Macintosh-SW
/
QuickDraw
mirror of https://github.com/jrk/QuickDraw.git
1
0
Fork 0
Code Issues Projects Releases Wiki Activity
QuickDraw/Graf3D.p

478 lines
12 KiB
OpenEdge ABL
Executable File
Raw Permalink Blame History

{$S Graf }
UNIT Graf3D;
{ three-dimensional graphics routines layered on top of QuickDraw }
INTERFACE
USES {$U obj:QuickDraw } QuickDraw;
CONST radConst=57.29578;
TYPE Point3D=RECORD
x: REAL;
y: REAL;
z: REAL;
END;
Point2D=RECORD
x: REAL;
y: REAL;
END;
XfMatrix = ARRAY[0..3,0..3] OF REAL;
Port3DPtr = ^Port3D;
Port3D = RECORD
GPort: GrafPtr;
viewRect: Rect;
xLeft,yTop,xRight,yBottom: REAL;
pen,penPrime,eye: Point3D;
hSize,vSize: REAL;
hCenter,vCenter: REAL;
xCotan,yCotan: REAL;
ident: BOOLEAN;
xForm: XfMatrix;
END;
VAR thePort3D: Port3DPtr;
PROCEDURE Open3DPort (port: Port3DPtr);
PROCEDURE SetPort3D (port: Port3DPtr);
PROCEDURE GetPort3D (VAR port: Port3DPtr);
PROCEDURE MoveTo2D(x,y: REAL); PROCEDURE MoveTo3D(x,y,z: REAL);
PROCEDURE LineTo2D(x,y: REAL); PROCEDURE LineTo3D(x,y,z: REAL);
PROCEDURE Move2D(dx,dy: REAL); PROCEDURE Move3D(dx,dy,dz: REAL);
PROCEDURE Line2D(dx,dy: REAL); PROCEDURE Line3D(dx,dy,dz: REAL);
PROCEDURE ViewPort (r: Rect);
PROCEDURE LookAt (left,top,right,bottom: REAL);
PROCEDURE ViewAngle (angle: REAL);
PROCEDURE Identity;
PROCEDURE Scale (xFactor,yFactor,zFactor: REAL);
PROCEDURE Translate (dx,dy,dz: REAL);
PROCEDURE Pitch (xAngle: REAL);
PROCEDURE Yaw (yAngle: REAL);
PROCEDURE Roll (zAngle: REAL);
PROCEDURE Skew (zAngle: REAL);
PROCEDURE TransForm (src: Point3D; VAR dst: Point3D);
FUNCTION Clip3D (src1,src2: Point3D; VAR dst1,dst2: POINT): BOOLEAN;
PROCEDURE SetPt3D (VAR pt3D: Point3D; x,y,z: REAL);
PROCEDURE SetPt2D (VAR pt2D: Point2D; x,y: REAL);
IMPLEMENTATION
PROCEDURE Open3DPort(* port: Port3DPtr *);
{ initialize all values in port^ to their defaults }
BEGIN
thePort3D:=port;
port^.GPort:=thePort;
ViewPort(thePort^.portRect);
WITH thePort^.portRect DO LookAt(left,top,right,bottom);
ViewAngle(0);
Identity;
MoveTo3D(0,0,0);
END;
PROCEDURE SetPort3D(* port: Port3DPtr *);
{ change to another Port3D }
BEGIN
thePort3D:=port;
SetPort(port^.GPort);
END;
PROCEDURE GetPort3D(* VAR port: Port3DPtr *);
{ inquire the current Port3D }
BEGIN
port:=thePort3D;
END;
PROCEDURE MoveTo3D(* x,y,z: REAL *);
{ Move from current position to x,y,z without drawing. }
VAR pt1,pt2: POINT;
oldPrime: Point3D;
BEGIN
WITH thePort3D^ DO
BEGIN
oldPrime:=penPrime;
pen.x:=x;
pen.y:=y;
pen.z:=z;
TransForm(pen,penPrime);
IF Clip3D(oldPrime,penPrime,pt1,pt2) THEN MoveTo(pt2.H,pt2.V);
END;
END;
PROCEDURE LineTo3D(* x,y,z: REAL *);
{ draw a 3-D line from current position to x,y,z. }
VAR oldPrime: Point3D;
