Changeset 43 for vendor/libpng/pngwrite.c

Timestamp:

02/15/10 11:37:15 (2 years ago)

Author:

Carsten

Message:

Upgraded vendor/libpng from 1.2.40 to 1.2.42.

Files:

• vendor/libpng/pngwrite.c (modified) (85 diffs)

vendor/libpng/pngwrite.c

@@ -2 +2 @@
 /* pngwrite.c - general routines to write a PNG file
  *
- * Last changed in libpng 1.2.37 [June 4, 2009]
- * Copyright (c) 1998-2009 Glenn Randers-Pehrson
+ * Last changed in libpng 1.2.42 [January 3, 2010]
+ * Copyright (c) 1998-2010 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.)
@@ -14 +14 @@
 /* Get internal access to png.h */
 #define PNG_INTERNAL
+#define PNG_NO_PEDANTIC_WARNINGS
 #include "png.h"
 #ifdef PNG_WRITE_SUPPORTED
@@ -30 +31 @@
 {
    png_debug(1, "in png_write_info_before_PLTE");
+
    if (png_ptr == NULL || info_ptr == NULL)
       return;
    if (!(png_ptr->mode & PNG_WROTE_INFO_BEFORE_PLTE))
    {
-   png_write_sig(png_ptr); /* Write PNG signature */
-#if defined(PNG_MNG_FEATURES_SUPPORTED)
+   /* Write PNG signature */
+   png_write_sig(png_ptr);
+#ifdef PNG_MNG_FEATURES_SUPPORTED
    if ((png_ptr->mode&PNG_HAVE_PNG_SIGNATURE)&&(png_ptr->mng_features_permitted))
    {
       png_warning(png_ptr, "MNG features are not allowed in a PNG datastream");
-      png_ptr->mng_features_permitted=0;
+      png_ptr->mng_features_permitted = 0;
    }
 #endif
@@ -46 +49 @@
       info_ptr->bit_depth, info_ptr->color_type, info_ptr->compression_type,
       info_ptr->filter_type,
-#if defined(PNG_WRITE_INTERLACING_SUPPORTED)
+#ifdef PNG_WRITE_INTERLACING_SUPPORTED
       info_ptr->interlace_type);
 #else
@@ -54 +57 @@
     * flag set, and if it does, writes the chunk.
     */
-#if defined(PNG_WRITE_gAMA_SUPPORTED)
+#ifdef PNG_WRITE_gAMA_SUPPORTED
    if (info_ptr->valid & PNG_INFO_gAMA)
    {
@@ -66 +69 @@
    }
 #endif
-#if defined(PNG_WRITE_sRGB_SUPPORTED)
+#ifdef PNG_WRITE_sRGB_SUPPORTED
    if (info_ptr->valid & PNG_INFO_sRGB)
       png_write_sRGB(png_ptr, (int)info_ptr->srgb_intent);
 #endif
-#if defined(PNG_WRITE_iCCP_SUPPORTED)
+#ifdef PNG_WRITE_iCCP_SUPPORTED
    if (info_ptr->valid & PNG_INFO_iCCP)
       png_write_iCCP(png_ptr, info_ptr->iccp_name, PNG_COMPRESSION_TYPE_BASE,
                      info_ptr->iccp_profile, (int)info_ptr->iccp_proflen);
 #endif
-#if defined(PNG_WRITE_sBIT_SUPPORTED)
+#ifdef PNG_WRITE_sBIT_SUPPORTED
    if (info_ptr->valid & PNG_INFO_sBIT)
       png_write_sBIT(png_ptr, &(info_ptr->sig_bit), info_ptr->color_type);
 #endif
-#if defined(PNG_WRITE_cHRM_SUPPORTED)
+#ifdef PNG_WRITE_cHRM_SUPPORTED
    if (info_ptr->valid & PNG_INFO_cHRM)
    {
@@ -99 +102 @@
    }
 #endif
-#if defined(PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED)
+#ifdef PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED
    if (info_ptr->unknown_chunks_num)
    {
@@ -110 +113 @@
            up++)
       {
-         int keep=png_handle_as_unknown(png_ptr, up->name);
+         int keep = png_handle_as_unknown(png_ptr, up->name);
          if (keep != PNG_HANDLE_CHUNK_NEVER &&
             up->location && !(up->location & PNG_HAVE_PLTE) &&
@@ -148 +151 @@
       png_error(png_ptr, "Valid palette required for paletted images");
 
