LocalToGlobal Obtain global ( screen) value of local point

#include <Quickdraw.h> Quickdraw

Point *thePoint ; address of point to convert; receives result

LocalToGlobal converts the coordinates of a local point (relative to the

current GrafPort origin) to global ( screen) coordinates. It can then be

compared to other global points or converted to the local coordinates of a

thePoint is the address of a 4-byte Point structure, expressed in coordinates

of the current GrafPort. Upon return, it will contain the coordinates

of that same position, expressed to the global, screen coordinates.

Notes: The result of the conversion is based relative to coordinate (0,0) of the

device's BitMap; typically the screen.

To convert the coordinates of a rectangle from local to global, you can apply

Rect theRect;

LocalToGlobal( & topleft( theRect);

LocalToGlobal( &.botRight( theRect) );

Rectangles and other graphic elements ( regions and polygons) can be

converted to the global coordinate system via a 3-step sequence:

1 Use LocalToGlobal to obtain the global coordinates of one corner of a

2 Use SubPt or DeltaPoint to determine the difference between the local

For instance, the following sequence converts a local Polygon to global

Point tmpPt, localPt;

PolyHandle thePoly;

tmpPt= localPt=topLeft( (*thePoly)->polyBBox ); /* get corner */

LocalToGlobal( &tmpPt ); /* convert to global */

SubPt( localPt, &tmpPt ); /* find difference */

OffsetPoly( thePoly, tmpPt.h, tmpPt.v ); /* move the item */