git.zarb.org Git - booh/blob - ext/rbbooh.c

   1 /*
   2  *                         *  BOOH  *
   3  *
   4  * A.k.a `Best web-album Of the world, Or your money back, Humerus'.
   5  *
   6  * The acronyn sucks, however this is a tribute to Dragon Ball by
   7  * Akira Toriyama, where the last enemy beaten by heroes of Dragon
   8  * Ball is named "Boo". But there was already a free software project
   9  * called Boo, so this one will be it "Booh". Or whatever.
  10  *
  11  *
  12  * Copyright (c) 2005 Guillaume Cottenceau
  13  *
  14  * This software may be freely redistributed under the terms of the GNU
  15  * public license version 2.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with this program; if not, write to the Free Software
  19  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  20  *
  21  */
  22
  23 #include <math.h>
  24
  25 #define GDK_PIXBUF_ENABLE_BACKEND
  26 #include <gdk-pixbuf/gdk-pixbuf.h>
  27 #include <gdk-pixbuf/gdk-pixdata.h>
  28 #include "rbgobject.h"
  29
  30 #define _SELF(s) GDK_PIXBUF(RVAL2GOBJ(s))
  31
  32 #include <libexif/exif-data.h>
  33
  34 static VALUE
  35 whitebalance(self, level)
  36     VALUE self, level;
  37 {
  38         double red_filter[256], blue_filter[256];
  39         int i, x, y;
  40         guchar* pixels = gdk_pixbuf_get_pixels(_SELF(self));
  41         int rowstride = gdk_pixbuf_get_rowstride(_SELF(self));
  42
  43         double factor = 1 + fabs(NUM2DBL(level))/100;
  44         if (NUM2DBL(level) < 0) {
  45                 factor = 1/factor;
  46         }
  47
  48         for (i = 0; i < 256; i++) {
  49                 red_filter[i]  = pow(((double)i)/255, 1/factor) * 255;
  50                 blue_filter[i] = pow(((double)i)/255, factor) * 255;
  51         }
  52
  53         for (y = 0; y < gdk_pixbuf_get_height(_SELF(self)); y++) {
  54                 guchar* pixline = &(pixels[rowstride*y]);
  55                 for (x = 0; x < gdk_pixbuf_get_width(_SELF(self)); x++) {
  56                         pixline[x*3]   = red_filter[pixline[x*3]];
  57                         pixline[x*3+2] = blue_filter[pixline[x*3+2]];
  58                 }
  59         }
  60
  61         return self;
  62 }
  63
  64 static VALUE
  65 gammacorrect(self, level)
  66     VALUE self, level;
  67 {
  68         double filter[256];
  69         int i, x, y;
  70         guchar* pixels = gdk_pixbuf_get_pixels(_SELF(self));
  71         int rowstride = gdk_pixbuf_get_rowstride(_SELF(self));
  72
  73         double factor = 1 + fabs(NUM2DBL(level))/100;
  74         if (NUM2DBL(level) > 0) {
  75                 factor = 1/factor;
  76         }
  77
  78         for (i = 0; i < 256; i++) {
  79                 filter[i] = pow(((double)i)/255, factor) * 255;
  80         }
  81
  82         for (y = 0; y < gdk_pixbuf_get_height(_SELF(self)); y++) {
  83                 guchar* pixline = &(pixels[rowstride*y]);
  84                 for (x = 0; x < gdk_pixbuf_get_width(_SELF(self)); x++) {
  85                         pixline[x*3]   = filter[pixline[x*3]];
  86                         pixline[x*3+1] = filter[pixline[x*3+1]];
  87                         pixline[x*3+2] = filter[pixline[x*3+2]];
  88                 }
  89         }
  90
  91         return self;
  92 }
  93
  94 static VALUE exif_orientation(VALUE module, VALUE filename) {
  95         VALUE ret = Qnil;
  96         ExifData* data;
  97         unsigned int i;
  98
  99         data = exif_data_new_from_file(StringValuePtr(filename));
 100         if (data == NULL) {
 101                 fprintf(stderr, "libexif failed loading file '%s'\n", StringValuePtr(filename));
 102                 return Qnil;
 103         }
 104
 105         for (i = 0; i < EXIF_IFD_COUNT; i++) {
 106                 ExifEntry* entry = exif_content_get_entry(data->ifd[i], EXIF_TAG_ORIENTATION);
 107                 if (entry) {
 108                         ExifByteOrder o;
 109                         ExifShort v_short;
 110                         if (!entry || !entry->parent || !entry->parent->parent)
 111                                 break;
 112                         o = exif_data_get_byte_order(entry->parent->parent);
 113                         v_short = exif_get_short(entry->data, o);
 114                         ret = INT2NUM(v_short);
 115                         break;
 116                 }
 117         }
 118
 119         exif_data_free(data);
 120         return ret;
 121 }
 122
 123
 124 void
 125 Init_libadds()
 126 {
 127     RGObjClassInfo* cinfo = (RGObjClassInfo*)rbgobj_lookup_class_by_gtype(GDK_TYPE_PIXBUF, Qnil);
 128     rb_define_method(cinfo->klass, "whitebalance!", whitebalance, 1);
 129     rb_define_method(cinfo->klass, "gammacorrect!", gammacorrect, 1);
 130
 131     VALUE exif = rb_define_module("Exif");
 132     rb_define_module_function(exif, "orientation", exif_orientation, 1);
 133 }