-#if defined(PNG_WRITE_tRNS_SUPPORTED)
+#ifdef PNG_WRITE_tRNS_SUPPORTED
    if (info_ptr->valid & PNG_INFO_tRNS)
    {
-#if defined(PNG_WRITE_INVERT_ALPHA_SUPPORTED)
+#ifdef PNG_WRITE_INVERT_ALPHA_SUPPORTED
       /* Invert the alpha channel (in tRNS) */
       if ((png_ptr->transformations & PNG_INVERT_ALPHA) &&
@@ -157 +160 @@
       {
          int j;
-         for (j=0; j<(int)info_ptr->num_trans; j++)
+         for (j = 0; j<(int)info_ptr->num_trans; j++)
             info_ptr->trans[j] = (png_byte)(255 - info_ptr->trans[j]);
       }
@@ -165 +168 @@
    }
 #endif
-#if defined(PNG_WRITE_bKGD_SUPPORTED)
+#ifdef PNG_WRITE_bKGD_SUPPORTED
    if (info_ptr->valid & PNG_INFO_bKGD)
       png_write_bKGD(png_ptr, &(info_ptr->background), info_ptr->color_type);
 #endif
-#if defined(PNG_WRITE_hIST_SUPPORTED)
+#ifdef PNG_WRITE_hIST_SUPPORTED
    if (info_ptr->valid & PNG_INFO_hIST)
       png_write_hIST(png_ptr, info_ptr->hist, info_ptr->num_palette);
 #endif
-#if defined(PNG_WRITE_oFFs_SUPPORTED)
+#ifdef PNG_WRITE_oFFs_SUPPORTED
    if (info_ptr->valid & PNG_INFO_oFFs)
       png_write_oFFs(png_ptr, info_ptr->x_offset, info_ptr->y_offset,
          info_ptr->offset_unit_type);
 #endif
-#if defined(PNG_WRITE_pCAL_SUPPORTED)
+#ifdef PNG_WRITE_pCAL_SUPPORTED
    if (info_ptr->valid & PNG_INFO_pCAL)
       png_write_pCAL(png_ptr, info_ptr->pcal_purpose, info_ptr->pcal_X0,
@@ -185 +188 @@
 #endif
 
-#if defined(PNG_sCAL_SUPPORTED)
+#ifdef PNG_sCAL_SUPPORTED
    if (info_ptr->valid & PNG_INFO_sCAL)
-#if defined(PNG_WRITE_sCAL_SUPPORTED)
-#if defined(PNG_FLOATING_POINT_SUPPORTED) && !defined(PNG_NO_STDIO)
+#ifdef PNG_WRITE_sCAL_SUPPORTED
+#if defined(PNG_FLOATING_POINT_SUPPORTED) && defined(PNG_STDIO_SUPPORTED)
       png_write_sCAL(png_ptr, (int)info_ptr->scal_unit,
           info_ptr->scal_pixel_width, info_ptr->scal_pixel_height);
@@ -203 +206 @@
 #endif /* sCAL */
 
-#if defined(PNG_WRITE_pHYs_SUPPORTED)
+#ifdef PNG_WRITE_pHYs_SUPPORTED
    if (info_ptr->valid & PNG_INFO_pHYs)
       png_write_pHYs(png_ptr, info_ptr->x_pixels_per_unit,
@@ -209 +212 @@
 #endif /* pHYs */
 
-#if defined(PNG_WRITE_tIME_SUPPORTED)
+#ifdef PNG_WRITE_tIME_SUPPORTED
    if (info_ptr->valid & PNG_INFO_tIME)
    {
@@ -217 +220 @@
 #endif /* tIME */
 
-#if defined(PNG_WRITE_sPLT_SUPPORTED)
+#ifdef PNG_WRITE_sPLT_SUPPORTED
    if (info_ptr->valid & PNG_INFO_sPLT)
      for (i = 0; i < (int)info_ptr->splt_palettes_num; i++)
@@ -223 +226 @@
 #endif /* sPLT */
 
-#if defined(PNG_WRITE_TEXT_SUPPORTED)
+#ifdef PNG_WRITE_TEXT_SUPPORTED
    /* Check to see if we need to write text chunks */
    for (i = 0; i < info_ptr->num_text; i++)
@@ -232 +235 @@
       if (info_ptr->text[i].compression > 0)
       {
-#if defined(PNG_WRITE_iTXt_SUPPORTED)
+#ifdef PNG_WRITE_iTXt_SUPPORTED
           /* Write international chunk */
           png_write_iTXt(png_ptr,
@@ -249 +252 @@
       else if (info_ptr->text[i].compression == PNG_TEXT_COMPRESSION_zTXt)
       {
-#if defined(PNG_WRITE_zTXt_SUPPORTED)
+#ifdef PNG_WRITE_zTXt_SUPPORTED
          /* Write compressed chunk */
          png_write_zTXt(png_ptr, info_ptr->text[i].key,
@@ -262 +265 @@
       else if (info_ptr->text[i].compression == PNG_TEXT_COMPRESSION_NONE)
       {
-#if defined(PNG_WRITE_tEXt_SUPPORTED)
+#ifdef PNG_WRITE_tEXt_SUPPORTED
          /* Write uncompressed chunk */
          png_write_tEXt(png_ptr, info_ptr->text[i].key,
@@ -277 +280 @@
 #endif /* tEXt */
 
