Base class for implementing custom chart types in OpenCPN plugins. More...

#include <ocpn_plugin.h>

Inheritance diagram for PlugInChartBase:

Public Member Functions
virtual wxString	GetFileSearchMask (void)
	Returns file pattern(s) for chart files this plugin can handle.

virtual int	Init (const wxString &full_path, int init_flags)
	Initializes a chart instance from a file.

virtual void	SetColorScheme (int cs, bool bApplyImmediate)
	Sets the color scheme for chart display.

virtual double	GetNormalScaleMin (double canvas_scale_factor, bool b_allow_overzoom)
	Returns the minimum recommended scale for this chart.

virtual double	GetNormalScaleMax (double canvas_scale_factor, int canvas_width)
	Returns the maximum recommended scale for this chart.

virtual double	GetNearestPreferredScalePPM (double target_scale_ppm)
	Returns the nearest preferred scale value for this chart.

virtual bool	GetChartExtent (ExtentPI *pext)
	Gets the geographic boundaries of the chart.

virtual wxBitmap &	RenderRegionView (const PlugIn_ViewPort &VPoint, const wxRegion &Region)
	Renders a region of the chart for display.

virtual bool	AdjustVP (PlugIn_ViewPort &vp_last, PlugIn_ViewPort &vp_proposed)
	Adjusts viewport parameters for chart-specific requirements.

virtual void	GetValidCanvasRegion (const PlugIn_ViewPort &VPoint, wxRegion *pValidRegion)
	Determines the valid display area for this chart.

virtual int	GetCOVREntries ()
	Returns the number of coverage table entries for this chart.

virtual int	GetCOVRTablePoints (int iTable)
	Returns the number of points in a specific coverage table entry.

virtual int	GetCOVRTablenPoints (int iTable)
	Alternative method to get the number of points in a coverage table entry.

virtual float *	GetCOVRTableHead (int iTable)
	Returns a pointer to the coverage table data for a specific entry.

virtual wxBitmap *	GetThumbnail (int tnx, int tny, int cs)
	Generates a thumbnail image of the chart.

virtual wxString	GetFullPath () const
	Returns the full file path of the chart.

virtual ChartTypeEnumPI	GetChartType ()
	Returns the chart type identifier.

virtual ChartFamilyEnumPI	GetChartFamily ()
	Returns the chart family classification.

virtual OcpnProjTypePI	GetChartProjection ()
	Returns the projection type used by the chart.

virtual wxString	GetName ()
	Returns the chart's name or title.

virtual wxString	GetDescription ()
	Returns a descriptive text about the chart.

virtual wxString	GetID ()
	Returns a unique identifier for the chart.

virtual wxString	GetSE ()
	Returns the chart's source edition identifier.

virtual wxString	GetDepthUnits ()
	Returns the depth units used in the chart.

virtual wxString	GetSoundingsDatum ()
	Returns the vertical datum used for soundings in the chart.

virtual wxString	GetDatumString ()
	Returns the horizontal geodetic datum of the chart.

virtual wxString	GetExtraInfo ()
	Returns additional information about the chart.

virtual wxString	GetPubDate ()
	Returns the publication date/year of the chart.

virtual double	GetChartErrorFactor ()
	Returns the error factor for the chart.

virtual ChartDepthUnitTypePI	GetDepthUnitId ()
	Returns the depth unit type identifier.

virtual bool	IsReadyToRender ()
	Indicates whether the chart is ready for rendering.

virtual int	GetNativeScale ()
	Returns the native scale of the chart.

virtual double	GetChartSkew ()
	Returns the skew/rotation angle of the chart.

virtual wxDateTime	GetEditionDate (void)
	Returns the edition date of the chart.

virtual void	ComputeSourceRectangle (const PlugIn_ViewPort &vp, wxRect *pSourceRect)
	Computes the source rectangle for the chart based on a given viewport.

virtual double	GetRasterScaleFactor ()
	Returns the scale factor for raster chart rendering.

virtual bool	GetChartBits (wxRect &source, unsigned char *pPix, int sub_samp)
	Gets pixel data for a portion of a raster chart.

virtual int	GetSize_X ()
	Gets the width of the chart in pixels.

virtual int	GetSize_Y ()
	Gets the height of the chart in pixels.

virtual void	latlong_to_chartpix (double lat, double lon, double &pixx, double &pixy)
	Converts geographic coordinates to chart pixel coordinates.

virtual void	chartpix_to_latlong (double pixx, double pixy, double plat, double plon)
	Converts chart pixel coordinates to geographic coordinates.

