1 /*
   2  * Copyright (c) 2008, 2009, 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 "utility/rect.h"
  27 
  28 #if defined(__cplusplus)
  29 extern "C" {
  30 #endif
  31 
  32 /**
  33  * bitsPerPixel must be 32 for now.
  34  * outBuf must be large enough to conatin all the rectangles.
  35  */
  36 int BitmapToYXBandedRectangles(int bitsPerPixel, int width, int height, unsigned char * buf, RECT_T * outBuf)
  37 {
  38     //XXX: we might want to reuse the code in the splashscreen library,
  39     // though we'd have to deal with the ALPHA_THRESHOLD and different
  40     // image formats in this case.
  41     int widthBytes = width * bitsPerPixel / 8;
  42     int alignedWidth = (((widthBytes - 1) / 4) + 1) * 4;
  43 
  44     RECT_T * out = outBuf;
  45 
  46     RECT_T *pPrevLine = NULL, *pFirst = out, *pThis = pFirst;
  47     int i, j, i0;
  48     int length;
  49 
  50     for (j = 0; j < height; j++) {
  51         /* generate data for a scanline */
  52 
  53         unsigned char *pSrc = (unsigned char *) buf + j * alignedWidth;
  54         RECT_T *pLine = pThis;
  55 
  56         i = 0;
  57 
  58         do {
  59             // pSrc[0,1,2] == B,G,R; pSrc[3] == Alpha
  60             while (i < width && !pSrc[3]) {
  61                 pSrc += 4;
  62                 ++i;
  63             }
  64             if (i >= width)
  65                 break;
  66             i0 = i;
  67             while (i < width && pSrc[3]) {
  68                 pSrc += 4;
  69                 ++i;
  70             }
  71             RECT_SET(*pThis, i0, j, i - i0, 1);
  72             ++pThis;
  73         } while (i < width);
  74 
  75         /*  check if the previous scanline is exactly the same, merge if so
  76             (this is the only optimization we can use for YXBanded rectangles,
  77             and win32 supports YXBanded only */
  78 
  79         length = (int)(pThis - pLine);
  80         if (pPrevLine && pLine - pPrevLine == length) {
  81             for (i = 0; i < length && RECT_EQ_X(pPrevLine[i], pLine[i]); ++i) {
  82             }
  83             if (i == pLine - pPrevLine) {
  84                 // do merge
  85                 for (i = 0; i < length; i++) {
  86                     RECT_INC_HEIGHT(pPrevLine[i]);
  87                 }
  88                 pThis = pLine;
  89                 continue;
  90             }
  91         }
  92         /* or else use the generated scanline */
  93 
  94         pPrevLine = pLine;
  95     }
  96 
  97     return (int)(pThis - pFirst);
  98 }
  99 
 100 #if defined(__cplusplus)
 101 }
 102 #endif