shithub: imgtools

ref: 2d0b976efe9cb2da0b01e396392c622b077ddac7
dir: /resample.c/

#include <u.h>
#include <libc.h>
#include <draw.h>
#include <memdraw.h>
#define STB_IMAGE_RESIZE_IMPLEMENTATION
#define STBIR_MALLOC(x,u) malloc(x)
#define STBIR_FREE(x,u) free(x)
#define STBIR_ASSERT(x) assert(x)
#define NULL nil
typedef uintptr size_t;
#include "stb_image_resize.h"

static char *filters[] = {
    [STBIR_FILTER_BOX] = "box",
    [STBIR_FILTER_TRIANGLE] = "triangle",
    [STBIR_FILTER_CUBICBSPLINE] = "cubicbspline",
    [STBIR_FILTER_CATMULLROM] = "catmullrom",
    [STBIR_FILTER_MITCHELL] = "mitchell",
};

static void
usage(void)
{
	fprint(2, "usage: %s [-x size] [-y size] [-f filter]\n", argv0);
	exits("usage");
}

void
main(int argc, char **argv)
{
	Memimage *a, *b;
	u8int *in, *out;
	char *flts, *s;
	int n, w, h, bp;
	int ow, oh, obp;
	int wp, hp, f;

	ow = oh = 0;
	wp = hp = 0;
	flts = filters[STBIR_FILTER_MITCHELL];
	ARGBEGIN{
	case 'x':
		s = EARGF(usage());
		wp = (ow = atoi(s)) > 0 && s[strlen(s)-1] == '%';
		break;
	case 'y':
		s = EARGF(usage());
		hp = (oh = atoi(s)) > 0 && s[strlen(s)-1] == '%';
		break;
	case 'f':
		flts = EARGF(usage());
		break;
	default:
		usage();
	}ARGEND

	if(ow < 1 && oh < 1)
		usage();
	for(f = 0; f < nelem(filters) && (filters[f] == nil || strcmp(flts, filters[f]) != 0); f++);
	if(f >= nelem(filters)){
		fprint(2, "invalid filter %s\n", flts);
		exits("filter");
	}

	memimageinit();
	if((a = readmemimage(0)) == nil)
		sysfatal("memory");
	if(a->chan != RGB24){
		if((b = allocmemimage(a->r, RGB24)) == nil)
			sysfatal("memory");
		memimagedraw(b, a->r, a, ZP, nil, ZP, S);
		freememimage(a);
		a = b;
	}
	w = Dx(a->r);
	h = Dy(a->r);
	ow = wp ? w*ow/100.0 : w;
	oh = hp ? h*oh/100.0 : h;
	if(w < 1 || h < 1)
		sysfatal("invalid size: %dx%d", ow, oh);
	bp = 3;
	n = w*h*bp;
	if((in = malloc(w*h*bp)) == nil)
		sysfatal("%r");
	if(unloadmemimage(a, a->r, in, n) < 0)
		sysfatal("%r");
	obp = 3;
	if((out = malloc(ow*oh*obp)) == nil)
		sysfatal("memory");
	stbir_resize_uint8_generic(
		in, w, h, w*bp,
		out, ow, oh, ow*obp,
		3, -1, 0,
		STBIR_EDGE_CLAMP, STBIR_FILTER_CATMULLROM, STBIR_COLORSPACE_LINEAR,
		NULL);
	if((b = allocmemimage(Rect(0,0,ow,oh), RGB24)) == nil)
		sysfatal("%r");
	loadmemimage(b, b->r, out, ow*oh*obp);
	writememimage(1, b);

	exits(nil);
}