Protected Attributes
ChartTypeEnumPI	m_ChartType

ChartFamilyEnumPI	m_ChartFamily

wxString	m_FullPath

OcpnProjTypePI	m_projection

int	m_Chart_Scale

double	m_Chart_Skew

wxDateTime	m_EdDate

bool	m_bReadyToRender

wxString	m_Name

wxString	m_Description

wxString	m_ID

wxString	m_SE

wxString	m_SoundingsDatum

wxString	m_datum_str

wxString	m_PubYear

wxString	m_DepthUnits

wxString	m_ExtraInfo

ChartDepthUnitTypePI	m_depth_unit_id

double	m_Chart_Error_Factor

Detailed Description

Base class for implementing custom chart types in OpenCPN plugins.

The PlugInChartBase class provides the interface between custom chart types implemented by plugins and OpenCPN's chart display and management system. Plugin developers can create derived classes to support custom chart formats, enabling the display of proprietary or specialized charts within OpenCPN.

When implementing a chart plugin, you need to:

Create a class derived from PlugInChartBase
Implement all required virtual methods
Set the INSTALLS_PLUGIN_CHART capability flag in your plugin

Examples: /home/runner/work/main/main/opencpn/include/ocpn_plugin.h.

Definition at line 445 of file ocpn_plugin.h.

Constructor & Destructor Documentation

◆ PlugInChartBase()

PlugInChartBase::PlugInChartBase ( )

Definition at line 3438 of file pluginmanager.cpp.

◆ ~PlugInChartBase()

PlugInChartBase::~PlugInChartBase ( )

virtual

Definition at line 3440 of file pluginmanager.cpp.

Member Function Documentation

◆ AdjustVP()

bool PlugInChartBase::AdjustVP	(	PlugIn_ViewPort &	vp_last,
		PlugIn_ViewPort &	vp_proposed
	)

virtual

Adjusts viewport parameters for chart-specific requirements.

This method allows charts to modify proposed viewport changes before they are applied. It can be used to enforce chart-specific constraints or optimize display for particular chart types.

Parameters

vp_last	Previous viewport parameters
vp_proposed	Proposed new viewport parameters (may be modified)

Returns: True if the viewport was modified, False if no changes were made

Note: Commonly used to handle special projections or boundary constraints; This is called during user navigation (pan/zoom) operations

Definition at line 3465 of file pluginmanager.cpp.

◆ chartpix_to_latlong()

void PlugInChartBase::chartpix_to_latlong	(	double	pixx,
		double	pixy,
		double *	plat,
		double *	plon
	)

virtual

Converts chart pixel coordinates to geographic coordinates.

This method transforms a position in the chart's native pixel coordinate system into latitude and longitude.

Parameters

pixx	X pixel coordinate
pixy	Y pixel coordinate
plat	Will receive latitude in decimal degrees
plon	Will receive longitude in decimal degrees

Note: For raster charts, origin (0,0) is typically top-left; Transforms depend on chart projection and calibration

Definition at line 3500 of file pluginmanager.cpp.

◆ ComputeSourceRectangle()

void PlugInChartBase::ComputeSourceRectangle	(	const PlugIn_ViewPort &	vp,
		wxRect *	pSourceRect
	)

virtual

Computes the source rectangle for the chart based on a given viewport.

This method calculates the rectangle within the chart's source image that corresponds to the visible area in the given viewport. It is used primarily by raster chart plugins to determine which portion of the chart needs to be rendered for the current view.

Parameters

vp	The viewport parameters defining the current view
pSourceRect	Pointer to a wxRect that will be filled with the calculated source rectangle

Note: This method is essential for efficient rendering of raster charts, allowing the plugin to extract only the needed portion of potentially very large charts.; Coordinates in the resulting rectangle are in the chart's native pixel space.

Definition at line 3483 of file pluginmanager.cpp.

◆ GetChartBits()

bool PlugInChartBase::GetChartBits	(	wxRect &	source,
		unsigned char *	pPix,
		int	sub_samp
	)

virtual

Gets pixel data for a portion of a raster chart.

This method retrieves bitmap data from the source chart image for a specified rectangular region. The data can be subsampled to support efficient chart display at different zoom levels.

Parameters

source	Rectangle defining the region to extract in chart native coordinates
pPix	Pointer to a pre-allocated buffer to receive the pixel data
sub_samp	Subsampling factor: 1 = every pixel 2 = every second pixel 4 = every fourth pixel, etc

Returns: True if data was successfully retrieved, False if error

Note: The pPix buffer must be large enough to hold the subsampled data; Used primarily by raster chart (CHART_FAMILY_RASTER) plugins; Buffer format depends on the chart's native pixel format

Definition at line 3488 of file pluginmanager.cpp.

◆ GetChartErrorFactor()

virtual double PlugInChartBase::GetChartErrorFactor ( )

inlinevirtual

Returns the error factor for the chart.

This method provides a scaling factor that represents the estimated positional error in the chart. It can be used to calculate accuracy at different scales.

