Screen Alpha Blending Modes

#include <screen/screen.h>
 

enum {
      SCREEN_NON_PRE_MULTIPLIED_ALPHA = 0   
      SCREEN_PRE_MULTIPLIED_ALPHA = 1   
};

Since:

BlackBerry 10.0.0

Data:

SCREEN_NON_PRE_MULTIPLIED_ALPHA

The non pre-multiplied alpha content.

This is the default. In this case, the source blending is done using the equation:

c(r,g,b) = s(r,g,b) * s(a) + d(r,g,b) * (1 - s(a))

SCREEN_PRE_MULTIPLIED_ALPHA

The pre-multiplied alpha content.

In this case, the source blending is done using the equation:

c(r,g,b) = s(r,g,b) + d(r,g,b) * (1 - s(a))

Library:

libscreen (For the qcc command, use the -l screen option to link against this library)

Description:

This enumeration is used when setting the SCREEN_PROPERTY_ALPHA_MODE property.