Deal with uncompressed data, and pass GL format value.

Ryan C. Gordon

2011-05-10 3a674323d9ead5086906742e78fadda97492407e

 mojodds.c

@@ -54,6 +54,12 @@
#define FOURCC_DXT5 0x35545844
#define FOURCC_DX10 0x30315844

#define GL_COMPRESSED_RGBA_S3TC_DXT1_EXT 0x83F1
#define GL_COMPRESSED_RGBA_S3TC_DXT3_EXT 0x83F2
#define GL_COMPRESSED_RGBA_S3TC_DXT5_EXT 0x83F3
#define GL_BGR 0x80E0
#define GL_BGRA 0x80E1

typedef struct
{
    uint32 dwSize;
@@ -101,7 +107,8 @@
    return retval;
} // readui32

static int parse_dds(MOJODDS_Header *header, const uint8 **ptr, size_t *len)
static int parse_dds(MOJODDS_Header *header, const uint8 **ptr, size_t *len,
                     unsigned int *_glfmt)
{
    const uint32 pitchAndLinear = (DDSD_PITCH | DDSD_LINEARSIZE);
    uint32 width = 0;
@@ -159,28 +166,66 @@
    else if ((header->dwFlags & pitchAndLinear) == pitchAndLinear)
        return 0;  // can't specify both.

    if ((header->ddspf.dwFlags & DDPF_FOURCC) == 0)  // !!! FIXME
        return 0;

    if (header->ddspf.dwFlags & DDPF_FOURCC)
    {
        switch (header->ddspf.dwFourCC)
        {
            case FOURCC_DXT1:
                *_glfmt = GL_COMPRESSED_RGBA_S3TC_DXT1_EXT;
                calcSize = ((width ? ((width + 3) / 4) : 1) * 8) * height;
                break;
            case FOURCC_DXT2:
            case FOURCC_DXT3:
            case FOURCC_DXT4:
            case FOURCC_DXT5:
                *_glfmt = GL_COMPRESSED_RGBA_S3TC_DXT3_EXT;
                calcSize = ((width ? ((width + 3) / 4) : 1) * 16) * height;
                break;
            case FOURCC_DXT5:
                *_glfmt = GL_COMPRESSED_RGBA_S3TC_DXT5_EXT;
                calcSize = ((width ? ((width + 3) / 4) : 1) * 16) * height;
                break;

            // !!! FIXME: DX10 is an extended header, introduced by DirectX 10.
            //case FOURCC_DX10:
            //case FOURCC_DX10: do_something(); break;

            //case FOURCC_DXT2:  // premultiplied alpha unsupported.
            //case FOURCC_DXT4:  // premultiplied alpha unsupported.
            default:
                return 0;  // unsupported data format.
        } // switch
    } // if

    // no FourCC...uncompressed data.
    else if (header->ddspf.dwFlags & DDPF_RGB)
    {
        if ( (header->ddspf.dwRBitMask != 0x00FF0000) ||
             (header->ddspf.dwGBitMask != 0x0000FF00) ||
             (header->ddspf.dwBBitMask != 0x000000FF) )
            return 0;  // !!! FIXME: deal with this.

        if (header->ddspf.dwFlags & DDPF_ALPHAPIXELS)
        {
            if ( (header->ddspf.dwRGBBitCount != 32) ||
                 (header->ddspf.dwABitMask != 0xFF000000) )
                return 0;  // unsupported.
            *_glfmt = GL_BGRA;
        } // if
        else
        {
            if (header->ddspf.dwRGBBitCount != 24)
                return 0;  // unsupported.
            *_glfmt = GL_BGR;
        } // else

        calcSizeFlag = DDSD_PITCH;
        calcSize = ((width * header->ddspf.dwRGBBitCount) + 7) / 8;
    } // else if

    //else if (header->ddspf.dwFlags & DDPF_LUMINANCE)  // !!! FIXME
    //else if (header->ddspf.dwFlags & DDPF_YUV)  // !!! FIXME
    //else if (header->ddspf.dwFlags & DDPF_ALPHA)  // !!! FIXME
    else
    {
        return 0;  // unsupported data format.
    } // else if

    // no pitch or linear size? Calculate it.
    if ((header->dwFlags & pitchAndLinear) == 0)
@@ -208,29 +253,23 @@
} // MOJODDS_isDDS

int MOJODDS_getTexture(const void *_ptr, const unsigned long _len,
                       const void **_tex, unsigned long *_texlen, int *_dxtver,
                       unsigned int *_w, unsigned int *_h)
                       const void **_tex, unsigned long *_texlen,
                       unsigned int *_glfmt, unsigned int *_w,
                       unsigned int *_h)
{
    size_t len = (size_t) _len;
    const uint8 *ptr = (const uint8 *) _ptr;
    MOJODDS_Header header;
    if (!parse_dds(&header, &ptr, &len))
    if (!parse_dds(&header, &ptr, &len, _glfmt))
        return 0;

    *_tex = (const void *) ptr;
    *_texlen = (unsigned long) header.dwPitchOrLinearSize;
    *_w = (unsigned int) header.dwWidth;
    *_h = (unsigned int) header.dwHeight;
    *_texlen = (unsigned long) header.dwPitchOrLinearSize;

    switch (header.ddspf.dwFourCC)
    {
        case FOURCC_DXT1: *_dxtver = 1; break;
        case FOURCC_DXT2: *_dxtver = 2; break;
        case FOURCC_DXT3: *_dxtver = 3; break;
        case FOURCC_DXT4: *_dxtver = 4; break;
        case FOURCC_DXT5: *_dxtver = 5; break;
        default: *_dxtver = 0; return 0;
    } // switch
    if (header.dwFlags & DDSD_PITCH)
        *_texlen *= header.dwHeight;

    return 1;
} // MOJODDS_getTexture

 mojodds.h

@@ -8,8 +8,9 @@

int MOJODDS_isDDS(const void *_ptr, const unsigned long _len);
int MOJODDS_getTexture(const void *_ptr, const unsigned long _len,
                       const void **_tex, unsigned long *_texlen, int *_dxtver,
                       unsigned int *_w, unsigned int *_h);
                       const void **_tex, unsigned long *_texlen,
                       unsigned int *_glfmt, unsigned int *_w,
                       unsigned int *_h);

#ifdef __cplusplus
}