shithub: subpixelize

ref: 048812d8e57dd440e13737c9c603cedc0228891b
dir: /unsubpixelize.c/

#include <u.h>
#include <libc.h>
#include <draw.h>
#include <memdraw.h>

static void
transformpx(Memimage *src, Memimage *dst, Point p)
{
	uchar *s;
	uchar *t;
	int c;
	
	t = byteaddr(dst, p);
	
	c = p.x % 3;
	p.x /= 3;
	p.y /= 3;
	
	s = byteaddr(src, p);
	
	t[0] = t[1] = t[2] = s[2-c];
}

static void
transform(Memimage *src, Memimage *dst)
{
	int x, y;
	
	for (y = dst->r.min.y; y < dst->r.max.y; y++)
		for (x = dst->r.min.x; x < dst->r.max.x; x++)
			transformpx(src, dst, Pt(x, y));
}

void
main(void)
{
	Memimage *in, *out;
	Rectangle r;
	
	if (memimageinit() < 0)
		sysfatal("%r");
	
	in = readmemimage(0);
	if (!in)
		sysfatal("%r");
	
	r.min.x = in->r.min.x * 3;
	r.min.y = in->r.min.y * 3;
	r.max.x = in->r.max.x * 3;
	r.max.y = in->r.max.y * 3;
	
	out = allocmemimage(r, RGB24);
	if (!out)
		sysfatal("%r");
	
	transform(in, out);
	writememimage(1, out);
	exits(nil);
}