MapPoly

MapPoly Scale and reposition a polygon

#include <Quickdraw.h> Quickdraw

void MapPoly(thePoly, srcRect, destRect );

PolyHandle thePoly ; handle leading to polygon to be mapped

Rect *srcRect ; address of Rect to convert from

Rect *destRect ; address of Rect to convert to

MapPoly resizes and re positions a polygon, converting its coordinates by the

size-ratio and offset of two rectangles. Use this to scale and reposition a

polygon.

thePoly is a handle leading to a variable-length Polygon structure. On

entry, it describes a polygon within srcRect that you wish to remap.

Upon return, all its vertex coordinates have been recalculated

relative to the size and position of destRect .

destRect are the addresses of two 8-byte Rect structures. For typical

operations, thePoly is enclosed by srcRect . It gets mapped to a

similar position within destRect .

Notes: Use this function to resize and reposition a polygon that you wish to expand

or shrink as you move it from one rectangular area to another (typically

smaller or larger) one.

srcRect destRect

thePoly is expanded or shrunk by the ratio of the sizes of srcRect and

destRect. It is moved to a similarly-located position within destRect . This

is a purely mathematical operation and has no effect on the screen unless

thePoly is subsequently drawn or filled.

Referenced by (6):