-#if defined(PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED)
+#ifdef PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED
    if (info_ptr->unknown_chunks_num)
    {
-       png_unknown_chunk *up;
-
-       png_debug(5, "writing extra chunks");
-
-       for (up = info_ptr->unknown_chunks;
-            up < info_ptr->unknown_chunks + info_ptr->unknown_chunks_num;
-            up++)
-       {
-         int keep=png_handle_as_unknown(png_ptr, up->name);
+      png_unknown_chunk *up;
+
+      png_debug(5, "writing extra chunks");
+
+      for (up = info_ptr->unknown_chunks;
+           up < info_ptr->unknown_chunks + info_ptr->unknown_chunks_num;
+           up++)
+      {
+         int keep = png_handle_as_unknown(png_ptr, up->name);
          if (keep != PNG_HANDLE_CHUNK_NEVER &&
             up->location && (up->location & PNG_HAVE_PLTE) &&
@@ -297 +300 @@
             png_write_chunk(png_ptr, up->name, up->data, up->size);
          }
-       }
+      }
    }
 #endif
@@ -311 +314 @@
 {
    png_debug(1, "in png_write_end");
+
    if (png_ptr == NULL)
       return;
@@ -319 +323 @@
    if (info_ptr != NULL)
    {
-#if defined(PNG_WRITE_TEXT_SUPPORTED)
-      int i; /* Local index variable */
-#endif
-#if defined(PNG_WRITE_tIME_SUPPORTED)
+#ifdef PNG_WRITE_TEXT_SUPPORTED
+      int i; /* local index variable */
+#endif
+#ifdef PNG_WRITE_tIME_SUPPORTED
       /* Check to see if user has supplied a time chunk */
       if ((info_ptr->valid & PNG_INFO_tIME) &&
@@ -328 +332 @@
          png_write_tIME(png_ptr, &(info_ptr->mod_time));
 #endif
-#if defined(PNG_WRITE_TEXT_SUPPORTED)
+#ifdef PNG_WRITE_TEXT_SUPPORTED
       /* Loop through comment chunks */
       for (i = 0; i < info_ptr->num_text; i++)
@@ -337 +341 @@
          if (info_ptr->text[i].compression > 0)
          {
-#if defined(PNG_WRITE_iTXt_SUPPORTED)
-             /* Write international chunk */
-             png_write_iTXt(png_ptr,
-                         info_ptr->text[i].compression,
-                         info_ptr->text[i].key,
-                         info_ptr->text[i].lang,
-                         info_ptr->text[i].lang_key,
-                         info_ptr->text[i].text);
-#else
-             png_warning(png_ptr, "Unable to write international text");
-#endif
-             /* Mark this chunk as written */
-             info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_NONE_WR;
+#ifdef PNG_WRITE_iTXt_SUPPORTED
+            /* Write international chunk */
+            png_write_iTXt(png_ptr,
+                        info_ptr->text[i].compression,
+                        info_ptr->text[i].key,
+                        info_ptr->text[i].lang,
+                        info_ptr->text[i].lang_key,
+                        info_ptr->text[i].text);
+#else
+            png_warning(png_ptr, "Unable to write international text");
+#endif
+            /* Mark this chunk as written */
+            info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_NONE_WR;
          }
          else if (info_ptr->text[i].compression >= PNG_TEXT_COMPRESSION_zTXt)
          {
-#if defined(PNG_WRITE_zTXt_SUPPORTED)
+#ifdef PNG_WRITE_zTXt_SUPPORTED
             /* Write compressed chunk */
             png_write_zTXt(png_ptr, info_ptr->text[i].key,
@@ -366 +370 @@
          else if (info_ptr->text[i].compression == PNG_TEXT_COMPRESSION_NONE)
          {
-#if defined(PNG_WRITE_tEXt_SUPPORTED)
+#ifdef PNG_WRITE_tEXt_SUPPORTED
             /* Write uncompressed chunk */
             png_write_tEXt(png_ptr, info_ptr->text[i].key,
@@ -379 +383 @@
       }
 #endif
-#if defined(PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED)
+#ifdef PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED
    if (info_ptr->unknown_chunks_num)
    {
-       png_unknown_chunk *up;
-
-       png_debug(5, "writing extra chunks");
-
-       for (up = info_ptr->unknown_chunks;
-            up < info_ptr->unknown_chunks + info_ptr->unknown_chunks_num;
-            up++)
-       {
-         int keep=png_handle_as_unknown(png_ptr, up->name);
+      png_unknown_chunk *up;
+
+      png_debug(5, "writing extra chunks");
+
+      for (up = info_ptr->unknown_chunks;
+           up < info_ptr->unknown_chunks + info_ptr->unknown_chunks_num;
+           up++)
+      {
+         int keep = png_handle_as_unknown(png_ptr, up->name);
          if (keep != PNG_HANDLE_CHUNK_NEVER &&
             up->location && (up->location & PNG_AFTER_IDAT) &&
@@ -398 +402 @@
             png_write_chunk(png_ptr, up->name, up->data, up->size);
          }
-       }
+      }
    }
 #endif
@@ -412 +416 @@
     * experiences a problem, please try building libpng with
     * PNG_WRITE_FLUSH_AFTER_IEND_SUPPORTED defined, and report the event to
-    * png-mng-implement at lists.sf.net .  This kludge will be removed
-    * from libpng-1.4.0.
+    * png-mng-implement at lists.sf.net .
     */
-#if defined(PNG_WRITE_FLUSH_SUPPORTED) && \
-    defined(PNG_WRITE_FLUSH_AFTER_IEND_SUPPORTED)
+#ifdef PNG_WRITE_FLUSH_SUPPORTED
+#  ifdef PNG_WRITE_FLUSH_AFTER_IEND_SUPPORTED
    png_flush(png_ptr);
-#endif
-}
-
-#if defined(PNG_WRITE_tIME_SUPPORTED)
-#if !defined(_WIN32_WCE)
-/* "time.h" functions are not supported on WindowsCE */
+#  endif
+#endif
+}
+
+#ifdef PNG_CONVERT_tIME_SUPPORTED
+/* "tm" structure is not supported on WindowsCE */
 void PNGAPI
 png_convert_from_struct_tm(png_timep ptime, struct tm FAR * ttime)
 {
    png_debug(1, "in png_convert_from_struct_tm");
+
    ptime->year = (png_uint_16)(1900 + ttime->tm_year);
    ptime->month = (png_byte)(ttime->tm_mon + 1);
@@ -442 +446 @@
 
