surface.c

Intro/: Directory containing introductory examples. HelloWorld.c A simple program that draws a bo

    include 'phigs.f1.0h';		/* get the HP-PHIGS aliases */
main()
{
    include 'phigs.f2.0h';		/* get the HP-PHIGS constants */

    int	WorkstnID;		/* workstation identifier */
    parameter (WorkstnID = 1);		/* value chosen by the user */
    int	ConnID;			/* connection identifier */
    int	WorkstnType;		/* workstation type */
    parameter (WorkstnType = POIDDX);	/* out/in, direct, sngl bfr, X */
    float	CtrlPtsX(12),CtrlPtsY(12),CtrlPtsZ(12)	/* control points */
    data	CtrlPtsX / 0.0, 0.5,1.0, 0.0, 0.5,1.0, 0.0, 0.5,1.0, 0.0, 0.5,1.0/
    data	CtrlPtsY / 0.0, 0.3, 0.2, 0.1, 0.5, 0.4, 0.3, 0.4, 0.1, 0.0, 0.2, 0.3/
    data	CtrlPtsZ / 0.0, 0.0, 0.0, 0.3, 0.3, 0.3, 0.6, 0.6, 0.6, 0.9, 0.9, 0.9/
    float	uKnotVector(6), vKnotVector(8)	/* knot vectors */
    data	uKnotVector /0.0, 0.0, 0.0, 1.0, 1.0, 1.0/
    data	vKnotVector /0.0, 0.0, 0.0, 0.0, 1.0, 1.0, 1.0, 1.0/
    float	StepSizeData(4);		/* sent to "pprec" */
    data	StepSizeData / 0.1, 0.1, 0.1, 0.1/	/* u, v exterior; u, v interior */
    int	TheMesh, MeshLabel;	/* structure identifier, label */
    parameter (TheMesh = 1, MeshLabel = 1)	/* values chosen by the user */
    int	LightsOn(2);		/* sent to "pslss" */
    data	LightsOn /1, 2/;		/* turn both lights on */
    float	Gray(3);			/* define RGB triple */
    data	Gray / 0.5, 0.0, 0.0/;	/* RGB for 50% gray */
    float	ThetaMin,ThetaMax, dTheta, Theta/* loop control variables */
    parameter (ThetaMin = 0.0, ThetaMax = 770.0, dTheta =  0.5);
    float	xform(4,4);		/* transformation matrix */
    int	Error;			/* error-return variable */
    char	DataRec[80]		(10);		/* sent to "pprec" */
    int	DataRecLen;		/* ditto */
    int	Dummy(1);		/* dummy variable */
    int ChoiceStatus, ChoiceNum;	/* choice status and value */
    int	u, v;			/* loop control variables */
    int	I, Iu, Iv;		/* temporary array indexes */


    float	rad, deg;		/* type the statement function */
    rad(deg) = 	((deg) * 3.14159265358979/180.0)	/* convert degrees to radians */

