axmol/core/base/astc.h

/******************************************************************************

 ASTC Texture Decompression.
 astc compression tool: https://github.com/ARM-software/astc-encoder/releases
 version required: v2.2+
 command:
   astcenc-sse4.2 -cl test1.png test1.astc 6x6 -medium -pp-premultiply

 ******************************************************************************/

#ifndef __ASTC_H__
#define __ASTC_H__

#include <stdint.h>

// ASTC parameters
#define ASTC_HEAD_SIZE 16

/* ============================================================================
        ASTC compressed file loading, see also: astcenccli_image_load_store.cpp
============================================================================ */
struct astc_header
{
    uint8_t magic[4];
    uint8_t block_x;
    uint8_t block_y;
    uint8_t block_z;
    uint8_t dim_x[3];  // dims = dim[0] + (dim[1] << 8) + (dim[2] << 16)
    uint8_t dim_y[3];  // Sizes are given in texels;
    uint8_t dim_z[3];  // block count is inferred
};

static const uint32_t ASTC_MAGIC_ID = 0x5CA1AB13;

static unsigned int astc_unpack_bytes(uint8_t a, uint8_t b, uint8_t c, uint8_t d)
{
    return ((unsigned int)(a)) + ((unsigned int)(b) << 8) + ((unsigned int)(c) << 16) + ((unsigned int)(d) << 24);
}


int astc_decompress_image(const uint8_t* in,
                          uint32_t inlen,
                          uint8_t* out,
                          uint32_t xdim,
                          uint32_t ydim,
                          uint32_t xblock,
                          uint32_t yblock);

#endif  //__ASTC_H__