new file added

[wxWidgets.git] / src / png / pngtrans.c

diff --git a/src/png/pngtrans.c b/src/png/pngtrans.c
index 741daf45b7c6d75b3dc2e8432838ecffcc782f39..6a6908dcd26892635ec6b1dd31d55ed848f9736c 100644 (file)
--- a/src/png/pngtrans.c
+++ b/src/png/pngtrans.c
@@ -1,8 +1,8 @@
 
 /* pngtrans.c - transforms the data in a row (used by both readers and writers)
  *
 
 /* pngtrans.c - transforms the data in a row (used by both readers and writers)
  *

- * Last changed in libpng 1.4.2 [April 29, 2010]
- * Copyright (c) 1998-2010 Glenn Randers-Pehrson
+ * Last changed in libpng 1.5.4 [July 7, 2011]
+ * Copyright (c) 1998-2011 Glenn Randers-Pehrson

  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
  * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
  *
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
  * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
  *


@@ -11,11 +11,10 @@
  * and license in png.h
  */
 
  * and license in png.h
  */
 

-#define PNG_NO_PEDANTIC_WARNINGS
-#include "png.h"
-#if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED)

 #include "pngpriv.h"
 
 #include "pngpriv.h"
 

+#if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED)
+

 #if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED)
 /* Turn on BGR-to-RGB mapping */
 void PNGAPI
 #if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED)
 /* Turn on BGR-to-RGB mapping */
 void PNGAPI


@@ -25,6 +24,7 @@ png_set_bgr(png_structp png_ptr)
 
    if (png_ptr == NULL)
       return;
 
    if (png_ptr == NULL)
       return;

+

    png_ptr->transformations |= PNG_BGR;
 }
 #endif
    png_ptr->transformations |= PNG_BGR;
 }
 #endif


@@ -38,6 +38,7 @@ png_set_swap(png_structp png_ptr)
 
    if (png_ptr == NULL)
       return;
 
    if (png_ptr == NULL)
       return;

+

    if (png_ptr->bit_depth == 16)
       png_ptr->transformations |= PNG_SWAP_BYTES;
 }
    if (png_ptr->bit_depth == 16)
       png_ptr->transformations |= PNG_SWAP_BYTES;
 }


@@ -52,6 +53,7 @@ png_set_packing(png_structp png_ptr)
 
    if (png_ptr == NULL)
       return;
 
    if (png_ptr == NULL)
       return;

+

    if (png_ptr->bit_depth < 8)
    {
       png_ptr->transformations |= PNG_PACK;
    if (png_ptr->bit_depth < 8)
    {
       png_ptr->transformations |= PNG_PACK;


@@ -69,6 +71,7 @@ png_set_packswap(png_structp png_ptr)
 
    if (png_ptr == NULL)
       return;
 
    if (png_ptr == NULL)
       return;

+

    if (png_ptr->bit_depth < 8)
       png_ptr->transformations |= PNG_PACKSWAP;
 }
    if (png_ptr->bit_depth < 8)
       png_ptr->transformations |= PNG_PACKSWAP;
 }


@@ -76,12 +79,13 @@ png_set_packswap(png_structp png_ptr)
 
 #if defined(PNG_READ_SHIFT_SUPPORTED) || defined(PNG_WRITE_SHIFT_SUPPORTED)
 void PNGAPI
 
 #if defined(PNG_READ_SHIFT_SUPPORTED) || defined(PNG_WRITE_SHIFT_SUPPORTED)
 void PNGAPI

-png_set_shift(png_structp png_ptr, png_color_8p true_bits)
+png_set_shift(png_structp png_ptr, png_const_color_8p true_bits)

 {
    png_debug(1, "in png_set_shift");
 
    if (png_ptr == NULL)
       return;
 {
    png_debug(1, "in png_set_shift");
 
    if (png_ptr == NULL)
       return;

