dds_api.cpp

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/*
 * ***** BEGIN GPL LICENSE BLOCK *****
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 *
 * Contributors: Amorilia (amorilia@users.sourceforge.net)
 *
 * ***** END GPL LICENSE BLOCK *****
 */

#include <stddef.h>
#include <dds_api.h>
#include <Stream.h>
#include <DirectDrawSurface.h>
#include <stdio.h> // printf
#include <fstream>

extern "C" {

#include "imbuf.h"
#include "IMB_imbuf_types.h"
#include "IMB_imbuf.h"
#include "IMB_allocimbuf.h"


int imb_save_dds(struct ImBuf * ibuf, const char *name, int flags)
{
    return(0); /* todo: finish this function */

    /* check image buffer */
    if (ibuf == 0) return (0);
    if (ibuf->rect == 0) return (0);

    /* open file for writing */
    std::ofstream fildes(name);

    /* write header */
    fildes << "DDS ";
    fildes.close();

    return(1);
}

int imb_is_a_dds(unsigned char *mem) // note: use at most first 32 bytes
{
    /* heuristic check to see if mem contains a DDS file */
    /* header.fourcc == FOURCC_DDS */
    if ((mem[0] != 'D') || (mem[1] != 'D') || (mem[2] != 'S') || (mem[3] != ' ')) return(0);
    /* header.size == 124 */
    if ((mem[4] != 124) || mem[5] || mem[6] || mem[7]) return(0);
    return(1);
}

struct ImBuf *imb_load_dds(unsigned char *mem, size_t size, int flags)
{
    struct ImBuf * ibuf = 0;
    DirectDrawSurface dds(mem, size); /* reads header */
    unsigned char bits_per_pixel;
    unsigned int *rect;
    Image img;
    unsigned int numpixels = 0;
    int col;
    unsigned char *cp = (unsigned char *) &col;
    Color32 pixel;
    Color32 *pixels = 0;

    if(!imb_is_a_dds(mem))
        return (0);

    /* check if DDS is valid and supported */
    if (!dds.isValid()) {
        /* no need to print error here, just testing if it is a DDS */
        if(flags & IB_test)
            return (0);

        printf("DDS: not valid; header follows\n");
        dds.printInfo();
        return(0);
    }
    if (!dds.isSupported()) {
        printf("DDS: format not supported\n");
        return(0);
    }
    if ((dds.width() > 65535) || (dds.height() > 65535)) {
        printf("DDS: dimensions too large\n");
        return(0);
    }

    /* convert DDS into ImBuf */
    dds.mipmap(&img, 0, 0); /* load first face, first mipmap */
    pixels = img.pixels();
    numpixels = dds.width() * dds.height();
    bits_per_pixel = 24;
    if (img.format() == Image::Format_ARGB) {
        /* check that there is effectively an alpha channel */
        for (unsigned int i = 0; i < numpixels; i++) {
            pixel = pixels[i];
            if (pixel.a != 255) {
                bits_per_pixel = 32;
                break;
            };
        };
    };
    ibuf = IMB_allocImBuf(dds.width(), dds.height(), bits_per_pixel, 0); 
    if (ibuf == 0) return(0); /* memory allocation failed */

    ibuf->ftype = DDS;
    ibuf->profile = IB_PROFILE_SRGB;

    if ((flags & IB_test) == 0) {
        if (!imb_addrectImBuf(ibuf)) return(ibuf);
        if (ibuf->rect == 0) return(ibuf);

        rect = ibuf->rect;
        cp[3] = 0xff; /* default alpha if alpha channel is not present */

        for (unsigned int i = 0; i < numpixels; i++) {
            pixel = pixels[i];
            cp[0] = pixel.r; /* set R component of col */
            cp[1] = pixel.g; /* set G component of col */
            cp[2] = pixel.b; /* set B component of col */
            if (bits_per_pixel == 32)
                cp[3] = pixel.a; /* set A component of col */
            rect[i] = col;
        }
        IMB_flipy(ibuf);
    }

    return(ibuf);
}

} // extern "C"