X-Git-Url: http://git.imager.perl.org/imager.git/blobdiff_plain/837a4b437e51425237d90f221fbd25b1a8bf3d3e..HEAD:/img16.c

diff --git a/img16.c b/img16.c
index e486c012..1b3e4521 100644
--- a/img16.c
+++ b/img16.c
@@ -5,7 +5,7 @@ img16.c - implements 16-bit images
 
 =head1 SYNOPSIS
 
-  i_img *im = i_img_16_new(int x, int y, int channels);
+  i_img *im = i_img_16_new(i_img_dim x, i_img_dim y, int channels);
   # use like a normal image
 
 =head1 DESCRIPTION
@@ -20,21 +20,29 @@ sample image type to work with.
 =cut
 */
 
+#define IMAGER_NO_CONTEXT
+
 #include "imager.h"
 #include "imageri.h"
 
-static int i_ppix_d16(i_img *im, int x, int y, const i_color *val);
-static int i_gpix_d16(i_img *im, int x, int y, i_color *val);
-static int i_glin_d16(i_img *im, int l, int r, int y, i_color *vals);
-static int i_plin_d16(i_img *im, int l, int r, int y, const i_color *vals);
-static int i_ppixf_d16(i_img *im, int x, int y, const i_fcolor *val);
-static int i_gpixf_d16(i_img *im, int x, int y, i_fcolor *val);
-static int i_glinf_d16(i_img *im, int l, int r, int y, i_fcolor *vals);
-static int i_plinf_d16(i_img *im, int l, int r, int y, const i_fcolor *vals);
-static int i_gsamp_d16(i_img *im, int l, int r, int y, i_sample_t *samps, 
+static int i_ppix_d16(i_img *im, i_img_dim x, i_img_dim y, const i_color *val);
+static int i_gpix_d16(i_img *im, i_img_dim x, i_img_dim y, i_color *val);
+static i_img_dim i_glin_d16(i_img *im, i_img_dim l, i_img_dim r, i_img_dim y, i_color *vals);
+static i_img_dim i_plin_d16(i_img *im, i_img_dim l, i_img_dim r, i_img_dim y, const i_color *vals);
+static int i_ppixf_d16(i_img *im, i_img_dim x, i_img_dim y, const i_fcolor *val);
+static int i_gpixf_d16(i_img *im, i_img_dim x, i_img_dim y, i_fcolor *val);
+static i_img_dim i_glinf_d16(i_img *im, i_img_dim l, i_img_dim r, i_img_dim y, i_fcolor *vals);
+static i_img_dim i_plinf_d16(i_img *im, i_img_dim l, i_img_dim r, i_img_dim y, const i_fcolor *vals);
+static i_img_dim i_gsamp_d16(i_img *im, i_img_dim l, i_img_dim r, i_img_dim y, i_sample_t *samps, 
                        int const *chans, int chan_count);
-static int i_gsampf_d16(i_img *im, int l, int r, int y, i_fsample_t *samps, 
+static i_img_dim i_gsampf_d16(i_img *im, i_img_dim l, i_img_dim r, i_img_dim y, i_fsample_t *samps, 
                         int const *chans, int chan_count);
+static i_img_dim i_gsamp_bits_d16(i_img *im, i_img_dim l, i_img_dim r, i_img_dim y, unsigned *samps, 
+			    int const *chans, int chan_count, int bits);
+static i_img_dim i_psamp_bits_d16(i_img *im, i_img_dim l, i_img_dim r, i_img_dim y, unsigned const *samps, 
+			    int const *chans, int chan_count, int bits);
+static i_img_dim i_psamp_d16(i_img *im, i_img_dim l, i_img_dim r, i_img_dim y, const i_sample_t *samps, const int *chans, int chan_count);
+static i_img_dim i_psampf_d16(i_img *im, i_img_dim l, i_img_dim r, i_img_dim y, const i_fsample_t *samps, const int *chans, int chan_count);
 
 /*
 =item IIM_base_16bit_direct
@@ -70,12 +78,20 @@ static i_img IIM_base_16bit_direct =
 
