eog-transform.c

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#include <time.h>
#include <stdlib.h>
#include <math.h>
#include <gtk/gtk.h>
#include <libart_lgpl/art_affine.h>

#include "eog-transform.h"
#include "eog-jobs.h"

/* The number of progress updates per transformation */
#define EOG_TRANSFORM_N_PROG_UPDATES 20

struct _EogTransformPrivate {
      double affine[6];
};

#define EOG_TRANSFORM_GET_PRIVATE(object) \
      (G_TYPE_INSTANCE_GET_PRIVATE ((object), EOG_TYPE_TRANSFORM, EogTransformPrivate))

G_DEFINE_TYPE (EogTransform, eog_transform, G_TYPE_OBJECT)

static void
eog_transform_init (EogTransform *trans)
{
      trans->priv = EOG_TRANSFORM_GET_PRIVATE (trans);
}

static void 
eog_transform_class_init (EogTransformClass *klass)
{
      g_type_class_add_private (klass, sizeof (EogTransformPrivate));
}

GdkPixbuf*    
eog_transform_apply (EogTransform *trans, GdkPixbuf *pixbuf, EogJob *job)
{
      ArtPoint dest_top_left;
      ArtPoint dest_bottom_right;
      ArtPoint vertices[4] = { {0, 0}, {1, 0}, {1, 1}, {0, 1} };
      double r_det;
      int inverted [6];
      ArtPoint dest;
      ArtPoint src;
      
      int src_width;
      int src_height;
      int src_rowstride;
      int src_n_channels;
      guchar *src_buffer;

      GdkPixbuf *dest_pixbuf;
      int dest_width;
      int dest_height;
      int dest_rowstride;
      int dest_n_channels;
      guchar *dest_buffer;

      guchar *src_pos;
      guchar *dest_pos;
      int dx, dy, sx, sy;
      int i, x, y;

      int progress_delta;

      g_return_val_if_fail (pixbuf != NULL, NULL);

      g_object_ref (pixbuf);

      src_width = gdk_pixbuf_get_width (pixbuf);
      src_height = gdk_pixbuf_get_height (pixbuf);
      src_rowstride = gdk_pixbuf_get_rowstride (pixbuf);
      src_n_channels = gdk_pixbuf_get_n_channels (pixbuf);
      src_buffer = gdk_pixbuf_get_pixels (pixbuf);

      /* find out the dimension of the destination pixbuf */
      dest_top_left.x = 100000;
      dest_top_left.y = 100000;
      dest_bottom_right.x = -100000;
      dest_bottom_right.y = -100000;

      for (i = 0; i < 4; i++) {
            src.x = vertices[i].x * (src_width - 1);
            src.y = vertices[i].y * (src_height -1);

            art_affine_point (&dest, &src, trans->priv->affine);

            dest_top_left.x = MIN (dest_top_left.x, dest.x);
            dest_top_left.y = MIN (dest_top_left.y, dest.y);

            dest_bottom_right.x = MAX (dest_bottom_right.x, dest.x);
            dest_bottom_right.y = MAX (dest_bottom_right.y, dest.y);
      }
      
      /* create the resulting pixbuf */
      dest_width = abs (dest_bottom_right.x - dest_top_left.x + 1);
      dest_height = abs (dest_bottom_right.y - dest_top_left.y + 1);

      dest_pixbuf = gdk_pixbuf_new (GDK_COLORSPACE_RGB,
                         gdk_pixbuf_get_has_alpha (pixbuf),
                         gdk_pixbuf_get_bits_per_sample (pixbuf),
                         dest_width,
                         dest_height);
      dest_rowstride = gdk_pixbuf_get_rowstride (dest_pixbuf);
      dest_n_channels = gdk_pixbuf_get_n_channels (dest_pixbuf);
      dest_buffer = gdk_pixbuf_get_pixels (dest_pixbuf);

