Add mixed comments to input code, make some tooltip clearer

Source/Core/InputCommon/ControllerEmu/StickGate.cpp

@@ -128,6 +128,7 @@ std::optional<u32> SquareStickGate::GetIdealCalibrationSampleCount() const
 ReshapableInput::ReshapableInput(std::string name_, std::string ui_name_, GroupType type_)
     : ControlGroup(std::move(name_), std::move(ui_name_), type_)
 {
+  // 50 is not always enough but users can set it to more with an expression
   AddDeadzoneSetting(&m_deadzone_setting, 50);
 }
 
@@ -285,6 +286,10 @@ ReshapableInput::ReshapeData ReshapableInput::Reshape(ControlState x, ControlSta
   x -= m_center.x;
   y -= m_center.y;
 
+  // We run this even if both x and y will be zero.
+  // In that case, std::atan2(0, 0) returns a valid non-NaN value, but the exact value
+  // (which depends on the signs of x and y) does not matter here as dist is zero
+
   // TODO: make the AtAngle functions work with negative angles:
   ControlState angle = std::atan2(y, x) + MathUtil::TAU;