Alacron FAST-UXGA, Technical Product Manual, Page: 18 / 28

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the control, this method can not be used across processes. The Update API is canned by the
Create API and is typically not used by a user. The Create API builds an image surface in
memory that matches the input image and then passes it to the Update method.
id(10) Move(long X, long Y);
This method moves the display window around on the image surface. The X and Y parameters
are in display window space, X being the display pixel (column) and Y being the display line
(row) of the image. The display window will move so X,Y is in the center of the display area.
id(11) ClientToImage(long X, long Y, long* iX, long* iY);
The method will take a point on the display surface of the image, and return its image
coordinates.
id(12) ImageToClient(long X, long Y, long* cX, long* cY);
This method will take a point on the image and return its coordinates on the display surface.
Note the returned values are not clipped, and could be out side the display area of the OCX.
id(13) UpdateROI(long* Image, long X, long Y, long sX, long sY,short Shift);
This method allows you to update a portion of an image. As big images can take a long time to
be processed into the control. This API allows a smaller are of an image to be updated. It can
be used to combine images on the same display surface. It uses the copy raster op to update
the image surface, the pixels of the ROI that are on the display surface are replaced with those
in the input image.
id(15) ClearROI(long X, long Y, long sX, long sY, long value);
This method updates an ROI to black, or all zero.
id(16) MoveI(long x, long y);
This method moves the display window so that the point (x,y) in the image is in the center of
the display window. X and y are in image coordinates.
id(17) SwapColors (long a, long b);
This method allows the user to swap the display planes of the image. The parameters are the
plane indexes (0=R,1=G,2=B etc.) to swap. It supports three cases (which are all there are):
Swap 0 with 1
Swap 0 with 2
Swap 1 with 2
id(DISPID_ABOUTBOX) void AboutBox();
This method will display the about box.
T
HE
I
MAGE
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TRUCTURE
The (long *) used in the methods above point to a structure called an image structure which is
used in Alacron’s OIL library and most other places in the Alacron software. It has the following
definition:
typedef struct image_struct {
int nr;
int nc;
int st;
itype_t itype;
int bpp;
void *data;
void (*pfree) ( struct image_struct *pi);
void *extension;