ScaleViewportExtEx

BOOL ScaleViewportExtEx(hdc, Xnum, Xdenom, Ynum, Ydenom, lpSize)
HDC hdc;	/* handle of device context	*/
int Xnum;	/* horizontal multiplicand	*/
int Xdenom;	/* horizontal divisor	*/
int Ynum;	/* vertical multiplicand	*/
int Ydenom;	/* vertical divisor	*/
LPSIZE lpSize;	/* address of previous viewport extents	*/

The ScaleViewportExtEx function modifies the viewport for the given device context using the ratios formed by the given multiplicands and divisors.

Parameters

hdc

Identifies the device context.

Xnum

Specifies the amount by which to multiply the current horizontal extent.

Xdenom

Specifies the amount by which to divide the current horizontal extent.

Ynum

Specifies the amount by which to multiply the current vertical extent.

Ydenom

Specifies the amount by which to divide the current vertical extent.

lpSize

Points to a SIZE structure. The previous viewport extents (specified in device units) are placed in this structure. If lpSize is NULL, nothing is returned. The SIZE structure has the following format:

typedef struct tagSIZE { /* siz */

LONG cx;

LONG cy;

} SIZE;

Return Value

The return value is TRUE if the function is successful. Otherwise, it is FALSE.

Comments

The viewport extents are modified as shown:

xNewVE = (xOldVE * Xnum) / Xdenom

yNewVE = (yOldVE * Ynum) / Ydenom