   NULL, /* i_f_gpal */
   NULL, /* i_f_ppal */
-  NULL, /* i_f_addcolor */
-  NULL, /* i_f_getcolor */
+  NULL, /* i_f_addcolors */
+  NULL, /* i_f_getcolors */
   NULL, /* i_f_colorcount */
+  NULL, /* i_f_maxcolors */
   NULL, /* i_f_findcolor */
+  NULL, /* i_f_setcolors */
 
   NULL, /* i_f_destroy */
+
+  i_gsamp_bits_d16,
+  i_psamp_bits_d16,
+
+  i_psamp_d16,
+  i_psampf_d16
 };
 
 /* it's possible some platforms won't have a 16-bit integer type,
@@ -111,12 +127,9 @@ typedef unsigned short i_sample16_t;
 #define STORE16(bytes, offset, word) \
    (((i_sample16_t *)(bytes))[offset] = (word))
 #define STORE8as16(bytes, offset, byte) \
-   (((i_sample16_t *)(bytes))[offset] = (byte) * 256)
+   (((i_sample16_t *)(bytes))[offset] = (byte) * 256 + (byte))
 #define GET16(bytes, offset) \
      (((i_sample16_t *)(bytes))[offset])
-#define GET16as8(bytes, offset) \
-     (((i_sample16_t *)(bytes))[offset] / 256)
-
 #else
 
 /* we have to do this the hard way */
@@ -125,38 +138,52 @@ typedef unsigned short i_sample16_t;
     (((unsigned char *)(bytes))[(offset)*2+1] = (word) & 0xFF))
 #define STORE8as16(bytes, offset, byte) \
    ((((unsigned char *)(bytes))[(offset)*2] = (byte)), \
-    (((unsigned char *)(bytes))[(offset)*2+1] = 0))
+    (((unsigned char *)(bytes))[(offset)*2+1] = (byte)))
    
 #define GET16(bytes, offset) \
    (((unsigned char *)(bytes))[(offset)*2] * 256 \
     + ((unsigned char *)(bytes))[(offset)*2+1])
-#define GET16as8(bytes, offset) \
-   (((unsigned char *)(bytes))[(offset)*2] << 8)
 
 #endif
 
+#define GET16as8(bytes, offset) \
+     ((((i_sample16_t *)(bytes))[offset]+127) / 257)
+
 /*
-=item i_img_16_new_low(int x, int y, int ch)
+=item im_img_16_new(ctx, x, y, ch)
+X<im_img_16_new API>X<i_img_16_new API>
+=category Image creation/destruction
+=synopsis i_img *img = im_img_16_new(aIMCTX, width, height, channels);
+=synopsis i_img *img = i_img_16_new(width, height, channels);
+
+Create a new 16-bit/sample image.
 
-Creates a new 16-bit per sample image.
+Returns the image on success, or NULL on failure.
+
+Also callable as C<i_img_16_new(x, y, ch)>
 
 =cut
 */
-i_img *i_img_16_new_low(i_img *im, int x, int y, int ch) {
-  int bytes, line_bytes;
-  mm_log((1,"i_img_16_new(x %d, y %d, ch %d)\n", x, y, ch));
+
+i_img *
+im_img_16_new(pIMCTX, i_img_dim x, i_img_dim y, int ch) {
+  i_img *im;
+  size_t bytes, line_bytes;
+
+  im_log((aIMCTX, 1,"i_img_16_new(x %" i_DF ", y %" i_DF ", ch %d)\n",
+	  i_DFc(x), i_DFc(y), ch));
 
   if (x < 1 || y < 1) {
-    i_push_error(0, "Image sizes must be positive");
+    im_push_error(aIMCTX, 0, "Image sizes must be positive");
     return NULL;
   }
   if (ch < 1 || ch > MAXCHANNELS) {
-    i_push_errorf(0, "channels must be between 1 and %d", MAXCHANNELS);
+    im_push_errorf(aIMCTX, 0, "channels must be between 1 and %d", MAXCHANNELS);
     return NULL;
   }
   bytes =  x * y * ch * 2;
   if (bytes / y / ch / 2 != x) {
-    i_push_errorf(0, "integer overflow calculating image allocation");
+    im_push_errorf(aIMCTX, 0, "integer overflow calculating image allocation");
     return NULL;
   }
   
