-- File: MagicViewing.mesa
-- Written by Martin Newell February 1980
-- Implements viewing part of Magic
-- Last edited (Pilot): 20-Jul-81 10:10:05

DIRECTORY

CIFUtilitiesDefs: FROM "CIFUtilitiesDefs" USING [DisplayContext, Rectangle,
	InitCedarGraphics, GetClipRectangle, SetClipRectangle,
	SetUniformView, TrackBox, GetDisplayContext, WatchKeys],
IODefs USING [WriteLine],
Graphics: FROM "Graphics" USING [Translate],
JaMFnsDefs: FROM "JaMFnsDefs" USING [Register, PopInteger, GetReal, PushReal],
Keys: FROM "Keys" USING [KeyName];
 
MagicViewing: PROGRAM
IMPORTS CIFUtilitiesDefs, Graphics, IODefs, JaMFnsDefs =
BEGIN
OPEN CIFUtilitiesDefs, Graphics, IODefs, JaMFnsDefs, Keys;

--Viewing control

CallTrackBox: PROCEDURE =
	BEGIN --expects <x,y, mouse(4,2,1)> (REAL)
	mouseButtons: Keys.KeyName;
	mouse: INTEGER _ PopInteger[];
	y: REAL _ GetReal[];
	x: REAL _ GetReal[];
	SELECT mouse FROM
	4 => mouseButtons _ Red;
	2 => mouseButtons _ Yellow;
	1 => mouseButtons _ Blue;
	ENDCASE => RETURN;
	TrackBox[x,y, mouseButtons];
	END;

Expand: PROCEDURE =
	BEGIN --expects <left,bottom,right,top> (REAL)
	r: Rectangle _ GetClipRectangle[];
	top: REAL _ GetReal[];
	right: REAL _ GetReal[];
	bottom: REAL _ GetReal[];
	left: REAL _ GetReal[];
	SetUniformView[[MIN[left,right],MIN[bottom,top],MAX[left,right],MAX[bottom,top]], r];
	END;

Contract: PROCEDURE =
	BEGIN --expects <left,bottom,right,top> (REAL)
	r: Rectangle _ GetClipRectangle[];
	top: REAL _ GetReal[];
	right: REAL _ GetReal[];
	bottom: REAL _ GetReal[];
	left: REAL _ GetReal[];
	SetUniformView[r, [MIN[left,right],MIN[bottom,top],MAX[left,right],MAX[bottom,top]]];
	END;

Scroll: PROCEDURE =
	BEGIN --expects <xfrom,yfrom, xto,yto> (REAL)
	dc: DisplayContext _ GetDisplayContext[];
	yto: REAL _ GetReal[];
	xto: REAL _ GetReal[];
	yfrom: REAL _ GetReal[];
	xfrom: REAL _ GetReal[];
	Translate[dc, xto-xfrom, yto-yfrom];
	END;

CallSetClipRegion: PROCEDURE =
	BEGIN --expects <left,bottom,right,top> (REAL)
	rt: Rectangle;
	rt.ury _ GetReal[];
	rt.urx _ GetReal[];
	rt.lly _ GetReal[];
	rt.llx _ GetReal[];
	SetClipRectangle[rt];
	END;

CallGetClipRegion: PROCEDURE =
	BEGIN --returns <left,bottom,right,top> (REAL)
	rt: Rectangle _ GetClipRectangle[];
	PushReal[rt.llx];
	PushReal[rt.lly];
	PushReal[rt.urx];
	PushReal[rt.ury];
	END;


--*** START Code ***

WriteLine["Calling InitCedarGraphics"];

InitCedarGraphics[];

WriteLine["Registering trackbox,expand,contract,scroll,watchkeys"];

--Viewing control
Register["trackbox",CallTrackBox];
Register["expand",Expand];
Register["contract",Contract];
Register["scroll",Scroll];
Register["watchkeys",WatchKeys];
Register["setclipregion",CallSetClipRegion];
Register["getclipregion",CallGetClipRegion];

WriteLine["Start code complete"];

END.
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