jdk/src/share/native/sun/awt/splashscreen/splashscreen_gif.c

/*
 * Copyright 2005-2006 Sun Microsystems, Inc.  All Rights Reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Sun designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Sun in the LICENSE file that accompanied this code.
 *
 * This code 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
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
 * CA 95054 USA or visit www.sun.com if you need additional information or
 * have any questions.
 */

#include "splashscreen_impl.h"
#include "splashscreen_gfx.h"

#include "../giflib/gif_lib.h"

#define GIF_TRANSPARENT     0x01
#define GIF_USER_INPUT      0x02
#define GIF_DISPOSE_MASK    0x07
#define GIF_DISPOSE_SHIFT   2

#define GIF_NOT_TRANSPARENT -1

#define GIF_DISPOSE_NONE    0   // No disposal specified. The decoder is
                                // not required to take any action.
#define GIF_DISPOSE_LEAVE   1   // Do not dispose. The graphic is to be left
                                // in place.
#define GIF_DISPOSE_BACKGND 2   // Restore to background color. The area used by the
                                // graphic must be restored to the background color.

#define GIF_DISPOSE_RESTORE 3   // Restore to previous. The decoder is required to
                                // restore the area overwritten by the graphic with
                                // what was there prior to rendering the graphic.

static const char szNetscape20ext[11] = "NETSCAPE2.0";

#define NSEXT_LOOP      0x01    // Loop Count field code

// convert libungif samples to our ones
#define MAKE_QUAD_GIF(c,a) MAKE_QUAD((c).Red, (c).Green, (c).Blue, (a))

/* stdio FILE* and memory input functions for libungif */
int
SplashStreamGifInputFunc(GifFileType * gif, GifByteType * buf, int n)
{
    SplashStream* io = (SplashStream*)gif->UserData;
    int rc = io->read(io, buf, n);
    return rc;
}

int
SplashDecodeGif(Splash * splash, GifFileType * gif)
{
    int stride;
    int bufferSize;
    byte_t *pBitmapBits, *pOldBitmapBits;
    int i, j;
    int imageIndex;
    const int interlacedOffset[] = { 0, 4, 2, 1, 0 };   /* The way Interlaced image should. */
    const int interlacedJumps[] = { 8, 8, 4, 2, 1 };    /* be read - offsets and jumps... */

    if (DGifSlurp(gif) == GIF_ERROR) {
        return 0;
    }

    SplashCleanup(splash);

    stride = gif->SWidth * splash->imageFormat.depthBytes;
    if (splash->byteAlignment > 1)
        stride =
            (stride + splash->byteAlignment - 1) & ~(splash->byteAlignment - 1);

    bufferSize = stride * gif->SHeight;
    pBitmapBits = (byte_t *) malloc(bufferSize);
    pOldBitmapBits = (byte_t *) malloc(bufferSize);
    memset(pBitmapBits, 0, bufferSize);

    splash->width = gif->SWidth;
    splash->height = gif->SHeight;
    splash->frameCount = gif->ImageCount;
    splash->frames = (SplashImage *)
        malloc(sizeof(SplashImage) * gif->ImageCount);
    memset(splash->frames, 0, sizeof(SplashImage) * gif->ImageCount);
    splash->loopCount = 1;

    for (imageIndex = 0; imageIndex < gif->ImageCount; imageIndex++) {
        SavedImage *image = &(gif->SavedImages[imageIndex]);
        GifImageDesc *desc = &(image->ImageDesc);
        ColorMapObject *colorMap =
            desc->ColorMap ? desc->ColorMap : gif->SColorMap;

        int transparentColor = -1;
        int frameDelay = 100;
        int disposeMethod = GIF_DISPOSE_RESTORE;
        int colorCount = 0;
        rgbquad_t colorMapBuf[SPLASH_COLOR_MAP_SIZE];

        if (colorMap) {
            if (colorMap->ColorCount <= SPLASH_COLOR_MAP_SIZE) {
                colorCount = colorMap->ColorCount;
            } else  {
                colorCount = SPLASH_COLOR_MAP_SIZE;
            }
        }

