m.stone September 26, 1980 5:12 PM
PointDefs
Last Edited by: Stone, January 26, 1983 4:22 pm
DIRECTORY
ControllerDefs: FROM "ControllerDefs",
PointDefs: FROM "PointDefs",
XFormDefs: FROM "XFormDefs",
Real: FROM "Real",
GriffinMemoryDefs USING [CZone];
PointFns: CEDAR PROGRAM
IMPORTS Real,XFormDefs,ControllerDefs, GriffinMemoryDefs
EXPORTS PointDefs=
BEGIN OPEN PointDefs, GriffinMemoryDefs;
xyzw: INTEGER;
ScrToObjMatrix: XFormDefs.XFMDescriptor ← CZone.NEW[XFormDefs.XFormMatrix];
ObjToScrMatrix: XFormDefs.XFMDescriptor ← CZone.NEW[XFormDefs.XFormMatrix];
ValScale: REAL;
OutOfRange: PUBLIC SIGNAL[value: REAL] = CODE;
real space to screen space. Float will return an error if pt is out of range of 32 bits
This will signal if pt is not in [32767..-32768]. ie, inside 16 bits, 2's compliment
ObjValToScrVal: PUBLIC PROCEDURE [val: REAL] RETURNS [INTEGER] =
BEGIN
int: INTEGER;
val ← val*ValScale;
int ← Real.RoundI[val];
RETURN[int];
END;
ObjToScr: PUBLIC PROCEDURE [pt: ObjPt] RETURNS [ScrPt] =
BEGIN
scr: ScrPt;
pt ← XFormDefs.XFormPt[pt,ObjToScrMatrix];
scr[X] ← Real.RoundI[pt[X]];
scr[Y] ← Real.RoundI[pt[Y]];
RETURN[scr];
END;
ScrValToObjVal: PUBLIC PROCEDURE [val: INTEGER] RETURNS [REAL] =
BEGIN
real: REAL ← val/ValScale;
RETURN[real];
END;
ScrToObj: PUBLIC PROCEDURE [pt: ScrPt] RETURNS [ObjPt] =
BEGIN
obj: ObjPt;
FOR xyzw
IN [X..Y]
DO
obj[xyzw] ← pt[xyzw]; --convert to REAL
ENDLOOP;
obj ← XFormDefs.XFormPt[obj,ScrToObjMatrix];
RETURN[obj];
END;
ObjToScrReal:
PUBLIC PROCEDURE [pt: ObjPt]
RETURNS [ScrRealPt] = {
srp: ScrRealPt ← XFormDefs.XFormPt[pt,ObjToScrMatrix];
RETURN[srp];
};
ScrRealToObj:
PUBLIC PROCEDURE [pt: ScrRealPt]
RETURNS [ObjPt] = {
obj: ObjPt ← XFormDefs.XFormPt[pt,ScrToObjMatrix];
RETURN[obj];
};
ScrToScrReal:
PUBLIC PROCEDURE [pt: ScrPt]
RETURNS [ScrRealPt] = {
RETURN[[pt[X], pt[Y]]];
};
ScrRealToScr:
PUBLIC PROCEDURE [pt: ScrRealPt]
RETURNS [ScrPt]= {
RETURN[[Real.RoundI[pt[X]], Real.RoundI[pt[Y]]]];
};
InitPointFns: PUBLIC PROCEDURE =
BEGIN OPEN XFormDefs;
DController: ControllerDefs.DisplayController ← ControllerDefs.ReadDisplayController[];
HController: ControllerDefs.HardcopyController ← ControllerDefs.ReadHardcopyController[];
realpt,dcenterobj: ObjPt;
hcenterscr: ScrPt;
BEGIN
OPEN DController,HController;
--only for open
InitXForms[ObjToScrMatrix];
Scale[[dxscale,dyscale],ObjToScrMatrix];
ValScale ← dxscale; --arbitrary choice
InitXForms[ScrToObjMatrix];
Scale[[1/dxscale,1/dyscale],ScrToObjMatrix];
dcenterobj ← XFormPt[[dxcenter,dycenter],ScrToObjMatrix];
realpt ← [hxcenter,hycenter];
hcenterscr ← ObjToScr[realpt];
Translate[[dcenterobj[X]-hxcenter,dcenterobj[Y]-hycenter],ObjToScrMatrix];
Translate
[[hcenterscr[X]-INTEGER[dxcenter],hcenterscr[Y]-INTEGER[dycenter]],ScrToObjMatrix];
END;
END;
END ..