pt1,pt2: POINT;
BEGIN
WITH thePort3D^ DO
BEGIN
oldPrime:=penPrime;
pen.x:=x;
pen.y:=y;
pen.z:=z;
TransForm(pen,penPrime);
IF Clip3D(oldPrime,penPrime,pt1,pt2) THEN
BEGIN
MoveTo(pt1.h,pt1.v);
LineTo(pt2.H,pt2.V);
END;
END;
END;
PROCEDURE Move3D(* dx,dy,dz: REAL *);
BEGIN
WITH thePort3D^ DO MoveTo3D(pen.x+dx,pen.y+dy,pen.z+dz);
END;
PROCEDURE Line3D(* dx,dy,dz: REAL *);
BEGIN
WITH thePort3D^ DO LineTo3D(pen.x+dx,pen.y+dy,pen.z+dz);
END;
PROCEDURE MoveTo2D(* x,y: REAL *);
BEGIN
MoveTo3D(x,y,thePort3D^.pen.z);
END;
PROCEDURE Move2D(* dx,dy: REAL *);
BEGIN
Move3D(dx,dy,0.0);
END;
PROCEDURE LineTo2D(* x,y: REAL *);
BEGIN
LineTo3D(x,y,thePort3D^.pen.z);
END;
PROCEDURE Line2D(* dx,dy: REAL *);
BEGIN
Line3D(dx,dy,0.0);
END;
PROCEDURE ViewLook;
{ re-calculate offsets and scales after LookAt or ViewPort }
BEGIN
WITH thePort3D^ DO
WITH viewRect DO
BEGIN
hSize:=(right-left)/2.0;
vSize:=(bottom-top)/(-2.0); { vert pos down, y pos up }
hCenter:=left + hSize;
vCenter:=top - vSize;
END;
END;
PROCEDURE ViewPort(* r: Rect *);
{ specify what portion of the folder to map onto }
BEGIN
thePort3D^.viewRect:=r;
ViewLook; { re-calculate scales and offsets }
END;
PROCEDURE LookAt(* left,top,right,bottom: REAL *);
{ specify the real number coordinates of the portRect }
BEGIN
WITH thePort3D^ DO
BEGIN
xLeft:=left;
xRight:=right;
yBottom:=bottom;
yTop:=top;
eye.x:=(left+right)/2.0;
eye.y:=(top+bottom)/2.0;
END;
ViewLook; { re-calculate scales and offsets }
END;
PROCEDURE ViewAngle(* angle: REAL *);
{ specify the horizontal angle subtended by the viewing pyramid }
BEGIN
WITH thePort3D^ DO
BEGIN
IF angle < 0.1 THEN angle:=0.1;
angle:=angle/(2.0*radConst); { halve angle & convert to rad }
xCotan:=COS(angle)/SIN(angle); { remember for perspective calc }
yCotan:=xCotan * (xRight-xLeft)/(yTop-yBottom);
eye.z:=xCotan * (xRight-xLeft)/2;
END;
END;
PROCEDURE TransForm(* src: Point3D; VAR dst: Point3D *);
{ use the current xForm matrix to transform }
{ a 3D source point into a 3D destination point. }
BEGIN
IF thePort3D^.ident THEN dst:=src
ELSE WITH thePort3D^ DO
BEGIN
dst.x:=src.x * xForm[0,0] + src.y * xForm[1,0]
+ src.z * xForm[2,0] + xForm[3,0];
dst.y:=src.x * xForm[0,1] + src.y * xForm[1,1]
+ src.z * xForm[2,1] + xForm[3,1];
dst.z:=src.x * xForm[0,2] + src.y * xForm[1,2]
+ src.z * xForm[2,2] + xForm[3,2];
END;
END;
FUNCTION Clip3D(* src1,src2: Point3D; VAR dst1,dst2: POINT *);
{ do full 3D clipping to viewing pyramid and return 2D }
{ screen coords in dst. Function value true if visible. }
LABEL 0;
TYPE Edge=(left,top,right,bottom);
OutCode=SET OF Edge;
VAR c,c1,c2: OutCode;
pt3D: Point3D;
t: REAL;
pt1,pt2: POINT;
PROCEDURE Code(pt3D: Point3D; VAR c: OutCode);
