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engine: common: imagelib: img_png.c: add support for indexed and grayscale PNG images.

pull/2/head
Andrey Akhmichin 2 years ago committed by Alibek Omarov
parent
commit
fd152e82e8
  1. 132
      engine/common/imagelib/img_png.c
  2. 2
      engine/common/imagelib/img_png.h

132
engine/common/imagelib/img_png.c

@ -26,6 +26,8 @@ GNU General Public License for more details. @@ -26,6 +26,8 @@ GNU General Public License for more details.
static const char png_sign[] = {0x89, 'P', 'N', 'G', '\r', '\n', 0x1a, '\n'};
static const char ihdr_sign[] = {'I', 'H', 'D', 'R'};
static const char trns_sign[] = {'t', 'R', 'N', 'S'};
static const char plte_sign[] = {'P', 'L', 'T', 'E'};
static const char idat_sign[] = {'I', 'D', 'A', 'T'};
static const char iend_sign[] = {'I', 'E', 'N', 'D'};
static const int iend_crc32 = 0xAE426082;
@ -40,8 +42,9 @@ qboolean Image_LoadPNG( const char *name, const byte *buffer, fs_offset_t filesi @@ -40,8 +42,9 @@ qboolean Image_LoadPNG( const char *name, const byte *buffer, fs_offset_t filesi
int ret;
short p, a, b, c, pa, pb, pc;
byte *buf_p, *pixbuf, *raw, *prior, *idat_buf = NULL, *uncompressed_buffer = NULL, *rowend;
uint chunk_len, crc32, crc32_check, oldsize = 0, newsize = 0, rowsize;
uint uncompressed_size, pixel_size, i, y, filter_type, chunk_sign;
byte *pallete = NULL, *trns = NULL;
uint chunk_len, trns_len, crc32, crc32_check, oldsize = 0, newsize = 0, rowsize;
uint uncompressed_size, pixel_size, i, y, filter_type, chunk_sign, r_alpha, g_alpha, b_alpha;
qboolean has_iend_chunk = false;
z_stream stream = {0};
png_t png_hdr;
@ -67,7 +70,7 @@ qboolean Image_LoadPNG( const char *name, const byte *buffer, fs_offset_t filesi @@ -67,7 +70,7 @@ qboolean Image_LoadPNG( const char *name, const byte *buffer, fs_offset_t filesi
// check IHDR chunk length (valid value - 13)
if( png_hdr.ihdr_len != sizeof( png_ihdr_t ) )
{
Con_DPrintf( S_ERROR "Image_LoadPNG: Invalid IHDR chunk size (%s)\n", name );
Con_DPrintf( S_ERROR "Image_LoadPNG: Invalid IHDR chunk size %u (%s)\n", png_hdr.ihdr_len, name );
return false;
}
@ -84,7 +87,7 @@ qboolean Image_LoadPNG( const char *name, const byte *buffer, fs_offset_t filesi @@ -84,7 +87,7 @@ qboolean Image_LoadPNG( const char *name, const byte *buffer, fs_offset_t filesi
if( png_hdr.ihdr_chunk.height == 0 || png_hdr.ihdr_chunk.width == 0 )
{
Con_DPrintf( S_ERROR "Image_LoadPNG: Invalid image size %dx%d (%s)\n", png_hdr.ihdr_chunk.width, png_hdr.ihdr_chunk.height, name );
Con_DPrintf( S_ERROR "Image_LoadPNG: Invalid image size %ux%u (%s)\n", png_hdr.ihdr_chunk.width, png_hdr.ihdr_chunk.height, name );
return false;
}
@ -94,21 +97,25 @@ qboolean Image_LoadPNG( const char *name, const byte *buffer, fs_offset_t filesi @@ -94,21 +97,25 @@ qboolean Image_LoadPNG( const char *name, const byte *buffer, fs_offset_t filesi
return false;
}
if( png_hdr.ihdr_chunk.colortype != PNG_CT_RGB && png_hdr.ihdr_chunk.colortype != PNG_CT_RGBA )
if( !( png_hdr.ihdr_chunk.colortype == PNG_CT_RGB
|| png_hdr.ihdr_chunk.colortype == PNG_CT_RGBA
|| png_hdr.ihdr_chunk.colortype == PNG_CT_GREY
|| png_hdr.ihdr_chunk.colortype == PNG_CT_ALPHA
|| png_hdr.ihdr_chunk.colortype == PNG_CT_PALLETE ) )
{