@@ -165,10 +192,11 @@ i_img *i_img_16_new_low(i_img *im, int x, int y, int ch) {
      working with the image */
   line_bytes = sizeof(i_fcolor) * x;
   if (line_bytes / x != sizeof(i_fcolor)) {
-    i_push_error(0, "integer overflow calculating scanline allocation");
+    im_push_error(aIMCTX, 0, "integer overflow calculating scanline allocation");
     return NULL;
   }
 
+  im = im_img_alloc(aIMCTX);
   *im = IIM_base_16bit_direct;
   i_tags_new(&im->tags);
   im->xsize = x;
@@ -177,44 +205,10 @@ i_img *i_img_16_new_low(i_img *im, int x, int y, int ch) {
   im->bytes = bytes;
   im->ext_data = NULL;
   im->idata = mymalloc(im->bytes);
-  if (im->idata) {
-    memset(im->idata, 0, im->bytes);
-  }
-  else {
-    i_tags_destroy(&im->tags);
-    im = NULL;
-  }
-  
-  return im;
-}
-
-/*
-=item i_img_16_new(x, y, ch)
+  memset(im->idata, 0, im->bytes);
 
-=category Image creation
+  im_img_init(aIMCTX, im);
 
-Create a new 16-bit/sample image.
-
-Returns the image on success, or NULL on failure.
-
-=cut
-*/
-
-i_img *i_img_16_new(int x, int y, int ch) {
-  i_img *im;
-  
-  i_clear_error();
-
-  im = mymalloc(sizeof(i_img));
-  if (im) {
-    if (!i_img_16_new_low(im, x, y, ch)) {
-      myfree(im);
-      im = NULL;
-    }
-  }
-  
-  mm_log((1, "(%p) <- i_img_16_new\n", im));
-  
   return im;
 }
 
@@ -234,9 +228,10 @@ i_img *
 i_img_to_rgb16(i_img *im) {
   i_img *targ;
   i_fcolor *line;
-  int y;
+  i_img_dim y;
+  dIMCTXim(im);
 
-  targ = i_img_16_new(im->xsize, im->ysize, im->channels);
+  targ = im_img_16_new(aIMCTX, im->xsize, im->ysize, im->channels);
   if (!targ)
     return NULL;
   line = mymalloc(sizeof(i_fcolor) * im->xsize);
@@ -250,8 +245,9 @@ i_img_to_rgb16(i_img *im) {
   return targ;
 }
 
-static int i_ppix_d16(i_img *im, int x, int y, const i_color *val) {
-  int off, ch;
+static int i_ppix_d16(i_img *im, i_img_dim x, i_img_dim y, const i_color *val) {
+  i_img_dim off;
+  int ch;
 
   if (x < 0 || x >= im->xsize || y < 0 || y >= im->ysize) 
     return -1;
@@ -270,8 +266,9 @@ static int i_ppix_d16(i_img *im, int x, int y, const i_color *val) {
   return 0;
 }
 
-static int i_gpix_d16(i_img *im, int x, int y, i_color *val) {
-  int off, ch;
+static int i_gpix_d16(i_img *im, i_img_dim x, i_img_dim y, i_color *val) {
+  i_img_dim off;
+  int ch;
 
   if (x < 0 || x >= im->xsize || y < 0 || y >= im->ysize) 
     return -1;
@@ -283,8 +280,9 @@ static int i_gpix_d16(i_img *im, int x, int y, i_color *val) {
   return 0;
 }
 
-static int i_ppixf_d16(i_img *im, int x, int y, const i_fcolor *val) {
-  int off, ch;
+static int i_ppixf_d16(i_img *im, i_img_dim x, i_img_dim y, const i_fcolor *val) {
+  i_img_dim off;
+  int ch;
 
   if (x < 0 || x >= im->xsize || y < 0 || y >= im->ysize) 
     return -1;
@@ -303,8 +301,9 @@ static int i_ppixf_d16(i_img *im, int x, int y, const i_fcolor *val) {
   return 0;
 }
 
-static int i_gpixf_d16(i_img *im, int x, int y, i_fcolor *val) {
-  int off, ch;
+static int i_gpixf_d16(i_img *im, i_img_dim x, i_img_dim y, i_fcolor *val) {
+  i_img_dim off;
+  int ch;
 
   if (x < 0 || x >= im->xsize || y < 0 || y >= im->ysize) 
     return -1;
@@ -316,9 +315,10 @@ static int i_gpixf_d16(i_img *im, int x, int y, i_fcolor *val) {
   return 0;
 }
 
