Update freetype sources (2.6.2) in third party.

third_party/freetype2/src/src/sfnt/pngshim.c

Index: third_party/freetype2/src/src/sfnt/pngshim.c
diff --git a/third_party/freetype2/src/src/sfnt/pngshim.c b/third_party/freetype2/src/src/sfnt/pngshim.c
new file mode 100644
index 0000000000000000000000000000000000000000..ea60452635a34c58d71c20bdec182fd4c1cc573b
--- /dev/null
+++ b/third_party/freetype2/src/src/sfnt/pngshim.c
@@ -0,0 +1,378 @@
+/***************************************************************************/
+/*                                                                         */
+/*  pngshim.c                                                              */
+/*                                                                         */
+/*    PNG Bitmap glyph support.                                            */
+/*                                                                         */
+/*  Copyright 2013-2015 by                                                 */
+/*  Google, Inc.                                                           */
+/*  Written by Stuart Gill and Behdad Esfahbod.                            */
+/*                                                                         */
+/*  This file is part of the FreeType project, and may only be used,       */
+/*  modified, and distributed under the terms of the FreeType project      */
+/*  license, LICENSE.TXT.  By continuing to use, modify, or distribute     */
+/*  this file you indicate that you have read the license and              */
+/*  understand and accept it fully.                                        */
+/*                                                                         */
+/***************************************************************************/
+
+
+#include <ft2build.h>
+#include FT_INTERNAL_DEBUG_H
+#include FT_INTERNAL_STREAM_H
+#include FT_TRUETYPE_TAGS_H
+#include FT_CONFIG_STANDARD_LIBRARY_H
+
+
+#ifdef FT_CONFIG_OPTION_USE_PNG
+
+  /* We always include <stjmp.h>, so make libpng shut up! */
+#define PNG_SKIP_SETJMP_CHECK 1
+#include <png.h>
+#include "pngshim.h"
+
+#include "sferrors.h"
+
+
+  /* This code is freely based on cairo-png.c.  There's so many ways */
+  /* to call libpng, and the way cairo does it is defacto standard.  */
+
+  static unsigned int
+  multiply_alpha( unsigned int  alpha,
+                  unsigned int  color )
+  {
+    unsigned int  temp = alpha * color + 0x80;
+
+
+    return ( temp + ( temp >> 8 ) ) >> 8;
+  }
+
+
+  /* Premultiplies data and converts RGBA bytes => native endian. */
+  static void
+  premultiply_data( png_structp    png,
+                    png_row_infop  row_info,
+                    png_bytep      data )
+  {
+    unsigned int  i;
+
+    FT_UNUSED( png );
+
+
+    for ( i = 0; i < row_info->rowbytes; i += 4 )
+    {
+      unsigned char*  base  = &data[i];
+      unsigned int    alpha = base[3];
+
+
+      if ( alpha == 0 )
+        base[0] = base[1] = base[2] = base[3] = 0;
+
+      else
+      {
+        unsigned int  red   = base[0];
+        unsigned int  green = base[1];
+        unsigned int  blue  = base[2];
+
+
+        if ( alpha != 0xFF )
+        {
+          red   = multiply_alpha( alpha, red   );
+          green = multiply_alpha( alpha, green );
+          blue  = multiply_alpha( alpha, blue  );
+        }
+
+        base[0] = (unsigned char)blue;
+        base[1] = (unsigned char)green;
+        base[2] = (unsigned char)red;
+        base[3] = (unsigned char)alpha;
+      }
+    }
+  }
+
+
+  /* Converts RGBx bytes to BGRA. */
+  static void
+  convert_bytes_to_data( png_structp    png,
+                         png_row_infop  row_info,
+                         png_bytep      data )