    png_debug(1, "in png_convert_from_time_t");
+
    tbuf = gmtime(&ttime);
    png_convert_from_struct_tm(ptime, tbuf);
 }
-#endif
 #endif
 
@@ -466 +470 @@
 #endif /* PNG_USER_MEM_SUPPORTED */
 #ifdef PNG_SETJMP_SUPPORTED
-    volatile
-#endif
-    png_structp png_ptr;
+   volatile
+#endif
+   png_structp png_ptr;
 #ifdef PNG_SETJMP_SUPPORTED
 #ifdef USE_FAR_KEYWORD
@@ -475 +479 @@
 #endif
    int i;
+
    png_debug(1, "in png_create_write_struct");
+
 #ifdef PNG_USER_MEM_SUPPORTED
    png_ptr = (png_structp)png_create_struct_2(PNG_STRUCT_PNG,
@@ -487 +493 @@
    /* Added at libpng-1.2.6 */
 #ifdef PNG_SET_USER_LIMITS_SUPPORTED
-   png_ptr->user_width_max=PNG_USER_WIDTH_MAX;
-   png_ptr->user_height_max=PNG_USER_HEIGHT_MAX;
+   png_ptr->user_width_max = PNG_USER_WIDTH_MAX;
+   png_ptr->user_height_max = PNG_USER_HEIGHT_MAX;
 #endif
 
@@ -499 +505 @@
    {
       png_free(png_ptr, png_ptr->zbuf);
-       png_ptr->zbuf=NULL;
-      png_destroy_struct(png_ptr);
+      png_ptr->zbuf = NULL;
+#ifdef PNG_USER_MEM_SUPPORTED
+      png_destroy_struct_2((png_voidp)png_ptr,
+         (png_free_ptr)free_fn, (png_voidp)mem_ptr);
+#else
+      png_destroy_struct((png_voidp)png_ptr);
+#endif
       return (NULL);
    }
@@ -515 +526 @@
    if (user_png_ver)
    {
-     i=0;
-     do
-     {
-       if (user_png_ver[i] != png_libpng_ver[i])
-          png_ptr->flags |= PNG_FLAG_LIBRARY_MISMATCH;
-     } while (png_libpng_ver[i++]);
+      i = 0;
+      do
+      {
+         if (user_png_ver[i] != png_libpng_ver[i])
+            png_ptr->flags |= PNG_FLAG_LIBRARY_MISMATCH;
+      } while (png_libpng_ver[i++]);
    }
 
