/******************************************************************************
* CagdCmpt.c - Make objects compatible.					      *
*******************************************************************************
* Written by Gershon Elber, Sep. 91.					      *
******************************************************************************/

#ifdef __MSDOS__
#include <stdlib.h>
#include <string.h>
#include <alloc.h>
#endif /* __MSDOS__ */

#include "cagd_loc.h"

/******************************************************************************
* Given two curves, make the compatible by:				      *
* 1. Coercing their point type to be the same.				      *
* 2. Make them have the same curve type.				      *
* 3. Raising the degree of the lower one to be the same.		      *
* 4. Refine them to a common knot vector (If Bspline).			      *
* Note 3 is preformed if SameOrder TRUE, 4 if SameKV TRUE.		      *
* Returns TRUE if succesfull. Both Curves are modified IN PLACE.	      *
******************************************************************************/
CagdBType CagdMakeCrvsCompatible(CagdCrvStruct **Crv1, CagdCrvStruct **Crv2,
				 CagdBType SameOrder, CagdBType SameKV)
{
    int i, KV1Len, KV2Len, RefLen;
    CagdRType *KV1, *KV2, *RefKV;
    CagdCrvStruct *TCrv;
    CagdPointType
	CommonPType = CagdMergePointType((*Crv1) -> PType, (*Crv2) -> PType);

    /* Make the point types compatible. */
    if (CommonPType != (*Crv1) -> PType) {
	TCrv = CagdCoerceCrvTo(*Crv1, CommonPType);
	CagdCrvFree(*Crv1);
	*Crv1 = TCrv;
    }
    if (CommonPType != (*Crv2) -> PType) {
	TCrv = CagdCoerceCrvTo(*Crv2, CommonPType);
	CagdCrvFree(*Crv2);
	*Crv2 = TCrv;
    }

    /* If incompatible curve type - make it the same as well. */
    if ((*Crv1) -> GType != (*Crv2) -> GType) {
	/* If power basis - promote to bezier: */
	if ((*Crv1) -> GType == CAGD_CPOWER_TYPE) {
	    TCrv = CnvrtPower2BezierCrv(*Crv1);
	    CagdCrvFree(*Crv1);
	    *Crv1 = TCrv;
	}
	if ((*Crv2) -> GType == CAGD_CPOWER_TYPE) {
	    TCrv = CnvrtPower2BezierCrv(*Crv2);
	    CagdCrvFree(*Crv2);
	    *Crv2 = TCrv;
	}

	/* Now both curves may be either bezier or bspline curves. */
	if ((*Crv1) -> GType != (*Crv2) -> GType) {
	    /* If bezier basis - promote to bspline: */
	    if ((*Crv1) -> GType == CAGD_CBEZIER_TYPE) {
		TCrv = CnvrtBezier2BsplineCrv(*Crv1);
		CagdCrvFree(*Crv1);
		*Crv1 = TCrv;
	    }
	    if ((*Crv2) -> GType == CAGD_CBEZIER_TYPE) {
		TCrv = CnvrtBezier2BsplineCrv(*Crv2);
		CagdCrvFree(*Crv2);
		*Crv2 = TCrv;
	    }

	}
    }

    if (SameOrder) {
	/* Raise the degree of the lower one. */
	for (i = (*Crv1) -> Order; i < (*Crv2) -> Order; i++) {
	    TCrv = CagdCrvDegreeRaise(*Crv1);
	    CagdCrvFree(*Crv1);
	    *Crv1 = TCrv;
	}
	for (i = (*Crv2) -> Order; i < (*Crv1) -> Order; i++) {
	    TCrv = CagdCrvDegreeRaise(*Crv2);
	    CagdCrvFree(*Crv2);
	    *Crv2 = TCrv;
	}
    }

    if (SameKV) {
	/* If bspline curve - make sure knot vectors are the same. */
	if ((*Crv1) -> GType == CAGD_CBSPLINE_TYPE) {
	    KV1 = (*Crv1) -> KnotVector;
	    KV2 = (*Crv2) -> KnotVector;
	    KV1Len = (*Crv1) -> Length + (*Crv1) -> Order;
	    KV2Len = (*Crv2) -> Length + (*Crv2) -> Order;

	    /* Affine map second knot vector to span same parametric domain. */
	    BspKnotAffineTrans(KV2, KV2Len, KV1[0] - KV2[0],
			       (KV1[KV1Len - 1] - KV1[0]) /
			       (KV2[KV2Len - 1] - KV2[0]));

	    /* Find knots in KV2 which are not in KV1 and refine Crv1 there. */
	    RefKV  = BspKnotSubtrTwo(KV2, KV2Len, KV1, KV1Len, &RefLen);
	    if (RefLen > 0) {
		TCrv = CagdCrvRefineAtParams(*Crv1, FALSE, RefKV, RefLen);
		CagdCrvFree(*Crv1);
		*Crv1 = TCrv;
		KV1 = (*Crv1) -> KnotVector;
		KV1Len = (*Crv1) -> Length + (*Crv1) -> Order;
	    }
	    CagdFree((VoidPtr) RefKV);

	    /* Find knots in KV1 which are not in KV2 and refine Crv2 there. */
	    RefKV  = BspKnotSubtrTwo(KV1, KV1Len, KV2, KV2Len, &RefLen);
	    if (RefLen > 0) {
		TCrv = CagdCrvRefineAtParams(*Crv2, FALSE, RefKV, RefLen);
		CagdCrvFree(*Crv2);
		*Crv2 = TCrv;
	    }
	    CagdFree((VoidPtr) RefKV);
	}
    }

    return TRUE;
}