+  {
+    unsigned int  i;
+
+    FT_UNUSED( png );
+
+
+    for ( i = 0; i < row_info->rowbytes; i += 4 )
+    {
+      unsigned char*  base  = &data[i];
+      unsigned int    red   = base[0];
+      unsigned int    green = base[1];
+      unsigned int    blue  = base[2];
+
+
+      base[0] = (unsigned char)blue;
+      base[1] = (unsigned char)green;
+      base[2] = (unsigned char)red;
+      base[3] = 0xFF;
+    }
+  }
+
+
+  /* Use error callback to avoid png writing to stderr. */
+  static void
+  error_callback( png_structp      png,
+                  png_const_charp  error_msg )
+  {
+    FT_Error*  error = (FT_Error*)png_get_error_ptr( png );
+
+    FT_UNUSED( error_msg );
+
+
+    *error = FT_THROW( Out_Of_Memory );
+#ifdef PNG_SETJMP_SUPPORTED
+    ft_longjmp( png_jmpbuf( png ), 1 );
+#endif
+    /* if we get here, then we have no choice but to abort ... */
+  }
+
+
+  /* Use warning callback to avoid png writing to stderr. */
+  static void
+  warning_callback( png_structp      png,
+                    png_const_charp  error_msg )
+  {
+    FT_UNUSED( png );
+    FT_UNUSED( error_msg );
+
+    /* Just ignore warnings. */
+  }
+
+
+  static void
+  read_data_from_FT_Stream( png_structp  png,
+                            png_bytep    data,
+                            png_size_t   length )
+  {
+    FT_Error   error;
+    png_voidp  p      = png_get_io_ptr( png );
+    FT_Stream  stream = (FT_Stream)p;
+
+
+    if ( FT_FRAME_ENTER( length ) )
+    {
+      FT_Error*  e = (FT_Error*)png_get_error_ptr( png );
+
+
+      *e = FT_THROW( Invalid_Stream_Read );
+      png_error( png, NULL );
+
+      return;
+    }
+
+    memcpy( data, stream->cursor, length );
+
+    FT_FRAME_EXIT();
+  }
+
+
+  FT_LOCAL_DEF( FT_Error )
+  Load_SBit_Png( FT_GlyphSlot     slot,
+                 FT_Int           x_offset,
+                 FT_Int           y_offset,
+                 FT_Int           pix_bits,
+                 TT_SBit_Metrics  metrics,
+                 FT_Memory        memory,
+                 FT_Byte*         data,
+                 FT_UInt          png_len,
+                 FT_Bool          populate_map_and_metrics )
+  {
+    FT_Bitmap    *map   = &slot->bitmap;
+    FT_Error      error = FT_Err_Ok;
+    FT_StreamRec  stream;
+
+    png_structp  png;
+    png_infop    info;
+    png_uint_32  imgWidth, imgHeight;
+
+    int         bitdepth, color_type, interlace;
+    FT_Int      i;
+    png_byte*  *rows = NULL; /* pacify compiler */
+
+
+    if ( x_offset < 0 ||
+         y_offset < 0 )
+    {
+      error = FT_THROW( Invalid_Argument );
+      goto Exit;
+    }
+
+    if ( !populate_map_and_metrics                            &&
+         ( (FT_UInt)x_offset + metrics->width  > map->width ||
+           (FT_UInt)y_offset + metrics->height > map->rows  ||
+           pix_bits != 32                                   ||
+           map->pixel_mode != FT_PIXEL_MODE_BGRA            ) )
+    {
+      error = FT_THROW( Invalid_Argument );
+      goto Exit;
+    }
+
+    FT_Stream_OpenMemory( &stream, data, png_len );
+
+    png = png_create_read_struct( PNG_LIBPNG_VER_STRING,
+                                  &error,
+                                  error_callback,
+                                  warning_callback );
+    if ( !png )
+    {
+      error = FT_THROW( Out_Of_Memory );
+      goto Exit;
+    }
+
+    info = png_create_info_struct( png );
+    if ( !info )
+    {
+      error = FT_THROW( Out_Of_Memory );
+      png_destroy_read_struct( &png, NULL, NULL );
+      goto Exit;
+    }
+
+    if ( ft_setjmp( png_jmpbuf( png ) ) )
+    {
+      error = FT_THROW( Invalid_File_Format );
+      goto DestroyExit;