@@ -534 +545 @@
          (user_png_ver[0] == '0' && user_png_ver[2] < '9'))
      {
-#if !defined(PNG_NO_STDIO) && !defined(_WIN32_WCE)
+#if defined(PNG_STDIO_SUPPORTED) && !defined(_WIN32_WCE)
         char msg[80];
         if (user_png_ver)
         {
-          png_snprintf(msg, 80,
-             "Application was compiled with png.h from libpng-%.20s",
-             user_png_ver);
-          png_warning(png_ptr, msg);
+           png_snprintf(msg, 80,
+              "Application was compiled with png.h from libpng-%.20s",
+              user_png_ver);
+           png_warning(png_ptr, msg);
         }
         png_snprintf(msg, 80,
@@ -549 +560 @@
 #endif
 #ifdef PNG_ERROR_NUMBERS_SUPPORTED
-        png_ptr->flags=0;
+        png_ptr->flags = 0;
 #endif
         png_error(png_ptr,
@@ -559 +570 @@
    png_ptr->zbuf_size = PNG_ZBUF_SIZE;
    png_ptr->zbuf = (png_bytep)png_malloc(png_ptr,
-      (png_uint_32)png_ptr->zbuf_size);
+     (png_uint_32)png_ptr->zbuf_size);
 
    png_set_write_fn(png_ptr, png_voidp_NULL, png_rw_ptr_NULL,
       png_flush_ptr_NULL);
 
-#if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED)
+#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
    png_set_filter_heuristics(png_ptr, PNG_FILTER_HEURISTIC_DEFAULT,
       1, png_doublep_NULL, png_doublep_NULL);
@@ -570 +581 @@
 
 #ifdef PNG_SETJMP_SUPPORTED
-/* Applications that neglect to set up their own setjmp() and then encounter
-   a png_error() will longjmp here.  Since the jmpbuf is then meaningless we
-   abort instead of returning. */
+   /* Applications that neglect to set up their own setjmp() and then
+    * encounter a png_error() will longjmp here.  Since the jmpbuf is
+    * then meaningless we abort instead of returning.
+    */
 #ifdef USE_FAR_KEYWORD
    if (setjmp(jmpbuf))
@@ -602 +614 @@
    /* We only come here via pre-1.0.12-compiled applications */
    if (png_ptr == NULL) return;
-#if !defined(PNG_NO_STDIO) && !defined(_WIN32_WCE)
+#if defined(PNG_STDIO_SUPPORTED) && !defined(_WIN32_WCE)
    if (png_sizeof(png_struct) > png_struct_size ||
       png_sizeof(png_info) > png_info_size)
    {
       char msg[80];
-      png_ptr->warning_fn=NULL;
+      png_ptr->warning_fn = NULL;
       if (user_png_ver)
       {
-        png_snprintf(msg, 80,
-           "Application was compiled with png.h from libpng-%.20s",
-           user_png_ver);
-        png_warning(png_ptr, msg);
+         png_snprintf(msg, 80,
+            "Application was compiled with png.h from libpng-%.20s",
+            user_png_ver);
+         png_warning(png_ptr, msg);
       }
       png_snprintf(msg, 80,
@@ -622 +634 @@
 #endif
    if (png_sizeof(png_struct) > png_struct_size)
-     {
-       png_ptr->error_fn=NULL;
+   {
+      png_ptr->error_fn = NULL;
 #ifdef PNG_ERROR_NUMBERS_SUPPORTED
-       png_ptr->flags=0;
-#endif
-       png_error(png_ptr,
-       "The png struct allocated by the application for writing is too small.");
-     }
+      png_ptr->flags = 0;
+#endif
+      png_error(png_ptr,
+      "The png struct allocated by the application for writing is too small.");
+   }
    if (png_sizeof(png_info) > png_info_size)
-     {
-       png_ptr->error_fn=NULL;
+   {
+      png_ptr->error_fn = NULL;
 #ifdef PNG_ERROR_NUMBERS_SUPPORTED
-       png_ptr->flags=0;
-#endif
-       png_error(png_ptr,
-       "The info struct allocated by the application for writing is too small.");
-     }
+      png_ptr->flags = 0;
+#endif
+      png_error(png_ptr,
+      "The info struct allocated by the application for writing is too small.");
+   }
    png_write_init_3(&png_ptr, user_png_ver, png_struct_size);
 }
@@ -648 +660 @@
    png_size_t png_struct_size)
 {
-   png_structp png_ptr=*ptr_ptr;
+   png_structp png_ptr = *ptr_ptr;
 #ifdef PNG_SETJMP_SUPPORTED
-   jmp_buf tmp_jmp; /* To save current jump buffer */
+   jmp_buf tmp_jmp; /* to save current jump buffer */
 #endif
 
@@ -660 +672 @@
    do
    {
-     if (user_png_ver[i] != png_libpng_ver[i])
-     {
+      if (user_png_ver[i] != png_libpng_ver[i])
+      {
 #ifdef PNG_LEGACY_SUPPORTED
-       png_ptr->flags |= PNG_FLAG_LIBRARY_MISMATCH;
-#else
-       png_ptr->warning_fn=NULL;
-       png_warning(png_ptr,
+         png_ptr->flags |= PNG_FLAG_LIBRARY_MISMATCH;
+#else
+         png_ptr->warning_fn = NULL;
+         png_warning(png_ptr,
  "Application uses deprecated png_write_init() and should be recompiled.");
-       break;
-#endif
-     }
+#endif
+      }
    } while (png_libpng_ver[i++]);
 
