#include <windows.h> BOOL32 ScaleViewportExtEx ( HDC32 hdc, INT32 xNum, INT32 xDenom, INT32 yNum, INT32 yDenom, LPSIZE32 size );
| U16 | Value | 
| 0 | yDenom | 
| 1 | yNum | 
| 2 | xDenom | 
| 3 | xNum | 
width = (width * xNum) / xDenom; height = (height * yNum) / yDenom;see this file for explanation.