ref: 19d022a35e52dcfcb999bf53db7e9e171d1f2176
dir: /ifilter.c/
#include <u.h> #include <libc.h> #include <draw.h> #include <memdraw.h> #define MIN(x,y) ((x)<(y)?(x):(y)) typedef struct Filter Filter; struct Filter { const char *name; void (*filter)(uchar[3], float); }; void grayscale(uchar p[3], float) { uchar v = 0.2126*p[2] + 0.7152*p[1] + 0.0722*p[0]; p[0] = p[1] = p[2] = v; } void sepia(uchar p[3], float) { float r, g, b; r = 0.393*p[2] + 0.769*p[1] + 0.189*p[0]; g = 0.349*p[2] + 0.686*p[1] + 0.168*p[0]; b = 0.272*p[2] + 0.534*p[1] + 0.131*p[0]; p[2] = MIN(r, 255); p[1] = MIN(g, 255); p[0] = MIN(b, 255); } void invert(uchar p[3], float) { p[0] = 255 - p[0]; p[1] = 255 - p[1]; p[2] = 255 - p[2]; } void shade(uchar p[3], float factor) { p[0] = p[0] * (1 - factor); p[1] = p[1] * (1 - factor); p[2] = p[2] * (1 - factor); } void tint(uchar p[3], float factor) { p[0] = p[0] + (255.0 - p[0]) * factor; p[1] = p[1] + (255.0 - p[1]) * factor; p[2] = p[2] + (255.0 - p[2]) * factor; } void usage(void) { fprint(2, "usage: %s [-f factor] [grayscale|sepia|invert|shade|tint]\n", argv0); exits("usage"); } static Filter filters[] = { { "grayscale", grayscale }, { "sepia", sepia }, { "invert", invert }, { "shade", shade }, { "tint", tint }, }; void main(int argc, char *argv[]) { Memimage *o, *i; int w, h, p, n; uchar *buf; Filter *f; float factor; f = nil; factor = 0.0; ARGBEGIN{ case 'f': factor = (float)atof(EARGF(usage())); break; default: usage(); break; }ARGEND; if(argc!=1) usage(); for(n=0; n<nelem(filters); n++){ if(strcmp(*argv, filters[n].name)==0){ f = filters+n; break; } } if(f==nil) usage(); if(factor<0.0 || factor>1.0){ fprint(2, "factor should be between 0.0 and 1.0\n"); exits("invalid factor"); } if(memimageinit()<0) sysfatal("memimageinit: %r"); o = readmemimage(0); if(o==nil) sysfatal("readmemimage: %r"); i = allocmemimage(o->r, XRGB32); memimagedraw(i, i->r, o, o->r.min, nil, ZP, S); freememimage(o); w = Dx(i->r); h = Dy(i->r); n = 4*w*h*sizeof(uchar); buf = malloc(n); if(buf==nil) sysfatal("malloc: %r"); if(unloadmemimage(i, i->r, buf, n)<0) sysfatal("unloadmemimage: %r"); freememimage(i); for(p = 0; p < n; p+=4) f->filter(buf+p, factor); print(" x8r8g8b8 %11d %11d %11d %11d ", 0, 0, w, h); write(1, buf, n); exits(nil); }