BEGIN
c:=[];
IF pt3D.x < -pt3D.z THEN c:=[left] ELSE IF pt3D.x > pt3D.z THEN c:=[right];
IF pt3D.y < -pt3D.z THEN c:=c+[bottom] ELSE IF pt3D.y > pt3D.z THEN c:=c+[top];
END;
BEGIN
Clip3D:=FALSE;
WITH thePort3D^ DO
BEGIN { convert both points into clipping coord system }
src1.x:=(src1.x - eye.x) * xCotan;
src1.y:=(src1.y - eye.y) * yCotan;
src1.z:=eye.z - src1.z;
src2.x:=(src2.x - eye.x) * xCotan;
src2.y:=(src2.y - eye.y) * yCotan;
src2.z:=eye.z - src2.z;
END;
Code(src1,c1); Code(src2,c2);
WHILE c1+c2 <> [] DO
BEGIN
IF c1*c2 <> [] THEN GOTO 0; { both out on same side }
c:=c1; IF c=[] THEN c:=c2;
IF left IN c THEN { calc intersect with left edge }
BEGIN
t:=(src1.z+src1.x) / ((src1.x-src2.x) - (src2.z-src1.z));
pt3D.z:=t*(src2.z-src1.z) + src1.z;
pt3D.x:=-pt3D.z;
pt3D.y:=t*(src2.y-src1.y) + src1.y;
END
ELSE IF right IN c THEN { calc intersect with right edge }
BEGIN
t:=(src1.z-src1.x) / ((src2.x-src1.x) - (src2.z-src1.z));
pt3D.z:=t*(src2.z-src1.z) + src1.z;
pt3D.x:=pt3D.z;
pt3D.y:=t*(src2.y-src1.y) + src1.y;
END
ELSE IF bottom IN c THEN { calc intersect with bottom edge }
BEGIN
t:=(src1.z+src1.y) / ((src1.y-src2.y) - (src2.z-src1.z));
pt3D.z:=t*(src2.z-src1.z) + src1.z;
pt3D.x:=t*(src2.x-src1.x) + src1.x;
pt3D.y:=-pt3D.z;
END
ELSE IF top IN c THEN { calc intersect with top edge }
BEGIN
t:=(src1.z-src1.y) / ((src2.y-src1.y) - (src2.z-src1.z));
pt3D.z:=t*(src2.z-src1.z) + src1.z;
pt3D.x:=t*(src2.x-src1.x) + src1.x;
pt3D.y:=pt3D.z;
END;
IF c=c1 THEN BEGIN src1:=pt3D; Code(src1,c1); END
ELSE BEGIN src2:=pt3D; Code(src2,c2); END;
END;
{ if we reach here, the line from src1 to src2 is visible }
Clip3D:=TRUE;
WITH thePort3D^ DO
WITH GPort^ DO
BEGIN { convert clip coords to screen coords }
dst1.H:=ROUND(hCenter + hSize * src1.x / src1.z);
dst1.V:=ROUND(vCenter + vSize * src1.y / src1.z);
dst2.H:=ROUND(hCenter + hSize * src2.x / src2.z);
dst2.V:=ROUND(vCenter + vSize * src2.y / src2.z);
END;
0: END;
PROCEDURE Identity;
{ reset the transform matrix to identity }
VAR ROW,COL: INTEGER;
BEGIN;
WITH thePort3D^ DO
BEGIN
FOR ROW:=0 TO 3 DO
FOR COL:=0 TO 3 DO
IF ROW=COL THEN xForm[ROW,COL]:=1.0
ELSE xForm[ROW,COL]:=0.0;
ident:=TRUE; { SET FLAG SO xForm CAN BE SKIPPED }
END;
END;
PROCEDURE Scale(* xFactor,yFactor,zFactor: REAL *);
{ change xForm matrix to provide scaling }
VAR ROW: INTEGER;
BEGIN
WITH thePort3D^ DO
BEGIN
ident:=FALSE;
FOR ROW:=0 TO 3 DO
BEGIN
xForm[ROW,0]:=xForm[ROW,0]*xFactor;
xForm[ROW,1]:=xForm[ROW,1]*yFactor;
xForm[ROW,2]:=xForm[ROW,2]*zFactor;
END;
END;
END;
PROCEDURE Translate(* dx,dy,dz: REAL *);
{ change xForm matrix to translate }
BEGIN
WITH thePort3D^ DO
BEGIN
ident:=FALSE;
xForm[3,0]:=xForm[3,0]+dx;
