cgen.c

这是一个高速多维插值算法。当我们建模以后

	/* The end of the pixel processing loop */
	dec(f);
	line(f, "}");

	/* The end of the function */
	dec(f);
	line(f, "}");

	/* Undefine all the macros */
	if (t->sort) {
		if (t->it_xs) {
			if (t->wo_xs) {
				line(f,"#undef IT_WE");
				line(f,"#undef IT_VO");
			} else
				line(f,"#undef IT_WO");
			line(f,"#undef IT_IX");
		} else {
			line(f,"#undef IT_IT");
		}
		line(f,"#undef CEX");
	} else {
		if (t->it_xs) {
			line(f,"#undef IT_IX");
			line(f,"#undef IT_SX");
		} else {
			line(f,"#undef IT_IT");
		}

		line(f,"#undef SW_O");
		if (t->wo_xs) {
			line(f,"#undef SX_WE");
			line(f,"#undef SX_VO");
		} else {
			line(f,"#undef SX_WO");
		}
	}
	line(f,"#undef IM_O");
	if (t->im_fn > 0) {
		if (timp && t->im_fn > 1) 
			line(f,"#undef IM_TP");
		line(f,"#undef IM_FE");
	}
	if (t->im_pn > 0) {
		line(f,"#undef IM_PE");
	}
	line(f,"#undef OT_E");

	/* =============================================== */
#ifdef VERBOSE
	printf("Done interpolation code\n"); fflush(stdout);
#endif /* VERBOSE */

	/* =============================================== */

	{
		int sog = sizeof(genspec);	/* Size of genspec structure */
		unsigned char *dp = (unsigned char *)g;

		int s_stres, s_itres;	/* Save values */

		s_stres = g->stres;
		s_itres = g->itres;
		g->stres = f->sxmxres;		/* Set maximum values */
		g->itres = f->ixmxres;
		
		/* Declare the generation structure data function */
		cr(f);
		line(f,"void");
		line(f, "imdi_k%d_gen(",index);
		line(f, "genspec *g			/* structure to be initialised */");
		line(f, ") {");
		inc(f);
	
		/* Declare the genspec initialisation data */
		line(f, "static unsigned char data[] = {");
		inc(f);
		for (i = 0; i < sog; i++) {
			if ((i & 7) == 0)
				sline(f,"");
			mline(f, "0x%02x%s ", dp[i], (i+1) < sog ? "," : "", dp[i]);
			if ((i & 7) == 7 || (i+1) == sog)
				eline(f,"");
		}
		dec(f);
		line(f, "};	/* Structure image */");

		cr(f);
		line(f, "memcpy(g, data, sizeof(data));	/* Initialise the structure */");
		/* The end of the function */
		dec(f);
		line(f, "}");

		g->stres = s_stres;		/* Restore entry values */
		g->itres = s_itres;
	}

	/* =============================================== */

	{
		int sot = sizeof(tabspec);	/* Size of tabspec structure */
		unsigned char *dp = (unsigned char *)t;

		/* Declare the generation structure data function */
		cr(f);
		line(f,"void");
		line(f, "imdi_k%d_tab(",index);
		line(f, "tabspec *t			/* structure to be initialised */");
		line(f, ") {");
		inc(f);
	
		/* Declare the genspec initialisation data */
		line(f, "static unsigned char data[] = {");
		inc(f);
		for (i = 0; i < sot; i++) {
			if ((i & 7) == 0)
				sline(f,"");
			mline(f, "0x%02x%s ", dp[i], (i+1) < sot ? "," : "", dp[i]);
			if ((i & 7) == 7 || (i+1) == sot)
				eline(f,"");
		}
		dec(f);
		line(f, "};	/* Structure image */");

		cr(f);
		line(f, "memcpy(t, data, sizeof(data));	/* Initialise the structure */");
		/* The end of the function */
		dec(f);
		line(f, "}");
	}