Returns: Double value representing the chart error factor

Note: Higher values indicate greater potential position error; Used for display of position accuracy indicators; Typically based on source data quality and survey methods

Definition at line 965 of file ocpn_plugin.h.

◆ GetChartExtent()

bool PlugInChartBase::GetChartExtent ( ExtentPI * pext )

virtual

Gets the geographic boundaries of the chart.

This method provides the latitude and longitude limits of the chart, which OpenCPN uses to determine chart coverage, selection, and quilting. The extent should encompass all valid data in the chart.

Parameters

pext	Pointer to an ExtentPI structure to be filled with boundary values: NLAT: Northern latitude bound (max latitude) SLAT: Southern latitude bound (min latitude) ELON: Eastern longitude bound (max longitude) WLON: Western longitude bound (min longitude)

Returns: True if successful, False if the extent cannot be determined

Note: All longitudes should be normalized to -180 to +180 range

Definition at line 3458 of file pluginmanager.cpp.

◆ GetChartFamily()

virtual ChartFamilyEnumPI PlugInChartBase::GetChartFamily ( )

inlinevirtual

Returns the chart family classification.

This method identifies the broader family category of the chart, grouping similar chart types. OpenCPN uses this for feature availability and rendering decisions.

Returns

ChartFamilyEnumPI value indicating the chart family:

CHART_FAMILY_UNKNOWN: Chart family not determined
CHART_FAMILY_RASTER: Raster chart type (e.g., KAP, GEO)
CHART_FAMILY_VECTOR: Vector chart type (e.g., S-57, CM93)
CHART_FAMILY_DONTCARE: Chart family not relevant

Definition at line 805 of file ocpn_plugin.h.

◆ GetChartProjection()

virtual OcpnProjTypePI PlugInChartBase::GetChartProjection ( )

inlinevirtual

Returns the projection type used by the chart.

This method identifies the cartographic projection used in the chart. Different projections have different characteristics for representing the curved Earth on a flat surface.

Returns

OcpnProjTypePI value indicating the projection:

PI_PROJECTION_UNKNOWN: Projection not determined
PI_PROJECTION_MERCATOR: Mercator projection
PI_PROJECTION_TRANSVERSE_MERCATOR: Transverse Mercator projection
PI_PROJECTION_POLYCONIC: Polyconic projection
PI_PROJECTION_ORTHOGRAPHIC: Orthographic projection
PI_PROJECTION_POLAR: Polar projection
PI_PROJECTION_STEREOGRAPHIC: Stereographic projection
PI_PROJECTION_GNOMONIC: Gnomonic projection
PI_PROJECTION_EQUIRECTANGULAR: Equirectangular/Plate Carrée projection

Definition at line 825 of file ocpn_plugin.h.

◆ GetChartSkew()

virtual double PlugInChartBase::GetChartSkew ( )

inlinevirtual

Returns the skew/rotation angle of the chart.

This method provides the rotation angle of the chart with respect to true north. It's used for proper alignment of the chart in the display.

Returns: Double value representing the chart skew in degrees

Note: Positive values indicate clockwise rotation; Zero indicates the chart is aligned with true north; Affects all coordinate transformations and display orientation

Definition at line 1022 of file ocpn_plugin.h.

◆ GetChartType()

virtual ChartTypeEnumPI PlugInChartBase::GetChartType ( )

inlinevirtual

Returns the chart type identifier.

This method identifies the general category of the chart, such as raster, vector, or other specialized types. OpenCPN uses this for chart management, display settings, and feature availability.

Returns

ChartTypeEnumPI value indicating the chart type:

CHART_TYPE_UNKNOWN: Chart type not determined
CHART_TYPE_DUMMY: Placeholder chart
CHART_TYPE_DONTCARE: Chart type not relevant
CHART_TYPE_KAP: BSB/KAP raster chart
CHART_TYPE_GEO: GEO raster chart
CHART_TYPE_S57: S-57 vector chart
CHART_TYPE_CM93: CM93 vector chart
CHART_TYPE_CM93COMP: CM93 composite vector chart
CHART_TYPE_PLUGIN: Plugin-defined chart type

Note: Plugin charts typically return CHART_TYPE_PLUGIN; This value affects how OpenCPN treats the chart in various operations

Definition at line 791 of file ocpn_plugin.h.

◆ GetCOVREntries()

virtual int PlugInChartBase::GetCOVREntries ( )

inlinevirtual

Returns the number of coverage table entries for this chart.

This method reports how many distinct coverage regions the chart contains. Charts may have multiple valid regions within the lat/lon box described by the chart extent. For example:

Raster charts (BSB/KAP) typically have only one coverage area
Vector charts (ENC/S-57) often have multiple coverage areas

Returns: Number of coverage table entries (0 if chart has no coverage data)

Note: For simple charts with rectangular coverage, this typically returns 1; For more complex charts with irregular boundaries, this may return multiple entries; Charts with no explicit coverage information should return 0

See also: GetCOVRTablePoints, GetCOVRTableHead

Definition at line 675 of file ocpn_plugin.h.

