QgsRasterImageBuffer Class Reference

A class encapsulates reading from a raster band and drawing the pixels to a painter. More...

#include <qgsrasterlayer.h>

Collaboration diagram for QgsRasterImageBuffer:

List of all members.

Public Member Functions

QgsRasterImageBuffer (GDALRasterBandH rasterBand, QPainter *p, QgsRasterViewPort *viewPort, const QgsMapToPixel *mapToPixel, double *mGeoTransform)

~QgsRasterImageBuffer ()

void reset (int maxPixelsInVirtualMemory=5000000)

bool nextScanLine (QRgb **imageScanLine, void **rasterScanLine)

Returns a pointer to the next scan line (or 0 if end).

void setWritingEnabled (bool enabled)

Private Member Functions

QgsRasterImageBuffer ()

bool createNextPartImage ()

Creates next part image.

void drawPixelRectangle ()

Peter's fix for zoomed in rasters.

Private Attributes

GDALRasterBandH mRasterBand

QPainter * mPainter

QgsRasterViewPort * mViewPort

const QgsMapToPixel * mMapToPixel

double * mGeoTransform

bool mValid

bool mWritingEnabled

True (default), if values are written to an image.

bool mDrawPixelRect

Draws the raster pixels as rectangles.

int mCurrentRow

int mNumPartImages

int mNumRasterRowsPerPart

int mCurrentPartRasterMin

int mCurrentPartRasterMax

int mCurrentPartImageRow

int mNumCurrentImageRows

QImage * mCurrentImage

void * mCurrentGDALData

Detailed Description

A class encapsulates reading from a raster band and drawing the pixels to a painter.

The class allows sequential reading of the scan lines and setting the image scan line pixels. It automatically decides on how much of the band / image should stay in virtual memory at a time

Definition at line 922 of file qgsrasterlayer.h.

Constructor & Destructor Documentation

QgsRasterImageBuffer::QgsRasterImageBuffer	(	GDALRasterBandH	rasterBand,
		QPainter *	p,
		QgsRasterViewPort *	viewPort,
		const QgsMapToPixel *	mapToPixel,
		double *	mGeoTransform
	)

Definition at line 5669 of file qgsrasterlayer.cpp.

QgsRasterImageBuffer::~QgsRasterImageBuffer ( )

Definition at line 5675 of file qgsrasterlayer.cpp.

References mCurrentGDALData, and mCurrentImage.

QgsRasterImageBuffer::QgsRasterImageBuffer ( ) [private]

Member Function Documentation

void QgsRasterImageBuffer::reset ( int maxPixelsInVirtualMemory = 5000000 )

bool QgsRasterImageBuffer::nextScanLine	(	QRgb **	imageScanLine,
		void **	rasterScanLine
	)

Returns a pointer to the next scan line (or 0 if end).

Definition at line 5711 of file qgsrasterlayer.cpp.

References createNextPartImage(), QgsRasterViewPort::drawableAreaXDim, mCurrentGDALData, mCurrentImage, mCurrentPartImageRow, mCurrentRow, mNumCurrentImageRows, mRasterBand, mValid, mViewPort, and mWritingEnabled.

Referenced by QgsRasterLayer::drawMultiBandColor(), QgsRasterLayer::drawPalettedSingleBandColor(), QgsRasterLayer::drawPalettedSingleBandGray(), QgsRasterLayer::drawPalettedSingleBandPseudoColor(), QgsRasterLayer::drawSingleBandGray(), and QgsRasterLayer::drawSingleBandPseudoColor().

void QgsRasterImageBuffer::setWritingEnabled ( bool enabled ) [inline]

Definition at line 932 of file qgsrasterlayer.h.

Referenced by QgsRasterLayer::drawMultiBandColor().

bool QgsRasterImageBuffer::createNextPartImage ( ) [private]

Creates next part image.

Returns false if at end

Definition at line 5746 of file qgsrasterlayer.cpp.

Referenced by nextScanLine(), and reset().

void QgsRasterImageBuffer::drawPixelRectangle ( ) [private]

Peter's fix for zoomed in rasters.

Definition at line 5870 of file qgsrasterlayer.cpp.

References QgsRasterViewPort::bottomRightPoint, QgsRasterViewPort::clippedHeight, QgsRasterViewPort::clippedWidth, QgsMapToPixel::mapUnitsPerPixel(), mCurrentImage, mGeoTransform, mMapToPixel, mPainter, mViewPort, QgsRasterViewPort::rectXOffset, QgsRasterViewPort::rectXOffsetFloat, QgsRasterViewPort::rectYOffset, QgsRasterViewPort::rectYOffsetFloat, QgsRasterViewPort::topLeftPoint, QgsPoint::x(), and QgsPoint::y().

Referenced by createNextPartImage().

Member Data Documentation

GDALRasterBandH QgsRasterImageBuffer::mRasterBand [private]

Definition at line 942 of file qgsrasterlayer.h.

