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Imported from libpng-1.0.4-pre1.tar

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This commit is contained in:
Glenn Randers-Pehrson
1999-09-17 12:27:26 -05:00
parent 87544ac62b
commit 4393a9ad6b
56 changed files with 5798 additions and 1904 deletions
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100
pngrtran.c
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@@ -1,7 +1,7 @@
/* pngrtran.c - transforms the data in a row for PNG readers
*
* libpng 1.0.3 - January 14, 1999
* libpng 1.0.4 - September 17, 1999
* 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
@@ -523,7 +523,7 @@ png_set_gamma(png_structp png_ptr, double scrn_gamma, double file_gamma)
#if defined(PNG_READ_EXPAND_SUPPORTED)
/* Expand paletted images to rgb, expand grayscale images of
* less than 8 bit depth to 8 bit depth, and expand tRNS chunks
* less than 8-bit depth to 8-bit depth, and expand tRNS chunks
* to alpha channels.
*/
void
@@ -532,7 +532,45 @@ png_set_expand(png_structp png_ptr)
png_debug(1, "in png_set_expand\n");
png_ptr->transformations |= PNG_EXPAND;
}
#endif
/* GRR 19990627: the following three functions currently are identical
* to png_set_expand(). However, it is entirely reasonable that someone
* might wish to expand an indexed image to RGB but *not* expand a single,
* fully transparent palette entry to a full alpha channel--perhaps instead
* convert tRNS to the grayscale/RGB format (16-bit RGB value), or replace
* the transparent color with a particular RGB value, or drop tRNS entirely.
* IOW, a future version of the library may make the transformations flag
* a bit more fine-grained, with separate bits for each of these three
* functions.
*
* More to the point, these functions make it obvious what libpng will be
* doing, whereas "expand" can (and does) mean any number of things.
*/
/* Expand paletted images to RGB. */
void
png_set_palette_to_rgb(png_structp png_ptr)
{
png_debug(1, "in png_set_expand\n");
png_ptr->transformations |= PNG_EXPAND;
}
/* Expand grayscale images of less than 8-bit depth to 8 bits. */
void
png_set_gray_1_2_4_to_8(png_structp png_ptr)
{
png_debug(1, "in png_set_expand\n");
png_ptr->transformations |= PNG_EXPAND;
}
/* Expand tRNS chunks to alpha channels. */
void
png_set_tRNS_to_alpha(png_structp png_ptr)
{
png_debug(1, "in png_set_expand\n");
png_ptr->transformations |= PNG_EXPAND;
}
#endif /* defined(PNG_READ_EXPAND_SUPPORTED) */
#if defined(PNG_READ_GRAY_TO_RGB_SUPPORTED)
void
@@ -548,8 +586,8 @@ png_set_gray_to_rgb(png_structp png_ptr)
* for example, to convert a 24 bpp RGB image into an 8 bpp grayscale image.
*/
void
png_set_rgb_to_gray(png_structp png_ptr, int error_action, float red,
float green)
png_set_rgb_to_gray(png_structp png_ptr, int error_action, double red,
double green)
{
png_debug(1, "in png_set_rgb_to_gray\n");
switch(error_action)
@@ -570,8 +608,8 @@ png_set_rgb_to_gray(png_structp png_ptr, int error_action, float red,
}
#endif
{
png_byte red_byte = (png_byte)(red*255.0 + 0.5);
png_byte green_byte = (png_byte)(green*255.0 + 0.5);
png_byte red_byte = (png_byte)((float)red*255.0 + 0.5);
png_byte green_byte = (png_byte)((float)green*255.0 + 0.5);
if(red < 0.0 || green < 0.0)
{
red_byte = 54;
@@ -1018,6 +1056,16 @@ png_read_transform_info(png_structp png_ptr, png_infop info_ptr)