      /* invert the matrix so that we can compute the source pixel
         from the target pixel and convert the values to integer
         ones (faster!)  FIXME: Maybe we can do some more
         improvements by using special mmx/3dnow features if
         available.
      */
      r_det = 1.0 / (trans->priv->affine[0] * trans->priv->affine[3] - trans->priv->affine[1] * trans->priv->affine[2]);
      inverted[0] =  trans->priv->affine[3] * r_det;
      inverted[1] = -trans->priv->affine[1] * r_det;
      inverted[2] = -trans->priv->affine[2] * r_det;
      inverted[3] =  trans->priv->affine[0] * r_det;
      inverted[4] = -trans->priv->affine[4] * inverted[0] - trans->priv->affine[5] * inverted[2];
      inverted[5] = -trans->priv->affine[4] * inverted[1] - trans->priv->affine[5] * inverted[3];

      progress_delta = MAX (1, dest_height / EOG_TRANSFORM_N_PROG_UPDATES);

      /* 
       * for every destination pixel (dx,dy) compute the source pixel (sx, sy)
       * and copy the color values
       */
      for (y = 0, dy = dest_top_left.y; y < dest_height; y++, dy++) {
            for (x = 0, dx = dest_top_left.x; x < dest_width; x++, dx++) {

                  sx = dx * inverted[0] + dy * inverted[2] + inverted[4];
                  sy = dx * inverted[1] + dy * inverted[3] + inverted[5];

                  if (sx >= 0 && sx < src_width && sy >= 0 && sy < src_height) {
                        src_pos  = src_buffer  + sy * src_rowstride  + sx * src_n_channels;
                        dest_pos = dest_buffer +  y * dest_rowstride +  x * dest_n_channels;
                  
                        for (i = 0; i <  src_n_channels; i++) {
                              dest_pos[i] = src_pos[i];
                        }
                  }
            }

            if (job != NULL && y % progress_delta == 0) {
                  gfloat progress;

                  progress = (gfloat) (y + 1.0) / (gfloat) dest_height;

                  eog_job_set_progress (job, progress);
            }
      }

      g_object_unref (pixbuf);

      if (job != NULL) {
            eog_job_set_progress (job, 1.0);
      }

      return dest_pixbuf;
}

EogTransform* 
eog_transform_reverse (EogTransform *trans)
{
      EogTransform *reverse; 

      g_return_val_if_fail (EOG_IS_TRANSFORM (trans), NULL);

      reverse = EOG_TRANSFORM (g_object_new (EOG_TYPE_TRANSFORM, NULL));

      art_affine_invert (reverse->priv->affine, trans->priv->affine);

      return reverse;
}

EogTransform*
eog_transform_compose (EogTransform *trans, EogTransform *compose)
{
      EogTransform *composition;

      g_return_val_if_fail (EOG_IS_TRANSFORM (trans), NULL);
      g_return_val_if_fail (EOG_IS_TRANSFORM (compose), NULL);

      composition = EOG_TRANSFORM (g_object_new (EOG_TYPE_TRANSFORM, NULL));

      art_affine_multiply (composition->priv->affine,
                       trans->priv->affine,
                       compose->priv->affine);

      return composition;
}

gboolean 
eog_transform_is_identity (EogTransform *trans)
{
      double identity[6] = { 1, 0, 0, 1, 0, 0 };

      g_return_val_if_fail (EOG_IS_TRANSFORM (trans), FALSE);

      return art_affine_equal (identity, trans->priv->affine);
}

EogTransform*
eog_transform_identity_new (void)
{
      EogTransform *trans; 

      trans = EOG_TRANSFORM (g_object_new (EOG_TYPE_TRANSFORM, NULL));
      
      art_affine_identity (trans->priv->affine);

      return trans;
}

EogTransform* 
eog_transform_rotate_new (int degree)
{
      EogTransform *trans; 

      trans = EOG_TRANSFORM (g_object_new (EOG_TYPE_TRANSFORM, NULL));
      
      art_affine_rotate (trans->priv->affine, degree);

      return trans;
}

EogTransform* 
eog_transform_flip_new   (EogTransformType type)
{
      EogTransform *trans; 
      gboolean horiz, vert;

      trans = EOG_TRANSFORM (g_object_new (EOG_TYPE_TRANSFORM, NULL));
      
      art_affine_identity (trans->priv->affine);