+

    png_ptr->transformations |= PNG_SHIFT;
    png_ptr->shift = *true_bits;
 }
    png_ptr->transformations |= PNG_SHIFT;
    png_ptr->shift = *true_bits;
 }


@@ -117,10 +121,13 @@ png_set_filler(png_structp png_ptr, png_uint_32 filler, int filler_loc)
 
    if (png_ptr == NULL)
       return;
 
    if (png_ptr == NULL)
       return;

+

    png_ptr->transformations |= PNG_FILLER;
    png_ptr->filler = (png_uint_16)filler;
    png_ptr->transformations |= PNG_FILLER;
    png_ptr->filler = (png_uint_16)filler;

+

    if (filler_loc == PNG_FILLER_AFTER)
       png_ptr->flags |= PNG_FLAG_FILLER_AFTER;
    if (filler_loc == PNG_FILLER_AFTER)
       png_ptr->flags |= PNG_FLAG_FILLER_AFTER;

+

    else
       png_ptr->flags &= ~PNG_FLAG_FILLER_AFTER;
 
    else
       png_ptr->flags &= ~PNG_FLAG_FILLER_AFTER;
 


@@ -135,7 +142,7 @@ png_set_filler(png_structp png_ptr, png_uint_32 filler, int filler_loc)
    }
 
    /* Also I added this in libpng-1.0.2a (what happens when we expand
    }
 
    /* Also I added this in libpng-1.0.2a (what happens when we expand

-    * a less-than-8-bit grayscale to GA? */
+    * a less-than-8-bit grayscale to GA?) */

 
    if (png_ptr->color_type == PNG_COLOR_TYPE_GRAY && png_ptr->bit_depth >= 8)
    {
 
    if (png_ptr->color_type == PNG_COLOR_TYPE_GRAY && png_ptr->bit_depth >= 8)
    {


@@ -151,6 +158,7 @@ png_set_add_alpha(png_structp png_ptr, png_uint_32 filler, int filler_loc)
 
    if (png_ptr == NULL)
       return;
 
    if (png_ptr == NULL)
       return;

+

    png_set_filler(png_ptr, filler, filler_loc);
    png_ptr->transformations |= PNG_ADD_ALPHA;
 }
    png_set_filler(png_ptr, filler, filler_loc);
    png_ptr->transformations |= PNG_ADD_ALPHA;
 }


@@ -166,6 +174,7 @@ png_set_swap_alpha(png_structp png_ptr)
 
    if (png_ptr == NULL)
       return;
 
    if (png_ptr == NULL)
       return;

+

    png_ptr->transformations |= PNG_SWAP_ALPHA;
 }
 #endif
    png_ptr->transformations |= PNG_SWAP_ALPHA;
 }
 #endif


@@ -179,6 +188,7 @@ png_set_invert_alpha(png_structp png_ptr)
 
    if (png_ptr == NULL)
       return;
 
    if (png_ptr == NULL)
       return;

+

    png_ptr->transformations |= PNG_INVERT_ALPHA;
 }
 #endif
    png_ptr->transformations |= PNG_INVERT_ALPHA;
 }
 #endif


@@ -191,6 +201,7 @@ png_set_invert_mono(png_structp png_ptr)
 
    if (png_ptr == NULL)
       return;
 
    if (png_ptr == NULL)
       return;

+

    png_ptr->transformations |= PNG_INVERT_MONO;
 }
 
    png_ptr->transformations |= PNG_INVERT_MONO;
 }
 


@@ -206,8 +217,8 @@ png_do_invert(png_row_infop row_info, png_bytep row)
    if (row_info->color_type == PNG_COLOR_TYPE_GRAY)
    {
       png_bytep rp = row;
    if (row_info->color_type == PNG_COLOR_TYPE_GRAY)
    {
       png_bytep rp = row;