@@ -681 +692 @@
 
    if (png_sizeof(png_struct) > png_struct_size)
-     {
-       png_destroy_struct(png_ptr);
-       png_ptr = (png_structp)png_create_struct(PNG_STRUCT_PNG);
-       *ptr_ptr = png_ptr;
-     }
+   {
+      png_destroy_struct(png_ptr);
+      png_ptr = (png_structp)png_create_struct(PNG_STRUCT_PNG);
+      *ptr_ptr = png_ptr;
+   }
 
    /* Reset all variables to 0 */
@@ -692 +703 @@
    /* Added at libpng-1.2.6 */
 #ifdef PNG_SET_USER_LIMITS_SUPPORTED
-   png_ptr->user_width_max=PNG_USER_WIDTH_MAX;
-   png_ptr->user_height_max=PNG_USER_HEIGHT_MAX;
+   png_ptr->user_width_max = PNG_USER_WIDTH_MAX;
+   png_ptr->user_height_max = PNG_USER_HEIGHT_MAX;
 #endif
 
@@ -707 +718 @@
    png_ptr->zbuf_size = PNG_ZBUF_SIZE;
    png_ptr->zbuf = (png_bytep)png_malloc(png_ptr,
-      (png_uint_32)png_ptr->zbuf_size);
-
-#if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED)
+     (png_uint_32)png_ptr->zbuf_size);
+#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
    png_set_filter_heuristics(png_ptr, PNG_FILTER_HEURISTIC_DEFAULT,
       1, png_doublep_NULL, png_doublep_NULL);
@@ -724 +734 @@
    png_uint_32 num_rows)
 {
-   png_uint_32 i; /* Row counter */
-   png_bytepp rp; /* Row pointer */
+   png_uint_32 i; /* row counter */
+   png_bytepp rp; /* row pointer */
 
    png_debug(1, "in png_write_rows");
@@ -745 +755 @@
 png_write_image(png_structp png_ptr, png_bytepp image)
 {
-   png_uint_32 i; /* Row index */
-   int pass, num_pass; /* Pass variables */
-   png_bytepp rp; /* Points to current row */
+   png_uint_32 i; /* row index */
+   int pass, num_pass; /* pass variables */
+   png_bytepp rp; /* points to current row */
 
    if (png_ptr == NULL)
@@ -753 +763 @@
 
    png_debug(1, "in png_write_image");
-#if defined(PNG_WRITE_INTERLACING_SUPPORTED)
+
+#ifdef PNG_WRITE_INTERLACING_SUPPORTED
    /* Initialize interlace handling.  If image is not interlaced,
     * this will set pass to 1
@@ -778 +789 @@
    if (png_ptr == NULL)
       return;
+
    png_debug2(1, "in png_write_row (row %ld, pass %d)",
       png_ptr->row_number, png_ptr->pass);
@@ -822 +834 @@
    }
 
-#if defined(PNG_WRITE_INTERLACING_SUPPORTED)
+#ifdef PNG_WRITE_INTERLACING_SUPPORTED
    /* If interlaced and not interested in row, return */
    if (png_ptr->interlaced && (png_ptr->transformations & PNG_INTERLACE))
@@ -903 +915 @@
       png_ptr->row_info.rowbytes);
 
-#if defined(PNG_WRITE_INTERLACING_SUPPORTED)
+#ifdef PNG_WRITE_INTERLACING_SUPPORTED
    /* Handle interlacing */
    if (png_ptr->interlaced && png_ptr->pass < 6 &&
@@ -923 +935 @@
       png_do_write_transformations(png_ptr);
 
-#if defined(PNG_MNG_FEATURES_SUPPORTED)
+#ifdef PNG_MNG_FEATURES_SUPPORTED
    /* Write filter_method 64 (intrapixel differencing) only if
     * 1. Libpng was compiled with PNG_MNG_FEATURES_SUPPORTED and
@@ -948 +960 @@
 }
 
-#if defined(PNG_WRITE_FLUSH_SUPPORTED)
+#ifdef PNG_WRITE_FLUSH_SUPPORTED
 /* Set the automatic flush interval or 0 to turn flushing off */
 void PNGAPI
@@ -954 +966 @@
 {
    png_debug(1, "in png_set_flush");
+
    if (png_ptr == NULL)
       return;
@@ -966 +979 @@
 
    png_debug(1, "in png_write_flush");
+
    if (png_ptr == NULL)
       return;
@@ -1026 +1040 @@
 
    png_debug(1, "in png_destroy_write_struct");
+
    if (png_ptr_ptr != NULL)
    {
@@ -1052 +1067 @@
         png_free_data(png_ptr, info_ptr, PNG_FREE_ALL, -1);
 
