// Get raw X,Y from Packet->Buffer USHORT rawX = *(PUSHORT)(Packet->Buffer + X_OFFSET); USHORT rawY = *(PUSHORT)(Packet->Buffer + Y_OFFSET); // Apply calibration LONG calibratedX = (LONG)(rawX * CalibA + rawY * CalibB + CalibC); LONG calibratedY = (LONG)(rawX * CalibD + rawY * CalibE + CalibF);
Calibration failures manifest as:
: The top layer that understands "touch" as a standard protocol. Kmdf Hid Minidriver For Touch I2c Device Calibration
Last insight: Always provide a user-mode calibration tool that sends new matrix values to the driver via DeviceIoControl . The driver stores them in registry, applies them live, and persists across reboots. That dual-layer (kernel enforcement + user control) is what separates production-grade solutions from prototypes. // Get raw X,Y from Packet->Buffer USHORT rawX