-      png_uint_32 i;
-      png_uint_32 istop = row_info->rowbytes;
+      png_size_t i;
+      png_size_t istop = row_info->rowbytes;

 
       for (i = 0; i < istop; i++)
       {
 
       for (i = 0; i < istop; i++)
       {


@@ -215,36 +226,41 @@ png_do_invert(png_row_infop row_info, png_bytep row)
          rp++;
       }
    }
          rp++;
       }
    }

+

    else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA &&
       row_info->bit_depth == 8)
    {
       png_bytep rp = row;
    else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA &&
       row_info->bit_depth == 8)
    {
       png_bytep rp = row;

-      png_uint_32 i;
-      png_uint_32 istop = row_info->rowbytes;
+      png_size_t i;
+      png_size_t istop = row_info->rowbytes;

 
 

-      for (i = 0; i < istop; i+=2)
+      for (i = 0; i < istop; i += 2)

       {
          *rp = (png_byte)(~(*rp));
       {
          *rp = (png_byte)(~(*rp));

-         rp+=2;
+         rp += 2;

       }
    }
       }
    }

+
+#ifdef PNG_16BIT_SUPPORTED

    else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA &&
       row_info->bit_depth == 16)
    {
       png_bytep rp = row;
    else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA &&
       row_info->bit_depth == 16)
    {
       png_bytep rp = row;

-      png_uint_32 i;
-      png_uint_32 istop = row_info->rowbytes;
+      png_size_t i;
+      png_size_t istop = row_info->rowbytes;

 
 

-      for (i = 0; i < istop; i+=4)
+      for (i = 0; i < istop; i += 4)

       {
          *rp = (png_byte)(~(*rp));
       {
          *rp = (png_byte)(~(*rp));

-         *(rp+1) = (png_byte)(~(*(rp+1)));
-         rp+=4;
+         *(rp + 1) = (png_byte)(~(*(rp + 1)));
+         rp += 4;

       }
    }
       }
    }

+#endif

 }
 #endif
 
 }
 #endif
 

+#ifdef PNG_16BIT_SUPPORTED

 #if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED)
 /* Swaps byte order on 16 bit depth images */
 void /* PRIVATE */
 #if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED)
 /* Swaps byte order on 16 bit depth images */
 void /* PRIVATE */


@@ -252,8 +268,7 @@ png_do_swap(png_row_infop row_info, png_bytep row)
 {
    png_debug(1, "in png_do_swap");
 
 {
    png_debug(1, "in png_do_swap");
 

-   if (
-       row_info->bit_depth == 16)
+   if (row_info->bit_depth == 16)

    {
       png_bytep rp = row;
       png_uint_32 i;
    {
       png_bytep rp = row;
       png_uint_32 i;


@@ -268,6 +283,7 @@ png_do_swap(png_row_infop row_info, png_bytep row)
    }
 }
 #endif
    }
 }
 #endif

+#endif

 
 #if defined(PNG_READ_PACKSWAP_SUPPORTED)||defined(PNG_WRITE_PACKSWAP_SUPPORTED)
 static PNG_CONST png_byte onebppswaptable[256] = {
 
 #if defined(PNG_READ_PACKSWAP_SUPPORTED)||defined(PNG_WRITE_PACKSWAP_SUPPORTED)
 static PNG_CONST png_byte onebppswaptable[256] = {


@@ -381,19 +397,22 @@ png_do_packswap(png_row_infop row_info, png_bytep row)
 {
    png_debug(1, "in png_do_packswap");
 
 {
    png_debug(1, "in png_do_packswap");
 

-   if (
-       row_info->bit_depth < 8)
+   if (row_info->bit_depth < 8)

    {
    {

-      png_bytep rp, end, table;
+      png_bytep rp;
+      png_const_bytep end, table;

 
       end = row + row_info->rowbytes;
 
       if (row_info->bit_depth == 1)
 
       end = row + row_info->rowbytes;
 
       if (row_info->bit_depth == 1)