	/* =============================================== */

	cr(f); cr(f); cr(f); cr(f); cr(f); cr(f);

	return 0;
}


/* Return bits needed to store index into table of */
/* given resolution and dimensionality. */
static int
calc_bits(
int dim,
int res) {

	return ceil(log((double)res) * (double)dim/log(2.0) - 1e-14);
}

/* Return maximum resolution possible given dimensionality */
/* and number of index bits. */
static int
calc_res(
int dim,
int bits) {
	double fres;

	fres = log(2.0) * (double)bits/(double)dim;
	if (fres > 12 || (fres = exp(fres)) > 65536.0)
		fres = 65536.0;		/* Limit to a sane value */
	return (int)(fres + 1e-14);
}

/* Return bits needed to store a relative offset of 1, */
/* into a table of given resolution, dimensionality , and */
/* entry size. */
static int
calc_obits(
int dim,
int res,
int esize) {
	double off;		/* Maximum diagonal offset value */
	int bits;

	if (res == 0 || res == 1)
		return 0;
	if (dim == 1)
		off = esize;
	else {
		off = (double)esize * floor(exp(log((double)res) * dim - log(res-1.0)));
	}

	bits = ceil(log(off)/log(2.0) - 1e-14);
	return bits;
}

/* Return maximum resolution possible given dimensionality */
/* number of index bits, and entry size */
static int
calc_ores(
int dim,
int bits,
int esize) {
	int res;

	/* Find resolution. Stop at arbitrary 65536 */
	for (res = 1; res < 65537; res++) {
		int bn;
		bn = calc_obits(dim, res, esize);
		if (bn > bits) {
			return res-1;
		}
	}
	return res-1;
}



/* Output the introductory comments */
static void
doheader(
	fileo *f
) {
	genspec *g = f->g;
	tabspec *t = f->t;
	mach_arch *a  = f->a;
	int e;

	/* - - - - - - - - - - - - */
	/* Output file title block */
	line(f,"/* Integer Multi-Dimensional Interpolation */");
	line(f,"/* Interpolation Kernel Code */");
	line(f,"/* Generated by cgen */");
	line(f,"/* Copyright 2000 - 2002 Graeme W. Gill */");
	line(f,"/* This material is licenced under the GNU GENERAL PUBLIC LICENCE :- */\n");
	line(f,"/* see the Licence.txt file for licencing details.*/\n");
	cr(f);

	/* - - - - - - - - - - - - */
	/* Output the specification */
	line(f,"/*");
	line(f,"   Interpolation kernel specs:");
	cr(f);
	line(f,"   Input channels per pixel = %d",g->id);
	for (e = 0; e < g->id; e++) {
		line(f,"   Input channel %d bits = %d",e, g->in.bpch[e]);
		line(f,"   Input channel %d increment = %d",e, g->in.chi[e]);
	}
	if (g->in.pint != 0)
		line(f,"   Input is channel interleaved");
	else
		line(f,"   Input is plane interleaved");

	if (g->in.packed != 0)
		line(f,"   Input channels are packed into one word");
	else
		line(f,"   Input channels are separate words");

	if (t->it_ix)
		line(f,"   Input value extraction is done in input table lookup");
	cr(f);
	
	line(f,"   Output channels per pixel = %d",g->od);
	for (e = 0; e < g->od; e++) {
		line(f,"   Output channel %d bits = %d",e, g->out.bpch[e]);
		line(f,"   Output channel %d increment = %d",e, g->out.chi[e]);
	}
	if (g->out.pint != 0)
		line(f,"   Output is channel interleaved");
	else
		line(f,"   Output is plane interleaved");
	cr(f);
	if (g->out.packed != 0)
		line(f,"   Output channels are packed into one word");
	else
		line(f,"   Output channels are separate words");

	
	if (t->sort)
		line(f,"   Weight+voffset bits       = %d",t->sx_ab);
	else
		line(f,"   Simplex table index bits       = %d",t->sx_ab);
	line(f,"   Interpolation table index bits = %d",t->ix_ab);
	if (!t->sort)
		line(f,"   Simplex table max resolution = %d",f->sxmxres);
	line(f,"   Interpolation table max resolution = %d",f->ixmxres);
	line(f," */");
	cr(f);

