Doc tweaks

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

diff --git a/src/png/pngwtran.c b/src/png/pngwtran.c
index 76cf3a3e5d9f638ee8ce253a5f579ebf50146036..94d8ecc1cecfcf0a5fab71d52d10859e70a7c4db 100644 (file)
--- a/src/png/pngwtran.c
+++ b/src/png/pngwtran.c
@@ -1,24 +1,28 @@
 
 /* pngwtran.c - transforms the data in a row for PNG writers
  *
 
 /* pngwtran.c - transforms the data in a row for PNG writers
  *

- * libpng 1.0.3 - January 14, 1999
+ * libpng version 1.2.7 - September 12, 2004

  * For conditions of distribution and use, see copyright notice in png.h
  * For conditions of distribution and use, see copyright notice in png.h

- * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.
- * Copyright (c) 1996, 1997 Andreas Dilger
- * Copyright (c) 1998, 1999 Glenn Randers-Pehrson
+ * Copyright (c) 1998-2004 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"
  */
 
 #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.
  */
 
 /* Transform the data according to the user's wishes.  The order of
  * transformations is significant.
  */

-void
+void /* PRIVATE */

 png_do_write_transformations(png_structp png_ptr)
 {
    png_debug(1, "in png_do_write_transformations\n");
 
 png_do_write_transformations(png_structp png_ptr)
 {
    png_debug(1, "in png_do_write_transformations\n");
 

+   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)
 #if defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED)
    if (png_ptr->transformations & PNG_USER_TRANSFORM)
       if(png_ptr->write_user_transform_fn != NULL)


@@ -79,7 +83,7 @@ png_do_write_transformations(png_structp png_ptr)
  * row_info bit depth should be 8 (one pixel per byte).  The channels
  * should be 1 (this only happens on grayscale and paletted images).
  */
  * row_info bit depth should be 8 (one pixel per byte).  The channels
  * should be 1 (this only happens on grayscale and paletted images).
  */

-void
+void /* PRIVATE */

 png_do_pack(png_row_infop row_info, png_bytep row, png_uint_32 bit_depth)
 {
    png_debug(1, "in png_do_pack\n");
 png_do_pack(png_row_infop row_info, png_bytep row, png_uint_32 bit_depth)
 {
    png_debug(1, "in png_do_pack\n");


@@ -137,7 +141,7 @@ png_do_pack(png_row_infop row_info, png_bytep row, png_uint_32 bit_depth)
             {
                png_byte value;
 
             {
                png_byte value;
 

-               value = (png_byte)(*sp & 0x3);
+               value = (png_byte)(*sp & 0x03);

                v |= (value << shift);
                if (shift == 0)
                {
                v |= (value << shift);
                if (shift == 0)
                {


@@ -169,7 +173,7 @@ png_do_pack(png_row_infop row_info, png_bytep row, png_uint_32 bit_depth)
             {
                png_byte value;
 
             {
                png_byte value;
 

-               value = (png_byte)(*sp & 0xf);
+               value = (png_byte)(*sp & 0x0f);

                v |= (value << shift);
 
                if (shift == 0)
                v |= (value << shift);
 
                if (shift == 0)


@@ -191,8 +195,8 @@ png_do_pack(png_row_infop row_info, png_bytep row, png_uint_32 bit_depth)
       }
       row_info->bit_depth = (png_byte)bit_depth;
       row_info->pixel_depth = (png_byte)(bit_depth * row_info->channels);
       }
       row_info->bit_depth = (png_byte)bit_depth;
       row_info->pixel_depth = (png_byte)(bit_depth * row_info->channels);

-      row_info->rowbytes =
-         ((row_info->width * row_info->pixel_depth + 7) >> 3);
+      row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth,
+         row_info->width);

    }
 }
 #endif
    }
 }
 #endif


@@ -205,7 +209,7 @@ png_do_pack(png_row_infop row_info, png_bytep row, png_uint_32 bit_depth)
  * would pass 3 as bit_depth, and this routine would translate the
  * data to 0 to 15.
  */
  * would pass 3 as bit_depth, and this routine would translate the
  * data to 0 to 15.
  */

-void
+void /* PRIVATE */

 png_do_shift(png_row_infop row_info, png_bytep row, png_color_8p bit_depth)
 {
    png_debug(1, "in png_do_shift\n");
 png_do_shift(png_row_infop row_info, png_bytep row, png_color_8p bit_depth)
 {
    png_debug(1, "in png_do_shift\n");


@@ -311,7 +315,7 @@ png_do_shift(png_row_infop row_info, png_bytep row, png_color_8p bit_depth)
             png_uint_16 value, v;
             int j;
 
             png_uint_16 value, v;
             int j;
 

-            v = ((png_uint_16)(*bp) << 8) + *(bp + 1);
+            v = (png_uint_16)(((png_uint_16)(*bp) << 8) + *(bp + 1));

             value = 0;
             for (j = shift_start[c]; j > -shift_dec[c]; j -= shift_dec[c])
             {
             value = 0;
             for (j = shift_start[c]; j > -shift_dec[c]; j -= shift_dec[c])
             {


@@ -329,7 +333,7 @@ png_do_shift(png_row_infop row_info, png_bytep row, png_color_8p bit_depth)
 #endif
 
 #if defined(PNG_WRITE_SWAP_ALPHA_SUPPORTED)
 #endif
 
 #if defined(PNG_WRITE_SWAP_ALPHA_SUPPORTED)

