mirror of https://github.com/AxioDL/libSquish.git
267 lines
11 KiB
C++
267 lines
11 KiB
C++
/* -----------------------------------------------------------------------------
|
|
|
|
Copyright (c) 2006 Simon Brown si@sjbrown.co.uk
|
|
|
|
Permission is hereby granted, free of charge, to any person obtaining
|
|
a copy of this software and associated documentation files (the
|
|
"Software"), to deal in the Software without restriction, including
|
|
without limitation the rights to use, copy, modify, merge, publish,
|
|
distribute, sublicense, and/or sell copies of the Software, and to
|
|
permit persons to whom the Software is furnished to do so, subject to
|
|
the following conditions:
|
|
|
|
The above copyright notice and this permission notice shall be included
|
|
in all copies or substantial portions of the Software.
|
|
|
|
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
|
|
OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
|
|
MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
|
|
IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
|
|
CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
|
|
TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
|
|
SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
|
|
|
|
-------------------------------------------------------------------------- */
|
|
|
|
#ifndef SQUISH_H
|
|
#define SQUISH_H
|
|
|
|
//! All squish API functions live in this namespace.
|
|
namespace squish {
|
|
|
|
// -----------------------------------------------------------------------------
|
|
|
|
//! Typedef a quantity that is a single unsigned byte.
|
|
typedef unsigned char u8;
|
|
|
|
// -----------------------------------------------------------------------------
|
|
|
|
enum
|
|
{
|
|
//! Use DXT1 compression.
|
|
kDxt1 = ( 1 << 0 ),
|
|
|
|
//! Use DXT3 compression.
|
|
kDxt3 = ( 1 << 1 ),
|
|
|
|
//! Use DXT5 compression.
|
|
kDxt5 = ( 1 << 2 ),
|
|
|
|
//! Use DXT1 compression with GCN byte-ordering
|
|
kDxt1GCN = ( 1 << 9 ),
|
|
|
|
//! Use a very slow but very high quality colour compressor.
|
|
kColourIterativeClusterFit = ( 1 << 8 ),
|
|
|
|
//! Use a slow but high quality colour compressor (the default).
|
|
kColourClusterFit = ( 1 << 3 ),
|
|
|
|
//! Use a fast but low quality colour compressor.
|
|
kColourRangeFit = ( 1 << 4 ),
|
|
|
|
//! Weight the colour by alpha during cluster fit (disabled by default).
|
|
kWeightColourByAlpha = ( 1 << 7 )
|
|
};
|
|
|
|
// -----------------------------------------------------------------------------
|
|
|
|
/*! @brief Compresses a 4x4 block of pixels.
|
|
|
|
@param rgba The rgba values of the 16 source pixels.
|
|
@param mask The valid pixel mask.
|
|
@param block Storage for the compressed DXT block.
|
|
@param flags Compression flags.
|
|
@param metric An optional perceptual metric.
|
|
|
|
The source pixels should be presented as a contiguous array of 16 rgba
|
|
values, with each component as 1 byte each. In memory this should be:
|
|
|
|
{ r1, g1, b1, a1, .... , r16, g16, b16, a16 }
|
|
|
|
The mask parameter enables only certain pixels within the block. The lowest
|
|
bit enables the first pixel and so on up to the 16th bit. Bits beyond the
|
|
16th bit are ignored. Pixels that are not enabled are allowed to take
|
|
arbitrary colours in the output block. An example of how this can be used
|
|
is in the CompressImage function to disable pixels outside the bounds of
|
|
the image when the width or height is not divisible by 4.
|
|
|
|
The flags parameter should specify either kDxt1, kDxt3 or kDxt5 compression,
|
|
however, DXT1 will be used by default if none is specified. When using DXT1
|
|
compression, 8 bytes of storage are required for the compressed DXT block.
|
|
DXT3 and DXT5 compression require 16 bytes of storage per block.
|
|
|
|
The flags parameter can also specify a preferred colour compressor to use
|
|
when fitting the RGB components of the data. Possible colour compressors
|
|
are: kColourClusterFit (the default), kColourRangeFit (very fast, low
|
|
quality) or kColourIterativeClusterFit (slowest, best quality).