	/* - - - - - - - - - - - - */
	line(f,"/*");
	line(f,"   Machine architecture specs:");
	cr(f);
	if (a->bigend != 0)
		line(f,"   Big Endian");
	else
		line(f,"   Little endian");

	if (a->uwa != 0)
		line(f,"   Using maximum sized memory accesses where possible");
	else
		line(f,"   Reading and writing pixel values separately");

	line(f,"   Pointer size = %d bits",a->pbits);
	cr(f);

	for (e = 0; e < a->nords; e++) {
		line(f,"   Ordinal size %2d bits is known as '%s'",
		        a->ords[e].bits,a->ords[e].name);
	}
	line(f,"   Natural ordinal is '%s'", a->ords[a->natord].name);
	cr(f);

	for (e = 0; e < a->nints; e++) {
		line(f,"   Integer size %2d bits is known as '%s'",
		        a->ints[e].bits,a->ints[e].name);
	}
	line(f,"   Natural integer is '%s'", a->ints[a->natint].name);
	cr(f);

	line(f," */");
	cr(f);
}


/* ---------------------------------------- */
/* Architecture support */
/* Find an ordinal with at least bits size */
/* Return -1 if failed */
int findord(
fileo *f,
int bits
) {
	mach_arch *a  = f->a;
	int i;

	for (i = 0; i < a->nords; i++) {
		if (a->ords[i].bits >= bits)
			return i;
	}
	return -1;
}

/* Round ordinal type up to natural size */
int nord(
	fileo *f,
	int ov
) {
	if (ov >= 0 && ov < f->a->natord)
		ov = f->a->natord;
	return ov;
}

/* Find an ordinal with at least bits size, */
/* or natural size, whichever is greater. */
/* Return -1 if failed */
int findnord(
	fileo *f,
	int bits
) {
	int ov;

	ov = findord(f, bits);
	ov = nord(f, ov);
	return ov;
}

/* Find an integer with at least bits size */
/* Return -1 if failed */
int findint(
	fileo *f,
	int bits
) {
	mach_arch *a  = f->a;
	int i;

	for (i = 0; i < a->nints; i++) {
		if (a->ints[i].bits >= bits)
			return i;
	}
	return -1;
}

/* Round integer type up to natural size */
int nint(
	fileo *f,
	int iv
) {
	if (iv >= 0 && iv < f->a->natint)
		iv = f->a->natint;
	return iv;
}

/* Find an interger with at least bits size, */
/* or natural size, whichever is greater. */
/* Return -1 if failed */
int findnint(
	fileo *f,
	int bits
) {
	int iv;

	iv = findint(f, bits);
	iv = nint(f, iv);
	return iv;
}


/* ------------------------------------ */
/* File output support */

/* Output a line to the file (including trailing \n) */
void
line(fileo *f, char *fmt, ...)
{
	int i;
	va_list args;

	/* Indent to the correct level */
	for (i = 0; i < f->indt; i++)
		fprintf(f->of,"	");
	
	va_start(args, fmt);
	vfprintf(f->of, fmt, args);
	va_end(args);
	fprintf(f->of, "\n");
}

/* Output the start of a line to the file) */
void
sline(fileo *f, char *fmt, ...)
{
	int i;
	va_list args;

	/* Indent to the correct level */
	for (i = 0; i < f->indt; i++)
		fprintf(f->of,"	");
	
	va_start(args, fmt);
	vfprintf(f->of, fmt, args);
	va_end(args);
}

/* Output the middle of a line to the file) */
void
mline(fileo *f, char *fmt, ...)
{
	int i;
	va_list args;

	va_start(args, fmt);
	vfprintf(f->of, fmt, args);
	va_end(args);
}

/* Output the end of a line to the file (including trailing \n) */
void
eline(fileo *f, char *fmt, ...)
{
	int i;
	va_list args;

	va_start(args, fmt);
	vfprintf(f->of, fmt, args);
	va_end(args);
	fprintf(f->of, "\n");
}
/* ------------------------------------ */