dds_api.cpp

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/*
 * $Id: dds_api.cpp 36541 2011-05-07 20:53:49Z jesterking $
 *
 * ***** 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"