/* This file is part of the KDE libraries
Copyright (C) 1998, 1999 Christian Tibirna
(C) 1998, 1999 Daniel M. Duley
(C) 1998, 1999 Dirk A. Mueller
*/
// $Id: kimageeffect_h.html 132191 2002-01-17 21:32:13Z dfaure $
#ifndef __KIMAGE_EFFECT_H
#define __KIMAGE_EFFECT_H
class QImage;
class QSize;
class QColor;
/**
* This class includes various @ref QImage based graphical effects.
*
*Everything is
* static, so there is no need to create an instance of this class. You can
* just call the static methods. They are encapsulated here merely to provide
* a common namespace.
*/
class KImageEffect
{
public:
enum GradientType { VerticalGradient, HorizontalGradient,
DiagonalGradient, CrossDiagonalGradient,
PyramidGradient, RectangleGradient,
PipeCrossGradient, EllipticGradient };
enum RGBComponent { Red, Green, Blue, Gray, All };
enum Lighting {NorthLite, NWLite, WestLite, SWLite,
SouthLite, SELite, EastLite, NELite};
enum ModulationType { Intensity, Saturation, HueShift, Contrast };
/**
* Create a gradient from color a to color b of the specified type.
*
* @param size The desired size of the gradient.
* @param ca Color a
* @param cb Color b
* @param type The type of gradient.
* @param ncols The number of colors to use when not running on a
* truecolor display. The gradient will be dithered to this number of
* colors. Pass 0 to prevent dithering.
*/
static QImage gradient(const QSize &size, const QColor &ca,
const QColor &cb, GradientType type, int ncols=3);
/**
* Create an unbalanced gradient.
* An unbalanced gradient is a gradient where the transition from
* color a to color b is not linear, but in this case, exponential.
*
* @param size The desired size of the gradient.
* @param ca Color a
* @param cb Color b
* @param type The type of gradient.
* @param xfactor The x decay length. Use a value between -200 and 200.
* @param yfactor The y decay length.
* @param ncols The number of colors. See KPixmapEffect:gradient.
*/
static QImage unbalancedGradient(const QSize &size, const QColor &ca,
const QColor &cb, GradientType type, int xfactor = 100,
int yfactor = 100, int ncols = 3);
/**
* Blend the provided image into a background of the indicated color.
*
* @param initial_intensity this parameter takes values from -1 to 1:
* a) if positive: how much to fade the image in its
* less affected spot
* b) if negative: roughly indicates how much of the image
* remains unaffected
* @param bgnd indicates the color of the background to blend in
* @param eff lets you choose what kind of blending you like
* @param anti_dir blend in the opposite direction (makes no much sense
* with concentric blending effects)
*/
static QImage& blend(QImage &image, float initial_intensity,
const QColor &bgnd, GradientType eff,
bool anti_dir=false);
/**
* Blend an image into another one, using a gradient type
* for blending from one to another.
*
* @param image1 source1 and result of blending
* @param image2 source2 of blending
* @param gt gradient type for blending between source1 and source2
* @param xf x decay length for unbalanced gradient tpye
* @param yf y decay length for unbalanced gradient tpye
*/
static QImage& blend(QImage &image1,QImage &image2,
GradientType gt, int xf=100, int yf=100);
/**
* Blend an image into another one, using a color channel of a
* third image for the decision of blending from one to another.
*
* @param image1 Source 1 and result of blending
* @param image2 Source 2 of blending
* @param blendImage If the gray value of of pixel is 0, the result
* for this pixel is that of image1; for a gray value
* of 1, the pixel of image2 is used; for a value
* inbetween, a corresponding blending is used.
* @param channel The RBG channel to use for the blending decision.
*/
static QImage& blend(QImage &image1, QImage &image2,
QImage &blendImage, RGBComponent channel);
/**
* Blend an image into another one, using alpha in the expected way.
* @author Rik Hemsley (rikkus)
*/
static bool blend(const QImage & upper, const QImage & lower, QImage & output);
// Not yet... static bool blend(const QImage & image1, const QImage & image2, QImage & output, const QRect & destRect);
/**
* Blend an image into another one, using alpha in the expected way and
* over coordinates @p x and @p y with respect to the lower image.
* The output is a QImage which is the @p upper image already blended
* with the @p lower one, so its size will be (in general) the same than
* @p upper instead of the same size than @p lower like the method above.
* In fact, the size of @p output is like upper's one only when it can be
* painted on lower, if there has to be some clipping, output's size will
* be the clipped area and x and y will be set to the correct up-left corner
* where the clipped rectangle begins.