        /* the code below is loosely based around gif extension processing from win32 libungif sample */

        for (i = 0; i < image->ExtensionBlockCount; i++) {
            byte_t *pExtension = (byte_t *) image->ExtensionBlocks[i].Bytes;
            unsigned size = image->ExtensionBlocks[i].ByteCount;

            switch (image->ExtensionBlocks[i].Function) {
            case GRAPHICS_EXT_FUNC_CODE:
                {
                    int flag = pExtension[0];

                    frameDelay = (pExtension[2] << 8) | pExtension[1];
                    if (frameDelay < 10)
                        frameDelay = 10;
                    if (flag & GIF_TRANSPARENT) {
                        transparentColor = pExtension[3];
                    } else {
                        transparentColor = GIF_NOT_TRANSPARENT;
                    }
                    disposeMethod =
                        (flag >> GIF_DISPOSE_SHIFT) & GIF_DISPOSE_MASK;
                    break;
                }
            case APPLICATION_EXT_FUNC_CODE:
                {
                    if (size == sizeof(szNetscape20ext)
                        && memcmp(pExtension, szNetscape20ext, size) == 0) {
                        int iSubCode;

                        if (++i >= image->ExtensionBlockCount)
                            break;
                        pExtension = (byte_t *) image->ExtensionBlocks[i].Bytes;
                        if (image->ExtensionBlocks[i].ByteCount != 3)
                            break;
                        iSubCode = pExtension[0] & 0x07;
                        if (iSubCode == NSEXT_LOOP) {
                            splash->loopCount =
                                (pExtension[1] | (pExtension[2] << 8)) - 1;
                        }
                    }
                    break;
                }
            default:
                break;
            }
        }

        if (colorMap) {
            for (i = 0; i < colorCount; i++) {
                colorMapBuf[i] = MAKE_QUAD_GIF(colorMap->Colors[i], 0xff);
            }
        }
        {

            byte_t *pSrc = image->RasterBits;
            ImageFormat srcFormat;
            ImageRect srcRect, dstRect;
            int pass, npass;

            if (desc->Interlace) {
                pass = 0;
                npass = 4;
            }
            else {
                pass = 4;
                npass = 5;
            }

            srcFormat.colorMap = colorMapBuf;
            srcFormat.depthBytes = 1;
            srcFormat.byteOrder = BYTE_ORDER_NATIVE;
            srcFormat.transparentColor = transparentColor;
            srcFormat.fixedBits = QUAD_ALPHA_MASK;      // fixed 100% alpha
            srcFormat.premultiplied = 0;

            for (; pass < npass; ++pass) {
                int jump = interlacedJumps[pass];
                int ofs = interlacedOffset[pass];
                int numLines = (desc->Height + jump - 1 - ofs) / jump;

                initRect(&srcRect, 0, 0, desc->Width, numLines, 1,
                    desc->Width, pSrc, &srcFormat);
                initRect(&dstRect, desc->Left, desc->Top + ofs, desc->Width,
                    numLines, jump, stride, pBitmapBits, &splash->imageFormat);
                pSrc += convertRect(&srcRect, &dstRect, CVT_ALPHATEST);
            }
        }

        // now dispose of the previous frame correctly

        splash->frames[imageIndex].bitmapBits =
            (rgbquad_t *) malloc(bufferSize);
        memcpy(splash->frames[imageIndex].bitmapBits, pBitmapBits, bufferSize);

        SplashInitFrameShape(splash, imageIndex);

        splash->frames[imageIndex].delay = frameDelay * 10;     // 100ths of second to milliseconds
        switch (disposeMethod) {
        case GIF_DISPOSE_LEAVE:
            memcpy(pOldBitmapBits, pBitmapBits, bufferSize);
            break;
        case GIF_DISPOSE_NONE:
            break;
        case GIF_DISPOSE_BACKGND:
            {
                ImageRect dstRect;
                rgbquad_t fillColor = 0;                        // 0 is transparent
                if (transparentColor < 0) {
                    fillColor= MAKE_QUAD_GIF(
                        colorMap->Colors[gif->SBackGroundColor], 0xff);
                }
                initRect(&dstRect, desc->Left, desc->Top,
                    desc->Width, desc->Height, 1, stride,
                    pBitmapBits, &splash->imageFormat);
                fillRect(fillColor, &dstRect);
            }
            break;
        case GIF_DISPOSE_RESTORE:
            {

                int lineSize = desc->Width * splash->imageFormat.depthBytes;

                for (j = 0; j < desc->Height; j++) {
                    int lineIndex = stride * (j + desc->Top) +
                        desc->Left * splash->imageFormat.depthBytes;

                    memcpy(pBitmapBits + lineIndex, pOldBitmapBits + lineIndex,
                        lineSize);
                }
            }
            break;
        }
    }

    free(pBitmapBits);
    free(pOldBitmapBits);

    DGifCloseFile(gif);

    return 1;
}

int
SplashDecodeGifStream(Splash * splash, SplashStream * stream)
{
    GifFileType *gif = DGifOpen((void *) stream, SplashStreamGifInputFunc);

    if (!gif)
        return 0;
    return SplashDecodeGif(splash, gif);
}