-         table = (png_bytep)onebppswaptable;
+         table = onebppswaptable;
+

       else if (row_info->bit_depth == 2)
       else if (row_info->bit_depth == 2)

-         table = (png_bytep)twobppswaptable;
+         table = twobppswaptable;
+

       else if (row_info->bit_depth == 4)
       else if (row_info->bit_depth == 4)

-         table = (png_bytep)fourbppswaptable;
+         table = fourbppswaptable;
+

       else
          return;
 
       else
          return;
 


@@ -405,158 +424,119 @@ png_do_packswap(png_row_infop row_info, png_bytep row)
 
 #if defined(PNG_WRITE_FILLER_SUPPORTED) || \
     defined(PNG_READ_STRIP_ALPHA_SUPPORTED)
 
 #if defined(PNG_WRITE_FILLER_SUPPORTED) || \
     defined(PNG_READ_STRIP_ALPHA_SUPPORTED)

-/* Remove filler or alpha byte(s) */
+/* Remove a channel - this used to be 'png_do_strip_filler' but it used a
+ * somewhat weird combination of flags to determine what to do.  All the calls
+ * to png_do_strip_filler are changed in 1.5.2 to call this instead with the
+ * correct arguments.
+ *
+ * The routine isn't general - the channel must be the channel at the start or
+ * end (not in the middle) of each pixel.
+ */

 void /* PRIVATE */
 void /* PRIVATE */

-png_do_strip_filler(png_row_infop row_info, png_bytep row, png_uint_32 flags)
+png_do_strip_channel(png_row_infop row_info, png_bytep row, int at_start)

 {
 {

-   png_debug(1, "in png_do_strip_filler");
-
+   png_bytep sp = row; /* source pointer */
+   png_bytep dp = row; /* destination pointer */
+   png_bytep ep = row + row_info->rowbytes; /* One beyond end of row */
+
+   /* At the start sp will point to the first byte to copy and dp to where
+    * it is copied to.  ep always points just beyond the end of the row, so
+    * the loop simply copies (channels-1) channels until sp reaches ep.
+    *
+    * at_start:        0 -- convert AG, XG, ARGB, XRGB, AAGG, XXGG, etc.
+    *            nonzero -- convert GA, GX, RGBA, RGBX, GGAA, RRGGBBXX, etc.
+    */
+
+   /* GA, GX, XG cases */
+   if (row_info->channels == 2)

    {
    {

-      png_bytep sp=row;
-      png_bytep dp=row;
-      png_uint_32 row_width=row_info->width;
-      png_uint_32 i;
+      if (row_info->bit_depth == 8)
+      {
+         if (at_start) /* Skip initial filler */
+            ++sp;
+         else          /* Skip initial channel and, for sp, the filler */
+            sp += 2, ++dp;
+
+         /* For a 1 pixel wide image there is nothing to do */
+         while (sp < ep)
+            *dp++ = *sp, sp += 2;

 
 

-      if ((row_info->color_type == PNG_COLOR_TYPE_RGB ||
-          (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA &&
-          (flags & PNG_FLAG_STRIP_ALPHA))) &&
-          row_info->channels == 4)
+         row_info->pixel_depth = 8;
+      }
+
+      else if (row_info->bit_depth == 16)