◆ GetCOVRTableHead()

virtual float * PlugInChartBase::GetCOVRTableHead ( int iTable )

inlinevirtual

Returns a pointer to the coverage table data for a specific entry.

This method provides access to the actual coordinate data defining the boundary polygon of a coverage area. The data is stored as an array of float values, organized as lat/lon pairs.

Parameters

iTable Index of the coverage table entry (0 to GetCOVREntries()-1)

Returns: Pointer to an array of float values containing lat/lon points: [lat0, lon0, lat1, lon1, ..., latN, lonN] Returns NULL if the index is invalid or no coverage data exists

Note: The data is arranged as consecutive (latitude, longitude) pairs; The total number of floats in the array is 2 * GetCOVRTablePoints(iTable); The coordinate system uses decimal degrees; The boundary polygon is implicitly closed (last point connects to first)

See also: GetCOVREntries, GetCOVRTablePoints

Definition at line 726 of file ocpn_plugin.h.

◆ GetCOVRTablenPoints()

virtual int PlugInChartBase::GetCOVRTablenPoints ( int iTable )

inlinevirtual

Alternative method to get the number of points in a coverage table entry.

This method is functionally identical to GetCOVRTablePoints() and exists for historical compatibility reasons.

Parameters

iTable Index of the coverage table entry (0 to GetCOVREntries()-1)

Returns: Number of points in the specified coverage table entry

Note: Implementations should typically delegate to GetCOVRTablePoints(); This method exists for backward compatibility

See also: GetCOVRTablePoints

Definition at line 705 of file ocpn_plugin.h.

◆ GetCOVRTablePoints()

virtual int PlugInChartBase::GetCOVRTablePoints ( int iTable )

inlinevirtual

Returns the number of points in a specific coverage table entry.

This method reports how many coordinate pairs (lat/lon points) define the boundary polygon of a particular coverage area.

Parameters

iTable Index of the coverage table entry (0 to GetCOVREntries()-1)

Returns: Number of points in the specified coverage table entry

Note: Each point in the coverage table consists of a lat/lon pair (2 floats); The points define a closed polygon boundary; Returns 0 if the index is out of range or no coverage data exists

See also: GetCOVREntries, GetCOVRTableHead

Definition at line 691 of file ocpn_plugin.h.

◆ GetDatumString()

virtual wxString PlugInChartBase::GetDatumString ( )

inlinevirtual

Returns the horizontal geodetic datum of the chart.

This method identifies the reference coordinate system used for horizontal positioning in the chart, which affects coordinate transformations.

Returns

wxString containing the datum identifier, such as:

"WGS84" (World Geodetic System 1984)
"NAD83" (North American Datum 1983)
"OSGB36" (Ordnance Survey Great Britain 1936)

Note: This affects coordinate conversions and positioning accuracy; Most modern charts use WGS84; OpenCPN applies datum shifts if necessary

Definition at line 924 of file ocpn_plugin.h.

◆ GetDepthUnitId()

virtual ChartDepthUnitTypePI PlugInChartBase::GetDepthUnitId ( )

inlinevirtual

Returns the depth unit type identifier.

This method provides an enumerated identifier for the depth units used in the chart, which can be used for programmatic unit conversions.

Returns

ChartDepthUnitTypePI enumeration value:

PI_DEPTH_UNIT_UNKNOWN: Unknown depth units
PI_DEPTH_UNIT_FEET: Depths in feet
PI_DEPTH_UNIT_METERS: Depths in meters
PI_DEPTH_UNIT_FATHOMS: Depths in fathoms

Note: This complements GetDepthUnits() by providing an enumerated value; Used for internal unit conversion and display settings

Definition at line 981 of file ocpn_plugin.h.

◆ GetDepthUnits()

virtual wxString PlugInChartBase::GetDepthUnits ( )

inlinevirtual

Returns the depth units used in the chart.

This method identifies the units used for depth measurements in the chart, which is important for display and conversion purposes.

Returns

wxString containing the depth units, typically:

"Meters" for metric charts
"Fathoms" for imperial/traditional charts
"Feet" for some inland or special purpose charts

Note: This affects how depth values are interpreted and displayed; OpenCPN can convert between units as needed; Should be properly capitalized for display purposes

Definition at line 891 of file ocpn_plugin.h.

◆ GetDescription()

virtual wxString PlugInChartBase::GetDescription ( )

inlinevirtual

Returns a descriptive text about the chart.

This method provides additional descriptive information about the chart, which OpenCPN displays in chart information panels and tooltips.

Returns: wxString containing the chart description

Note: Can include information like area coverage, source, etc.

