1 /*
   2  * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle in the LICENSE file that accompanied this code.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any
  23  * questions.
  24  */
  25 
  26 #include "splashscreen_impl.h"
  27 
  28 #include "../libpng/png.h"
  29 
  30 #include <setjmp.h>
  31 
  32 #define SIG_BYTES 8
  33 
  34 void PNGAPI
  35 my_png_read_stream(png_structp png_ptr, png_bytep data, png_size_t length)
  36 {
  37     png_uint_32 check;
  38 
  39     SplashStream * stream = (SplashStream*)png_get_io_ptr(png_ptr);
  40     check = stream->read(stream, data, length);
  41     if (check != length)
  42         png_error(png_ptr, "Read Error");
  43 }
  44 
  45 int
  46 SplashDecodePng(Splash * splash, png_rw_ptr read_func, void *io_ptr)
  47 {
  48     int stride;
  49     ImageFormat srcFormat;
  50     png_uint_32 i, rowbytes;
  51     png_bytepp row_pointers = NULL;
  52     png_bytep image_data = NULL;
  53     int success = 0;
  54     double gamma;
  55 
  56     png_structp png_ptr = NULL;
  57     png_infop info_ptr = NULL;
  58 
  59     png_uint_32 width, height;
  60     int bit_depth, color_type;
  61 
  62     ImageRect srcRect, dstRect;
  63 
  64     png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
  65     if (!png_ptr) {
  66         goto done;
  67     }
  68 
  69     info_ptr = png_create_info_struct(png_ptr);
  70     if (!info_ptr) {
  71         goto done;
  72     }
  73 
  74     if (setjmp(png_jmpbuf(png_ptr))) {
  75         goto done;
  76     }
  77 
  78     png_set_read_fn(png_ptr, io_ptr, read_func);
  79 
  80     png_set_sig_bytes(png_ptr, SIG_BYTES);      /* we already read the 8 signature bytes */
  81 
  82     png_read_info(png_ptr, info_ptr);   /* read all PNG info up to image data */
  83 
  84     png_get_IHDR(png_ptr, info_ptr, &width, &height, &bit_depth, &color_type,
  85         NULL, NULL, NULL);
  86 
  87     /* expand palette images to RGB, low-bit-depth grayscale images to 8 bits,
  88      * transparency chunks to full alpha channel; strip 16-bit-per-sample
  89      * images to 8 bits per sample; and convert grayscale to RGB[A]
  90      * this may be sub-optimal but this simplifies implementation */
  91 
  92     png_set_expand(png_ptr);
  93     png_set_tRNS_to_alpha(png_ptr);
  94     png_set_filler(png_ptr, 0xff, PNG_FILLER_AFTER);
  95     png_set_strip_16(png_ptr);
  96     png_set_gray_to_rgb(png_ptr);
  97 
  98     if (png_get_gAMA(png_ptr, info_ptr, &gamma))
  99         png_set_gamma(png_ptr, 2.2, gamma);
 100 
 101     png_read_update_info(png_ptr, info_ptr);
 102 
 103     rowbytes = png_get_rowbytes(png_ptr, info_ptr);
 104 
 105     if (!SAFE_TO_ALLOC(rowbytes, height)) {
 106         goto done;
 107     }
 108 
 109     if ((image_data = (unsigned char *) malloc(rowbytes * height)) == NULL) {
 110         goto done;
 111     }
 112 
 113     if (!SAFE_TO_ALLOC(height, sizeof(png_bytep))) {
 114         goto done;
 115     }
 116     if ((row_pointers = (png_bytepp) malloc(height * sizeof(png_bytep)))
 117             == NULL) {
 118         goto done;
 119     }
 120 
 121     for (i = 0; i < height; ++i)
 122         row_pointers[i] = image_data + i * rowbytes;
 123 
 124     png_read_image(png_ptr, row_pointers);
 125 
 126     SplashCleanup(splash);
 127 
 128     splash->width = width;
 129     splash->height = height;
 130 
 131     if (!SAFE_TO_ALLOC(splash->width, splash->imageFormat.depthBytes)) {
 132         goto done;
 133     }
 134     stride = splash->width * splash->imageFormat.depthBytes;
 135 
 136     if (!SAFE_TO_ALLOC(splash->height, stride)) {
 137         goto done;
 138     }
 139     splash->frameCount = 1;
 140     splash->frames = (SplashImage *)
 141         malloc(sizeof(SplashImage) * splash->frameCount);
 142 
 143     if (splash->frames == NULL) {
 144         goto done;
 145     }
 146 
 147     splash->loopCount = 1;
 148     splash->frames[0].bitmapBits = malloc(stride * splash->height);
 149     if (splash->frames[0].bitmapBits == NULL) {
 150         free(splash->frames);
 151         goto done;
 152     }
 153     splash->frames[0].delay = 0;
 154 
 155     /* FIXME: sort out the real format */
 156     initFormat(&srcFormat, 0xFF000000, 0x00FF0000, 0x0000FF00, 0x000000FF);
 157     srcFormat.byteOrder = BYTE_ORDER_MSBFIRST;
 158 
 159     initRect(&srcRect, 0, 0, width, height, 1, rowbytes,
 160         image_data, &srcFormat);
 161     initRect(&dstRect, 0, 0, width, height, 1, stride,
 162         splash->frames[0].bitmapBits, &splash->imageFormat);
 163     convertRect(&srcRect, &dstRect, CVT_COPY);
 164 
 165     SplashInitFrameShape(splash, 0);
 166 
 167     png_read_end(png_ptr, NULL);
 168     success = 1;
 169 
 170   done:
 171     free(row_pointers);
 172     free(image_data);
 173     png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
 174     return success;
 175 }
 176 
 177 int
 178 SplashDecodePngStream(Splash * splash, SplashStream * stream)
 179 {
 180     unsigned char sig[SIG_BYTES];
 181     int success = 0;
 182 
 183     stream->read(stream, sig, SIG_BYTES);
 184     if (png_sig_cmp(sig, 0, SIG_BYTES)) {
 185         goto done;
 186     }
 187     success = SplashDecodePng(splash, my_png_read_stream, stream);
 188 
 189   done:
 190     return success;
 191 }
--- EOF ---