juce/source/src/gui/graphics/effects/juce_DropShadowEffect.cpp

   1 /*
   2   ==============================================================================
   3
   4    This file is part of the JUCE library - "Jules' Utility Class Extensions"
   5    Copyright 2004-11 by Raw Material Software Ltd.
   6
   7   ------------------------------------------------------------------------------
   8
   9    JUCE can be redistributed and/or modified under the terms of the GNU General
  10    Public License (Version 2), as published by the Free Software Foundation.
  11    A copy of the license is included in the JUCE distribution, or can be found
  12    online at www.gnu.org/licenses.
  13
  14    JUCE is distributed in the hope that it will be useful, but WITHOUT ANY
  15    WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
  16    A PARTICULAR PURPOSE.  See the GNU General Public License for more details.
  17
  18   ------------------------------------------------------------------------------
  19
  20    To release a closed-source product which uses JUCE, commercial licenses are
  21    available: visit www.rawmaterialsoftware.com/juce for more information.
  22
  23   ==============================================================================
  24 */
  25
  26 #include "../../../core/juce_StandardHeader.h"
  27
  28 BEGIN_JUCE_NAMESPACE
  29
  30 #include "juce_DropShadowEffect.h"
  31 #include "../imaging/juce_Image.h"
  32 #include "../colour/juce_PixelFormats.h"
  33
  34 #if JUCE_MSVC && JUCE_DEBUG
  35   #pragma optimize ("t", on)
  36 #endif
  37
  38 //==============================================================================
  39 DropShadowEffect::DropShadowEffect()
  40   : offsetX (0),
  41     offsetY (0),
  42     radius (4),
  43     opacity (0.6f)
  44 {
  45 }
  46
  47 DropShadowEffect::~DropShadowEffect()
  48 {
  49 }
  50
  51 void DropShadowEffect::setShadowProperties (const float newRadius,
  52                                             const float newOpacity,
  53                                             const int newShadowOffsetX,
  54                                             const int newShadowOffsetY)
  55 {
  56     radius = jmax (1.1f, newRadius);
  57     offsetX = newShadowOffsetX;
  58     offsetY = newShadowOffsetY;
  59     opacity = newOpacity;
  60 }
  61
  62 void DropShadowEffect::applyEffect (Image& image, Graphics& g, float alpha)
  63 {
  64     const int w = image.getWidth();
  65     const int h = image.getHeight();
  66
  67     Image shadowImage (Image::SingleChannel, w, h, false);
  68
  69     {
  70         const Image::BitmapData srcData (image, Image::BitmapData::readOnly);
  71         const Image::BitmapData destData (shadowImage, Image::BitmapData::readWrite);
  72
  73         const int filter = roundToInt (63.0f / radius);
  74         const int radiusMinus1 = roundToInt ((radius - 1.0f) * 63.0f);
  75
  76         for (int x = w; --x >= 0;)
  77         {
  78             int shadowAlpha = 0;
  79
  80             const PixelARGB* src = ((const PixelARGB*) srcData.data) + x;
  81             uint8* shadowPix = destData.data + x;
  82
  83             for (int y = h; --y >= 0;)
  84             {
  85                 shadowAlpha = ((shadowAlpha * radiusMinus1 + (src->getAlpha() << 6)) * filter) >> 12;
  86
  87                 *shadowPix = (uint8) shadowAlpha;
  88                 src = addBytesToPointer (src, srcData.lineStride);
  89                 shadowPix += destData.lineStride;
  90             }
  91         }
  92
  93         for (int y = h; --y >= 0;)
  94         {
  95             int shadowAlpha = 0;
  96             uint8* shadowPix = destData.getLinePointer (y);
  97
  98             for (int x = w; --x >= 0;)
  99             {
 100                 shadowAlpha = ((shadowAlpha * radiusMinus1 + (*shadowPix << 6)) * filter) >> 12;
 101                 *shadowPix++ = (uint8) shadowAlpha;
 102             }
 103         }
 104     }
 105
 106     g.setColour (Colours::black.withAlpha (opacity * alpha));
 107     g.drawImageAt (shadowImage, offsetX, offsetY, true);
 108
 109     g.setOpacity (alpha);
 110     g.drawImageAt (image, 0, 0);
 111 }
 112
 113 #if JUCE_MSVC && JUCE_DEBUG
 114   #pragma optimize ("", on)  // resets optimisations to the project defaults
 115 #endif
 116
 117 END_JUCE_NAMESPACE