Quantum GIS API Documentation  1.7.4
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QgsColorRampShader Class Reference

A ramp shader will color a raster pixel based on a list of values ranges in a ramp. More...

#include <qgscolorrampshader.h>

Inheritance diagram for QgsColorRampShader:
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Collaboration diagram for QgsColorRampShader:
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List of all members.

Classes

struct  ColorRampItem

Public Types

enum  ColorRamp_TYPE { INTERPOLATED, DISCRETE, EXACT }

Public Member Functions

 QgsColorRampShader (double theMinimumValue=0.0, double theMaximumValue=255.0)
QList
< QgsColorRampShader::ColorRampItem
colorRampItemList () const
 Get the custom colormap.
QgsColorRampShader::ColorRamp_TYPE colorRampType ()
 Get the color ramp type.
QString colorRampTypeAsQString ()
 Get the color ramp type as a string.
int maximumColorCacheSize ()
 Get the maximum size the color cache can be.
void setColorRampItemList (const QList< QgsColorRampShader::ColorRampItem > &theList)
 Set custom colormap.
void setColorRampType (QgsColorRampShader::ColorRamp_TYPE theColorRampType)
 Set the color ramp type.
void setColorRampType (QString)
 Set the color ramp type.
void setMaximumColorCacheSize (int theSize)
 Set the maximum size the color cache can be.
bool shade (double, int *, int *, int *)
 Generates and new RGB value based on one input value.
bool shade (double, double, double, int *, int *, int *)
 Generates and new RGB value based on original RGB value.

Private Member Functions

bool discreteColor (double, int *, int *, int *)
 Gets the color for a pixel value from the classification vector mValueClassification.
bool exactColor (double, int *, int *, int *)
 Gets the color for a pixel value from the classification vector mValueClassification.
bool interpolatedColor (double, int *, int *, int *)
 Gets the color for a pixel value from the classification vector mValueClassification.

Private Attributes

int mCurrentColorRampItemIndex
 Current index from which to start searching the color table.
QList
< QgsColorRampShader::ColorRampItem
mColorRampItemList
 This vector holds the information for classification based on values.
QgsColorRampShader::ColorRamp_TYPE mColorRampType
 The color ramp type.
QMap< double, QColor > mColorCache
 Cache of values that have already been looked up.
int mMaximumColorCacheSize
 Maximum size of the color cache.

Detailed Description

A ramp shader will color a raster pixel based on a list of values ranges in a ramp.

Definition at line 32 of file qgscolorrampshader.h.


Member Enumeration Documentation

Enumerator:
INTERPOLATED 
DISCRETE 
EXACT 

Definition at line 57 of file qgscolorrampshader.h.


Constructor & Destructor Documentation

QgsColorRampShader::QgsColorRampShader ( double  theMinimumValue = 0.0,
double  theMaximumValue = 255.0 
)

Member Function Documentation

Get the custom colormap.

Definition at line 65 of file qgscolorrampshader.h.

Get the color ramp type.

Definition at line 68 of file qgscolorrampshader.h.

Get the color ramp type as a string.

Definition at line 35 of file qgscolorrampshader.cpp.

References DISCRETE, EXACT, INTERPOLATED, and mColorRampType.

bool QgsColorRampShader::discreteColor ( double  theValue,
int *  theReturnRedValue,
int *  theReturnGreenValue,
int *  theReturnBlueValue 
) [private]

Gets the color for a pixel value from the classification vector mValueClassification.

Assigns the color of the lower class for every pixel between two class breaks.

Definition at line 52 of file qgscolorrampshader.cpp.

References QgsColorRampShader::ColorRampItem::color, DOUBLE_DIFF_THRESHOLD, mColorCache, mColorRampItemList, mCurrentColorRampItemIndex, mMaximumColorCacheSize, and QgsColorRampShader::ColorRampItem::value.

Referenced by shade().

bool QgsColorRampShader::exactColor ( double  theValue,
int *  theReturnRedValue,
int *  theReturnGreenValue,
int *  theReturnBlueValue 
) [private]

Gets the color for a pixel value from the classification vector mValueClassification.

