QGIS/python/core/qgsmaptopixel.sip

/** \ingroup core
  * Perform transforms between map coordinates and device coordinates.
  *
  * This class can convert device coordinates to map coordinates and vice versa.
  */
class QgsMapToPixel
{
%TypeHeaderCode
#include <qgsmaptopixel.h>
%End

  public:

    /**
     * Constructor
     * @param mapUnitsPerPixel Map units per pixel
     * @param centerX X coordinate of map center, in geographical units
     * @param centerY Y coordinate of map center, in geographical units
     * @param widthPixels Output width, in pixels
     * @param heightPixels Output height, in pixels
     * @param rotation clockwise rotation in degrees
     * @note added in 2.8
     */
    QgsMapToPixel( double mapUnitsPerPixel, double centerX, double centerY, int widthPixels, int heightPixels, double rotation );

    /**
     * Constructor
     * @param mapUnitsPerPixel Map units per pixel
     */
    QgsMapToPixel( double mapUnitsPerPixel );

    /** Returns a new QgsMapToPixel created using a specified scale and distance unit.
     * @param scale map scale
     * @param dpi screen DPI
     * @param mapUnits map units
     * @returns matching QgsMapToPixel
     * @note added in QGIS 3.0
     */
    static QgsMapToPixel fromScale( double scale, QgsUnitTypes::DistanceUnit mapUnits, double dpi = 96 );

    /**
     * Constructor
     *
     * Use setParameters to fill
     */
    QgsMapToPixel();

    /**
     * Transform the point from map (world) coordinates to device coordinates
     * @param p Point to transform
     * @return QgsPoint in device coordinates
     */
    QgsPoint transform( const QgsPoint &p ) const;

    void transform( QgsPoint *p ) const;

    /**
     * Transform the point specified by x,y from map (world)
     * coordinates to device coordinates
     * @param x x cordinate o point to transform
     * @param y y coordinate of point to transform
     * @return QgsPoint in device coordinates
     */
    QgsPoint transform( double x, double y ) const;

    /**
     * Transform device coordinates to map coordinates. Modifies the
     * given coordinates in place. Intended as a fast way to do the
     * transform.
     */
    void transformInPlace( double &x, double &y ) const;

    // @note not available in python bindings
    // void transformInPlace( qreal &x, qreal &y ) const;

    /**
     * Transform device coordinates to map coordinates. Modifies the
     * given coordinates in place. Intended as a fast way to do the
     * transform.
     * @note not available in python bindings
     */
    // template <class T>
    // void transformInPlace( QVector<double> &x, QVector<double> &y ) const;

    QgsPoint toMapCoordinates( int x, int y ) const;

    //! Transform device coordinates to map (world) coordinates
    QgsPoint toMapCoordinatesF( double x, double y ) const;

    /**
     * Transform device coordinates to map (world) coordinates
     * @param p Point to be converted to map cooordinates
     * @return QgsPoint in map coorndiates
     */
    QgsPoint toMapCoordinates( QPoint p ) const;

    QgsPoint toMapPoint( double x, double y ) const;

    /**
     * Set map units per pixel
     * @param mapUnitsPerPixel Map units per pixel
     */
    void setMapUnitsPerPixel( double mapUnitsPerPixel );

    //! Return current map units per pixel
    double mapUnitsPerPixel() const;

    /**
     * Return current map width in pixels
     * The information is only known if setRotation was used
     * @note added in 2.8
     */
    int mapWidth() const;

    /**
     * Return current map height in pixels
     * @note added in 2.8
     */
    int mapHeight() const;

    /**
     * Set map rotation in degrees (clockwise)
     * @param degrees clockwise rotation in degrees
     * @param cx X ordinate of map center in geographical units
     * @param cy Y ordinate of map center in geographical units
     * @note added in 2.8
     */
    void setMapRotation( double degrees, double cx, double cy );

    /**
     * Return current map rotation in degrees
     * @note added in 2.8
     */
    double mapRotation() const;

    /**
     * Set parameters for use in transforming coordinates
     * @param mapUnitsPerPixel Map units per pixel
     * @param centerX X coordinate of map center, in geographical units
     * @param centerY Y coordinate of map center, in geographical units
     * @param widthPixels Output width, in pixels
     * @param heightPixels Output height, in pixels
     * @param rotation clockwise rotation in degrees
     * @note added in 2.8
     */
    void setParameters( double mapUnitsPerPixel, double centerX, double centerY, int widthPixels, int heightPixels, double rotation );

    //! String representation of the parameters used in the transform
    QString showParameters() const;

    QTransform transform() const;

    /** Returns the center x-coordinate for the transform.
     * @see yCenter()
     * @note added in QGIS 3.0
     */
    double xCenter() const;

    /** Returns the center y-coordinate for the transform.
     * @see xCenter()
     * @note added in QGIS 3.0
     */
    double yCenter() const;
};