xForm[3,1]:=xForm[3,1]+dy;
xForm[3,2]:=xForm[3,2]+dz;
END;
END;
PROCEDURE Pitch(* xAngle: REAL *);
{ change xForm matrix to rotate xAngle degrees around x-Axis }
VAR si,co,TEMP: REAL;
BEGIN
xAngle:=xAngle/radConst; { convert degrees to rads }
si:=SIN(xAngle); co:=COS(xAngle);
WITH thePort3D^ DO
BEGIN
ident:=FALSE;
TEMP:=xForm[0,1]*co+xForm[0,2]*si;
xForm[0,2]:=xForm[0,2]*co-xForm[0,1]*si; xForm[0,1]:=TEMP;
TEMP:=xForm[1,1]*co+xForm[1,2]*si;
xForm[1,2]:=xForm[1,2]*co-xForm[1,1]*si; xForm[1,1]:=TEMP;
TEMP:=xForm[2,1]*co+xForm[2,2]*si;
xForm[2,2]:=xForm[2,2]*co-xForm[2,1]*si; xForm[2,1]:=TEMP;
TEMP:=xForm[3,1]*co+xForm[3,2]*si;
xForm[3,2]:=xForm[3,2]*co-xForm[3,1]*si; xForm[3,1]:=TEMP;
END;
END;
PROCEDURE Yaw(* yAngle: REAL *);
{ change xForm matrix to rotate yAngle degrees around y-Axis }
VAR si,co,TEMP: REAL;
BEGIN
yAngle:=yAngle/radConst; { convert degrees to rads }
si:=SIN(yAngle); co:=COS(yAngle);
WITH thePort3D^ DO
BEGIN
ident:=FALSE;
TEMP:=xForm[0,0]*co-xForm[0,2]*si;
xForm[0,2]:=xForm[0,0]*si+xForm[0,2]*co; xForm[0,0]:=TEMP;
TEMP:=xForm[1,0]*co-xForm[1,2]*si;
xForm[1,2]:=xForm[1,0]*si+xForm[1,2]*co; xForm[1,0]:=TEMP;
TEMP:=xForm[2,0]*co-xForm[2,2]*si;
xForm[2,2]:=xForm[2,0]*si+xForm[2,2]*co; xForm[2,0]:=TEMP;
TEMP:=xForm[3,0]*co-xForm[3,2]*si;
xForm[3,2]:=xForm[3,0]*si+xForm[3,2]*co; xForm[3,0]:=TEMP;
END;
END;
PROCEDURE Roll(* zAngle: REAL *);
{ change xForm matrix to rotate zAngle degrees around z-Axis }
VAR si,co,TEMP: REAL;
BEGIN
zAngle:=zAngle/radConst; { convert degrees to rads }
si:=SIN(zAngle); co:=COS(zAngle);
WITH thePort3D^ DO
BEGIN
ident:=FALSE;
TEMP:=xForm[0,0]*co+xForm[0,1]*si;
xForm[0,1]:=xForm[0,1]*co-xForm[0,0]*si; xForm[0,0]:=TEMP;
TEMP:=xForm[1,0]*co+xForm[1,1]*si;
xForm[1,1]:=xForm[1,1]*co-xForm[1,0]*si; xForm[1,0]:=TEMP;
TEMP:=xForm[2,0]*co+xForm[2,1]*si;
xForm[2,1]:=xForm[2,1]*co-xForm[2,0]*si; xForm[2,0]:=TEMP;
TEMP:=xForm[3,0]*co+xForm[3,1]*si;
xForm[3,1]:=xForm[3,1]*co-xForm[3,0]*si; xForm[3,0]:=TEMP;
END;
END;
PROCEDURE Skew(* zAngle: REAL *);
{ change xForm matrix to skew zAngle degrees around z-Axis }
{ x := (x + y*TAN(zAngle)) zAngle limited to +-90 degrees }
VAR co,TA: REAL;
COL: INTEGER;
BEGIN
zAngle:=zAngle/radConst; { convert degrees to rads }
co:= COS(zAngle);
IF ABS(co) > 1.0E-5 THEN
BEGIN
TA:= SIN(zAngle)/co;
WITH thePort3D^ DO
BEGIN
ident:=FALSE;
FOR COL:=0 TO 2 DO
xForm[1,COL]:=xForm[1,COL]+xForm[0,COL]*TA;
END;
END;
END;
PROCEDURE SetPt3D(* VAR pt3D: Point3D; x,y,z: REAL *);
BEGIN
pt3D.x:=x;
pt3D.y:=y;
pt3D.z:=z;
END;
PROCEDURE SetPt2D(* VAR pt2D: Point2D; x,y: REAL *);
BEGIN
pt2D.x:=x;
pt2D.y:=y;
END;
END. { of Unit }
Reference in New Issue View Git Blame Copy Permalink