Definition at line 849 of file ocpn_plugin.h.

◆ GetEditionDate()

virtual wxDateTime PlugInChartBase::GetEditionDate ( void )

inlinevirtual

Returns the edition date of the chart.

This method provides the date of the current edition or update of the chart, which can be used to identify the most recent version.

Returns: wxDateTime object containing the edition date

Note: Different from publication date and file modification date; Used for chart update management and information display; Should reflect the date of the latest corrections included

Definition at line 1035 of file ocpn_plugin.h.

◆ GetExtraInfo()

virtual wxString PlugInChartBase::GetExtraInfo ( )

inlinevirtual

Returns additional information about the chart.

This method provides any extra information about the chart that doesn't fit into the other specific accessor methods. OpenCPN displays this in chart information panels.

Returns: wxString containing extra chart information

Note: Can include any supplementary details about the chart; Often includes copyright, disclaimer, or usage information; Can include information about updates or modifications

Definition at line 938 of file ocpn_plugin.h.

◆ GetFileSearchMask()

wxString PlugInChartBase::GetFileSearchMask ( void )

virtual

Returns file pattern(s) for chart files this plugin can handle.

This method is called by OpenCPN during chart directory scanning to identify which files should be examined by this chart type. The returned pattern is used with wxDir::GetAllFiles() to locate potential chart files.

Returns: wxString containing file pattern wildcards (e.g., "*.os63" or "*.abc;*.xyz")

Note: For plugins supporting multiple file extensions, separate them with semicolons without spaces between patterns (e.g., "*.000;*.S57").; On non-Windows platforms, OpenCPN automatically checks for both uppercase and lowercase variants of the pattern.; The search performance directly impacts chart loading times, so specific file extensions are preferred over complex patterns.; For plugins that don't use file-based charts, return an empty string.

See also: ChartDatabase::SearchDirAndAddCharts() for usage details

Definition at line 3442 of file pluginmanager.cpp.

◆ GetFullPath()

virtual wxString PlugInChartBase::GetFullPath ( ) const

inlinevirtual

Returns the full file path of the chart.

This method provides access to the complete file path of the chart as it was loaded. OpenCPN uses this for chart identification, database management, and subsequent loading operations.

Returns: wxString containing the full path to the chart file

Note: This should return the same path passed to Init(); For non-file-based charts, return a unique identifier string; The path should use platform-appropriate path separators

Definition at line 768 of file ocpn_plugin.h.

◆ GetID()

virtual wxString PlugInChartBase::GetID ( )

inlinevirtual

Returns a unique identifier for the chart.

This method provides a unique string identifier for the chart that can be used for database references and identification.

Returns: wxString containing the chart ID

Note: This should be a unique identifier across all charts; For standard chart types, use the official chart number/ID

Definition at line 861 of file ocpn_plugin.h.

◆ GetName()

virtual wxString PlugInChartBase::GetName ( )

inlinevirtual

Returns the chart's name or title.

This method provides the human-readable name of the chart as displayed in chart information panels, selection dialogs, and tooltips.

Returns: wxString containing the chart name/title

Note: This should be a concise, descriptive name; For standardized charts, use the official chart name; The name should not normally include the file extension

Definition at line 838 of file ocpn_plugin.h.

◆ GetNativeScale()

virtual int PlugInChartBase::GetNativeScale ( )

inlinevirtual

Returns the native scale of the chart.

This method provides the natural or intended display scale of the chart, typically expressed as the scale denominator (e.g., 50000 for 1:50,000).

Returns: Integer value representing the chart's native scale

Note: This is the scale at which the chart was designed to be viewed; Used for scale-based chart selection and display indicators; Lower values (larger fractions) represent more detailed charts

Definition at line 1009 of file ocpn_plugin.h.

◆ GetNearestPreferredScalePPM()

double PlugInChartBase::GetNearestPreferredScalePPM ( double target_scale_ppm )

virtual

Returns the nearest preferred scale value for this chart.

This method allows charts to define preferred or standard scale points that OpenCPN should snap to when zooming. If your chart type doesn't have specific preferred scales, simply return the input value.

Parameters

target_scale_ppm Target scale in pixels per meter

Returns: Nearest preferred scale value in pixels per meter

Note: For many charts, returning target_scale_ppm is appropriate; Some chart types (like S-57) have standard display scales defined; PPM (pixels per meter) = 2540 / (chart_scale * inches_per_meter)

Definition at line 3475 of file pluginmanager.cpp.

◆ GetNormalScaleMax()

double PlugInChartBase::GetNormalScaleMax	(	double	canvas_scale_factor,
		int	canvas_width
	)

virtual

Returns the maximum recommended scale for this chart.

This method defines how far a user can zoom out before the chart is considered "under-zoomed" or too small to be useful. The value is expressed as a multiple of the chart's native scale. OpenCPN uses this for chart selection in quilt mode.