       {
       {

-         if (row_info->bit_depth == 8)
-         {
-            /* This converts from RGBX or RGBA to RGB */
-            if (flags & PNG_FLAG_FILLER_AFTER)
-            {
-               dp+=3; sp+=4;
-               for (i = 1; i < row_width; i++)
-               {
-                  *dp++ = *sp++;
-                  *dp++ = *sp++;
-                  *dp++ = *sp++;
-                  sp++;
-               }
-            }
-            /* This converts from XRGB or ARGB to RGB */
-            else
-            {
-               for (i = 0; i < row_width; i++)
-               {
-                  sp++;
-                  *dp++ = *sp++;
-                  *dp++ = *sp++;
-                  *dp++ = *sp++;
-               }
-            }
-            row_info->pixel_depth = 24;
-            row_info->rowbytes = row_width * 3;
-         }
-         else /* if (row_info->bit_depth == 16) */
-         {
-            if (flags & PNG_FLAG_FILLER_AFTER)
-            {
-               /* This converts from RRGGBBXX or RRGGBBAA to RRGGBB */
-               sp += 8; dp += 6;
-               for (i = 1; i < row_width; i++)
-               {
-                  /* This could be (although png_memcpy is probably slower):
-                  png_memcpy(dp, sp, 6);
-                  sp += 8;
-                  dp += 6;
-                  */
-
-                  *dp++ = *sp++;
-                  *dp++ = *sp++;
-                  *dp++ = *sp++;
-                  *dp++ = *sp++;
-                  *dp++ = *sp++;
-                  *dp++ = *sp++;
-                  sp += 2;
-               }
-            }
-            else
-            {
-               /* This converts from XXRRGGBB or AARRGGBB to RRGGBB */
-               for (i = 0; i < row_width; i++)
-               {
-                  /* This could be (although png_memcpy is probably slower):
-                  png_memcpy(dp, sp, 6);
-                  sp += 8;
-                  dp += 6;
-                  */
-
-                  sp+=2;
-                  *dp++ = *sp++;
-                  *dp++ = *sp++;
-                  *dp++ = *sp++;
-                  *dp++ = *sp++;
-                  *dp++ = *sp++;
-                  *dp++ = *sp++;
-               }
-            }
-            row_info->pixel_depth = 48;
-            row_info->rowbytes = row_width * 6;
-         }
-         row_info->channels = 3;
+         if (at_start) /* Skip initial filler */
+            sp += 2;
+         else          /* Skip initial channel and, for sp, the filler */
+            sp += 4, dp += 2;
+
+         while (sp < ep)
+            *dp++ = *sp++, *dp++ = *sp, sp += 3;
+
+         row_info->pixel_depth = 16;
+      }
+
+      else
+         return; /* bad bit depth */
+
+      row_info->channels = 1;
+
+      /* Finally fix the color type if it records an alpha channel */
+      if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
+         row_info->color_type = PNG_COLOR_TYPE_GRAY;
+   }
+
+   /* RGBA, RGBX, XRGB cases */
+   else if (row_info->channels == 4)
+   {
+      if (row_info->bit_depth == 8)
+      {
+         if (at_start) /* Skip initial filler */
+            ++sp;
+         else          /* Skip initial channels and, for sp, the filler */
+            sp += 4, dp += 3;
+
+         /* Note that the loop adds 3 to dp and 4 to sp each time. */
+         while (sp < ep)
+            *dp++ = *sp++, *dp++ = *sp++, *dp++ = *sp, sp += 2;
+
+         row_info->pixel_depth = 24;

       }
       }

-      else if ((row_info->color_type == PNG_COLOR_TYPE_GRAY ||
-         (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA &&
-         (flags & PNG_FLAG_STRIP_ALPHA))) &&
-          row_info->channels == 2)
+
+      else if (row_info->bit_depth == 16)

       {
       {

-         if (row_info->bit_depth == 8)
-         {
-            /* This converts from GX or GA to G */
-            if (flags & PNG_FLAG_FILLER_AFTER)
-            {
-               for (i = 0; i < row_width; i++)
-               {
-                  *dp++ = *sp++;
-                  sp++;
-               }
-            }
-            /* This converts from XG or AG to G */
-            else
-            {
-               for (i = 0; i < row_width; i++)
-               {
-                  sp++;
-                  *dp++ = *sp++;
-               }
-            }
-            row_info->pixel_depth = 8;
-            row_info->rowbytes = row_width;
-         }
-         else /* if (row_info->bit_depth == 16) */
+         if (at_start) /* Skip initial filler */
+            sp += 2;
+         else          /* Skip initial channels and, for sp, the filler */
+            sp += 8, dp += 6;
+
+         while (sp < ep)