-static int i_glin_d16(i_img *im, int l, int r, int y, i_color *vals) {
-  int ch, count, i;
-  int off;
+static i_img_dim i_glin_d16(i_img *im, i_img_dim l, i_img_dim r, i_img_dim y, i_color *vals) {
+  int ch;
+  i_img_dim count, i;
+  i_img_dim off;
   if (y >=0 && y < im->ysize && l < im->xsize && l >= 0) {
     if (r > im->xsize)
       r = im->xsize;
@@ -337,9 +337,10 @@ static int i_glin_d16(i_img *im, int l, int r, int y, i_color *vals) {
   }
 }
 
-static int i_plin_d16(i_img *im, int l, int r, int y, const i_color *vals) {
-  int ch, count, i;
-  int off;
+static i_img_dim i_plin_d16(i_img *im, i_img_dim l, i_img_dim r, i_img_dim y, const i_color *vals) {
+  int ch;
+  i_img_dim count, i;
+  i_img_dim off;
   if (y >=0 && y < im->ysize && l < im->xsize && l >= 0) {
     if (r > im->xsize)
       r = im->xsize;
@@ -369,9 +370,10 @@ static int i_plin_d16(i_img *im, int l, int r, int y, const i_color *vals) {
   }
 }
 
-static int i_glinf_d16(i_img *im, int l, int r, int y, i_fcolor *vals) {
-  int ch, count, i;
-  int off;
+static i_img_dim i_glinf_d16(i_img *im, i_img_dim l, i_img_dim r, i_img_dim y, i_fcolor *vals) {
+  int ch;
+  i_img_dim count, i;
+  i_img_dim off;
   if (y >=0 && y < im->ysize && l < im->xsize && l >= 0) {
     if (r > im->xsize)
       r = im->xsize;
@@ -390,9 +392,10 @@ static int i_glinf_d16(i_img *im, int l, int r, int y, i_fcolor *vals) {
   }
 }
 
-static int i_plinf_d16(i_img *im, int l, int r, int y, const i_fcolor *vals) {
-  int ch, count, i;
-  int off;
+static i_img_dim i_plinf_d16(i_img *im, i_img_dim l, i_img_dim r, i_img_dim y, const i_fcolor *vals) {
+  int ch;
+  i_img_dim count, i;
+  i_img_dim off;
   if (y >=0 && y < im->ysize && l < im->xsize && l >= 0) {
     if (r > im->xsize)
       r = im->xsize;
@@ -422,10 +425,11 @@ static int i_plinf_d16(i_img *im, int l, int r, int y, const i_fcolor *vals) {
   }
 }
 
-static int i_gsamp_d16(i_img *im, int l, int r, int y, i_sample_t *samps, 
+static i_img_dim i_gsamp_d16(i_img *im, i_img_dim l, i_img_dim r, i_img_dim y, i_sample_t *samps, 
                        int const *chans, int chan_count) {
-  int ch, count, i, w;
-  int off;
+  int ch;
+  i_img_dim count, i, w;
+  i_img_dim off;
 
   if (y >=0 && y < im->ysize && l < im->xsize && l >= 0) {
     if (r > im->xsize)
@@ -438,7 +442,8 @@ static int i_gsamp_d16(i_img *im, int l, int r, int y, i_sample_t *samps,
       /* make sure we have good channel numbers */
       for (ch = 0; ch < chan_count; ++ch) {
         if (chans[ch] < 0 || chans[ch] >= im->channels) {
-          i_push_errorf(0, "No channel %d in this image", chans[ch]);
+	  dIMCTXim(im);
+          im_push_errorf(aIMCTX, 0, "No channel %d in this image", chans[ch]);
           return 0;
         }
       }
@@ -451,6 +456,12 @@ static int i_gsamp_d16(i_img *im, int l, int r, int y, i_sample_t *samps,
       }
     }
     else {
+      if (chan_count <= 0 || chan_count > im->channels) {
+	dIMCTXim(im);
+	im_push_errorf(aIMCTX, 0, "chan_count %d out of range, must be >0, <= channels", 
+		      chan_count);
+	return 0;
+      }
       for (i = 0; i < w; ++i) {
         for (ch = 0; ch < chan_count; ++ch) {
           *samps++ = GET16as8(im->idata, off+ch);
@@ -467,10 +478,11 @@ static int i_gsamp_d16(i_img *im, int l, int r, int y, i_sample_t *samps,
   }
 }
 
