The mix attribute determines how each primitive an application draws is combined with any existing drawing. In color applications, the mix attribute determines the color that results when one primitive is drawn on top of another. There are two forms of the mix attribute: foreground mix and background mix.
The foreground mix attribute governs how the foreground of a primitive is combined with the existing drawing, and it applies to all primitive types. The background mix attribute governs how the background of a primitive is combined with the existing drawing, and it is applicable only to those primitives that have a background. Primitives that can be affected by the background mix attribute are areas, character strings, images, and markers. The primitive attribute data structures contain fields for both foreground and background color and mix attributes.
There are 17 foreground mix attributes. For each mix attribute, the indexes of the foreground and current drawing-surface colors are combined by using one of the bitwise operators. The available foreground mix settings are listed in the following table.
Foreground Mix Attributes
旼컴컴컴컴컴컴컴쩡컴컴컴컴컴컴컴쩡컴컴컴컴컴컴컴컴컴컴컴컴컴컴커 쿘ix Attribute 쿐ffect 쿏escription � 쳐컴컴컴컴컴컴컴탠컴컴컴컴컴컴컴탠컴컴컴컴컴컴컴컴컴컴컴컴컴컴캑 쿑M_DEFAULT 쿏efault 쿏efault foreground mix � � � 쿪ttribute (overpaint). � 쳐컴컴컴컴컴컴컴탠컴컴컴컴컴컴컴탠컴컴컴컴컴컴컴컴컴컴컴컴컴컴캑 쿑M_OR 쿚R 쿔ndex value of the final color� � � 쿶s determined by a bitwise OR � � � 쿽peration on the index of the � � � 쿯oreground color and the index� � � 쿽f the color of the drawing � � � 퀂urface. � 쳐컴컴컴컴컴컴컴탠컴컴컴컴컴컴컴탠컴컴컴컴컴컴컴컴컴컴컴컴컴컴캑 쿑M_OVERPAINT 쿚verpaint 쿔ndex value of the final color� � � 쿶s that of the foreground � � � 쿬olor. This is the default � � � 쿯oreground mix attribute. � 쳐컴컴컴컴컴컴컴탠컴컴컴컴컴컴컴탠컴컴컴컴컴컴컴컴컴컴컴컴컴컴캑 쿑M_XOR 쿐xclusive-OR 쿔ndex value of the final color� � �(XOR) 쿶s determined by a bitwise XOR� � � 쿽peration on the index of the � � � 쿯oreground color and the index� � � 쿽f the color of the drawing � � � 퀂urface. � 쳐컴컴컴컴컴컴컴탠컴컴컴컴컴컴컴탠컴컴컴컴컴컴컴컴컴컴컴컴컴컴캑 쿑M_LEAVEALONE 쿗eave-alone 쿔ndex value of the final color� � �(Invisible) 쿶s that of the index of the � � � 쿬olor of the drawing surface. � 쳐컴컴컴컴컴컴컴탠컴컴컴컴컴컴컴탠컴컴컴컴컴컴컴컴컴컴컴컴컴컴캑 쿑M_AND 쿌ND 쿔ndex value of the final color� � � 쿶s determined by a bitwise AND� � � 쿽peration on the index of the � � � 쿯oreground color and the index� � � 쿽f the color of the drawing � � � 퀂urface. � 쳐컴컴컴컴컴컴컴탠컴컴컴컴컴컴컴탠컴컴컴컴컴컴컴컴컴컴컴컴컴컴캑 쿑M_SUBTRACT �(Inverse 쿔ndex value of the final color� � 쿞ource) AND 쿶s determined by inverting the� � 쿏estination 쿶ndex of the foreground color � � � 쿪nd performing a bitwise AND � � � 쿽peration on this value and � � � 퀃he index of the color of the � � � 쿭rawing surface. � 쳐컴컴컴컴컴컴컴탠컴컴컴컴컴컴컴탠컴컴컴컴컴컴컴컴컴컴컴컴컴컴캑 쿑M_MASKSRCNOT 쿞ource AND 쿔ndex value of the final color� � �(Inverse 쿶s determined by inverting the� � 쿏estination) 쿶ndex value of the � � � 쿭rawing-surface color and � � � 쿾erforming a bitwise AND � � � 쿽peration on this value and � � � 퀃he index value of the � � � 쿯oreground color. � 쳐컴컴컴컴컴컴컴탠컴컴컴컴컴컴컴탠컴컴컴컴컴컴컴컴컴컴컴컴컴컴캑 쿑M_ZERO 쿌ll zeros 쿝GB value of the final color's� � � 쿶s always 0x00000000. � 쳐컴컴컴컴컴컴컴탠컴컴컴컴컴컴컴탠컴컴컴컴컴컴컴컴컴컴컴컴컴컴캑 쿑M_NOTMERGESRC 쿔nverse (Source쿔ndex value of the final color� � 쿚R Destination)쿶s always the inverse of the � � � 쿑M_OR result. � 쳐컴컴컴컴컴컴컴탠컴컴컴컴컴컴컴탠컴컴컴컴컴컴컴컴컴컴컴컴컴컴캑 쿑M_NOTXORSRC 쿔nverse (Source쿔ndex value of the final color� � 쿦OR 쿶s always the inverse of the � � 쿏estination) 쿑M_XOR result. � 쳐컴컴컴컴컴컴컴탠컴컴컴컴컴컴컴탠컴컴컴컴컴컴컴컴컴컴컴컴컴컴캑 쿑M_INVERT 쿔nverse 쿔ndex value of the final color� � �(Destination) 쿶s always the inverse of the � � � 쿶ndex of the color of the � � � 쿭rawing surface. � 쳐컴컴컴컴컴컴컴탠컴컴컴컴컴컴컴탠컴컴컴컴컴컴컴컴컴컴컴컴컴컴캑 쿑M_MERGESRCNOT 쿞ource OR 쿔ndex value of the final color� � �(Inverse 쿶s determined by performing a � � 쿏estination) 쿫itwise OR operation on the � � � 쿶ndex of the foreground color � � � 쿪nd the inverse of the index � � � 쿽f the color of the drawing � � � 퀂urface. � 쳐컴컴컴컴컴컴컴탠컴컴컴컴컴컴컴탠컴컴컴컴컴컴컴컴컴컴컴컴컴컴캑 쿑M_NOTCOPYSRC 쿔nverse 쿔ndex value of the final color� � �(Source) 쿶s the inverse of the index of� � � 퀃he foreground color. � 쳐컴컴컴컴컴컴컴탠컴컴컴컴컴컴컴탠컴컴컴컴컴컴컴컴컴컴컴컴컴컴캑 쿑M_MERGENOTSRC �(Inverse 쿔ndex value of the final color� � 쿞ource) OR 쿶s determined by performing a � � 쿏estination 쿫itwise AND operation on the � � � 쿶ndex of the drawing surface's� � � 쿬olor and the inverse of the � � � 쿶ndex of the foreground color.� 쳐컴컴컴컴컴컴컴탠컴컴컴컴컴컴컴탠컴컴컴컴컴컴컴컴컴컴컴컴컴컴캑 쿑M_NOTMASKSRC 쿔nverse (Source쿔ndex value of the final color� � 쿌ND 쿶s the inverse of the FM_AND � � 쿏estination) 퀁esult. � 쳐컴컴컴컴컴컴컴탠컴컴컴컴컴컴컴탠컴컴컴컴컴컴컴컴컴컴컴컴컴컴캑 쿑M_ONE 쿌ll 1's. 쿝GB value of the final color � � � 쿶s always 0x00FFFFFF. � 읕컴컴컴컴컴컴컴좔컴컴컴컴컴컴컴좔컴컴컴컴컴컴컴컴컴컴컴컴컴컴켸
There are five background mix attributes. For each mix attribute, the index value for the background color and the current drawing-surface color (in the device's physical color table) are combined using one of the bitwise operators.
The RGB values are those from the physical color table. When the result of the mix attribute's bitwise operation defines a color different from that of both the drawing surface and the drawing attribute, the resulting index accesses an RGB color in the physical table. The color, therefore, is unpredictable unless the logical color table has been realized (using the palette manager).
The first five of the foreground mix attributes also are available as background mix attributes. The background mix attributes are listed in the following table.
Background Mix Attributes
旼컴컴컴컴컴컴컴쩡컴컴컴컴컴컴컴쩡컴컴컴컴컴컴컴컴컴컴컴컴컴컴커 쿘ix Attribute 쿐ffect 쿏escription � 쳐컴컴컴컴컴컴컴탠컴컴컴컴컴컴컴탠컴컴컴컴컴컴컴컴컴컴컴컴컴컴캑 쿍M_DEFAULT 쿏efault 쿏efault background mix � � � 쿪ttribute (Leave-alone). � 쳐컴컴컴컴컴컴컴탠컴컴컴컴컴컴컴탠컴컴컴컴컴컴컴컴컴컴컴컴컴컴캑 쿍M_OR 쿚R 쿔ndex value of the final color� � � 쿶s determined by a bitwise OR � � � 쿽peration on the index of the � � � 쿫ackground color and the index� � � 쿽f the color of the drawing � � � 퀂urface. � 쳐컴컴컴컴컴컴컴탠컴컴컴컴컴컴컴탠컴컴컴컴컴컴컴컴컴컴컴컴컴컴캑 쿍M_OVERPAINT 쿚verpaint 쿔ndex value of the final color� � � 쿶s that of the background � � � 쿬olor. � 쳐컴컴컴컴컴컴컴탠컴컴컴컴컴컴컴탠컴컴컴컴컴컴컴컴컴컴컴컴컴컴캑 쿍M_XOR 쿐xclusive-OR 쿔ndex value of the final color� � �(XOR) 쿶s determined by a bitwise XOR� � � 쿽peration on the index of the � � � 쿫ackground color and the index� � � 쿽f the color of the drawing � � � 퀂urface. � 쳐컴컴컴컴컴컴컴탠컴컴컴컴컴컴컴탠컴컴컴컴컴컴컴컴컴컴컴컴컴컴캑 쿍M_LEAVEALONE 쿗eave-alone 쿔ndex value of the final color� � �(Invisible) 쿶s that of the drawing-surface� � � 쿬olor. � 읕컴컴컴컴컴컴컴좔컴컴컴컴컴컴컴좔컴컴컴컴컴컴컴컴컴컴컴컴컴컴켸
The most frequently used foreground mix attributes are FM_OVERPAINT, which is the default value, FM_OR, and FM_XOR. The most frequently used background mix attributes are BM_LEAVEALONE, which is the default value, and BM_OVERPAINT.