*/
static bool blend(int &x, int &y, const QImage & upper, const QImage & lower, QImage & output);
/**
* Blend an image into another one, using alpha in the expected way and
* over coordinates @p x and @p y with respect to the lower image.
* The output is painted in the own @p lower image. This is an optimization
* of the @ref blend method above provided by convenience.
*/
static bool blendOnLower(int x, int y, const QImage & upper, const QImage & lower);
/**
* Modifies the intensity of a pixmap's RGB channel component.
*
* @param image The QImage to process.
* @param percent Percent value. Use a negative value to dim.
* @param channel Which channel(s) should be modified
* @return The @ref image, provided for convenience.
*/
static QImage& channelIntensity(QImage &image, float percent,
RGBComponent channel);
/**
* Fade an image to a certain background color.
*
* The number of colors will not be changed.
*
* @param image The QImage to process.
* @param val The strength of the effect. 0 <= val <= 1.
* @param color The background color.
* @return Returns the @ref image(), provided for convenience.
*/
static QImage& fade(QImage &img, float val, const QColor &color);
/**
* This recolors a pixmap. The most dark color will become color a,
* the most bright one color b, and in between.
*
* @param image A QImage to process.
* @param ca Color a
* @param cb Color b
*/
static QImage& flatten(QImage &image, const QColor &ca,
const QColor &cb, int ncols=0);
/**
* Build a hash on any given @ref QImage
*
* @param image The QImage to process
* @param lite The hash faces the indicated lighting (cardinal poles).
* @param spacing How many unmodified pixels inbetween hashes.
* @return Returns the @ref image(), provided for convenience.
*/
static QImage& hash(QImage &image, Lighting lite=NorthLite,
unsigned int spacing=0);
/**
* Either brighten or dim the image by a specified percent.
* For example, .50 will modify the colors by 50%.
*
* @param image The QImage to process.
* @param percent The percent value. Use a negative value to dim.
* @return Returns The @ref image(), provided for convenience.
*/
static QImage& intensity(QImage &image, float percent);
/**
* Modulate the image with a color channel of another image.
*
* @param image The QImage to modulate and result.
* @param modImage The QImage to use for modulation.
* @param reverse Invert the meaning of image/modImage; result is image!
* @param type The modulation Type to use.
* @param factor The modulation amplitude; with 0 no effect [-200;200].
* @param channel The RBG channel of image2 to use for modulation.
* @return Returns the @ref image(), provided for convenience.
*/
static QImage& modulate(QImage &image, QImage &modImage, bool reverse,
ModulationType type, int factor, RGBComponent channel);
/**
* Convert an image to grayscale.
*
* @param image The @ref QImage to process.
* @param fast Set to @p true in order to use a faster but non-photographic
* quality algorithm. Appropriate for things such as toolbar icons.
* @return Returns the @ref image(), provided for convenience.
*/
static QImage& toGray(QImage &image, bool fast = false);
/**
* Desaturate an image evenly.
*
* @param image The QImage to process.
* @param desat A value between 0 and 1 setting the degree of desaturation
* @return Returns the @ref image(), provided for convenience.
*/
static QImage& desaturate(QImage &image, float desat = 0.3);
/**
* Modifie the contrast of an image.
*
* @param image The QImage to process.
* @param c A contrast value between -255 to 255.
* @return The @ref image(), provided for convenience.
*/
static QImage& contrast(QImage &image, int c);
/**
* Dither an image using Floyd-Steinberg dithering for low-color
* situations.
*
* @param image The QImage to process.
* @param palette The color palette to use
* @param size The size of the palette
* @return Returns the @ref image(), provided for convenience.
*/
static QImage& dither(QImage &img, const QColor *palette, int size);
/**
* Paints (copy) an image @p src over another one (@p tgt)
* at the specified point, x,y relative to tgt.
* @p return Returns true if everything was ok, or false
* if it couldn't be copied (because they're not 32-bit images).
* Note that if you specify x,y outside a reasonable range
* (outside the tgt image), then the return value is true.
*/
static bool paint(int x, int y, QImage &tgt, const QImage &src);
private:
/**
* Helper function to fast calc some altered (lighten, shaded) colors
*
*/
static unsigned int lHash(unsigned int c);
static unsigned int uHash(unsigned int c);
/**
* Helper function to find the nearest color to the RBG triplet
*/
static int nearestColor( int r, int g, int b, const QColor *pal, int size );
};
#endif
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