quyse/flaw

#include "alpha.h"
#include "clusterfit.h"
#include "colourset.h"
#include "singlecolourfit.h"
#include <cstring>
using namespace squish;

extern "C" void flaw_squish_compress_bc1(u8 const* input, int inputLinePitch, u8* output)
{
    // make rgba input block
    u8 rgbaInput[64];
    for(int i = 0; i < 16; ++i)
    {
        int k = (i / 4) * inputLinePitch + (i % 4) * 3;
        rgbaInput[i * 4 + 0] = input[k + 0];
        rgbaInput[i * 4 + 1] = input[k + 1];
        rgbaInput[i * 4 + 2] = input[k + 2];
        rgbaInput[i * 4 + 3] = 255;
    }

    const int flags = kDxt1 | kColourIterativeClusterFit;

    // calculate color set
    ColourSet colours(rgbaInput, 0xffff, flags);
    // if there's just one color, do single color fit
    if(colours.GetCount() == 1)
    {
        SingleColourFit fit(&colours, flags);
        fit.Compress(output);
    }
    else
    {
        ClusterFit fit(&colours, flags, NULL);
        fit.Compress(output);
    }
}

extern "C" void flaw_squish_compress_bc2(u8 const* input, int inputLinePitch, u8* output)
{
    // make rgba input block
    u8 rgbaInput[64];
    for(int i = 0; i < 4; ++i)
        memcpy(rgbaInput + i * 16, input + i * inputLinePitch, 16);

    const int flags = kDxt1 | kColourIterativeClusterFit;

    // calculate color set
    ColourSet colours(rgbaInput, 0xffff, flags);
    // if there's just one color, do single color fit
    if(colours.GetCount() == 1)
    {
        SingleColourFit fit(&colours, flags);
        fit.Compress(output);
    }
    else
    {
        ClusterFit fit(&colours, flags, NULL);
        fit.Compress(output);
    }

    // compress alpha
    CompressAlphaDxt5(rgbaInput, 0xffff, output + 8);
}

// Compress 16-byte alpha block to 8 bytes using BC4 format.
// BC4 is used in DXT5 for alpha.
extern "C" void flaw_squish_compress_bc4(u8 const* input, int inputLinePitch, u8* output)
{
    // make rgba input block
    u8 rgbaInput[64];
    for(int i = 0; i < 16; ++i)
        rgbaInput[i * 4 + 3] = input[(i / 4) * inputLinePitch + i % 4];
    // compress
    CompressAlphaDxt5(rgbaInput, 0xffff, output);
}

// Compress 32-byte RG block to 16 bytes using BC5 format.
// BC5 format is simply two BC4 blocks.
extern "C" void flaw_squish_compress_bc5(u8 const* input, int inputLinePitch, u8* output)
{
    u8 rgbaInput[64];
    // compress first block
    for(int i = 0; i < 16; ++i)
        rgbaInput[i * 4 + 3] = input[(i / 4) * inputLinePitch + (i % 4) * 2 + 0];
    CompressAlphaDxt5(rgbaInput, 0xffff, output);
    // compress second block
    for(int i = 0; i < 16; ++i)
        rgbaInput[i * 4 + 3] = input[(i / 4) * inputLinePitch + (i % 4) * 2 + 1];
    CompressAlphaDxt5(rgbaInput, 0xffff, output + 8);
}