2.1.1.2 BinaryRasterOperation Enumeration

The BinaryRasterOperation Enumeration section lists the binary raster-operation codes. Raster-operation codes define how metafile processing combines the bits from the selected pen with the bits in the destination bitmap.

Each raster-operation code represents a Boolean operation in which the values of the pixels in the selected pen and the destination bitmap are combined. Following are the two operands used in these operations.

Operand	Meaning
P	Selected pen
D	Destination bitmap

Following are the Boolean operators used in these operations.

Operator	Meaning
a	Bitwise AND
n	Bitwise NOT (inverse)
o	Bitwise OR
x	Bitwise exclusive OR (XOR)

All Boolean operations are presented in reverse Polish notation. For example, the following operation replaces the values of the pixels in the destination bitmap with a combination of the pixel values of the pen and the selected brush: DPo.

Each raster-operation code is a 32-bit integer whose high-order word is a Boolean operation index and whose low-order word is the operation code. The 16-bit operation index is a zero-extended, 8-bit value that represents all possible outcomes resulting from the Boolean operation on two parameters (in this case, the pen and destination values). For example, the operation indexes for the DPo and DPan operations are shown in the following list.

P	D	DPo	DPan
0	0	0	1
0	1	1	1
1	0	1	1
1	1	1	0

The following enumeration lists the drawing modes and the Boolean operations that they represent.

 typedef  enum
 {
   R2_BLACK = 0x0001,
   R2_NOTMERGEPEN = 0x0002,
   R2_MASKNOTPEN = 0x0003,
   R2_NOTCOPYPEN = 0x0004,
   R2_MASKPENNOT = 0x0005,
   R2_NOT = 0x0006,
   R2_XORPEN = 0x0007,
   R2_NOTMASKPEN = 0x0008,
   R2_MASKPEN = 0x0009,
   R2_NOTXORPEN = 0x000A,
   R2_NOP = 0x000B,
   R2_MERGENOTPEN = 0x000C,
   R2_COPYPEN = 0x000D,
   R2_MERGEPENNOT = 0x000E,
   R2_MERGEPEN = 0x000F,
   R2_WHITE = 0x0010
 } BinaryRasterOperation;

R2_BLACK: 0, Pixel is always 0.

R2_NOTMERGEPEN: DPon, Pixel is the inverse of the R2_MERGEPEN color.

R2_MASKNOTPEN: DPna, Pixel is a combination of the screen color and the inverse of the pen color.

R2_NOTCOPYPEN: Pn, Pixel is the inverse of the pen color.

R2_MASKPENNOT: PDna, Pixel is a combination of the colors common to both the pen and the inverse of the screen.

R2_NOT: Dn, Pixel is the inverse of the screen color.

R2_XORPEN: DPx, Pixel is a combination of the colors in the pen or in the screen, but not in both.

R2_NOTMASKPEN: DPan, Pixel is the inverse of the R2_MASKPEN color.

R2_MASKPEN: DPa, Pixel is a combination of the colors common to both the pen and the screen.

R2_NOTXORPEN: DPxn, Pixel is the inverse of the R2_XORPEN color.

R2_NOP: D, Pixel remains unchanged.

R2_MERGENOTPEN: DPno, Pixel is a combination of the colors common to both the screen and the inverse of the pen.

R2_COPYPEN: P, Pixel is the pen color.

R2_MERGEPENNOT: PDno, Pixel is a combination of the pen color and the inverse of the screen color.

R2_MERGEPEN: DPo, Pixel is a combination of the pen color and the screen color.

R2_WHITE: 1, Pixel is always 1

For a monochrome device, WMF format maps the value 0 to black and the value 1 to white. If an application attempts to draw with a black pen on a white destination by using the available binary raster operations, the following results occur.

Raster operation	Result
R2_BLACK	Visible black line
R2_COPYPEN	Visible black line
R2_MASKNOTPEN	No visible line
R2_MASKPEN	Visible black line
R2_MASKPENNOT	Visible black line
R2_MERGENOTPEN	No visible line
R2_MERGEPEN	Visible black line
R2_MERGEPENNOT	Visible black line
R2_NOP	No visible line
R2_NOT	Visible black line
R2_NOTCOPYPEN	No visible line
R2_NOTMASKPEN	No visible line
R2_NOTMERGEPEN	Visible black line
R2_NOTXORPEN	Visible black line
R2_WHITE	No visible line
R2_XORPEN	No visible line

For a color device, WMF format uses RGB values to represent the colors of the pen and the destination. An RGB color value is a long integer that contains a red, a green, and a blue color field, each specifying the intensity of the given color. Intensities range from 0 through 255. The values are packed in the three low-order bytes of the long integer. The color of a pen is always a solid color, but the color of the destination can be a mixture of any two or three colors. If an application attempts to draw with a white pen on a blue destination by using the available binary raster operations, the following results occur.

Raster operation	Result
R2_BLACK	Visible black line
R2_COPYPEN	Visible white line
R2_MASKNOTPEN	Visible black line
R2_MASKPEN	Invisible blue line
R2_MASKPENNOT	Visible red/green line
R2_MERGENOTPEN	Invisible blue line
R2_MERGEPEN	Visible white line
R2_MERGEPENNOT	Visible white line
R2_NOP	Invisible blue line
R2_NOT	Visible red/green line
R2_NOTCOPYPEN	Visible black line
R2_NOTMASKPEN	Visible red/green line
R2_NOTMERGEPEN	Visible black line
R2_NOTXORPEN	Invisible blue line
R2_WHITE	Visible white line
R2_XORPEN	Visible red/green line