+    }
+
+    png_set_read_fn( png, &stream, read_data_from_FT_Stream );
+
+    png_read_info( png, info );
+    png_get_IHDR( png, info,
+                  &imgWidth, &imgHeight,
+                  &bitdepth, &color_type, &interlace,
+                  NULL, NULL );
+
+    if ( error                                        ||
+         ( !populate_map_and_metrics                &&
+           ( (FT_Int)imgWidth  != metrics->width  ||
+             (FT_Int)imgHeight != metrics->height ) ) )
+      goto DestroyExit;
+
+    if ( populate_map_and_metrics )
+    {
+      FT_ULong  size;
+
+
+      metrics->width  = (FT_UShort)imgWidth;
+      metrics->height = (FT_UShort)imgHeight;
+
+      map->width      = metrics->width;
+      map->rows       = metrics->height;
+      map->pixel_mode = FT_PIXEL_MODE_BGRA;
+      map->pitch      = (int)( map->width * 4 );
+      map->num_grays  = 256;
+
+      /* reject too large bitmaps similarly to the rasterizer */
+      if ( map->rows > 0x7FFF || map->width > 0x7FFF )
+      {
+        error = FT_THROW( Array_Too_Large );
+        goto DestroyExit;
+      }
+
+      /* this doesn't overflow: 0x7FFF * 0x7FFF * 4 < 2^32 */
+      size = map->rows * (FT_ULong)map->pitch;
+
+      error = ft_glyphslot_alloc_bitmap( slot, size );
+      if ( error )
+        goto DestroyExit;
+    }
+
+    /* convert palette/gray image to rgb */
+    if ( color_type == PNG_COLOR_TYPE_PALETTE )
+      png_set_palette_to_rgb( png );
+
+    /* expand gray bit depth if needed */
+    if ( color_type == PNG_COLOR_TYPE_GRAY )
+    {
+#if PNG_LIBPNG_VER >= 10209
+      png_set_expand_gray_1_2_4_to_8( png );
+#else
+      png_set_gray_1_2_4_to_8( png );
+#endif
+    }
+
+    /* transform transparency to alpha */
+    if ( png_get_valid(png, info, PNG_INFO_tRNS ) )
+      png_set_tRNS_to_alpha( png );
+
+    if ( bitdepth == 16 )
+      png_set_strip_16( png );
+
+    if ( bitdepth < 8 )
+      png_set_packing( png );
+
+    /* convert grayscale to RGB */
+    if ( color_type == PNG_COLOR_TYPE_GRAY       ||
+         color_type == PNG_COLOR_TYPE_GRAY_ALPHA )
+      png_set_gray_to_rgb( png );
+
+    if ( interlace != PNG_INTERLACE_NONE )
+      png_set_interlace_handling( png );
+
+    png_set_filler( png, 0xFF, PNG_FILLER_AFTER );
+
+    /* recheck header after setting EXPAND options */
+    png_read_update_info(png, info );
+    png_get_IHDR( png, info,
+                  &imgWidth, &imgHeight,
+                  &bitdepth, &color_type, &interlace,
+                  NULL, NULL );
+
+    if ( bitdepth != 8                              ||
+        !( color_type == PNG_COLOR_TYPE_RGB       ||
+           color_type == PNG_COLOR_TYPE_RGB_ALPHA ) )
+    {
+      error = FT_THROW( Invalid_File_Format );
+      goto DestroyExit;
+    }
+
+    switch ( color_type )
+    {
+    default:
+      /* Shouldn't happen, but fall through. */
+
+    case PNG_COLOR_TYPE_RGB_ALPHA:
+      png_set_read_user_transform_fn( png, premultiply_data );
+      break;
+
+    case PNG_COLOR_TYPE_RGB:
+      /* Humm, this smells.  Carry on though. */
+      png_set_read_user_transform_fn( png, convert_bytes_to_data );
+      break;
+    }
+
+    if ( FT_NEW_ARRAY( rows, imgHeight ) )
+    {
+      error = FT_THROW( Out_Of_Memory );
+      goto DestroyExit;
+    }
+
+    for ( i = 0; i < (FT_Int)imgHeight; i++ )
+      rows[i] = map->buffer + ( y_offset + i ) * map->pitch + x_offset * 4;
+
+    png_read_image( png, rows );
+
+    FT_FREE( rows );
+
+    png_read_end( png, info );
+
+  DestroyExit:
+    png_destroy_read_struct( &png, &info, NULL );
+    FT_Stream_Close( &stream );
+
+  Exit:
+    return error;
+  }
+
+#endif /* FT_CONFIG_OPTION_USE_PNG */
+
+
+/* END */