Referenced by createNextPartImage(), nextScanLine(), and reset().

QPainter* QgsRasterImageBuffer::mPainter [private]

Definition at line 943 of file qgsrasterlayer.h.

Referenced by createNextPartImage(), drawPixelRectangle(), and reset().

QgsRasterViewPort* QgsRasterImageBuffer::mViewPort [private]

Definition at line 944 of file qgsrasterlayer.h.

Referenced by createNextPartImage(), drawPixelRectangle(), nextScanLine(), and reset().

const QgsMapToPixel* QgsRasterImageBuffer::mMapToPixel [private]

Definition at line 945 of file qgsrasterlayer.h.

Referenced by createNextPartImage(), and drawPixelRectangle().

double* QgsRasterImageBuffer::mGeoTransform [private]

Definition at line 946 of file qgsrasterlayer.h.

Referenced by createNextPartImage(), and drawPixelRectangle().

bool QgsRasterImageBuffer::mValid [private]

Definition at line 948 of file qgsrasterlayer.h.

Referenced by nextScanLine(), and reset().

bool QgsRasterImageBuffer::mWritingEnabled [private]

True (default), if values are written to an image.

If false, the class only reads the values, but does not create an image

Definition at line 950 of file qgsrasterlayer.h.

Referenced by createNextPartImage(), and nextScanLine().

bool QgsRasterImageBuffer::mDrawPixelRect [private]

Draws the raster pixels as rectangles.

This is only used if the map units per pixel is very, very small

Definition at line 952 of file qgsrasterlayer.h.

Referenced by reset().

int QgsRasterImageBuffer::mCurrentRow [private]

Definition at line 953 of file qgsrasterlayer.h.

Referenced by createNextPartImage(), and nextScanLine().

int QgsRasterImageBuffer::mNumPartImages [private]

Definition at line 954 of file qgsrasterlayer.h.

Referenced by reset().

int QgsRasterImageBuffer::mNumRasterRowsPerPart [private]

Definition at line 955 of file qgsrasterlayer.h.

Referenced by createNextPartImage(), and reset().

int QgsRasterImageBuffer::mCurrentPartRasterMin [private]

Definition at line 956 of file qgsrasterlayer.h.

Referenced by createNextPartImage(), and reset().

int QgsRasterImageBuffer::mCurrentPartRasterMax [private]

Definition at line 957 of file qgsrasterlayer.h.

Referenced by createNextPartImage(), and reset().

int QgsRasterImageBuffer::mCurrentPartImageRow [private]

Definition at line 958 of file qgsrasterlayer.h.

Referenced by createNextPartImage(), nextScanLine(), and reset().

int QgsRasterImageBuffer::mNumCurrentImageRows [private]

Definition at line 959 of file qgsrasterlayer.h.

Referenced by createNextPartImage(), nextScanLine(), and reset().

QImage* QgsRasterImageBuffer::mCurrentImage [private]

Definition at line 962 of file qgsrasterlayer.h.

Referenced by createNextPartImage(), drawPixelRectangle(), nextScanLine(), and ~QgsRasterImageBuffer().

void* QgsRasterImageBuffer::mCurrentGDALData [private]

Definition at line 963 of file qgsrasterlayer.h.

Referenced by createNextPartImage(), nextScanLine(), and ~QgsRasterImageBuffer().

The documentation for this class was generated from the following files:

src/core/raster/qgsrasterlayer.h
src/core/raster/qgsrasterlayer.cpp


Public Member Functions
	QgsRasterImageBuffer (GDALRasterBandH rasterBand, QPainter p, QgsRasterViewPort viewPort, const QgsMapToPixel mapToPixel, double mGeoTransform)
	~QgsRasterImageBuffer ()
void	reset (int maxPixelsInVirtualMemory=5000000)
bool	nextScanLine (QRgb imageScanLine, void rasterScanLine)
	Returns a pointer to the next scan line (or 0 if end).
void	setWritingEnabled (bool enabled)
Private Member Functions
	QgsRasterImageBuffer ()
bool	createNextPartImage ()
	Creates next part image.
void	drawPixelRectangle ()
	Peter's fix for zoomed in rasters.
Private Attributes
GDALRasterBandH	mRasterBand
QPainter *	mPainter
QgsRasterViewPort *	mViewPort
const QgsMapToPixel *	mMapToPixel
double *	mGeoTransform
bool	mValid
bool	mWritingEnabled
	True (default), if values are written to an image.
bool	mDrawPixelRect
	Draws the raster pixels as rectangles.
int	mCurrentRow
int	mNumPartImages
int	mNumRasterRowsPerPart
int	mCurrentPartRasterMin
int	mCurrentPartRasterMax
int	mCurrentPartImageRow
int	mNumCurrentImageRows
QImage *	mCurrentImage
void *	mCurrentGDALData