## 12.11 Logical Operations

The EZwgl supports logical operations when drawing into the front buffer or a `EZ_PIXMAP` back buffer. Support for logical operations in `EZ_XIMAGE` back buffer is not yet implemented.

The default logical operation is `EZ_COPY`.

`void EZ_LogicOp(int op)`

This function sets the current logical operation. Possible logical operations are listed in the following table. In this table, `s` is the incoming pixel value and `d` is the pixel value stored in the framebuffer or the pixmap.

Symbolic Name | Operation
`EZ_CLEAR` | 0
`EZ_AND` | s
`EZ_AND_REVERSE` | s
`EZ_COPY` | s
`EZ_AND_INVERTED` | s d
`EZ_NOOP` | d
`EZ_XOR` | s `xor` d
`EZ_OR` | sd
`EZ_NOR` | (sd)
`EZ_EQUIV` | (s `xor` d)
`EZ_INVERT` | d
`EZ_OR_REVERSE` | sd
`EZ_COPY_INVERTED` | s
`EZ_OR_INVERTED` | sd
`EZ_NAND` | (sd)
`EZ_SET` | 1

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