtensions));
}
static uint FindAppropriateQueueFamilyForSurface(
IMgPhysicalDevice gpu,
IMgSurfaceKHR presentationSurface,
MgQueueFamilyProperties[] queueProps,
MgQueueFlagBits requestedQueueType)
{
bool[] supportsPresent = new bool[queueProps.Length];
// Iterate over each queue to learn whether it supports presenting:
for (UInt32 i = 0; i < queueProps.Length; ++i)
{
gpu.GetPhysicalDeviceSurfaceSupportKHR(i, presentationSurface, ref supportsPresent [i]);
}
// Search for a graphics and a present queue in the array of queue
// families, try to find one that supports both
UInt32 requestedQueueNodeIndex = UInt32.MaxValue;
UInt32 presentQueueNodeIndex = UInt32.MaxValue;
for (UInt32 i = 0; i < queueProps.Length; i++)
{
var queue = queueProps [i];
if ((queue.QueueFlags & requestedQueueType) != 0)
{
if (requestedQueueNodeIndex == UInt32.MaxValue)
{
requestedQueueNodeIndex = i;
}
if (supportsPresent [i])
{
requestedQueueNodeIndex = i;
presentQueueNodeIndex = i;
break;
}
}
}
if (presentQueueNodeIndex == UInt32.MaxValue)
{
// If didn't find a queue that supports both graphics and present, then
// find a separate present queue.
for (UInt32 i = 0; i < queueProps.Length; ++i)
{
if (supportsPresent [i])
{
presentQueueNodeIndex = i;
break;
}
}
}
if (requestedQueueNodeIndex == UInt32.MaxValue)
{
throw new Exception("Could not find queue of requested queue type");
}
// Generate error if could not find both a graphics and a present queue
if (presentQueueNodeIndex == UInt32.MaxValue)
{
throw new Exception("Could not find a presentation queue");
}
// VERBATIM from cube.c
// TODO: Add support for separate queues, including presentation,
// synchronization, and appropriate tracking for QueueSubmit.
// NOTE: While it is possible for an application to use a separate graphics
// and a present queues, this demo program assumes it is only using
// one:
if (requestedQueueNodeIndex != presentQueueNodeIndex)
{
throw new Exception("Could not find an common queue");
}
return(requestedQueueNodeIndex);
}