|
|
|
|
When using kColourClusterFit or kColourIterativeClusterFit, an additional
|
|
flag can be specified to weight the importance of each pixel by its alpha
|
|
value. For images that are rendered using alpha blending, this can
|
|
significantly increase the perceived quality.
|
|
|
|
The metric parameter can be used to weight the relative importance of each
|
|
colour channel, or pass NULL to use the default uniform weight of
|
|
{ 1.0f, 1.0f, 1.0f }. This replaces the previous flag-based control that
|
|
allowed either uniform or "perceptual" weights with the fixed values
|
|
{ 0.2126f, 0.7152f, 0.0722f }. If non-NULL, the metric should point to a
|
|
contiguous array of 3 floats.
|
|
*/
|
|
void CompressMasked( u8 const* rgba, int mask, void* block, int flags, float* metric = 0 );
|
|
|
|
// -----------------------------------------------------------------------------
|
|
|
|
/*! @brief Compresses a 4x4 block of pixels.
|
|
|
|
@param rgba The rgba values of the 16 source pixels.
|
|
@param block Storage for the compressed DXT block.
|
|
@param flags Compression flags.
|
|
@param metric An optional perceptual metric.
|
|
|
|
The source pixels should be presented as a contiguous array of 16 rgba
|
|
values, with each component as 1 byte each. In memory this should be:
|
|
|
|
{ r1, g1, b1, a1, .... , r16, g16, b16, a16 }
|
|
|
|
The flags parameter should specify either kDxt1, kDxt3 or kDxt5 compression,
|
|
however, DXT1 will be used by default if none is specified. When using DXT1
|
|
compression, 8 bytes of storage are required for the compressed DXT block.
|
|
DXT3 and DXT5 compression require 16 bytes of storage per block.
|
|
|
|
The flags parameter can also specify a preferred colour compressor to use
|
|
when fitting the RGB components of the data. Possible colour compressors
|
|
are: kColourClusterFit (the default), kColourRangeFit (very fast, low
|
|
quality) or kColourIterativeClusterFit (slowest, best quality).
|
|
|
|
When using kColourClusterFit or kColourIterativeClusterFit, an additional
|
|
flag can be specified to weight the importance of each pixel by its alpha
|
|
value. For images that are rendered using alpha blending, this can
|
|
significantly increase the perceived quality.
|
|
|
|
The metric parameter can be used to weight the relative importance of each
|
|
colour channel, or pass NULL to use the default uniform weight of
|
|
{ 1.0f, 1.0f, 1.0f }. This replaces the previous flag-based control that
|
|
allowed either uniform or "perceptual" weights with the fixed values
|
|
{ 0.2126f, 0.7152f, 0.0722f }. If non-NULL, the metric should point to a
|
|
contiguous array of 3 floats.
|
|
|
|
This method is an inline that calls CompressMasked with a mask of 0xffff,
|
|
provided for compatibility with older versions of squish.
|
|
*/
|
|
inline void Compress( u8 const* rgba, void* block, int flags, float* metric = 0 )
|
|
{
|
|
CompressMasked( rgba, 0xffff, block, flags, metric );
|
|
}
|
|
|
|
// -----------------------------------------------------------------------------
|
|
|
|
/*! @brief Decompresses a 4x4 block of pixels.
|
|
|
|
@param rgba Storage for the 16 decompressed pixels.
|
|
@param block The compressed DXT block.
|
|
@param flags Compression flags.
|
|
|
|
The decompressed pixels will be written as a contiguous array of 16 rgba
|
|
values, with each component as 1 byte each. In memory this is:
|
|
|
|
{ r1, g1, b1, a1, .... , r16, g16, b16, a16 }
|
|
|
|
The flags parameter should specify either kDxt1, kDxt3 or kDxt5 compression,
|
|
however, DXT1 will be used by default if none is specified. All other flags
|
|
are ignored.
|
|
*/
|
|
void Decompress( u8* rgba, void const* block, int flags );
|
|
|
|
// -----------------------------------------------------------------------------
|
|
|
|
/*! @brief Computes the amount of compressed storage required.
