/* Copyright 2014 Adobe Systems Incorporated (http://www.adobe.com/). All Rights Reserved.
   This software is licensed as OpenSource, under the Apache License, Version 2.0.
   This license is available at: http://opensource.org/licenses/Apache-2.0. */

/*
  blend.h -- interface to weight vector computations
*/

#ifndef BLEND_H
#define BLEND_H

#include "supportaszone.h"

#ifndef MAXAXES
#define MAXAXES 15 /* maximum number of dimensions of the design space */
#endif             /* MAXAXES */

#ifndef MAXWEIGHT
#define MAXWEIGHT 16 /* maximum number of elements in the weight vector */
#endif               /* MAXWEIGHT */

#define MAXFONTFIT 2 /* maximum number of axes that FontFit() can handle */

/* DS_allocfunc -- type of a DesignSpace allocation function, ARGDECL workaround */
typedef void *(*DS_allocfunc)(IntX nbytes, void *tag);

/* DesignSpace -- the normalized design space for a particular font */
typedef struct DesignSpace DesignSpace;

extern DesignSpace *MakeDesignSpace(
    IntX ndimen,        /* the number of axes */
    IntX nmasters,      /* the number of designs in the master */
    DS_allocfunc alloc, /* a memory allocation function */
    void *tag           /* a tag to be passed to the allocator */
);

extern boolean SetMasterDesignPosition(DesignSpace *ds, CardX n, Fixed *dv);

/*  
 * If ndvSubroutine and cdvSubroutine are both NULL, then an old-style
 * 2^ds->ndimen mapping will be attempted; *ndv will be read and *wv
 * will be written.  lenBuildCharArray, SureMalloc and Free will
 * not be examined.
 * 
 * If ndvSubroutine is non-NULL then *udv will be read and *ndv will be
 * written.  If cdvSubroutine is non-NULL, then it will be
 * executed; if cdvSubroutine is NULL and wv is non-NULL, an old-style
 * 2^ds->ndimen mapping will be attempted.  Successful conversion to a
 * weight vector by either means causes a write to *wv.
 * 
 * Unless the storage pointed to by udv, ndv, or wv is specified here as
 * being read or written, the pointer will not be examined.
 * 
 * lenBuildCharArray must be greater than the highest-numbered BCA entry
 * addressed by *ndvSubroutine or *cdvSubroutine.
 * 
 * Neither SureMalloc nor Free are permitted to raise exceptions,
 * that is, to call longjmp().  SureMalloc may indicate failure to
 * allocate storage only by returning NULL.
 * 
 * XXX: Should GetWeightVector() be enhanced to be able to convert 
 *      UDV to NDV according to a Type 1 /BlendDesignMap array?
 */

extern boolean GetWeightVector(
    DesignSpace *ds,         /* design space structure pointer */
    Fixed *wv,               /* weight vector (W), maximal length */
    Fixed *ndv,              /* normalized design vector (RW) */
    Fixed *udv,              /* user design vector (R) */
    Card16 charStringType,   /* (R) */
    Card8 *cdvSubroutine,    /* pointer to CDV subroutine */
    Card8 *ndvSubroutine,    /* pointer to NDV subroutine */
    Fixed *blendDesignMap,   /* array of pairs: {user, normalized} */
    CardX lenBuildCharArray, /* how much storage might be required? */
    ASZone oneSizeZone,      /* analogous to BCProcs.oneSizeZone in buildch.h */
    void *pClientHook        /* passed through to Memory callbacks */

);

/*
 * FontFit -- multiple master contraint matching
 */

typedef struct {
    Fixed lo, hi; /* in normalized design vector space */
} FontFitBounds;

extern boolean FontFit(
    DesignSpace *ds,
    Fixed *dv,
    Fixed *wv,
    IntX nvary,
    Int16 *vary,
    FontFitBounds *clamp,
    Fixed *target,
    Fixed **metric);

typedef struct {
    Fixed origdv[MAXAXES];
    Int16 nvary;
    Int16 vary[MAXFONTFIT];
    FontFitBounds clamp[MAXFONTFIT];
    Int16 npreset;
    Fixed target[MAXFONTFIT - 1];
    Fixed collapsed[MAXFONTFIT - 1][1 << MAXFONTFIT];
    Int16 nextrema[MAXFONTFIT - 1];
    FCd extrema[MAXFONTFIT - 1][1 << MAXFONTFIT];
} FontFitDomain;

extern boolean SetupFontFit(
    FontFitDomain *domain,
    DesignSpace *ds,
    Fixed *origdv,
    IntX nvary,
    Int16 *vary,
    FontFitBounds *clamp,
    IntX npreset,
    Fixed *target,
    Fixed **metric);

extern boolean SolveFontFit(
    FontFitDomain *domain,
    DesignSpace *ds,
    Fixed *dv,
    Fixed *wv,
    Fixed *target,
    Fixed **metric);

typedef struct {
    Fixed lo0, lo1, hi0, hi1; /* clamp.lo @ 0, clamp.lo @ 1, ... */
} FontFitExtra;

extern boolean ExtrapolateFontFit(
    FontFitDomain *domain,
    DesignSpace *ds,
    Fixed *dv,
    Fixed *wv,
    Fixed *target,
    Fixed **metric,
    FontFitExtra *extra);

#endif /* BLEND_H */