-static int i_gsampf_d16(i_img *im, int l, int r, int y, i_fsample_t *samps, 
+static i_img_dim i_gsampf_d16(i_img *im, i_img_dim l, i_img_dim r, i_img_dim y, i_fsample_t *samps, 
                         int const *chans, int chan_count) {
-  int ch, count, i, w;
-  int off;
+  int ch;
+  i_img_dim count, i, w;
+  i_img_dim off;
 
   if (y >=0 && y < im->ysize && l < im->xsize && l >= 0) {
     if (r > im->xsize)
@@ -483,7 +495,8 @@ static int i_gsampf_d16(i_img *im, int l, int r, int y, i_fsample_t *samps,
       /* make sure we have good channel numbers */
       for (ch = 0; ch < chan_count; ++ch) {
         if (chans[ch] < 0 || chans[ch] >= im->channels) {
-          i_push_errorf(0, "No channel %d in this image", chans[ch]);
+	  dIMCTXim(im);
+          im_push_errorf(aIMCTX, 0, "No channel %d in this image", chans[ch]);
           return 0;
         }
       }
@@ -496,6 +509,12 @@ static int i_gsampf_d16(i_img *im, int l, int r, int y, i_fsample_t *samps,
       }
     }
     else {
+      if (chan_count <= 0 || chan_count > im->channels) {
+	dIMCTXim(im);
+	im_push_errorf(aIMCTX, 0, "chan_count %d out of range, must be >0, <= channels", 
+		      chan_count);
+	return 0;
+      }
       for (i = 0; i < w; ++i) {
         for (ch = 0; ch < chan_count; ++ch) {
           *samps++ = Sample16ToF(GET16(im->idata, off+ch));
@@ -512,6 +531,319 @@ static int i_gsampf_d16(i_img *im, int l, int r, int y, i_fsample_t *samps,
   }
 }
 