    popen_phigs(stderr, 0)	/* open phigs */
    pescape_u4('/dev/screen/phigs_window', ConnID)	/* get connection ID */
    popen_ws(WorkstnID, ConnID, WorkstnType)/* open workstation */
    pescape_u250(WorkstnID, 0);		/* set colour env.: Direct */
    pset_hlhsr_mode(WorkstnID, PHRZBF);	/* set HLHSR mode */
    DefineLight(WorkstnID, 1,;	/* define light source 1.0.. */
      + 	1,;				/*   type: ambient */
      + 	0.0, 0.0, 0.0,;			/*   location: don't care */
      + 	 0.2, 0.2, 0.2,;			/*   colour: gray */
      + 	0.0, 0.0);				/*   attenuation: don't care */
    DefineLight(WorkstnID, 2,;	/* define light source 2.0.. */
      + 	2,;				/*   type: directional */
      + 	5.0, 2.0, 7.0,;			/*   location: right shoulder */
      + 	 0.5, 0.5, 0.5,;			/*   colour: gray */
      + 	0.0, 0.0);				/*   attenuation: don't care */
    ppost_struct(WorkstnID, TheMesh, 1.0)	/* mark structure for display */
    /* =  =  =  define the spline-generating structure  =  =  =  =  =  =  =  =  =  =  =  =  =  =  =  =  =  =  =  =  =  =  =  =  =  =  =  =  */
    popen_struct(TheMesh);		/* open structure */
    pset_light_source_st(2, LightsOn, 0, Dummy);	/* set light source state */
    psire(4);			/* set int. reflectance eq'n */
    /*---- set up transformations -------------------------------------------*/
    ptranslate3(- 0.5, 0.0, - 0.5, Error, xform)	/* 3d translate: to origin */
    pset_local_tran3(xform, PTYPE_REPLACE);	/* set local transformation */
    pscale3(0.7, 0.7, 0.7, Error, xform)	/* 3d scale to 70% */
    pset_local_tran3(xform, PTYPE_POSTCONCAT);	/* set local transformation */
    protate_x(rad(30), Error, xform);	/* rotate about X axis */
    pset_local_tran3(xform, PTYPE_POSTCONCAT);	/* set local transformation */
    protate_y(rad(0), Error, xform);	/* rotate about Y axis */
    plabel(MeshLabel);		/* label */
    pset_local_tran3(xform, PTYPE_POSTCONCAT);	/* set local transformation */
    ptranslate3(0.5, 0.3, 0.5, Error, xform)	/* 3d translate: into position */
    pset_local_tran3(xform, PTYPE_POSTCONCAT);	/* set local transformation */
    /*---- delta t (independent variable) of 0.1 ----------------------------*/
    pprec(0, Dummy, 4, StepSizeData,	/* pack data record */
      + 	0, 0, '', 10, Error, DataRecLen, DataRec);
    if (Error <> 0){
	printf("Error", Error, "in pprec.");
	exit(1);
    }
    pset_surf_approx_crit(-3, DataRecLen, DataRec)	/* set surface approx. criteria */
    /*---- define the b-spline surface --------------------------------------*/
    pset_int_colr(1, 0, Gray);		/* set interior colour */
    pset_int_style(PSTYLE_SOLID);			/* set interior style */
    pnubss(;			/* non-uniform b-spline surface */
      + 	3, 4,;				/*   u, v order */
      + 	3, 4,;				/*   u, v control points */
      + 	6, 8,;				/*   u, v knots */
      + 	uKnotVector, vKnotVector,;	/*   u, v knot vectors */
      + 	PNRAT,;				/*   non-rational surface */
      + 	CtrlPtsX, CtrlPtsY, CtrlPtsZ,;	/*   control points' XYZs */
      + 	Dummy,;				/*   dummy homogeneous coords */
      + 	0.0, 0.0, 0.0, 0.0,;			/*   u/v min/max: ignored */
      + 	0, Dummy);			/*   no trimming curves */
    /*---- draw control-point grid ------------------------------------------*/
    pset_linetype(PLINE_DOT);			/* set line type */
    for (u = 1; u <= 3; u++) {
	for (v = 1; v <= 4; v++) {
	  I = (v-1) * 3 + u;		/* index of X(u,v) */
	  Iu = (v-1) * 3 + u + 1;		/* index of X(u + 1,v) */
	  Iv = v * 3 + u;			/* index of X(u,v + 1) */
	  if (u < 3);		/* unless on right edge... */
      +           Line(CtrlPtsX(I), CtrlPtsY(I), CtrlPtsZ(I),
      +           CtrlPtsX(Iu), CtrlPtsY(Iu), CtrlPtsZ(Iu));
	  if (v < 4);		/* unless on right edge... */
      +           Line(CtrlPtsX(I), CtrlPtsY(I), CtrlPtsZ(I),
      +           CtrlPtsX(Iv), CtrlPtsY(Iv), CtrlPtsZ(Iv));
	}
    }
    pclst;			/* close structure */
    /* =  =  =  rotate the spline surface  =  =  =  =  =  =  =  =  =  =  =  =  =  =  =  =  =  =  =  =  =  =  =  =  =  =  =  =  =  =  =  =  =  =  =  =  =  =  =  =  =  */
    Theta = ThetaMin;			/* initialize loop control var. */
    do while (Theta < ThetaMax);	/* for each angle... */
	popen_struct(TheMesh);		/* open structure */
	protate_y(rad(Theta), Error, xform)	/* rotate about Y axis */
	pset_elem_ptranslate(1);			/* set element pointer: BOS */
	pseplabel(MeshLabel);	/* set element pointer at label */
	poffset_elem_ptranslate(1);			/* offset element pointer:  + 1 */
	pset_edit_mode(PEDIT_REPLACE);		/* set edit mode */
	pset_local_tran3(xform, PTYPE_POSTCONCAT);	/* set local transformation */
	pclst;			/* close structure */
	pupd_ws(WorkstnID, PFLAG_PERFORM);	/* update the workstation */
	Theta = Theta + dTheta;		/* increment angle */
    }
    /*---- make keyboard a choice device so "[Return] to quit." works ------*/
    pset_choice_mode(WorkstnID, 2, POP_REQ, PSWITCH_NO_ECHO)/* set choice mode on keyboard */
    preq_choice(WorkstnID, 2, ChoiceStatus, ChoiceNum) /* request choice */
    pclose_ws(WorkstnID);		/* close workstation */
    pclph;			/* close phigs */

