Ternary raster operations

This section lists the ternary raster-operation codes used by the putimage functions.

Ternary raster-operation codes define how to combine the bits in a source bitmap with the bits in the destination bitmap. The combine is a Boolean operation of the following three operands.

Boolean operators used in these operations follow.

All Boolean operations are presented in reverse Polish notation. For example, the following operation replaces the values of the pixels in the destination image with a combination of the pixel values of the source and current fill color: PSo. (there are alternative spellings of the same function, so although a particular spelling may not be in the list, an equivalent form would be)

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 the result of the Boolean operation on current fill color, source, and destination values. For example, the operation indexes for the PSo and DPSoo operations are shown in the following list.

In this case, PSo has the operation index 00FC (read from the bottom up); DPSoo has the operation index 00FE. These values define the location of the corresponding raster-operation codes. The PSo operation is in line 252 (00FCh) of the table; DPSoo is in line 254 (00FEh).

Raster-Operation Codes