Assigns the color of the exact matching value in the color ramp item list

Definition at line 94 of file qgscolorrampshader.cpp.

References QgsColorRampShader::ColorRampItem::color, DOUBLE_DIFF_THRESHOLD, mColorCache, mColorRampItemList, mCurrentColorRampItemIndex, mMaximumColorCacheSize, and QgsColorRampShader::ColorRampItem::value.

Referenced by shade().

bool QgsColorRampShader::interpolatedColor ( double  theValue,
int *  theReturnRedValue,
int *  theReturnGreenValue,
int *  theReturnBlueValue 
) [private]

Gets the color for a pixel value from the classification vector mValueClassification.

Interpolates the color between two class breaks linearly.

Definition at line 141 of file qgscolorrampshader.cpp.

References QgsColorRampShader::ColorRampItem::color, DOUBLE_DIFF_THRESHOLD, mColorCache, mColorRampItemList, mCurrentColorRampItemIndex, mMaximumColorCacheSize, and QgsColorRampShader::ColorRampItem::value.

Referenced by shade().

Get the maximum size the color cache can be.

Definition at line 74 of file qgscolorrampshader.h.

Set the color ramp type.

Definition at line 216 of file qgscolorrampshader.cpp.

References mColorCache, and mColorRampType.

Referenced by QgsRasterLayer::paletteAsPixmap(), QgsRasterLayer::readSymbology(), and QgsRasterLayer::setDataProvider().

void QgsColorRampShader::setColorRampType ( QString  theType)

Set the color ramp type.

Definition at line 223 of file qgscolorrampshader.cpp.

References DISCRETE, EXACT, INTERPOLATED, mColorCache, and mColorRampType.

void QgsColorRampShader::setMaximumColorCacheSize ( int  theSize) [inline]

Set the maximum size the color cache can be.

Definition at line 86 of file qgscolorrampshader.h.

bool QgsColorRampShader::shade ( double  theValue,
int *  theReturnRedValue,
int *  theReturnGreenValue,
int *  theReturnBlueValue 
) [virtual]

Generates and new RGB value based on one input value.

Reimplemented from QgsRasterShaderFunction.

Definition at line 241 of file qgscolorrampshader.cpp.

References discreteColor(), EXACT, exactColor(), INTERPOLATED, interpolatedColor(), mColorCache, mColorRampItemList, mColorRampType, and mCurrentColorRampItemIndex.

Referenced by QgsRasterLayer::paletteAsPixmap().

bool QgsColorRampShader::shade ( double  theRedValue,
double  theGreenValue,
double  theBlueValue,
int *  theReturnRedValue,
int *  theReturnGreenValue,
int *  theReturnBlueValue 
) [virtual]

Generates and new RGB value based on original RGB value.

Reimplemented from QgsRasterShaderFunction.

Definition at line 278 of file qgscolorrampshader.cpp.


Member Data Documentation

QMap<double, QColor> QgsColorRampShader::mColorCache [private]

Cache of values that have already been looked up.

Definition at line 106 of file qgscolorrampshader.h.

Referenced by discreteColor(), exactColor(), interpolatedColor(), setColorRampItemList(), setColorRampType(), and shade().

This vector holds the information for classification based on values.

Each item holds a value, a label and a color. The member mDiscreteClassification holds if one color is applied for all values between two class breaks (true) or if the item values are (linearly) interpolated for values between the item values (false)

Definition at line 100 of file qgscolorrampshader.h.

Referenced by discreteColor(), exactColor(), interpolatedColor(), setColorRampItemList(), and shade().

The color ramp type.

Definition at line 103 of file qgscolorrampshader.h.

Referenced by colorRampTypeAsQString(), setColorRampType(), and shade().

Current index from which to start searching the color table.

Definition at line 96 of file qgscolorrampshader.h.

Referenced by discreteColor(), exactColor(), interpolatedColor(), QgsColorRampShader(), and shade().

Maximum size of the color cache.

The color cache could eat a ton of memory if you have 32-bit data

Definition at line 109 of file qgscolorrampshader.h.

Referenced by discreteColor(), exactColor(), interpolatedColor(), and QgsColorRampShader().


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