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androidbitmappixelargb

Create ARGB Platte in Android

I am trying to create ARGB pixel, I have seen this example:

int createPixel(int r, int g, int b, int a) 
{
 return (a<<24) | (r<<16) | (g<<8) | (b<<0);
}

For understanding I would like get answers to this questions:

  1. What am getting as result (return)?
  2. What is << means?
  3. If value of each color is 255, so for RED 16 is 255 and 23 is 0?
Solution

  • << is binary shift left, this means a will be shifted 24 bits to the left, red 16,... you get an 4byte integer as result, first byte is a (because shifted 24 bits (3Bytes) to the left), second byte is r, third is g, fourth b.

    resulting 0xaarrggbb

    example input (255,255,0,16) returns 0xFFFF000F

    0x stands for "in hex format"

    | is a bitwise or.