+static i_img_dim 
+i_gsamp_bits_d16(i_img *im, i_img_dim l, i_img_dim r, i_img_dim y, unsigned *samps, 
+			    int const *chans, int chan_count, int bits) {
+  int ch;
+  i_img_dim count, i, w;
+  i_img_dim off;
+
+  if (bits != 16) {
+    return i_gsamp_bits_fb(im, l, r, y, samps, chans, chan_count, bits);
+  }
+
+  if (y >=0 && y < im->ysize && l < im->xsize && l >= 0) {
+    if (r > im->xsize)
+      r = im->xsize;
+    off = (l+y*im->xsize) * im->channels;
+    w = r - l;
+    count = 0;
+
+    if (chans) {
+      /* make sure we have good channel numbers */
+      for (ch = 0; ch < chan_count; ++ch) {
+        if (chans[ch] < 0 || chans[ch] >= im->channels) {
+	  dIMCTXim(im);
+          im_push_errorf(aIMCTX, 0, "No channel %d in this image", chans[ch]);
+          return -1;
+        }
+      }
+      for (i = 0; i < w; ++i) {
+        for (ch = 0; ch < chan_count; ++ch) {
+          *samps++ = GET16(im->idata, off+chans[ch]);
+          ++count;
+        }
+        off += im->channels;
+      }
+    }
+    else {
+      if (chan_count <= 0 || chan_count > im->channels) {
+	dIMCTXim(im);
+	i_push_error(0, "Invalid channel count");
+	return -1;
+      }
+      for (i = 0; i < w; ++i) {
+        for (ch = 0; ch < chan_count; ++ch) {
+          *samps++ = GET16(im->idata, off+ch);
+          ++count;
+        }
+        off += im->channels;
+      }
+    }
+
+    return count;
+  }
+  else {
+    dIMCTXim(im);
+    i_push_error(0, "Image position outside of image");
+    return -1;
+  }
+}
+
+static i_img_dim 
+i_psamp_bits_d16(i_img *im, i_img_dim l, i_img_dim r, i_img_dim y, unsigned const *samps, 
+			    int const *chans, int chan_count, int bits) {
+  int ch;
+  i_img_dim count, i, w;
+  i_img_dim off;
+
+  if (bits != 16) {
+    dIMCTXim(im);
+    i_push_error(0, "Invalid bits for 16-bit image");
+    return -1;
+  }
+
+  if (y >=0 && y < im->ysize && l < im->xsize && l >= 0) {
+    if (r > im->xsize)
+      r = im->xsize;
+    off = (l+y*im->xsize) * im->channels;
+    w = r - l;
+    count = 0;
+
+    if (chans) {
+      /* make sure we have good channel numbers */
+      for (ch = 0; ch < chan_count; ++ch) {
+        if (chans[ch] < 0 || chans[ch] >= im->channels) {
+	  dIMCTXim(im);
+          im_push_errorf(aIMCTX, 0, "No channel %d in this image", chans[ch]);
+          return -1;
+        }
+      }
+      for (i = 0; i < w; ++i) {
+        for (ch = 0; ch < chan_count; ++ch) {
+	  if (im->ch_mask & (1 << ch))
+	    STORE16(im->idata, off+chans[ch], *samps);
+	  ++samps;
+	  ++count;
+        }
+        off += im->channels;
+      }
+    }
+    else {
+      if (chan_count <= 0 || chan_count > im->channels) {
+	dIMCTXim(im);
+	i_push_error(0, "Invalid channel count");
+	return -1;
+      }
+      for (i = 0; i < w; ++i) {
+        for (ch = 0; ch < chan_count; ++ch) {
+	  if (im->ch_mask & (1 << ch)) 
+	    STORE16(im->idata, off+ch, *samps);
+	  ++samps;
+          ++count;
+        }
+        off += im->channels;
+      }
+    }
+
+    return count;
+  }
+  else {
+    dIMCTXim(im);
+    i_push_error(0, "Image position outside of image");
+    return -1;
+  }
+}
+
+/*
+=item i_psamp_d16(i_img *im, i_img_dim l, i_img_dim r, i_img_dim y, const i_sample_t *samps, int *chans, int chan_count)
+
+Writes sample values to im for the horizontal line (l, y) to (r-1,y)
+for the channels specified by chans, an array of int with chan_count
+elements.
+
+Returns the number of samples written (which should be (r-l) *
+bits_set(chan_mask)
+
+=cut
+*/
+
+static
+i_img_dim
+i_psamp_d16(i_img *im, i_img_dim l, i_img_dim r, i_img_dim y, 
+	  const i_sample_t *samps, const int *chans, int chan_count) {
+  int ch;
+  i_img_dim count, i, w;
+
+  if (y >=0 && y < im->ysize && l < im->xsize && l >= 0) {
+    i_img_dim offset;
+    if (r > im->xsize)
+      r = im->xsize;
+    offset = (l+y*im->xsize) * im->channels;
+    w = r - l;
+    count = 0;
+
+    if (chans) {
+      /* make sure we have good channel numbers */
+      /* and test if all channels specified are in the mask */
