#include <stdlib.h>
#include <stdio.h>
#include <math.h>
#include <pict.h>
#ifdef THINK_C
#include <console.h>
#endif
#ifdef MYGETOPT
char getopt( int	argc, char	*argv[], char *format );
#endif

void	scalepict(char *,char *);
unsigned int	w = 0, h = 0;
double	scale = 0.0;
char	verb=0;

void	usage(char *name)
{
	fprintf(stderr,"Uso: %s [-o output] -w -h | -s file [file...]\n",name);
	exit(1);
}

main( int	argc, char	*argv[] )
{
	int	i,opcion;
	char	scname[256];
	int	theError=0;
	int	OutputOpt=0;
	
	extern char     *optarg;
	extern int      optind,opterr;


#ifdef THINK_C
	argc = ccommand(&argv);
#endif
	while ( (opcion=getopt(argc,argv,"o:w:h:s:v")) != EOF )
	{
		switch(opcion)
		{
			case 'w':	theError += ( *optarg==0x00 );
					w = atoi(optarg);
					scale = 0.0;
					break;
			case 'h':	theError += ( *optarg==0x00 );
					h = atoi(optarg);
					scale = 0.0;
					break;
			case 's':	theError += ( *optarg==0x00 );
					scale = atof(optarg);
					w = h = 0;
					break;
			case 'v':	printf("%s: vers. 14 agosto 1993\n",argv[0]);
					verb=1;
					break;
			case 'o':	theError += ( *optarg==0x00 );
					OutputOpt=optind-1;
					break;
			defatult:	usage(argv[0]);
		}
	}

	if ((optind==argc)||(theError!=0))
		usage(argv[0]);

	for (i=optind; i<argc; i++)
	{
		if(OutputOpt==0)
			sprintf(scname,"%s.s",argv[i]);
		else
			sprintf(scname,"%s",argv[OutputOpt]);

		if ( verb )
		{
			printf("%s:\t%s\t->\t%s\n",argv[0],argv[i],scname);
			fflush(stdout);
		}
		
		scalepict(argv[i],scname);
	}
}

void	set_whs(int pw,int ph)
{
	if (scale!=0.0)
	{
		w = (int)(scale*pw);
		h = (int)(scale*ph);
	}
	else
	{
		if (w==0 && h==0)
		{
			usage("scpict");
			exit(1);
		}
		if (h==0) h = (int)((double)w*((double)ph/(double)pw));
		if (w==0) w = (int)((double)h*((double)pw/(double)ph));
	}
}

void	scalepict(char *orgname,char *dstname)
{
	int	oldw,oldh;
	double	oldscale;
	U_char	r00,g00,b00;
	U_char	r01,g01,b01;
	U_char	r10,g10,b10;
	U_char	r11,g11,b11;
	U_char	*r,*g,*b;
	U_char	*buff;
	double	ki,kj;
	double	ri,rj,ri1,rj1;
	int	oi,oj,di,dj;
	Pict	org,dst;

	oldh = h;
	oldw = w;
	oldscale = scale;
	
	org = pict_read_pict(orgname);
	set_whs(org->image_W,org->image_H);
	
	dst = pict_open(dstname,P_WRITE,h,w,M_RGB24,NULL);
	
	if ( verb ) printf("Scaling:\t%dx%d\t->\t%dx%d\n",
				org->image_W,org->image_H,w,h);

	buff = (U_char *)malloc(3*(size_t)w+10);
	if ( buff == NULL )
	{
		fprintf(stderr,"No memory! Bye...\n");
		exit(-1);
	}

	ki = (double)(org->image_W-1.0)/(double)(dst->image_W-1.0);
	kj = (double)(org->image_H-1.0)/(double)(dst->image_H-1.0);
	for (dj=0; dj<h; dj++)
	{
		r = buff;
		g = buff+w;
		b = buff+2*w;
		oj = (int)floor(kj*dj);
		rj = kj*dj - oj;
		rj1 = 1.0 - rj;
		for (di=0; di<w; di++)
		{
			oi = (int)floor(ki*di);
			ri = ki*di - oi;
			ri1 = 1.0 - ri;
			pict_pixel_rgba(org,oj  ,oi  ,&r00,&g00,&b00,NULL);
			pict_pixel_rgba(org,oj+1,oi  ,&r10,&g10,&b10,NULL);
			pict_pixel_rgba(org,oj  ,oi+1,&r01,&g01,&b01,NULL);
			pict_pixel_rgba(org,oj+1,oi+1,&r11,&g11,&b11,NULL);
			
			*r++ = ri1*rj1*r00+ri*rj1*r01+ri1*rj*r10+ri*rj*r11;
			*g++ = ri1*rj1*g00+ri*rj1*g01+ri1*rj*g10+ri*rj*g11;
			*b++ = ri1*rj1*b00+ri*rj1*b01+ri1*rj*b10+ri*rj*b11;
		}
		pict_put_line(dst,buff);
	}

	pict_close(dst);
	pict_free(org);
	free(dst);
	free(buff);

	h = oldh;
	w = oldw;
	scale = oldscale;
}