Manipulating Images

The functions described below can be used to create animated graphics. The _getimage and _putimage functions act like a rubber stamp; after capturing a shape, you can make copies anywhere on the screen.

_getimage

Stores a screen image in memory. Pass four integers (the coordinates of the bounding rectangle) and a pointer to a storage buffer. Call _imagesize to find out how much memory is required. No return value.

_getimage_w

Stores a screen image in memory. Pass four doubles (the coordinates of the bounding rectangle) and a pointer to a storage buffer. Call _imagesize_w to find out how much memory is required. No return value.

_getimage_wxy

Same as _getimage_w, but you pass two _wxycoord structures and a pointer to memory.

_imagesize

Returns a long integer representing the size of an image in bytes. Call this function in preparation for a call to _getimage. Pass four integers: the x and y coordinates of opposite corners of the portion of the screen to be saved.

_imagesize_w

Returns the size of an image in bytes in preparation for a call to _getimage_w and _putimage_w. Pass four doubles: the x and y window coordinates of opposite corners of the portion of the screen to be saved.

_imagesize_wxy

Same as _imagesize_w, but you pass two _wxycoord structures.

_putimage

Retrieves an image from memory and displays it on the active screen page. The image should previously have been saved to memory with _getimage. Pass two short integers (coordinates where the image is to be placed), a pointer to the image, and a short integer indicating what kind of action to take: _GAND, _GOR, _GPRESET, _GPSET, or _GXOR. No return value.

_putimage_w

Displays an image from memory within a window. The image should previously have been saved to memory with _getimage_w. Pass two doubles (coordinates where the image is to be placed), a pointer to the image, and a short integer indicating what kind of action to take: _GAND, _GOR, _GPRESET, _GPSET, or _GXOR. No return value.