public DeviceBuilder WithQueueFamily(VkQueueFlag preferredFlags, VkQueueFlag requiredFlags,
Func <PhysicalDevice, uint, bool> preferredPred,
Func <PhysicalDevice, uint, bool> requiredPred,
params float[] priorities)
{
var family = _physicalDevice.FindQueueFamily(preferredFlags, requiredFlags, preferredPred, requiredPred);
_queueInfo.Add(new Device.QueueCreateInfo(family, priorities));
return(this);
}
/// <summary>
/// Finds all queue families with the given options
/// </summary>
/// <param name="flags">Require these options</param>
/// <param name="pred">Predicate that is required to be true, or null to ignore</param>
/// <returns>the queue family indices</returns>
public IEnumerable <uint> FindQueueFamilies(VkQueueFlag flags, Func <PhysicalDevice, uint, bool> pred = null)
{
var queues = Handle.GetQueueFamilyProperties();
for (var i = 0; i < queues.Length; i++)
{
if ((queues[i].QueueFlags & flags) == flags &&
(pred == null || pred.Invoke(this, (uint)i)))
{
yield return((uint)i);
}
}
}
public DeviceBuilder WithQueueFamily(VkQueueFlag preferredFlags, VkQueueFlag requiredFlags,
params float[] priorities)
{
return(WithQueueFamily(preferredFlags, requiredFlags, null, null, priorities));
}
/// <summary>
/// Finds the queue family index with the given options
/// </summary>
/// <param name="preferredFlags">Prefer to have these options</param>
/// <param name="requiredFlags">Require these options</param>
/// <param name="preferredPred">Predicate that is preferred to be true, or null to ignore</param>
/// <param name="requiredPred">Predicate that is required to be true, or null to ignore</param>
/// <returns>the queue family index</returns>
/// <exception cref="NotSupportedException">no such queue family exists</exception>
public uint FindQueueFamily(VkQueueFlag preferredFlags, VkQueueFlag requiredFlags,
Func <PhysicalDevice, uint, bool> preferredPred = null,
Func <PhysicalDevice, uint, bool> requiredPred = null)
{
uint BitDelta(VkQueueFlag a, VkQueueFlag b)
{
var score = 0u;
for (uint j = 1; j < Math.Max((uint)a, (uint)b); j <<= 1)
{
var flag = (VkQueueFlag)j;
if ((a & flag) != (b & flag))
{
score++;
}
}
return(score);
}
var queues = Handle.GetQueueFamilyProperties();
var both = preferredFlags | requiredFlags;
uint bestQueue = uint.MaxValue;
uint bestScore = uint.MaxValue;
for (var i = 0; i < queues.Length; i++)
{
if ((queues[i].QueueFlags & both) == both &&
(preferredPred == null || preferredPred.Invoke(this, (uint)i)) &&
(requiredPred == null || requiredPred.Invoke(this, (uint)i)))
{
var score = BitDelta(queues[i].QueueFlags, both);
if (score >= bestScore)
{
continue;
}
bestQueue = (uint)i;
bestScore = score;
}
}
if (bestQueue != uint.MaxValue)
{
return(bestQueue);
}
for (var i = 0; i < queues.Length; i++)
{
if ((queues[i].QueueFlags & requiredFlags) == requiredFlags &&
(requiredPred == null || requiredPred.Invoke(this, (uint)i)))
{
var score = BitDelta(queues[i].QueueFlags, requiredFlags);
if (score >= bestScore)
{
continue;
}
bestQueue = (uint)i;
bestScore = score;
}
}
if (bestQueue != uint.MaxValue)
{
return(bestQueue);
}
throw new NotSupportedException($"Queue family with flags {requiredFlags} isn't supported");
}