Parameters

canvas_scale_factor	Current display scale factor
canvas_width	Width of the display canvas in pixels

Returns: Maximum recommended scale value (usually a multiple of native scale)

Note: Larger values allow viewing the chart from further out; Many charts use 2x to 4x native scale as the maximum; Consider legibility of text and symbols when choosing this value

Definition at line 3453 of file pluginmanager.cpp.

◆ GetNormalScaleMin()

double PlugInChartBase::GetNormalScaleMin	(	double	canvas_scale_factor,
		bool	b_allow_overzoom
	)

virtual

Returns the minimum recommended scale for this chart.

This method defines how far a user can zoom in before the chart is considered "over-zoomed". The value is expressed as a fraction of the chart's native scale. OpenCPN uses this to determine when to display over-zoom indicators and to manage chart selection in quilt mode.

Parameters

canvas_scale_factor	Current display scale factor
b_allow_overzoom	Whether the user has enabled chart over-zoom in settings

Returns: Minimum recommended scale value (usually a fraction of native scale)

Note: Smaller values allow deeper zoom (e.g., 0.125 allows zooming to 8x native scale); Consider visual quality, data density, and accuracy when choosing this value; Many charts use 1/4 or 1/8 of native scale as the minimum

Definition at line 3448 of file pluginmanager.cpp.

◆ GetPubDate()

virtual wxString PlugInChartBase::GetPubDate ( )

inlinevirtual

Returns the publication date/year of the chart.

This method provides the original publication date of the chart, which can be different from the edition date or file modification date.

Returns: wxString containing the publication date/year

Note: Format varies depending on chart type and source; Often just contains the year of publication; Used for chart information display, not for update checking

Definition at line 951 of file ocpn_plugin.h.

◆ GetRasterScaleFactor()

double PlugInChartBase::GetRasterScaleFactor ( )

virtual

Returns the scale factor for raster chart rendering.

This method provides the scale factor needed to convert between the chart's native pixel resolution and the display resolution. It is used by OpenCPN to properly scale raster chart images during rendering.

Returns

Scale factor as a double value:

Values > 1.0 indicate chart needs to be scaled up
Values < 1.0 indicate chart needs to be scaled down
Value of 1.0 indicates no scaling needed

Note: Used primarily by raster chart (CHART_FAMILY_RASTER) plugins

Definition at line 3486 of file pluginmanager.cpp.

◆ GetSE()

virtual wxString PlugInChartBase::GetSE ( )

inlinevirtual

Returns the chart's source edition identifier.

This method provides information about the source edition of the chart, which can be used to identify its origin and version.

Returns: wxString containing the source edition identifier

Note: For official charts, this should contain the edition or update information; Format varies depending on chart type and source; For derived charts, this can indicate the source data

Definition at line 875 of file ocpn_plugin.h.

◆ GetSize_X()

int PlugInChartBase::GetSize_X ( )

virtual

Gets the width of the chart in pixels.

This method returns the full width of the source chart image in pixels. This is used for coordinate transforms and display calculations.

Returns: Width of chart in pixels

Note: For raster charts, this is the actual image pixel width; For vector charts, this may be a nominal value

Definition at line 3493 of file pluginmanager.cpp.

◆ GetSize_Y()

int PlugInChartBase::GetSize_Y ( )

virtual

Gets the height of the chart in pixels.

This method returns the full height of the source chart image in pixels. This is used for coordinate transforms and display calculations.

Returns: Height of chart in pixels

Note: For raster charts, this is the actual image pixel height; For vector charts, this may be a nominal value

Definition at line 3495 of file pluginmanager.cpp.

◆ GetSoundingsDatum()

virtual wxString PlugInChartBase::GetSoundingsDatum ( )

inlinevirtual

Returns the vertical datum used for soundings in the chart.

This method identifies the reference level used for depth measurements in the chart, which is important for navigational safety.

Returns

wxString containing the sounding datum identifier, such as:

"MLLW" (Mean Lower Low Water)
"MLW" (Mean Low Water)
"LAT" (Lowest Astronomical Tide)
"MSL" (Mean Sea Level)

Note: This affects how depth values relate to actual water depth; Different regions use different standard datums; Critical for tide calculations and safe navigation

Definition at line 908 of file ocpn_plugin.h.

◆ GetThumbnail()

wxBitmap * PlugInChartBase::GetThumbnail	(	int	tnx,
		int	tny,
		int	cs
	)

virtual

Generates a thumbnail image of the chart.

This method creates a small preview image for the chart manager and chart selection interfaces. It should produce a representative, simplified view of the chart that helps users identify it.