-#if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED)
+#ifdef PNG_UNKNOWN_CHUNKS_SUPPORTED
         if (png_ptr->num_chunk_list)
         {
            png_free(png_ptr, png_ptr->chunk_list);
-           png_ptr->chunk_list=NULL;
+           png_ptr->chunk_list = NULL;
            png_ptr->num_chunk_list = 0;
         }
@@ -1100 +1115 @@
 
    png_debug(1, "in png_write_destroy");
+
    /* Free any memory zlib uses */
    deflateEnd(&png_ptr->zstream);
@@ -1106 +1122 @@
    png_free(png_ptr, png_ptr->zbuf);
    png_free(png_ptr, png_ptr->row_buf);
-#ifndef PNG_NO_WRITE_FILTER
+#ifdef PNG_WRITE_FILTER_SUPPORTED
    png_free(png_ptr, png_ptr->prev_row);
    png_free(png_ptr, png_ptr->sub_row);
@@ -1114 +1130 @@
 #endif
 
-#if defined(PNG_TIME_RFC1123_SUPPORTED)
+#ifdef PNG_TIME_RFC1123_SUPPORTED
    png_free(png_ptr, png_ptr->time_buffer);
 #endif
 
-#if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED)
+#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
    png_free(png_ptr, png_ptr->prev_filters);
    png_free(png_ptr, png_ptr->filter_weights);
@@ -1157 +1173 @@
 {
    png_debug(1, "in png_set_filter");
-   if (png_ptr == NULL)
-      return;
-#if defined(PNG_MNG_FEATURES_SUPPORTED)
+
+   if (png_ptr == NULL)
+      return;
+#ifdef PNG_MNG_FEATURES_SUPPORTED
    if ((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) &&
       (method == PNG_INTRAPIXEL_DIFFERENCING))
@@ -1168 +1185 @@
       switch (filters & (PNG_ALL_FILTERS | 0x07))
       {
-#ifndef PNG_NO_WRITE_FILTER
+#ifdef PNG_WRITE_FILTER_SUPPORTED
          case 5:
          case 6:
          case 7: png_warning(png_ptr, "Unknown row filter for method 0");
-#endif /* PNG_NO_WRITE_FILTER */
+#endif /* PNG_WRITE_FILTER_SUPPORTED */
          case PNG_FILTER_VALUE_NONE:
-              png_ptr->do_filter=PNG_FILTER_NONE; break;
-#ifndef PNG_NO_WRITE_FILTER
+              png_ptr->do_filter = PNG_FILTER_NONE; break;
+#ifdef PNG_WRITE_FILTER_SUPPORTED
          case PNG_FILTER_VALUE_SUB:
-              png_ptr->do_filter=PNG_FILTER_SUB; break;
+              png_ptr->do_filter = PNG_FILTER_SUB; break;
          case PNG_FILTER_VALUE_UP:
-              png_ptr->do_filter=PNG_FILTER_UP; break;
+              png_ptr->do_filter = PNG_FILTER_UP; break;
          case PNG_FILTER_VALUE_AVG:
-              png_ptr->do_filter=PNG_FILTER_AVG; break;
+              png_ptr->do_filter = PNG_FILTER_AVG; break;
          case PNG_FILTER_VALUE_PAETH:
-              png_ptr->do_filter=PNG_FILTER_PAETH; break;
+              png_ptr->do_filter = PNG_FILTER_PAETH; break;
          default: png_ptr->do_filter = (png_byte)filters; break;
 #else
          default: png_warning(png_ptr, "Unknown row filter for method 0");
-#endif /* PNG_NO_WRITE_FILTER */
+#endif /* PNG_WRITE_FILTER_SUPPORTED */
       }
 
@@ -1201 +1218 @@
       if (png_ptr->row_buf != NULL)
       {
-#ifndef PNG_NO_WRITE_FILTER
+#ifdef PNG_WRITE_FILTER_SUPPORTED
          if ((png_ptr->do_filter & PNG_FILTER_SUB) && png_ptr->sub_row == NULL)
          {
@@ -1256 +1273 @@
 
          if (png_ptr->do_filter == PNG_NO_FILTERS)
-#endif /* PNG_NO_WRITE_FILTER */
+#endif /* PNG_WRITE_FILTER_SUPPORTED */
             png_ptr->do_filter = PNG_FILTER_NONE;
       }
@@ -1271 +1288 @@
  * better compression.
  */
-#if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED)      /* GRR 970116 */
+#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED      /* GRR 970116 */
 void PNGAPI
 png_set_filter_heuristics(png_structp png_ptr, int heuristic_method,
@@ -1280 +1297 @@
 
    png_debug(1, "in png_set_filter_heuristics");
+
    if (png_ptr == NULL)
       return;
@@ -1394 +1412 @@
 {
    png_debug(1, "in png_set_compression_level");
+
    if (png_ptr == NULL)
       return;
@@ -1404 +1423 @@
 {
    png_debug(1, "in png_set_compression_mem_level");
+
    if (png_ptr == NULL)
       return;
@@ -1414 +1434 @@
 {
    png_debug(1, "in png_set_compression_strategy");
+
    if (png_ptr == NULL)
       return;
@@ -1434 +1455 @@
      {
        png_warning(png_ptr, "Compression window is being reset to 512");
-       window_bits=9;
+       window_bits = 9;
      }
 #endif
@@ -1445 +1466 @@
 {
    png_debug(1, "in png_set_compression_method");
+
    if (png_ptr == NULL)
       return;
@@ -1461 +1483 @@
 }
 