++info_ptr->channels;
#endif
#if defined(PNG_READ_USER_TRANSFORM_SUPPORTED)
if(png_ptr->transformations & PNG_USER_TRANSFORM)
{
if(info_ptr->bit_depth < png_ptr->user_transform_depth)
info_ptr->bit_depth = png_ptr->user_transform_depth;
if(info_ptr->channels < png_ptr->user_transform_channels)
info_ptr->channels = png_ptr->user_transform_channels;
}
#endif
info_ptr->pixel_depth = (png_byte)(info_ptr->channels *
info_ptr->bit_depth);
info_ptr->rowbytes = ((info_ptr->width * info_ptr->pixel_depth + 7) >> 3);
@@ -1223,6 +1271,7 @@ From Andreas Dilger e-mail to png-implement, 26 March 1998:
#if defined(PNG_READ_USER_TRANSFORM_SUPPORTED)
if (png_ptr->transformations & PNG_USER_TRANSFORM)
{
if(png_ptr->read_user_transform_fn != NULL)
(*(png_ptr->read_user_transform_fn)) /* user read transform function */
(png_ptr, /* png_ptr */
@@ -1234,6 +1283,15 @@ From Andreas Dilger e-mail to png-implement, 26 March 1998:
/* 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 */
if(png_ptr->user_transform_depth)
png_ptr->row_info.bit_depth = png_ptr->user_transform_depth;
if(png_ptr->user_transform_channels)
png_ptr->row_info.channels = png_ptr->user_transform_channels;
png_ptr->row_info.pixel_depth = (png_byte)(png_ptr->row_info.bit_depth *
png_ptr->row_info.channels);
png_ptr->row_info.rowbytes = (png_ptr->row_info.width *
png_ptr->row_info.pixel_depth+7)>>3;
}
#endif
}
@@ -1737,7 +1795,7 @@ png_do_read_filler(png_row_infop row_info, png_bytep row,
*(--dp) = lo_filler;
row_info->channels = 2;
row_info->pixel_depth = 32;
row_info->rowbytes = row_width * 2;
row_info->rowbytes = row_width * 4;
}
/* This changes the data from GG to XXGG */
else
@@ -1752,8 +1810,8 @@ png_do_read_filler(png_row_infop row_info, png_bytep row,
*(--dp) = lo_filler;
}
row_info->channels = 2;
row_info->pixel_depth = 16;
row_info->rowbytes = row_width * 2;
row_info->pixel_depth = 32;
row_info->rowbytes = row_width * 4;
}
}
} /* COLOR_TYPE == GRAY */
@@ -1817,7 +1875,7 @@ png_do_read_filler(png_row_infop row_info, png_bytep row,
*(--dp) = lo_filler;
row_info->channels = 4;
row_info->pixel_depth = 64;
row_info->rowbytes = row_width * 4;
row_info->rowbytes = row_width * 8;
}
/* This changes the data from RRGGBB to XXRRGGBB */
else
@@ -1837,7 +1895,7 @@ png_do_read_filler(png_row_infop row_info, png_bytep row,
}
row_info->channels = 4;
row_info->pixel_depth = 64;
row_info->rowbytes = row_width * 4;
row_info->rowbytes = row_width * 8;
}
}
} /* COLOR_TYPE == RGB */
@@ -1869,8 +1927,7 @@ png_do_gray_to_rgb(png_row_infop row_info, png_bytep row)
{
*(dp--) = *sp;
*(dp--) = *sp;
*(dp--) = *sp;
sp--;
*(dp--) = *(sp--);
}
}
else
@@ -1883,10 +1940,8 @@ png_do_gray_to_rgb(png_row_infop row_info, png_bytep row)
*(dp--) = *(sp - 1);
*(dp--) = *sp;
*(dp--) = *(sp - 1);
*(dp--) = *sp;
*(dp--) = *(sp - 1);
sp--;
sp--;
*(dp--) = *(sp--);
*(dp--) = *(sp--);
}
}
}
@@ -1901,8 +1956,7 @@ png_do_gray_to_rgb(png_row_infop row_info, png_bytep row)
*(dp--) = *(sp--);
*(dp--) = *sp;
*(dp--) = *sp;
*(dp--) = *sp;
sp--;
*(dp--) = *(sp--);
}
}
else
@@ -1917,10 +1971,8 @@ png_do_gray_to_rgb(png_row_infop row_info, png_bytep row)
*(dp--) = *(sp - 1);
*(dp--) = *sp;
*(dp--) = *(sp - 1);
*(dp--) = *sp;
*(dp--) = *(sp - 1);
sp--;
sp--;
*(dp--) = *(sp--);
*(dp--) = *(sp--);
}
}
}