Xor (Graphics Put)

Parameter to the KeyPgPutgraphicsPut graphics statement which uses a bit-wise KeyPgOpXorXor as the 
blitting method

Syntax
	Put [ target, ] [ STEP ] ( x,y ), source [ ,( x1,y1 )-( x2,y2 ) ], Xor

Parameters
	Xor
		Required.

Description
	The Xor method combines each source pixel with the corresponding 
	destination pixel, using the bit-wise KeyPgOpXorXor function.  The result of this 
	is output as the destination pixel.
	This method works in all graphics modes.  There is no mask color, 
	although color values of 0 (KeyPgRgbaRGBA(0, 0, 0, 0) in full-color modes) will 
	have no effect, because of the behavior of KeyPgOpXorXor.

	In full-color modes, each component (red, green, blue and alpha) is kept 
	in a discrete set of bits, so the operation can be made to only affect 
	some of the channels, by making sure the all the values of the other 
	channels are set to 0.

Example
	''open a graphics window
	ScreenRes 320, 200, 16

	''create a sprite containing a circle
	Const As Integer r = 32
	Dim c As Any Ptr = ImageCreate(r * 2 + 1, r * 2 + 1, 0)
	Circle c, (r, r), r, RGBA(255, 255, 255, 0), , , 1, f

	''put the three sprites, overlapping each other in the middle
	Put (146 - r, 108 - r), c, Xor
	Put (174 - r, 108 - r), c, Xor
	Put (160 - r,  84 - r), c, Xor

	''free the memory used by the sprite
	ImageDestroy c

	''pause the program before closing
	Sleep

Differences from QB
	* None

See also
	* KeyPgOpXorXor
	* KeyPgPutgraphicsPut (Graphics)