-#if defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED)
+#ifdef PNG_WRITE_USER_TRANSFORM_SUPPORTED
 void PNGAPI
 png_set_write_user_transform_fn(png_structp png_ptr, png_user_transform_ptr
@@ -1467 +1489 @@
 {
    png_debug(1, "in png_set_write_user_transform_fn");
+
    if (png_ptr == NULL)
       return;
@@ -1475 +1498 @@
 
 
-#if defined(PNG_INFO_IMAGE_SUPPORTED)
+#ifdef PNG_INFO_IMAGE_SUPPORTED
 void PNGAPI
 png_write_png(png_structp png_ptr, png_infop info_ptr,
@@ -1482 +1505 @@
    if (png_ptr == NULL || info_ptr == NULL)
       return;
-#if defined(PNG_WRITE_INVERT_ALPHA_SUPPORTED)
-   /* Invert the alpha channel from opacity to transparency */
-   if (transforms & PNG_TRANSFORM_INVERT_ALPHA)
-      png_set_invert_alpha(png_ptr);
-#endif
 
    /* Write the file header information. */
@@ -1493 +1511 @@
    /* ------ these transformations don't touch the info structure ------- */
 
-#if defined(PNG_WRITE_INVERT_SUPPORTED)
+#ifdef PNG_WRITE_INVERT_SUPPORTED
    /* Invert monochrome pixels */
    if (transforms & PNG_TRANSFORM_INVERT_MONO)
@@ -1499 +1517 @@
 #endif
 
-#if defined(PNG_WRITE_SHIFT_SUPPORTED)
+#ifdef PNG_WRITE_SHIFT_SUPPORTED
    /* Shift the pixels up to a legal bit depth and fill in
     * as appropriate to correctly scale the image.
@@ -1508 +1526 @@
 #endif
 
-#if defined(PNG_WRITE_PACK_SUPPORTED)
+#ifdef PNG_WRITE_PACK_SUPPORTED
    /* Pack pixels into bytes */
    if (transforms & PNG_TRANSFORM_PACKING)
@@ -1514 +1532 @@
 #endif
 
-#if defined(PNG_WRITE_SWAP_ALPHA_SUPPORTED)
+#ifdef PNG_WRITE_SWAP_ALPHA_SUPPORTED
    /* Swap location of alpha bytes from ARGB to RGBA */
    if (transforms & PNG_TRANSFORM_SWAP_ALPHA)
@@ -1520 +1538 @@
 #endif
 
-#if defined(PNG_WRITE_FILLER_SUPPORTED)
+#ifdef PNG_WRITE_FILLER_SUPPORTED
    /* Pack XRGB/RGBX/ARGB/RGBA into * RGB (4 channels -> 3 channels) */
    if (transforms & PNG_TRANSFORM_STRIP_FILLER_AFTER)
@@ -1528 +1546 @@
 #endif
 
-#if defined(PNG_WRITE_BGR_SUPPORTED)
+#ifdef PNG_WRITE_BGR_SUPPORTED
    /* Flip BGR pixels to RGB */
    if (transforms & PNG_TRANSFORM_BGR)
@@ -1534 +1552 @@
 #endif
 
-#if defined(PNG_WRITE_SWAP_SUPPORTED)
+#ifdef PNG_WRITE_SWAP_SUPPORTED
    /* Swap bytes of 16-bit files to most significant byte first */
    if (transforms & PNG_TRANSFORM_SWAP_ENDIAN)
@@ -1540 +1558 @@
 #endif
 
-#if defined(PNG_WRITE_PACKSWAP_SUPPORTED)
+#ifdef PNG_WRITE_PACKSWAP_SUPPORTED
    /* Swap bits of 1, 2, 4 bit packed pixel formats */
    if (transforms & PNG_TRANSFORM_PACKSWAP)
@@ -1546 +1564 @@
 #endif
 
+#ifdef PNG_WRITE_INVERT_ALPHA_SUPPORTED
+   /* Invert the alpha channel from opacity to transparency */
+   if (transforms & PNG_TRANSFORM_INVERT_ALPHA)
+      png_set_invert_alpha(png_ptr);
+#endif
+
    /* ----------------------- end of transformations ------------------- */