diff options
Diffstat (limited to 'modules/freetype2/src/sfnt/pngshim.c')
| -rw-r--r-- | modules/freetype2/src/sfnt/pngshim.c | 465 |
1 files changed, 465 insertions, 0 deletions
diff --git a/modules/freetype2/src/sfnt/pngshim.c b/modules/freetype2/src/sfnt/pngshim.c new file mode 100644 index 0000000000..423b07b02a --- /dev/null +++ b/modules/freetype2/src/sfnt/pngshim.c @@ -0,0 +1,465 @@ +/**************************************************************************** + * + * pngshim.c + * + * PNG Bitmap glyph support. + * + * Copyright (C) 2013-2023 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 <freetype/internal/ftdebug.h> +#include <freetype/internal/ftstream.h> +#include <freetype/tttags.h> +#include FT_CONFIG_STANDARD_LIBRARY_H + + +#if defined( TT_CONFIG_OPTION_EMBEDDED_BITMAPS ) && \ + defined( FT_CONFIG_OPTION_USE_PNG ) + + /* We always include <setjmp.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 => BGRA. */ + static void + premultiply_data( png_structp png, + png_row_infop row_info, + png_bytep data ) + { + unsigned int i = 0, limit; + + /* The `vector_size' attribute was introduced in gcc 3.1, which */ + /* predates clang; the `__BYTE_ORDER__' preprocessor symbol was */ + /* introduced in gcc 4.6 and clang 3.2, respectively. */ + /* `__builtin_shuffle' for gcc was introduced in gcc 4.7.0. */ + /* */ + /* Intel compilers do not currently support __builtin_shuffle; */ + + /* The Intel check must be first. */ +#if !defined( __INTEL_COMPILER ) && \ + ( ( defined( __GNUC__ ) && \ + ( ( __GNUC__ >= 5 ) || \ + ( ( __GNUC__ == 4 ) && ( __GNUC_MINOR__ >= 7 ) ) ) ) || \ + ( defined( __clang__ ) && \ + ( ( __clang_major__ >= 4 ) || \ + ( ( __clang_major__ == 3 ) && ( __clang_minor__ >= 2 ) ) ) ) ) && \ + defined( __OPTIMIZE__ ) && \ + defined( __SSE__ ) && \ + __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__ + +#ifdef __clang__ + /* the clang documentation doesn't cover the two-argument case of */ + /* `__builtin_shufflevector'; however, it is is implemented since */ + /* version 2.8 */ +#define vector_shuffle __builtin_shufflevector +#else +#define vector_shuffle __builtin_shuffle +#endif + + typedef unsigned short v82 __attribute__(( vector_size( 16 ) )); + + + if ( row_info->rowbytes > 15 ) + { + /* process blocks of 16 bytes in one rush, which gives a nice speed-up */ + limit = row_info->rowbytes - 16 + 1; + for ( ; i < limit; i += 16 ) + { + unsigned char* base = &data[i]; + + v82 s, s0, s1, a; + + /* clang <= 3.9 can't apply scalar values to vectors */ + /* (or rather, it needs a different syntax) */ + v82 n0x80 = { 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80 }; + v82 n0xFF = { 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF }; + v82 n8 = { 8, 8, 8, 8, 8, 8, 8, 8 }; + + v82 ma = { 1, 1, 3, 3, 5, 5, 7, 7 }; + v82 o1 = { 0, 0xFF, 0, 0xFF, 0, 0xFF, 0, 0xFF }; + v82 m0 = { 1, 0, 3, 2, 5, 4, 7, 6 }; + + + ft_memcpy( &s, base, 16 ); /* RGBA RGBA RGBA RGBA */ + s0 = s & n0xFF; /* R B R B R B R B */ + s1 = s >> n8; /* G A G A G A G A */ + + a = vector_shuffle( s1, ma ); /* A A A A A A A A */ + s1 |= o1; /* G 1 G 1 G 1 G 1 */ + s0 = vector_shuffle( s0, m0 ); /* B R B R B R B R */ + + s0 *= a; + s1 *= a; + s0 += n0x80; + s1 += n0x80; + s0 = ( s0 + ( s0 >> n8 ) ) >> n8; + s1 = ( s1 + ( s1 >> n8 ) ) >> n8; + + s = s0 | ( s1 << n8 ); + ft_memcpy( base, &s, 16 ); + } + } +#endif /* use `vector_size' */ + + FT_UNUSED( png ); + + limit = row_info->rowbytes; + for ( ; i < limit; 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; (never reached) */ + } + + ft_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_Bool metrics_only ) + { + 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; + + /* `rows` gets modified within a 'setjmp' scope; */ + /* we thus need the `volatile` keyword. */ + png_byte* *volatile rows = NULL; + + + 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 ) + { + /* reject too large bitmaps similarly to the rasterizer */ + if ( imgHeight > 0x7FFF || imgWidth > 0x7FFF ) + { + error = FT_THROW( Array_Too_Large ); + goto DestroyExit; + } + + 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; + } + + /* 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; + } + + if ( metrics_only ) + 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 ( populate_map_and_metrics ) + { + /* this doesn't overflow: 0x7FFF * 0x7FFF * 4 < 2^32 */ + FT_ULong size = map->rows * (FT_ULong)map->pitch; + + + error = ft_glyphslot_alloc_bitmap( slot, size ); + if ( error ) + goto DestroyExit; + } + + if ( FT_QNEW_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 ); + + png_read_end( png, info ); + + DestroyExit: + /* even if reading fails with longjmp, rows must be freed */ + FT_FREE( rows ); + png_destroy_read_struct( &png, &info, NULL ); + FT_Stream_Close( &stream ); + + Exit: + return error; + } + +#else /* !(TT_CONFIG_OPTION_EMBEDDED_BITMAPS && FT_CONFIG_OPTION_USE_PNG) */ + + /* ANSI C doesn't like empty source files */ + typedef int _pngshim_dummy; + +#endif /* !(TT_CONFIG_OPTION_EMBEDDED_BITMAPS && FT_CONFIG_OPTION_USE_PNG) */ + + +/* END */ |