Parameters

tnx	Desired thumbnail width in pixels
tny	Desired thumbnail height in pixels
cs	Color scheme to use for rendering: PI_GLOBAL_COLOR_SCHEME_RGB (0): RGB color scheme PI_GLOBAL_COLOR_SCHEME_DAY (1): Day color scheme PI_GLOBAL_COLOR_SCHEME_DUSK (2): Dusk/twilight color scheme PI_GLOBAL_COLOR_SCHEME_NIGHT (3): Night/dark color scheme

Returns: Pointer to a newly created bitmap containing the thumbnail (caller is responsible for deleting it)

Note: The thumbnail should be a reduced-detail representation of the chart; For best results, maintain the aspect ratio of the chart's geographic extent; If unable to generate a thumbnail, return NULL

Definition at line 3479 of file pluginmanager.cpp.

◆ GetValidCanvasRegion()

void PlugInChartBase::GetValidCanvasRegion	(	const PlugIn_ViewPort &	VPoint,
		wxRegion *	pValidRegion
	)

virtual

Determines the valid display area for this chart.

This method defines the region of the viewport where the chart has valid data. OpenCPN uses this information for chart quilting to determine where this chart should be displayed versus other charts.

Parameters

VPoint	Current viewport parameters
pValidRegion	Pointer to wxRegion to be filled with the valid area

Note: For charts with irregular boundaries, this should reflect the actual coverage; For rectangular charts, this is typically the entire viewport; The region should be specified in screen pixel coordinates

Definition at line 3470 of file pluginmanager.cpp.

◆ Init()

int PlugInChartBase::Init	(	const wxString &	full_path,
		int	init_flags
	)

virtual

Initializes a chart instance from a file.

This method is called when OpenCPN needs to load a chart that matches the file search mask. It should parse the chart file's headers or content based on the initialization level requested and populate the chart object's properties.

Parameters

full_path	Full path to the chart file to be loaded
init_flags	Level of initialization to perform: PI_FULL_INIT (0): Load complete chart for display PI_HEADER_ONLY (1): Load only chart metadata (for database building) PI_THUMB_ONLY (2): Load minimal data needed for thumbnail generation

Returns

An integer status:

INIT_OK (0) if initialization was successful
INIT_FAIL_RETRY if initialization failed but should be retried
INIT_FAIL_REMOVE if initialization failed and the chart should be removed
INIT_FAIL_NOERROR if initialization failed but no error message is needed

Definition at line 3444 of file pluginmanager.cpp.

◆ IsReadyToRender()

virtual bool PlugInChartBase::IsReadyToRender ( )

inlinevirtual

Indicates whether the chart is ready for rendering.

This method tells OpenCPN whether the chart has loaded sufficient data to be rendered. It can be used to defer rendering until asynchronous loading operations are complete.

Returns: Boolean value: True if the chart is ready to render, False otherwise

Note: Should return True once all required rendering data is available; Can be used to implement background loading for large charts; OpenCPN may delay display until this returns True

Definition at line 996 of file ocpn_plugin.h.

◆ latlong_to_chartpix()

void PlugInChartBase::latlong_to_chartpix	(	double	lat,
		double	lon,
		double &	pixx,
		double &	pixy
	)

virtual

Converts geographic coordinates to chart pixel coordinates.

This method transforms a latitude/longitude position into the chart's native pixel coordinate system.

Parameters

lat	Latitude in decimal degrees
lon	Longitude in decimal degrees
pixx	Will receive X pixel coordinate
pixy	Will receive Y pixel coordinate

Note: For raster charts, the origin (0,0) is typically top-left; Transforms depend on chart projection and calibration

Definition at line 3497 of file pluginmanager.cpp.

◆ RenderRegionView()

wxBitmap & PlugInChartBase::RenderRegionView	(	const PlugIn_ViewPort &	VPoint,
		const wxRegion &	Region
	)

virtual

Renders a region of the chart for display.

This is the primary rendering method called when the chart needs to be drawn. It should create and return a bitmap containing the rendered chart image for the specified view parameters and region.

Parameters

VPoint	Current viewport parameters: clat/clon: Center latitude/longitude view_scale_ppm: Current scale in pixels per meter skew: Chart rotation skew rotation: Display rotation pix_width/pix_height: Viewport size in pixels rv_rect: Rectangle region in screen coordinates b_quilt: Whether chart quilting is active
Region	wxRegion defining the area to be rendered (in screen coordinates)

Returns: wxBitmap containing the rendered chart image

Note: The implementation should be optimized as this is called frequently during navigation; For large charts, consider caching rendered results for improved performance; The bitmap should match the viewport dimensions (VPoint.pix_width/height)

Definition at line 3460 of file pluginmanager.cpp.

◆ SetColorScheme()

void PlugInChartBase::SetColorScheme	(	int	cs,
		bool	bApplyImmediate
	)

virtual

Sets the color scheme for chart display.