Con_DPrintf( S_WARN "Image_LoadPNG: Only 8-bit RGB and RGBA images is supported (%s)\n", name );
Con_DPrintf( S_WARN "Image_LoadPNG: Unknown color type %u (%s)\n", png_hdr.ihdr_chunk.colortype, name );
return false;
}
if( png_hdr.ihdr_chunk.compression > 0 )
{
Con_DPrintf( S_ERROR "Image_LoadPNG: Unknown compression method (%s)\n", name );
Con_DPrintf( S_ERROR "Image_LoadPNG: Unknown compression method %u (%s)\n", png_hdr.ihdr_chunk.compression, name );
return false;
}
if( png_hdr.ihdr_chunk.filter > 0 )
{
Con_DPrintf( S_ERROR "Image_LoadPNG: Unknown filter type (%s)\n", name );
Con_DPrintf( S_ERROR "Image_LoadPNG: Unknown filter type %u (%s)\n", png_hdr.ihdr_chunk.filter, name );
return false;
}
@ -120,7 +127,7 @@ qboolean Image_LoadPNG( const char *name, const byte *buffer, fs_offset_t filesi @@ -120,7 +127,7 @@ qboolean Image_LoadPNG( const char *name, const byte *buffer, fs_offset_t filesi
if( png_hdr.ihdr_chunk.interlace > 0 )
{
Con_DPrintf( S_ERROR "Image_LoadPNG: Unknown interlacing type (%s)\n", name );
Con_DPrintf( S_ERROR "Image_LoadPNG: Unknown interlacing type %u (%s)\n", png_hdr.ihdr_chunk.interlace, name );
return false;
}
@ -158,8 +165,19 @@ qboolean Image_LoadPNG( const char *name, const byte *buffer, fs_offset_t filesi @@ -158,8 +165,19 @@ qboolean Image_LoadPNG( const char *name, const byte *buffer, fs_offset_t filesi
// move pointer
buf_p += sizeof( chunk_sign );
// find transparency
if( !memcmp( buf_p, trns_sign, sizeof( trns_sign ) ) )
{
trns = buf_p + sizeof( trns_sign );
trns_len = chunk_len;
}
// find pallete for indexed image
else if( !memcmp( buf_p, plte_sign, sizeof( plte_sign ) ) )
{
pallete = buf_p + sizeof( plte_sign );
}
// get all IDAT chunks data
if( !memcmp( buf_p, idat_sign, sizeof( idat_sign ) ) )
else if( !memcmp( buf_p, idat_sign, sizeof( idat_sign ) ) )
{
newsize = oldsize + chunk_len;
idat_buf = (byte *)Mem_Realloc( host.imagepool, idat_buf, newsize );
@ -193,6 +211,13 @@ qboolean Image_LoadPNG( const char *name, const byte *buffer, fs_offset_t filesi @@ -193,6 +211,13 @@ qboolean Image_LoadPNG( const char *name, const byte *buffer, fs_offset_t filesi
buf_p += sizeof( crc32 );
}
if( png_hdr.ihdr_chunk.colortype == PNG_CT_PALLETE && !pallete )
{
Con_DPrintf( S_ERROR "Image_LoadPNG: PLTE chunk not found (%s)\n", name );
Mem_Free( idat_buf );
return false;
}
if( !has_iend_chunk )
{
Con_DPrintf( S_ERROR "Image_LoadPNG: IEND chunk not found (%s)\n", name );
@ -202,7 +227,7 @@ qboolean Image_LoadPNG( const char *name, const byte *buffer, fs_offset_t filesi @@ -202,7 +227,7 @@ qboolean Image_LoadPNG( const char *name, const byte *buffer, fs_offset_t filesi
if( chunk_len != 0 )
{
Con_DPrintf( S_ERROR "Image_LoadPNG: IEND chunk has wrong size (%s)\n", name );
Con_DPrintf( S_ERROR "Image_LoadPNG: IEND chunk has wrong size %u (%s)\n", chunk_len, name );
Mem_Free( idat_buf );
return false;
}
@ -215,6 +240,13 @@ qboolean Image_LoadPNG( const char *name, const byte *buffer, fs_offset_t filesi @@ -215,6 +240,13 @@ qboolean Image_LoadPNG( const char *name, const byte *buffer, fs_offset_t filesi
switch( png_hdr.ihdr_chunk.colortype )
{
case PNG_CT_GREY:
case PNG_CT_PALLETE:
pixel_size = 1;
break;
case PNG_CT_ALPHA:
pixel_size = 2;
break;
case PNG_CT_RGB:
pixel_size = 3;
break;
@ -231,9 +263,11 @@ qboolean Image_LoadPNG( const char *name, const byte *buffer, fs_offset_t filesi @@ -231,9 +263,11 @@ qboolean Image_LoadPNG( const char *name, const byte *buffer, fs_offset_t filesi
image.width = png_hdr.ihdr_chunk.width;
image.height = png_hdr.ihdr_chunk.height;
image.size = image.height * image.width * 4;
if( png_hdr.ihdr_chunk.colortype & PNG_CT_RGB )
image.flags |= IMAGE_HAS_COLOR;
if( png_hdr.ihdr_chunk.colortype == PNG_CT_RGBA )
if( trns || ( png_hdr.ihdr_chunk.colortype & PNG_CT_ALPHA ) )
image.flags |= IMAGE_HAS_ALPHA;
image.depth = 1;
@ -275,7 +309,7 @@ qboolean Image_LoadPNG( const char *name, const byte *buffer, fs_offset_t filesi @@ -275,7 +309,7 @@ qboolean Image_LoadPNG( const char *name, const byte *buffer, fs_offset_t filesi
raw = uncompressed_buffer;
if( png_hdr.ihdr_chunk.colortype == PNG_CT_RGB )
if( png_hdr.ihdr_chunk.colortype != PNG_CT_RGBA )
prior = pixbuf = raw;
filter_type = *raw++;
@ -377,12 +411,19 @@ qboolean Image_LoadPNG( const char *name, const byte *buffer, fs_offset_t filesi @@ -377,12 +411,19 @@ qboolean Image_LoadPNG( const char *name, const byte *buffer, fs_offset_t filesi
prior = pixbuf;
}
// convert RGB-to-RGBA
if( png_hdr.ihdr_chunk.colortype == PNG_CT_RGB )
{
pixbuf = image.rgba;
raw = uncompressed_buffer;
switch( png_hdr.ihdr_chunk.colortype )
{
case PNG_CT_RGB:
if( trns )
{
r_alpha = trns[0] << 8 | trns[1];
g_alpha = trns[2] << 8 | trns[3];
b_alpha = trns[4] << 8 | trns[5];
}
for( y = 0; y < image.height; y++ )
{
rowend = raw + rowsize;
@ -391,9 +432,68 @@ qboolean Image_LoadPNG( const char *name, const byte *buffer, fs_offset_t filesi @@ -391,9 +432,68 @@ qboolean Image_LoadPNG( const char *name, const byte *buffer, fs_offset_t filesi
*pixbuf++ = raw[0];
*pixbuf++ = raw[1];
*pixbuf++ = raw[2];
if( trns && r_alpha == raw[0]
&& g_alpha == raw[1]
&& b_alpha == raw[2] )
*pixbuf++ = 0;
else
*pixbuf++ = 0xFF;
}
}
break;
case PNG_CT_GREY:
if( trns )
r_alpha = trns[0] << 8 | trns[1];
for( y = 0; y < image.height; y++ )
{
rowend = raw + rowsize;
for( ; raw < rowend; raw += pixel_size )
{
*pixbuf++ = raw[0];
*pixbuf++ = raw[0];
*pixbuf++ = raw[0];
if( trns && r_alpha == raw[0] )
*pixbuf++ = 0;
else
*pixbuf++ = 0xFF;
}
}
break;
case PNG_CT_ALPHA:
for( y = 0; y < image.height; y++ )
{
rowend = raw + rowsize;
for( ; raw < rowend; raw += pixel_size )
{
*pixbuf++ = raw[0];
*pixbuf++ = raw[0];
*pixbuf++ = raw[0];
*pixbuf++ = raw[1];
}
}
break;
case PNG_CT_PALLETE:
for( y = 0; y < image.height; y++ )
{
rowend = raw + rowsize;
for( ; raw < rowend; raw += pixel_size )
{
*pixbuf++ = pallete[raw[0] + 2];
*pixbuf++ = pallete[raw[0] + 1];
*pixbuf++ = pallete[raw[0] + 0];
if( trns && raw[0] < trns_len )
*pixbuf++ = trns[raw[0]];
else
*pixbuf++ = 0xFF;
}
}
break;
default:
break;
}
Mem_Free( uncompressed_buffer );

2
engine/common/imagelib/img_png.h

@ -25,8 +25,8 @@ GNU General Public License for more details. @@ -25,8 +25,8 @@ GNU General Public License for more details.
enum png_colortype
{
PNG_CT_GREY,
PNG_CT_PALLETE = BIT(0),
PNG_CT_RGB = BIT(1),
PNG_CT_PALLETE = (PNG_CT_RGB|BIT(0)),
PNG_CT_ALPHA = BIT(2),
PNG_CT_RGBA = (PNG_CT_RGB|PNG_CT_ALPHA)
};

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