};				/* end of program */
/* ***************************************************************************** */
    subroutine Line(X1, Y1, Z1, X2, Y2, Z2);
    float	X1, Y1, Z1, X2, Y2, Z2;	/* "from" point, "to" point */
    
    float	X(2), Y(2), Z(2);	/* for 3D polyline */
    
    X(1) = X1;				/* \ */
    Y(1) = Y1;				/*  \ */
    Z(1) = Z1;				/*   \ put the individual */
    X(2) = X2;				/*   / values into the arrays */
    Y(2) = Y2;				/*  / */
    Z(2) = Z2;				/* / */
    ppolyline3(2, X, Y, Z);		/* polyline 3D */
    return
}
/* ***************************************************************************** */
    subroutine DefineLight(WorkstnID, LightNo, LightType, X,Y,Z,
      +   R,G,B, A1,A2);
    int	WorkstnID;		/* workstation identifier */
    int	LightNo;			/* which light being defined? */
    int LightType;		/* ambient? directional? posit.? */
    float	X, Y, Z;			/* location/direction of light */
    float	R, G, B;			/* color of light */
    float	A1, A2;			/* atten. factors for positional */

    int Offset;			/* to put RGB values in array */
    int	Error;			/* error-return variable */
    int UseRGB(2);		/* use RGB, not indexes */
    data	UseRGB /1, 0/;		/* say it so "pprec" understands */
    float	Reals(8);		/* defined for "pprec" */
    int	Recs;			/* defined by "pprec" */
    char	DataRec[80]		(8);		/* defined by "pprec" */

    if (LightType == 1){;	/* defining ambient light */
	Offset = 0;			/* offset of RGB in float array */
    else
	Reals(1) = X;			/* \ */
	Reals(2) = Y;			/*  > insert location/direction */
	Reals(3) = Z;			/* / */
	if (LightType == 2){;	/* defining directional light */
	  Offset = 3;			/* offset of RGB in float array */
	else /* (LightType = 3)			! defining positional light */
	  Offset = 5;			/* offset of RGB in float array */
	  Reals(4) = A1;		/* 1st attenuation coefficient */
	  Reals(5) = A2;		/* 2nd attenuation coefficient */
	}
    }
    Reals(Offset + 1) = R;			/* \ */
    Reals(Offset + 2) = G;			/*  > install colour value */
    Reals(Offset + 3) = B;			/* / */
    if (LightType == 1);		/* ambient */
      +   pprec(2,UseRGB, 3,Reals, 0,80,'', 8, Error, Recs,DataRec);
    if (LightType == 2);		/* directional */
      +   pprec(2,UseRGB, 6,Reals, 0,80,'', 8, Error, Recs,DataRec);
    if (LightType == 3);		/* positional */
      +   pprec(2,UseRGB, 8,Reals, 0,80,'', 8, Error, Recs,DataRec);
    if (Error <> 0){
	printf("Error", Error, "in pprec.  Terminating.");
	exit(1);
    }
    pset_light_source_rep(WorkstnID, LightNo, LightType,	/* set light source rep. */
      + 	Recs, DataRec);
    return
}