function BlendRegEx(F, B, M: TColor32): TColor32;
procedure BlendMemEx(F: TColor32; var B: TColor32; M: TColor32);
Mixes a foreground color with the background color using alpha of the foreground color scaled by the master alpha value M.
SRGB = (M * FA) * FRGB + (1 – (M * FA)) * BRGB;
M is defined as TColor32 to avoid unnecessary type conversions, it must store only values in [0..255] range, the function does not perform range checking and the result in case M > 255 is not specified.
BlendRegEx takes parameters and produces the result operating on CPU registers.
BlendMemEx operates with the background color referenced by a memory address.
Using BlendMemEx is more efficient when blending/combining data to a bitmap since it excludes writing operation for transparent pixels and reading operation for opaque ones.
Note, that after using BlendEx functions, you have to call EMMS. Otherwise CPU will be unable to handle floating point instructions.
Blend, Combine, EMMS, Merge, MergeEx, Color Types
Copyright ©2000-2012 Alex Denisov and the Graphics32 Team - Graphics32 v1.9.1 - Build on 28-August-2012