#ifndef lint
static const char RCSid[] = "$Id: dctimestep.c,v 2.28 2014/01/20 21:29:04 greg Exp $";
#endif
/*
 * Compute time-step result using Daylight Coefficient method.
 *
 *	G. Ward
 */

#include <ctype.h>
#include "standard.h"
#include "cmatrix.h"
#include "platform.h"
#include "resolu.h"

char	*progname;			/* global argv[0] */

/* Sum together a set of images and write result to fout */
static int
sum_images(const char *fspec, const CMATRIX *cv, FILE *fout)
{
	int	myDT = DTfromHeader;
	COLOR	*scanline = NULL;
	CMATRIX	*pmat = NULL;
	int	myXR=0, myYR=0;
	int	i, y;

	if (cv->ncols != 1)
		error(INTERNAL, "expected vector in sum_images()");
	for (i = 0; i < cv->nrows; i++) {
		const COLORV	*scv = cv_lval(cv,i);
		char		fname[1024];
		FILE		*fp;
		int		dt, xr, yr;
		COLORV		*psp;
							/* check for zero */
		if ((scv[RED] == 0) & (scv[GRN] == 0) & (scv[BLU] == 0) &&
				(myDT != DTfromHeader) | (i < cv->nrows-1))
			continue;
							/* open next picture */
		sprintf(fname, fspec, i);
		if ((fp = fopen(fname, "r")) == NULL) {
			sprintf(errmsg, "cannot open picture '%s'", fname);
			error(SYSTEM, errmsg);
		}
		SET_FILE_BINARY(fp);
		dt = getDTfromHeader(fp);
		if ((dt != DTrgbe) & (dt != DTxyze) ||
				!fscnresolu(&xr, &yr, fp)) {
			sprintf(errmsg, "file '%s' not a picture", fname);
			error(USER, errmsg);
		}
		if (myDT == DTfromHeader) {		/* on first one */
			myDT = dt;
			myXR = xr; myYR = yr;
			scanline = (COLOR *)malloc(sizeof(COLOR)*myXR);
			if (scanline == NULL)
				error(SYSTEM, "out of memory in sum_images()");
			pmat = cm_alloc(myYR, myXR);
			memset(pmat->cmem, 0, sizeof(COLOR)*myXR*myYR);
							/* finish header */
			fputformat(myDT==DTrgbe ? COLRFMT : CIEFMT, fout);
			fputc('\n', fout);
			fprtresolu(myXR, myYR, fout);
			fflush(fout);
		} else if ((dt != myDT) | (xr != myXR) | (yr != myYR)) {
			sprintf(errmsg, "picture '%s' format/size mismatch",
					fname);
			error(USER, errmsg);
		}
		psp = pmat->cmem;
		for (y = 0; y < yr; y++) {		/* read it in */
			int	x;
			if (freadscan(scanline, xr, fp) < 0) {
				sprintf(errmsg, "error reading picture '%s'",
						fname);
				error(SYSTEM, errmsg);
			}
							/* sum in scanline */
			for (x = 0; x < xr; x++, psp += 3) {
				multcolor(scanline[x], scv);
				addcolor(psp, scanline[x]);
			}
		}
		fclose(fp);				/* done this picture */
	}
	free(scanline);
							/* write scanlines */
	for (y = 0; y < myYR; y++)
		if (fwritescan((COLOR *)cm_lval(pmat, y, 0), myXR, fout) < 0)
			return(0);
	cm_free(pmat);					/* all done */
	return(fflush(fout) == 0);
}

/* check to see if a string contains a %d or %o specification */
static int
hasNumberFormat(const char *s)
{
	if (s == NULL)
		return(0);

	while (*s) {
		while (*s != '%')
			if (!*s++)
				return(0);
		if (*++s == '%') {		/* ignore "%%" */
			++s;
			continue;
		}
		while (isdigit(*s))		/* field length */
			++s;
						/* field we'll use? */
		if ((*s == 'd') | (*s == 'i') | (*s == 'o') |
					(*s == 'x') | (*s == 'X'))
			return(1);
	}
	return(0);				/* didn't find one */
}

int
main(int argc, char *argv[])
{
	int		skyfmt = DTascii;
	int		nsteps = 1;
	char		*ofspec = NULL;
	FILE		*ofp = stdout;
	CMATRIX		*cmtx;		/* component vector/matrix result */
	char		fnbuf[256];
	int		a, i;

	progname = argv[0];
					/* get options */
	for (a = 1; a < argc && argv[a][0] == '-'; a++)
		switch (argv[a][1]) {
		case 'n':
			nsteps = atoi(argv[++a]);
			if (nsteps <= 0)
				goto userr;
			break;
		case 'o':
			ofspec = argv[++a];
			break;
		case 'i':
			switch (argv[a][2]) {
			case 'f':
				skyfmt = DTfloat;
				break;
			case 'd':
				skyfmt = DTdouble;
				break;
			case 'a':
				skyfmt = DTascii;
				break;
			default:
				goto userr;
			}
			break;
		default:
			goto userr;
		}
	if ((argc-a < 1) | (argc-a > 4))
		goto userr;

