vcl/source/bitmap/BlendFrameCache.cxx

   1 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4; fill-column: 100 -*- */
   2 /*
   3  * This file is part of the LibreOffice project.
   4  *
   5  * This Source Code Form is subject to the terms of the Mozilla Public
   6  * License, v. 2.0. If a copy of the MPL was not distributed with this
   7  * file, You can obtain one at http://mozilla.org/MPL/2.0/.
   8  *
   9  * This file incorporates work covered by the following license notice:
  10  *
  11  *   Licensed to the Apache Software Foundation (ASF) under one or more
  12  *   contributor license agreements. See the NOTICE file distributed
  13  *   with this work for additional information regarding copyright
  14  *   ownership. The ASF licenses this file to you under the Apache
  15  *   License, Version 2.0 (the "License"); you may not use this file
  16  *   except in compliance with the License. You may obtain a copy of
  17  *   the License at http://www.apache.org/licenses/LICENSE-2.0 .
  18  */
  19
  20 #include <tools/color.hxx>
  21
  22 #include <vcl/BitmapColor.hxx>
  23 #include <vcl/BitmapWriteAccess.hxx>
  24
  25 #include <bitmap/BlendFrameCache.hxx>
  26
  27 BlendFrameCache::BlendFrameCache(Size const& rSize, sal_uInt8 nAlpha, Color const& rColorTopLeft,
  28                                  Color const& rColorTopRight, Color const& rColorBottomRight,
  29                                  Color const& rColorBottomLeft)
  30     : m_aLastSize(rSize)
  31     , m_nLastAlpha(nAlpha)
  32     , m_aLastColorTopLeft(rColorTopLeft)
  33     , m_aLastColorTopRight(rColorTopRight)
  34     , m_aLastColorBottomRight(rColorBottomRight)
  35     , m_aLastColorBottomLeft(rColorBottomLeft)
  36 {
  37     if (rSize.Width() <= 1 || rSize.Height() <= 1)
  38         return;
  39
  40     sal_uInt8 aEraseTrans(0xff);
  41     Bitmap aContent(rSize, vcl::PixelFormat::N24_BPP);
  42     AlphaMask aAlpha(rSize, &aEraseTrans);
  43
  44     aContent.Erase(COL_BLACK);
  45
  46     {
  47         BitmapScopedWriteAccess pContent(aContent);
  48         BitmapScopedWriteAccess pAlpha(aAlpha);
  49
  50         if (!pContent || !pAlpha)
  51             return;
  52
  53         Scanline pScanContent = pContent->GetScanline(0);
  54         Scanline pScanAlpha = pContent->GetScanline(0);
  55
  56         // x == 0, y == 0, top-left corner
  57         pContent->SetPixelOnData(pScanContent, 0, rColorTopLeft);
  58         pAlpha->SetPixelOnData(pScanAlpha, 0, BitmapColor(nAlpha));
  59
  60         tools::Long x(0);
  61         const tools::Long nW(rSize.Width());
  62
  63         // y == 0, top line left to right
  64         for (x = 1; x < nW - 1; x++)
  65         {
  66             Color aMix(rColorTopLeft);
  67
  68             aMix.Merge(rColorTopRight, 255 - sal_uInt8((x * 255) / nW));
  69             pContent->SetPixelOnData(pScanContent, x, aMix);
  70             pAlpha->SetPixelOnData(pScanAlpha, x, BitmapColor(nAlpha));
  71         }
  72
  73         // x == nW - 1, y == 0, top-right corner
  74         // #i123690# Caution! When nW is 1, x == nW is possible (!)
  75         if (x < nW)
  76         {
  77             pContent->SetPixelOnData(pScanContent, x, rColorTopRight);
  78             pAlpha->SetPixelOnData(pScanAlpha, x, BitmapColor(nAlpha));
  79         }
  80
  81         tools::Long y(0);
  82         const tools::Long nH(rSize.Height());
  83
  84         // x == 0 and nW - 1, left and right line top-down
  85         for (y = 1; y < nH - 1; y++)
  86         {
  87             pScanContent = pContent->GetScanline(y);
  88             pScanAlpha = pContent->GetScanline(y);
  89             Color aMixA(rColorTopLeft);
  90
  91             aMixA.Merge(rColorBottomLeft, 255 - sal_uInt8((y * 255) / nH));
  92             pContent->SetPixelOnData(pScanContent, 0, aMixA);
  93             pAlpha->SetPixelOnData(pScanAlpha, 0, BitmapColor(nAlpha));
  94
  95             // #i123690# Caution! When nW is 1, x == nW is possible (!)
  96             if (x < nW)
  97             {
  98                 Color aMixB(rColorTopRight);
  99
 100                 aMixB.Merge(rColorBottomRight, 255 - sal_uInt8((y * 255) / nH));
 101                 pContent->SetPixelOnData(pScanContent, x, aMixB);
 102                 pAlpha->SetPixelOnData(pScanAlpha, x, BitmapColor(nAlpha));
 103             }
 104         }
 105
 106         // #i123690# Caution! When nH is 1, y == nH is possible (!)
 107         if (y < nH)
 108         {
 109             // x == 0, y == nH - 1, bottom-left corner
 110             pContent->SetPixelOnData(pScanContent, 0, rColorBottomLeft);
 111             pAlpha->SetPixelOnData(pScanAlpha, 0, BitmapColor(nAlpha));
 112
 113             // y == nH - 1, bottom line left to right
 114             for (x = 1; x < nW - 1; x++)
 115             {
 116                 Color aMix(rColorBottomLeft);
 117
 118                 aMix.Merge(rColorBottomRight, 255 - sal_uInt8(((x - 0) * 255) / nW));
 119                 pContent->SetPixelOnData(pScanContent, x, aMix);
 120                 pAlpha->SetPixelOnData(pScanAlpha, x, BitmapColor(nAlpha));
 121             }
 122
 123             // x == nW - 1, y == nH - 1, bottom-right corner
 124             // #i123690# Caution! When nW is 1, x == nW is possible (!)
 125             if (x < nW)
 126             {
 127                 pContent->SetPixelOnData(pScanContent, x, rColorBottomRight);
 128                 pAlpha->SetPixelOnData(pScanAlpha, x, BitmapColor(nAlpha));
 129             }
 130         }
 131     }
 132
 133     m_aLastResult = BitmapEx(aContent, aAlpha);
 134 }
 135
 136 /* vim:set shiftwidth=4 softtabstop=4 expandtab cinoptions=b1,g0,N-s cinkeys+=0=break: */