void GetReportCaps(NativeMethods.HIDP_REPORT_TYPE reportType, ushort buttonCount, ushort valueCount, ushort reportLength)
{
var caps = new ReportCaps(); ushort count;
var buttons = new NativeMethods.HIDP_DATA_CAPS[buttonCount];
var values = new NativeMethods.HIDP_DATA_CAPS[valueCount];
count = buttonCount;
if (count > 0)
{
if (NativeMethods.HidP_GetButtonCaps(reportType, buttons, ref count, _preparsed) != NativeMethods.HIDP_STATUS_SUCCESS || count != buttonCount)
{
throw new NotImplementedException();
}
}
count = valueCount;
if (count > 0)
{
if (NativeMethods.HidP_GetValueCaps(reportType, values, ref count, _preparsed) != NativeMethods.HIDP_STATUS_SUCCESS || count != valueCount)
{
throw new NotImplementedException();
}
}
caps.Items = buttons.Select(b => new ItemCaps()
{
Button = true, Item = b
})
.Concat(values.Select(v => new ItemCaps()
{
Button = false, Item = v
}))
.ToArray();
caps.ReportLength = reportLength;
_types[(int)reportType] = caps;
}
void EncodeReports(NativeMethods.HIDP_REPORT_TYPE reportType, MainItemTag mainItemTag)
{
var types = _types[(int)reportType];
var reportBytes = new byte[types.ReportLength];
var reports = types.Items.GroupBy(y => y.Item.ReportID);
foreach (var report in reports)
{
var reportID = report.Key;
var reportItemList = report.ToArray();
if (reportID != 0)
{
_builder.AddGlobalItem(GlobalItemTag.ReportID, reportID);
}
int maxBit = (reportBytes.Length - 1) * 8;
// Determine the location of all report items.
for (int reportItemIndex = 0; reportItemIndex < reportItemList.Length; reportItemIndex++)
{
var reportItem = reportItemList[reportItemIndex];
var button = reportItem.Button;
var item = reportItem.Item;
if (item.IsAlias != 0)
{
throw new NotImplementedException();
}
var flags = (DataItemFlags)item.BitField;
int dataIndexCount = (item.IsRange != 0) ? item.DataIndexMax - item.DataIndex + 1 : 1;
if (button)
{
reportItem.ReportCount = dataIndexCount;
reportItem.ReportSize = 1;
}
else
{
reportItem.ReportCount = item.VALUE_ReportCount;
reportItem.ReportSize = item.VALUE_ReportSize;
}
InitData(reportBytes, reportID);
if (dataIndexCount == reportItem.ReportCount)
{
// Individual fields...
var dataList = new NativeMethods.HIDP_DATA()
{
DataIndex = item.DataIndex, RawValue = 0xffffffffu
}; int dataCount = 1;
int hr = NativeMethods.HidP_SetData(reportType, ref dataList, ref dataCount, _preparsed, reportBytes, reportBytes.Length);
if (hr == NativeMethods.HIDP_STATUS_SUCCESS)
{
GetDataStartBit(reportBytes, reportItem, maxBit);
}
else if (hr == NativeMethods.HIDP_STATUS_IS_VALUE_ARRAY)
{
// TODO
reportItem.BitOffset = maxBit;
// According to https://docs.microsoft.com/en-us/windows-hardware/drivers/hid/button-capability-arrays#button-usages-in-a-variable-main-item:
/*
* If the number of usages specified for a variable item is less than the number of buttons in the item,
* the capability array contains only one capability structure that describes one button usage (the last
* usage specified in the report descriptor for the variable main item). However, see Usage Value Array
* for information about usage values that have a report count greater than one.
*/
// How to reconstruct it, then? The following does not work:
/*
* var usage = (ushort)item.UsageIndex; int usageCount = 1;
* hr = NativeMethods.HidP_SetUsages(reportType, item.UsagePage, 0, ref usage, ref usageCount, _preparsed, reportBytes, reportBytes.Length);
* if (hr != NativeMethods.HIDP_STATUS_SUCCESS) { throw new NotImplementedException(); }
*/
}
else
{
throw new NotImplementedException();
}
}
else if (dataIndexCount == 1)
{
// Array...
int bitCount = reportItem.ReportCount * reportItem.ReportSize;
var usageValue = new byte[(bitCount + 7) / 8];
for (int i = 0; i < usageValue.Length; i++)
{
usageValue[i] = 0xff;
}
int hr = NativeMethods.HidP_SetUsageValueArray(reportType, item.UsagePage, item.LinkCollection, item.UsageIndex, usageValue, (ushort)usageValue.Length, _preparsed, reportBytes, reportBytes.Length);
if (hr == NativeMethods.HIDP_STATUS_SUCCESS)
{
GetDataStartBit(reportBytes, reportItem, maxBit);
}
else
{
// TODO need to set the usage value array here instead
// but we only want to find the bit offset, let's just do an educated guess
if (reportItemIndex == 0)
{
reportItem.BitOffset = 0;
}
else
{
var prevItem = reportItemList[reportItemIndex - 1];
reportItem.BitOffset = prevItem.BitOffset + prevItem.ReportCount * prevItem.ReportSize;
}
}
}
else
{
// Not sure...
reportItem.BitOffset = maxBit;
}
}
// Write the report descriptors.
int currentBit = 0;
var reportItems = report.Where(x => x.BitOffset != maxBit).OrderBy(x => x.BitOffset).ToArray();
foreach (var reportItem in reportItems)
{
var button = reportItem.Button;
var item = reportItem.Item;
int startBit = reportItem.BitOffset;
int bitCount = reportItem.ReportCount * reportItem.ReportSize;
if (currentBit > startBit)
{
throw new NotImplementedException();
} // Overlapping...
SetCollection(item.LinkCollection);
PadReport(mainItemTag, startBit, ref currentBit);
// The entry...
_builder.AddGlobalItem(GlobalItemTag.UsagePage, item.UsagePage);
uint usageMin = item.UsageIndex, usageMax = (item.IsRange != 0) ? item.UsageMax : usageMin;
if (item.IsRange != 0)
{
_builder.AddLocalItem(LocalItemTag.UsageMinimum, usageMin);
_builder.AddLocalItem(LocalItemTag.UsageMaximum, usageMax);
}
else
{
_builder.AddLocalItem(LocalItemTag.Usage, usageMin);
}
if (button)
{
AddButtonGlobalItems(reportItem.ReportCount);
}
else
{
_builder.AddGlobalItemSigned(GlobalItemTag.LogicalMinimum, item.VALUE_LogicalMin);
_builder.AddGlobalItemSigned(GlobalItemTag.LogicalMaximum, item.VALUE_LogicalMax);
_builder.AddGlobalItemSigned(GlobalItemTag.PhysicalMinimum, item.VALUE_PhysicalMin);
_builder.AddGlobalItemSigned(GlobalItemTag.PhysicalMaximum, item.VALUE_PhysicalMax);
_builder.AddGlobalItem(GlobalItemTag.Unit, item.VALUE_Units);
_builder.AddGlobalItem(GlobalItemTag.UnitExponent, item.VALUE_UnitsExp);
_builder.AddGlobalItem(GlobalItemTag.ReportSize, (uint)reportItem.ReportSize);
_builder.AddGlobalItem(GlobalItemTag.ReportCount, (uint)reportItem.ReportCount);
}
_builder.AddMainItem(mainItemTag, item.BitField);
currentBit += bitCount;
}
PadReport(mainItemTag, maxBit, ref currentBit);
}
}