          {
          {

-            if (flags & PNG_FLAG_FILLER_AFTER)
-            {
-               /* This converts from GGXX or GGAA to GG */
-               sp += 4; dp += 2;
-               for (i = 1; i < row_width; i++)
-               {
-                  *dp++ = *sp++;
-                  *dp++ = *sp++;
-                  sp += 2;
-               }
-            }
-            else
-            {
-               /* This converts from XXGG or AAGG to GG */
-               for (i = 0; i < row_width; i++)
-               {
-                  sp += 2;
-                  *dp++ = *sp++;
-                  *dp++ = *sp++;
-               }
-            }
-            row_info->pixel_depth = 16;
-            row_info->rowbytes = row_width * 2;
+            /* Copy 6 bytes, skip 2 */
+            *dp++ = *sp++, *dp++ = *sp++;
+            *dp++ = *sp++, *dp++ = *sp++;
+            *dp++ = *sp++, *dp++ = *sp, sp += 3;

          }
          }

-         row_info->channels = 1;
+
+         row_info->pixel_depth = 48;

       }
       }

-      if (flags & PNG_FLAG_STRIP_ALPHA)
-        row_info->color_type &= ~PNG_COLOR_MASK_ALPHA;
+
+      else
+         return; /* bad bit depth */
+
+      row_info->channels = 3;
+
+      /* Finally fix the color type if it records an alpha channel */
+      if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
+         row_info->color_type = PNG_COLOR_TYPE_RGB;

    }
    }

+
+   else
+      return; /* The filler channel has gone already */
+
+   /* Fix the rowbytes value. */
+   row_info->rowbytes = dp-row;

 }
 #endif
 
 }
 #endif
 


@@ -567,8 +547,7 @@ png_do_bgr(png_row_infop row_info, png_bytep row)
 {
    png_debug(1, "in png_do_bgr");
 
 {
    png_debug(1, "in png_do_bgr");
 

-   if (
-       (row_info->color_type & PNG_COLOR_MASK_COLOR))
+   if ((row_info->color_type & PNG_COLOR_MASK_COLOR))

    {
       png_uint_32 row_width = row_info->width;
       if (row_info->bit_depth == 8)
    {
       png_uint_32 row_width = row_info->width;
       if (row_info->bit_depth == 8)


@@ -585,6 +564,7 @@ png_do_bgr(png_row_infop row_info, png_bytep row)
                *(rp + 2) = save;
             }
          }
                *(rp + 2) = save;
             }
          }

+

          else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
          {
             png_bytep rp;
          else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
          {
             png_bytep rp;


@@ -598,6 +578,8 @@ png_do_bgr(png_row_infop row_info, png_bytep row)
             }
          }
       }
             }
          }
       }

+
+#ifdef PNG_16BIT_SUPPORTED

       else if (row_info->bit_depth == 16)
       {
          if (row_info->color_type == PNG_COLOR_TYPE_RGB)
       else if (row_info->bit_depth == 16)
       {
          if (row_info->color_type == PNG_COLOR_TYPE_RGB)


@@ -615,6 +597,7 @@ png_do_bgr(png_row_infop row_info, png_bytep row)
                *(rp + 5) = save;
             }
          }
                *(rp + 5) = save;
             }
          }

+

          else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
          {
             png_bytep rp;
          else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
          {
             png_bytep rp;


@@ -631,12 +614,14 @@ png_do_bgr(png_row_infop row_info, png_bytep row)
             }
          }
       }
             }
          }
       }

+#endif

    }
 }
 #endif /* PNG_READ_BGR_SUPPORTED or PNG_WRITE_BGR_SUPPORTED */
 
 #if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \
     defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED)
    }
 }
 #endif /* PNG_READ_BGR_SUPPORTED or PNG_WRITE_BGR_SUPPORTED */
 
