juce/source/src/gui/graphics/effects/juce_GlowEffect.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_GlowEffect.h"
  31 #include "../../graphics/imaging/juce_ImageConvolutionKernel.h"
  32
  33
  34 //==============================================================================
  35 GlowEffect::GlowEffect()
  36   : radius (2.0f),
  37     colour (Colours::white)
  38 {
  39 }
  40
  41 GlowEffect::~GlowEffect()
  42 {
  43 }
  44
  45 void GlowEffect::setGlowProperties (const float newRadius,
  46                                     const Colour& newColour)
  47 {
  48     radius = newRadius;
  49     colour = newColour;
  50 }
  51
  52 void GlowEffect::applyEffect (Image& image, Graphics& g, float alpha)
  53 {
  54     Image temp (image.getFormat(), image.getWidth(), image.getHeight(), true);
  55
  56     ImageConvolutionKernel blurKernel (roundToInt (radius * 2.0f));
  57
  58     blurKernel.createGaussianBlur (radius);
  59     blurKernel.rescaleAllValues (radius);
  60
  61     blurKernel.applyToImage (temp, image, image.getBounds());
  62
  63     g.setColour (colour.withMultipliedAlpha (alpha));
  64     g.drawImageAt (temp, 0, 0, true);
  65
  66     g.setOpacity (alpha);
  67     g.drawImageAt (image, 0, 0, false);
  68 }
  69
  70 END_JUCE_NAMESPACE