/*  GadTools layout toolkit
**
**  Copyright © 1993-1995 by Olaf `Olsen' Barthel
**  Freely distributable.
*/

#include "gtlayout_global.h"

VOID __regargs
LTP_GetDisplayClip(struct Screen *screen,WORD *left,WORD *top,WORD *width,WORD *height)
{
	struct TagItem tags[2] = { VTAG_VIEWPORTEXTRA_GET, NULL, TAG_DONE };

	if(!VideoControl(screen -> ViewPort . ColorMap,tags))
	{
		struct ViewPortExtra	*vpe = (struct ViewPortExtra *)tags[0] . ti_Data;
		struct Rectangle		 clip;

		QueryOverscan(GetVPModeID(&screen -> ViewPort),&clip,OSCAN_TEXT);

		*width	= vpe -> DisplayClip . MaxX - vpe -> DisplayClip . MinX + 1;
		*height = vpe -> DisplayClip . MaxY - vpe -> DisplayClip . MinY + 1;

		if(*width < clip . MaxX - clip . MinX + 1)
			*width = clip . MaxX - clip . MinX + 1;

		if(*height < clip . MaxY - clip . MinY + 1)
			*height = clip . MaxY - clip . MinY + 1;

		if(*width > screen -> Width)
			*width = screen -> Width;

		if(*height > screen -> Height)
			*height = screen -> Height;
	}
	else
	{
		*width	= screen -> Width;
		*height = screen -> Height;
	}

	*left = screen -> LeftEdge;
	*top  = screen -> TopEdge;

	if(*left > 0)
		*left = 0;
	else
		*left = -(*left);

	if(*top > 0)
		*top = 0;
	else
		*top = -(*top);

	if((*left > screen -> Width) || (*left < 0))
		*left = 0;

	if ((*top > screen -> Height) || (*top < 0))
		*top = 0;
}