Function qt_gui::q_gray_1a

source · 
pub unsafe fn q_gray_1a(rgb: c_uint) -> c_int
Expand description

This is an overloaded function.

Calls C++ function: int qGray(unsigned int rgb).

C++ documentation:

This is an overloaded function.

Returns a gray value (0 to 255) from the given ARGB quadruplet rgb.

The gray value is calculated using the formula (R * 11 + G * 16 + B * 5)/32; the alpha-channel is ignored.