Updates the PNG library to 1.2.37, enables some functionality for O3D

third_party/libpng/pngwtran.c

 
 /* pngwtran.c - transforms the data in a row for PNG writers
  *
- * Last changed in libpng 1.2.9 April 14, 2006
+ * Last changed in libpng 1.2.37 [June 4, 2009]
  * For conditions of distribution and use, see copyright notice in png.h
- * Copyright (c) 1998-2006 Glenn Randers-Pehrson
+ * Copyright (c) 1998-2009 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.)
  */
 
 #define PNG_INTERNAL
 #include "png.h"
 #ifdef PNG_WRITE_SUPPORTED
 
 /* Transform the data according to the user's wishes.  The order of
  * transformations is significant.
  */
 void /* PRIVATE */
 png_do_write_transformations(png_structp png_ptr)
 {
    png_debug(1, "in png_do_write_transformations");
 
    if (png_ptr == NULL)
       return;
 
 #if defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED)
    if (png_ptr->transformations & PNG_USER_TRANSFORM)
       if (png_ptr->write_user_transform_fn != NULL)
-        (*(png_ptr->write_user_transform_fn)) /* user write transform function */
+        (*(png_ptr->write_user_transform_fn)) /* User write transform function */
           (png_ptr,                    /* png_ptr */
            &(png_ptr->row_info),       /* row_info:     */
              /*  png_uint_32 width;          width of row */
              /*  png_uint_32 rowbytes;       number of bytes in row */
              /*  png_byte color_type;        color type of pixels */
              /*  png_byte bit_depth;         bit depth of samples */
              /*  png_byte channels;          number of channels (1-4) */
              /*  png_byte pixel_depth;       bits per pixel (depth*channels) */
            png_ptr->row_buf + 1);      /* start of pixel data for row */
 #endif
@@ skipping 201 matching lines @@
          shift_dec[channels] = bit_depth->gray;
          channels++;
       }
       if (row_info->color_type & PNG_COLOR_MASK_ALPHA)
       {
          shift_start[channels] = row_info->bit_depth - bit_depth->alpha;
          shift_dec[channels] = bit_depth->alpha;
          channels++;
       }
 
-      /* with low row depths, could only be grayscale, so one channel */
+      /* With low row depths, could only be grayscale, so one channel */
       if (row_info->bit_depth < 8)
       {
          png_bytep bp = row;
          png_uint_32 i;
          png_byte mask;
          png_uint_32 row_bytes = row_info->rowbytes;
 
          if (bit_depth->gray == 1 && row_info->bit_depth == 2)
             mask = 0x55;
          else if (row_info->bit_depth == 4 && bit_depth->gray == 3)
@@ skipping 170 matching lines @@
       if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
       {
          /* This inverts the alpha channel in RGBA */
          if (row_info->bit_depth == 8)
          {
             png_bytep sp, dp;
             png_uint_32 i;
             png_uint_32 row_width = row_info->width;
             for (i = 0, sp = dp = row; i < row_width; i++)
             {
-               /* does nothing
+               /* Does nothing
                *(dp++) = *(sp++);
                *(dp++) = *(sp++);
                *(dp++) = *(sp++);
                */
                sp+=3; dp = sp;
                *(dp++) = (png_byte)(255 - *(sp++));
             }
          }
          /* This inverts the alpha channel in RRGGBBAA */
          else
          {
             png_bytep sp, dp;
             png_uint_32 i;
             png_uint_32 row_width = row_info->width;
 
             for (i = 0, sp = dp = row; i < row_width; i++)
             {
-               /* does nothing
+               /* Does nothing
                *(dp++) = *(sp++);
                *(dp++) = *(sp++);
                *(dp++) = *(sp++);
                *(dp++) = *(sp++);
                *(dp++) = *(sp++);
                *(dp++) = *(sp++);
                */
                sp+=6; dp = sp;
                *(dp++) = (png_byte)(255 - *(sp++));
                *(dp++) = (png_byte)(255 - *(sp++));
@@ skipping 17 matching lines @@
          }
          /* This inverts the alpha channel in GGAA */
          else
          {
             png_bytep sp, dp;
             png_uint_32 i;
             png_uint_32 row_width = row_info->width;
 
             for (i = 0, sp = dp = row; i < row_width; i++)
             {
-               /* does nothing
+               /* Does nothing
                *(dp++) = *(sp++);
                *(dp++) = *(sp++);
                */
                sp+=2; dp = sp;
                *(dp++) = (png_byte)(255 - *(sp++));
                *(dp++) = (png_byte)(255 - *(sp++));
             }
          }
       }
    }
 }
 #endif
 
 #if defined(PNG_MNG_FEATURES_SUPPORTED)
-/* undoes intrapixel differencing  */
+/* Undoes intrapixel differencing  */
 void /* PRIVATE */
 png_do_write_intrapixel(png_row_infop row_info, png_bytep row)
 {
    png_debug(1, "in png_do_write_intrapixel");
    if (
 #if defined(PNG_USELESS_TESTS_SUPPORTED)
        row != NULL && row_info != NULL &&
 #endif
        (row_info->color_type & PNG_COLOR_MASK_COLOR))
    {
@@ skipping 39 matching lines @@
             *(rp  ) = (png_byte)((red >> 8) & 0xff);
             *(rp+1) = (png_byte)(red & 0xff);
             *(rp+4) = (png_byte)((blue >> 8) & 0xff);
             *(rp+5) = (png_byte)(blue & 0xff);
          }
       }
    }
 }
 #endif /* PNG_MNG_FEATURES_SUPPORTED */
 #endif /* PNG_WRITE_SUPPORTED */