 #if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \
     defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED)

+#ifdef PNG_USER_TRANSFORM_PTR_SUPPORTED

 void PNGAPI
 png_set_user_transform_info(png_structp png_ptr, png_voidp
    user_transform_ptr, int user_transform_depth, int user_transform_channels)
 void PNGAPI
 png_set_user_transform_info(png_structp png_ptr, png_voidp
    user_transform_ptr, int user_transform_depth, int user_transform_channels)


@@ -645,33 +630,49 @@ png_set_user_transform_info(png_structp png_ptr, png_voidp
 
    if (png_ptr == NULL)
       return;
 
    if (png_ptr == NULL)
       return;

-#ifdef PNG_USER_TRANSFORM_PTR_SUPPORTED

    png_ptr->user_transform_ptr = user_transform_ptr;
    png_ptr->user_transform_depth = (png_byte)user_transform_depth;
    png_ptr->user_transform_channels = (png_byte)user_transform_channels;
    png_ptr->user_transform_ptr = user_transform_ptr;
    png_ptr->user_transform_depth = (png_byte)user_transform_depth;
    png_ptr->user_transform_channels = (png_byte)user_transform_channels;

-#else
-   if (user_transform_ptr || user_transform_depth || user_transform_channels)
-      png_warning(png_ptr,
-        "This version of libpng does not support user transform info");
-#endif

 }
 }

+#endif

 
 /* This function returns a pointer to the user_transform_ptr associated with
  * the user transform functions.  The application should free any memory
  * associated with this pointer before png_write_destroy and png_read_destroy
  * are called.
  */
 
 /* This function returns a pointer to the user_transform_ptr associated with
  * the user transform functions.  The application should free any memory
  * associated with this pointer before png_write_destroy and png_read_destroy
  * are called.
  */

+#ifdef PNG_USER_TRANSFORM_PTR_SUPPORTED

 png_voidp PNGAPI
 png_voidp PNGAPI

-png_get_user_transform_ptr(png_structp png_ptr)
+png_get_user_transform_ptr(png_const_structp png_ptr)

 {
    if (png_ptr == NULL)
       return (NULL);
 {
    if (png_ptr == NULL)
       return (NULL);

-#ifdef PNG_USER_TRANSFORM_PTR_SUPPORTED
+

    return ((png_voidp)png_ptr->user_transform_ptr);
    return ((png_voidp)png_ptr->user_transform_ptr);

-#else
-   return (NULL);
+}

 #endif
 #endif

+
+#ifdef PNG_USER_TRANSFORM_INFO_SUPPORTED
+png_uint_32 PNGAPI
+png_get_current_row_number(png_const_structp png_ptr)
+{
+   /* See the comments in png.h - this is the sub-image row when reading and
+    * interlaced image.
+    */
+   if (png_ptr != NULL)
+      return png_ptr->row_number;
+
+   return PNG_UINT_32_MAX; /* help the app not to fail silently */
+}
+
+png_byte PNGAPI
+png_get_current_pass_number(png_const_structp png_ptr)
+{
+   if (png_ptr != NULL)
+      return png_ptr->pass;
+   return 8; /* invalid */

 }
 }

+#endif /* PNG_USER_TRANSFORM_INFO_SUPPORTED */

 #endif /* PNG_READ_USER_TRANSFORM_SUPPORTED ||
           PNG_WRITE_USER_TRANSFORM_SUPPORTED */
 #endif /* PNG_READ_SUPPORTED || PNG_WRITE_SUPPORTED */
 #endif /* PNG_READ_USER_TRANSFORM_SUPPORTED ||
           PNG_WRITE_USER_TRANSFORM_SUPPORTED */
 #endif /* PNG_READ_SUPPORTED || PNG_WRITE_SUPPORTED */