	if (argc-a > 2) {			/* VTDs expression */
		CMATRIX	*smtx, *Dmat, *Tmat, *imtx;
		COLOR	tLamb;
						/* get sky vector/matrix */
		smtx = cm_load(argv[a+3], 0, nsteps, skyfmt);
						/* load BSDF */
		Tmat = cm_loadBSDF(argv[a+1], tLamb);
						/* load Daylight matrix */
		Dmat = cm_load(argv[a+2], Tmat==NULL ? 0 : Tmat->ncols,
					smtx->nrows, DTfromHeader);
						/* multiply vector through */
		imtx = cm_multiply(Dmat, smtx);
		cm_free(Dmat); cm_free(smtx);
		if (Tmat == NULL) {		/* diffuse only */
			cmtx = cm_scale(imtx, tLamb);
		} else {			/* else apply BTDF matrix */
			cmtx = cm_multiply(Tmat, imtx);
			cm_free(Tmat); 
		}
		cm_free(imtx);
	} else {				/* sky vector/matrix only */
		cmtx = cm_load(argv[a+1], 0, nsteps, skyfmt);
	}
						/* prepare output stream */
	if ((ofspec != NULL) & (nsteps == 1) && hasNumberFormat(ofspec)) {
		sprintf(fnbuf, ofspec, 1);
		ofspec = fnbuf;
	}
	if (ofspec != NULL && !hasNumberFormat(ofspec)) {
		if ((ofp = fopen(ofspec, "w")) == NULL) {
			fprintf(stderr, "%s: cannot open '%s' for output\n",
					progname, ofspec);
			return(1);
		}
		ofspec = NULL;			/* only need to open once */
	}
	if (hasNumberFormat(argv[a])) {		/* generating image(s) */
		if (ofspec == NULL) {
			SET_FILE_BINARY(ofp);
			newheader("RADIANCE", ofp);
			printargs(argc, argv, ofp);
			fputnow(ofp);
		}
		if (nsteps > 1)			/* multiple output frames? */
			for (i = 0; i < nsteps; i++) {
				CMATRIX	*cvec = cm_column(cmtx, i);
				if (ofspec != NULL) {
					sprintf(fnbuf, ofspec, i+1);
					if ((ofp = fopen(fnbuf, "wb")) == NULL) {
						fprintf(stderr,
					"%s: cannot open '%s' for output\n",
							progname, fnbuf);
						return(1);
					}
					newheader("RADIANCE", ofp);
					printargs(argc, argv, ofp);
					fputnow(ofp);
				}
				fprintf(ofp, "FRAME=%d\n", i+1);
				if (!sum_images(argv[a], cvec, ofp))
					return(1);
				if (ofspec != NULL) {
					if (fclose(ofp) == EOF) {
						fprintf(stderr,
						"%s: error writing to '%s'\n",
							progname, fnbuf);
						return(1);
					}
					ofp = stdout;
				}
				cm_free(cvec);
			}
		else if (!sum_images(argv[a], cmtx, ofp))
			return(1);
	} else {				/* generating vector/matrix */
		CMATRIX	*Vmat = cm_load(argv[a], 0, cmtx->nrows, DTfromHeader);
		CMATRIX	*rmtx = cm_multiply(Vmat, cmtx);
		cm_free(Vmat);
		if (ofspec != NULL)		/* multiple vector files? */
			for (i = 0; i < nsteps; i++) {
				CMATRIX	*rvec = cm_column(rmtx, i);
				sprintf(fnbuf, ofspec, i+1);
				if ((ofp = fopen(fnbuf, "w")) == NULL) {
					fprintf(stderr,
					"%s: cannot open '%s' for output\n",
							progname, fnbuf);
					return(1);
				}
				cm_print(rvec, ofp);
				if (fclose(ofp) == EOF) {
					fprintf(stderr,
						"%s: error writing to '%s'\n",
							progname, fnbuf);
					return(1);
				}
				ofp = stdout;
				cm_free(rvec);
			}
		else
			cm_print(rmtx, ofp);
		cm_free(rmtx);
	}
	if (fflush(ofp) == EOF) {		/* final clean-up */
		fprintf(stderr, "%s: write error on output\n", progname);
		return(1);
	}
	cm_free(cmtx);
	return(0);
userr:
	fprintf(stderr, "Usage: %s [-n nsteps][-o ospec][-i{f|d}] DCspec [skyf]\n",
				progname);
	fprintf(stderr, "   or: %s [-n nsteps][-o ospec][-i{f|d}] Vspec Tbsdf.xml Dmat.dat [skyf]\n",
				progname);
	return(1);
}