-void
+void /* PRIVATE */

 png_do_write_swap_alpha(png_row_infop row_info, png_bytep row)
 {
    png_debug(1, "in png_do_write_swap_alpha\n");
 png_do_write_swap_alpha(png_row_infop row_info, png_bytep row)
 {
    png_debug(1, "in png_do_write_swap_alpha\n");


@@ -417,7 +421,7 @@ png_do_write_swap_alpha(png_row_infop row_info, png_bytep row)
 #endif
 
 #if defined(PNG_WRITE_INVERT_ALPHA_SUPPORTED)
 #endif
 
 #if defined(PNG_WRITE_INVERT_ALPHA_SUPPORTED)

-void
+void /* PRIVATE */

 png_do_write_invert_alpha(png_row_infop row_info, png_bytep row)
 {
    png_debug(1, "in png_do_write_invert_alpha\n");
 png_do_write_invert_alpha(png_row_infop row_info, png_bytep row)
 {
    png_debug(1, "in png_do_write_invert_alpha\n");


@@ -438,7 +442,7 @@ png_do_write_invert_alpha(png_row_infop row_info, png_bytep row)
                *(dp++) = *(sp++);
                *(dp++) = *(sp++);
                *(dp++) = *(sp++);
                *(dp++) = *(sp++);
                *(dp++) = *(sp++);
                *(dp++) = *(sp++);

-               *(dp++) = 255 - *(sp++);
+               *(dp++) = (png_byte)(255 - *(sp++));

             }
          }
          /* This inverts the alpha channel in RRGGBBAA */
             }
          }
          /* This inverts the alpha channel in RRGGBBAA */


@@ -456,8 +460,8 @@ png_do_write_invert_alpha(png_row_infop row_info, png_bytep row)
                *(dp++) = *(sp++);
                *(dp++) = *(sp++);
                *(dp++) = *(sp++);
                *(dp++) = *(sp++);
                *(dp++) = *(sp++);
                *(dp++) = *(sp++);

-               *(dp++) = 255 - *(sp++);
-               *(dp++) = 255 - *(sp++);
+               *(dp++) = (png_byte)(255 - *(sp++));
+               *(dp++) = (png_byte)(255 - *(sp++));

             }
          }
       }
             }
          }
       }


@@ -473,7 +477,7 @@ png_do_write_invert_alpha(png_row_infop row_info, png_bytep row)
             for (i = 0, sp = dp = row; i < row_width; i++)
             {
                *(dp++) = *(sp++);
             for (i = 0, sp = dp = row; i < row_width; i++)
             {
                *(dp++) = *(sp++);

-               *(dp++) = 255 - *(sp++);
+               *(dp++) = (png_byte)(255 - *(sp++));

             }
          }
          /* This inverts the alpha channel in GGAA */
             }
          }
          /* This inverts the alpha channel in GGAA */


@@ -487,11 +491,73 @@ png_do_write_invert_alpha(png_row_infop row_info, png_bytep row)
             {
                *(dp++) = *(sp++);
                *(dp++) = *(sp++);
             {
                *(dp++) = *(sp++);
                *(dp++) = *(sp++);

-               *(dp++) = 255 - *(sp++);
-               *(dp++) = 255 - *(sp++);
+               *(dp++) = (png_byte)(255 - *(sp++));
+               *(dp++) = (png_byte)(255 - *(sp++));

             }
          }
       }
    }
 }
 #endif
             }
          }
       }
    }
 }
 #endif

+
+#if defined(PNG_MNG_FEATURES_SUPPORTED)
+/* 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\n");
+   if (
+#if defined(PNG_USELESS_TESTS_SUPPORTED)
+       row != NULL && row_info != NULL &&
+#endif
+       (row_info->color_type & PNG_COLOR_MASK_COLOR))
+   {
+      int bytes_per_pixel;
+      png_uint_32 row_width = row_info->width;
+      if (row_info->bit_depth == 8)
+      {
+         png_bytep rp;
+         png_uint_32 i;
+
+         if (row_info->color_type == PNG_COLOR_TYPE_RGB)
+            bytes_per_pixel = 3;
+         else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
+            bytes_per_pixel = 4;
+         else
+            return;
+
+         for (i = 0, rp = row; i < row_width; i++, rp += bytes_per_pixel)
+         {
+            *(rp)   = (png_byte)((*rp     - *(rp+1))&0xff);
+            *(rp+2) = (png_byte)((*(rp+2) - *(rp+1))&0xff);
+         }
+      }
+      else if (row_info->bit_depth == 16)
+      {
+         png_bytep rp;
+         png_uint_32 i;
+
+         if (row_info->color_type == PNG_COLOR_TYPE_RGB)
+            bytes_per_pixel = 6;
+         else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
+            bytes_per_pixel = 8;
+         else
+            return;
+
+         for (i = 0, rp = row; i < row_width; i++, rp += bytes_per_pixel)
+         {
+            png_uint_32 s0   = (*(rp  ) << 8) | *(rp+1);
+            png_uint_32 s1   = (*(rp+2) << 8) | *(rp+3);
+            png_uint_32 s2   = (*(rp+4) << 8) | *(rp+5);
+            png_uint_32 red  = (png_uint_32)((s0-s1) & 0xffffL);
+            png_uint_32 blue = (png_uint_32)((s2-s1) & 0xffffL);
+            *(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 */