      horiz = (type == EOG_TRANSFORM_FLIP_HORIZONTAL);
      vert = (type == EOG_TRANSFORM_FLIP_VERTICAL);

      art_affine_flip (trans->priv->affine,
                   trans->priv->affine, 
                   horiz, vert);

      return trans;
}

#if 0
EogTransform* 
eog_transform_scale_new  (double sx, double sy)
{
      EogTransform *trans; 

      trans = EOG_TRANSFORM (g_object_new (EOG_TYPE_TRANSFORM, 0));
      
      art_affine_scale (trans->priv->affine, sx, sy);

      return trans;
}
#endif

EogTransform*
eog_transform_new (EogTransformType type)
{
      EogTransform *trans = NULL;
      EogTransform *temp1 = NULL, *temp2 = NULL;

      switch (type) {
      case EOG_TRANSFORM_NONE:
            trans = eog_transform_identity_new ();
            break;
      case EOG_TRANSFORM_FLIP_HORIZONTAL:
            trans = eog_transform_flip_new (EOG_TRANSFORM_FLIP_HORIZONTAL);
            break;
      case EOG_TRANSFORM_ROT_180:
            trans = eog_transform_rotate_new (180);
            break;
      case EOG_TRANSFORM_FLIP_VERTICAL:
            trans = eog_transform_flip_new (EOG_TRANSFORM_FLIP_VERTICAL);
            break;
      case EOG_TRANSFORM_TRANSPOSE:
            temp1 = eog_transform_rotate_new (90);
            temp2 = eog_transform_flip_new (EOG_TRANSFORM_FLIP_HORIZONTAL);
            trans = eog_transform_compose (temp1, temp2);
            g_object_unref (temp1);
            g_object_unref (temp2);
            break;
      case EOG_TRANSFORM_ROT_90:
            trans = eog_transform_rotate_new (90);
            break;
      case EOG_TRANSFORM_TRANSVERSE:
            temp1 = eog_transform_rotate_new (90);
            temp2 = eog_transform_flip_new (EOG_TRANSFORM_FLIP_VERTICAL);
            trans = eog_transform_compose (temp1, temp2);
            g_object_unref (temp1);
            g_object_unref (temp2);
            break;
      case EOG_TRANSFORM_ROT_270:
            trans = eog_transform_rotate_new (270);
            break;
      default:
            trans = eog_transform_identity_new ();
            break;
      }

      return trans;
}

EogTransformType
eog_transform_get_transform_type (EogTransform *trans)
{
      double affine[6];
      EogTransformPrivate *priv;

      g_return_val_if_fail (EOG_IS_TRANSFORM (trans), EOG_TRANSFORM_NONE);

      priv = trans->priv;

        art_affine_rotate (affine, 90);
      if (art_affine_equal (affine, priv->affine)) {
            return EOG_TRANSFORM_ROT_90;
      }

        art_affine_rotate (affine, 180);
      if (art_affine_equal (affine, priv->affine)) {
            return EOG_TRANSFORM_ROT_180;
      }

        art_affine_rotate (affine, 270);
      if (art_affine_equal (affine, priv->affine)) {
            return EOG_TRANSFORM_ROT_270;
      }

      art_affine_identity (affine);
      art_affine_flip (affine, affine, TRUE, FALSE);
      if (art_affine_equal (affine, priv->affine)) {
            return EOG_TRANSFORM_FLIP_HORIZONTAL;
      }

      art_affine_identity (affine);
      art_affine_flip (affine, affine, FALSE, TRUE);
      if (art_affine_equal (affine, priv->affine)) {
            return EOG_TRANSFORM_FLIP_VERTICAL;
      }

      art_affine_rotate (affine, 90);
      art_affine_flip (affine, affine, TRUE, FALSE);
      if (art_affine_equal (affine, priv->affine)) {
            return EOG_TRANSFORM_TRANSPOSE;
      }

      art_affine_rotate (affine, 90);
      art_affine_flip (affine, affine, FALSE, TRUE);
      if (art_affine_equal (affine, priv->affine)) {
            return EOG_TRANSFORM_TRANSVERSE;
      }

      return EOG_TRANSFORM_NONE;
}