|
|
|
|
@param width The width of the image.
|
|
@param height The height of the image.
|
|
@param flags Compression flags.
|
|
|
|
The flags parameter should specify either kDxt1, kDxt3 or kDxt5 compression,
|
|
however, DXT1 will be used by default if none is specified. All other flags
|
|
are ignored.
|
|
|
|
Most DXT images will be a multiple of 4 in each dimension, but this
|
|
function supports arbitrary size images by allowing the outer blocks to
|
|
be only partially used.
|
|
*/
|
|
int GetStorageRequirements( int width, int height, int flags );
|
|
|
|
// -----------------------------------------------------------------------------
|
|
|
|
/*! @brief Compresses an image in memory.
|
|
|
|
@param rgba The pixels of the source.
|
|
@param width The width of the source image.
|
|
@param height The height of the source image.
|
|
@param blocks Storage for the compressed output.
|
|
@param flags Compression flags.
|
|
@param metric An optional perceptual metric.
|
|
|
|
The source pixels should be presented as a contiguous array of width*height
|
|
rgba values, with each component as 1 byte each. In memory this should be:
|
|
|
|
{ r1, g1, b1, a1, .... , rn, gn, bn, an } for n = width*height
|
|
|
|
The flags parameter should specify either kDxt1, kDxt3 or kDxt5 compression,
|
|
however, DXT1 will be used by default if none is specified. When using DXT1
|
|
compression, 8 bytes of storage are required for each compressed DXT block.
|
|
DXT3 and DXT5 compression require 16 bytes of storage per block.
|
|
|
|
The flags parameter can also specify a preferred colour compressor to use
|
|
when fitting the RGB components of the data. Possible colour compressors
|
|
are: kColourClusterFit (the default), kColourRangeFit (very fast, low
|
|
quality) or kColourIterativeClusterFit (slowest, best quality).
|
|
|
|
When using kColourClusterFit or kColourIterativeClusterFit, an additional
|
|
flag can be specified to weight the importance of each pixel by its alpha
|
|
value. For images that are rendered using alpha blending, this can
|
|
significantly increase the perceived quality.
|
|
|
|
The metric parameter can be used to weight the relative importance of each
|
|
colour channel, or pass NULL to use the default uniform weight of
|
|
{ 1.0f, 1.0f, 1.0f }. This replaces the previous flag-based control that
|
|
allowed either uniform or "perceptual" weights with the fixed values
|
|
{ 0.2126f, 0.7152f, 0.0722f }. If non-NULL, the metric should point to a
|
|
contiguous array of 3 floats.
|
|
|
|
Internally this function calls squish::CompressMasked for each block, which
|
|
allows for pixels outside the image to take arbitrary values. The function
|
|
squish::GetStorageRequirements can be called to compute the amount of memory
|
|
to allocate for the compressed output.
|
|
*/
|
|
void CompressImage( u8 const* rgba, int width, int height, void* blocks, int flags, float* metric = 0 );
|
|
|
|
// -----------------------------------------------------------------------------
|
|
|
|
/*! @brief Decompresses an image in memory.
|
|
|
|
@param rgba Storage for the decompressed pixels.
|
|
@param width The width of the source image.
|
|
@param height The height of the source image.
|
|
@param blocks The compressed DXT blocks.
|
|
@param flags Compression flags.
|
|
|
|
The decompressed pixels will be written as a contiguous array of width*height
|
|
16 rgba values, with each component as 1 byte each. In memory this is:
|
|
|
|
{ r1, g1, b1, a1, .... , rn, gn, bn, an } for n = width*height
|
|
|
|
The flags parameter should specify either kDxt1, kDxt3 or kDxt5 compression,
|
|
however, DXT1 will be used by default if none is specified. All other flags
|
|
are ignored.
|
|
|
|
Internally this function calls squish::Decompress for each block.
|
|
*/
|
|
void DecompressImage( u8* rgba, int width, int height, void const* blocks, int flags );
|
|
|
|
// -----------------------------------------------------------------------------
|
|
|
|
} // namespace squish
|
|
|
|
#endif // ndef SQUISH_H
|
|
|