+      int all_in_mask = 1;
+      for (ch = 0; ch < chan_count; ++ch) {
+        if (chans[ch] < 0 || chans[ch] >= im->channels) {
+	  dIMCTXim(im);
+          im_push_errorf(aIMCTX, 0, "No channel %d in this image", chans[ch]);
+          return -1;
+        }
+	if (!((1 << chans[ch]) & im->ch_mask))
+	  all_in_mask = 0;
+      }
+      if (all_in_mask) {
+	for (i = 0; i < w; ++i) {
+	  for (ch = 0; ch < chan_count; ++ch) {
+	    STORE8as16(im->idata, offset + chans[ch], *samps);
+	    ++samps;
+	    ++count;
+	  }
+	  offset += im->channels;
+	}
+      }
+      else {
+	for (i = 0; i < w; ++i) {
+	  for (ch = 0; ch < chan_count; ++ch) {
+	    if (im->ch_mask & (1 << (chans[ch])))
+	    STORE8as16(im->idata, offset + chans[ch], *samps);
+	    ++samps;
+	    ++count;
+	  }
+	  offset += im->channels;
+	}
+      }
+    }
+    else {
+      if (chan_count <= 0 || chan_count > im->channels) {
+	dIMCTXim(im);
+	im_push_errorf(aIMCTX, 0, "chan_count %d out of range, must be >0, <= channels", 
+		      chan_count);
+	return -1;
+      }
+      for (i = 0; i < w; ++i) {
+	unsigned mask = 1;
+        for (ch = 0; ch < chan_count; ++ch) {
+	  if (im->ch_mask & mask)
+	    STORE8as16(im->idata, offset + ch, *samps);
+	  ++samps;
+          ++count;
+	  mask <<= 1;
+        }
+        offset += im->channels;
+      }
+    }
+
+    return count;
+  }
+  else {
+    dIMCTXim(im);
+    i_push_error(0, "Image position outside of image");
+    return -1;
+  }
+}
+
+/*
+=item i_psampf_d16(i_img *im, i_img_dim l, i_img_dim r, i_img_dim y, const i_fsample_t *samps, int *chans, int chan_count)
+
+Writes sample values to im for the horizontal line (l, y) to (r-1,y)
+for the channels specified by chans, an array of int with chan_count
+elements.
+
+Returns the number of samples written (which should be (r-l) *
+bits_set(chan_mask)
+
+=cut
+*/
+
+static
+i_img_dim
+i_psampf_d16(i_img *im, i_img_dim l, i_img_dim r, i_img_dim y, 
+	  const i_fsample_t *samps, const int *chans, int chan_count) {
+  int ch;
+  i_img_dim count, i, w;
+
+  if (y >=0 && y < im->ysize && l < im->xsize && l >= 0) {
+    i_img_dim offset;
+    if (r > im->xsize)
+      r = im->xsize;
+    offset = (l+y*im->xsize) * im->channels;
+    w = r - l;
+    count = 0;
+
+    if (chans) {
+      /* make sure we have good channel numbers */
+      /* and test if all channels specified are in the mask */
+      int all_in_mask = 1;
+      for (ch = 0; ch < chan_count; ++ch) {
+        if (chans[ch] < 0 || chans[ch] >= im->channels) {
+	  dIMCTXim(im);
+          im_push_errorf(aIMCTX, 0, "No channel %d in this image", chans[ch]);
+          return -1;
+        }
+	if (!((1 << chans[ch]) & im->ch_mask))
+	  all_in_mask = 0;
+      }
+      if (all_in_mask) {
+	for (i = 0; i < w; ++i) {
+	  for (ch = 0; ch < chan_count; ++ch) {
+	    unsigned samp16 = SampleFTo16(*samps);
+	    STORE16(im->idata, offset + chans[ch], samp16);
+	    ++samps;
+	    ++count;
+	  }
+	  offset += im->channels;
+	}
+      }
+      else {
+	for (i = 0; i < w; ++i) {
+	  for (ch = 0; ch < chan_count; ++ch) {
+	    if (im->ch_mask & (1 << (chans[ch]))) {
+	      unsigned samp16 = SampleFTo16(*samps);
+	      STORE16(im->idata, offset + chans[ch], samp16);
+	    }
+	    ++samps;
+	    ++count;
+	  }
+	  offset += im->channels;
+	}
+      }
+    }
+    else {
+      if (chan_count <= 0 || chan_count > im->channels) {
+	dIMCTXim(im);
+	im_push_errorf(aIMCTX, 0, "chan_count %d out of range, must be >0, <= channels", 
+		      chan_count);
+	return -1;
+      }
+      for (i = 0; i < w; ++i) {
+	unsigned mask = 1;
+        for (ch = 0; ch < chan_count; ++ch) {
+	  if (im->ch_mask & mask) {
+	    unsigned samp16 = SampleFTo16(*samps);
+	    STORE16(im->idata, offset + ch, samp16);
+	  }
+	  ++samps;
+          ++count;
+	  mask <<= 1;
+        }
+        offset += im->channels;
+      }
+    }
+
+    return count;
+  }
+  else {
+    dIMCTXim(im);
+    i_push_error(0, "Image position outside of image");
+    return -1;
+  }
+}
+
 /*
 =back