This method is called when the user changes OpenCPN's color scheme (day/dusk/night). Chart plugins should update their rendering colors and styles to match the specified scheme.

Parameters

cs	Color scheme to use: PI_GLOBAL_COLOR_SCHEME_RGB (0): RGB color scheme PI_GLOBAL_COLOR_SCHEME_DAY (1): Day color scheme PI_GLOBAL_COLOR_SCHEME_DUSK (2): Dusk/twilight color scheme PI_GLOBAL_COLOR_SCHEME_NIGHT (3): Night/dark color scheme
bApplyImmediate	True to immediately refresh display, False to defer

Note: If bApplyImmediate is true, any cached rendering should be invalidated; For optimal night viewing, reduce brightness of whites and increase contrast

Definition at line 3473 of file pluginmanager.cpp.

Member Data Documentation

◆ m_bReadyToRender

bool PlugInChartBase::m_bReadyToRender

protected

Definition at line 1163 of file ocpn_plugin.h.

◆ m_Chart_Error_Factor

double PlugInChartBase::m_Chart_Error_Factor

protected

Definition at line 1177 of file ocpn_plugin.h.

◆ m_Chart_Scale

int PlugInChartBase::m_Chart_Scale

protected

Definition at line 1159 of file ocpn_plugin.h.

◆ m_Chart_Skew

double PlugInChartBase::m_Chart_Skew

protected

Definition at line 1160 of file ocpn_plugin.h.

◆ m_ChartFamily

ChartFamilyEnumPI PlugInChartBase::m_ChartFamily

protected

Definition at line 1155 of file ocpn_plugin.h.

◆ m_ChartType

ChartTypeEnumPI PlugInChartBase::m_ChartType

protected

Definition at line 1154 of file ocpn_plugin.h.

◆ m_datum_str

wxString PlugInChartBase::m_datum_str

protected

Definition at line 1170 of file ocpn_plugin.h.

◆ m_depth_unit_id

ChartDepthUnitTypePI PlugInChartBase::m_depth_unit_id

protected

Definition at line 1175 of file ocpn_plugin.h.

◆ m_DepthUnits

wxString PlugInChartBase::m_DepthUnits

protected

Definition at line 1172 of file ocpn_plugin.h.

◆ m_Description

wxString PlugInChartBase::m_Description

protected

Definition at line 1166 of file ocpn_plugin.h.

◆ m_EdDate

wxDateTime PlugInChartBase::m_EdDate

protected

Definition at line 1162 of file ocpn_plugin.h.

◆ m_ExtraInfo

wxString PlugInChartBase::m_ExtraInfo

protected

Definition at line 1173 of file ocpn_plugin.h.

◆ m_FullPath

wxString PlugInChartBase::m_FullPath

protected

Definition at line 1157 of file ocpn_plugin.h.

◆ m_ID

wxString PlugInChartBase::m_ID

protected

Definition at line 1167 of file ocpn_plugin.h.

◆ m_Name

wxString PlugInChartBase::m_Name

protected

Definition at line 1165 of file ocpn_plugin.h.

◆ m_projection

OcpnProjTypePI PlugInChartBase::m_projection

protected

Definition at line 1158 of file ocpn_plugin.h.

◆ m_PubYear

wxString PlugInChartBase::m_PubYear

protected

Definition at line 1171 of file ocpn_plugin.h.

◆ m_SE

wxString PlugInChartBase::m_SE

protected

Definition at line 1168 of file ocpn_plugin.h.

◆ m_SoundingsDatum

wxString PlugInChartBase::m_SoundingsDatum

protected

Definition at line 1169 of file ocpn_plugin.h.

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

/home/runner/work/main/main/opencpn/include/ocpn_plugin.h
/home/runner/work/main/main/opencpn/gui/src/pluginmanager.cpp

Public Member Functions

Protected Attributes

Detailed Description

Constructor & Destructor Documentation

◆ PlugInChartBase()

◆ ~PlugInChartBase()

Member Function Documentation

◆ AdjustVP()

◆ chartpix_to_latlong()

◆ ComputeSourceRectangle()

◆ GetChartBits()

◆ GetChartErrorFactor()

◆ GetChartExtent()

◆ GetChartFamily()

◆ GetChartProjection()

◆ GetChartSkew()

◆ GetChartType()

◆ GetCOVREntries()

◆ GetCOVRTableHead()

◆ GetCOVRTablenPoints()

◆ GetCOVRTablePoints()

◆ GetDatumString()

◆ GetDepthUnitId()

◆ GetDepthUnits()

◆ GetDescription()

◆ GetEditionDate()

◆ GetExtraInfo()

◆ GetFileSearchMask()

◆ GetFullPath()

◆ GetID()

◆ GetName()

◆ GetNativeScale()

◆ GetNearestPreferredScalePPM()

◆ GetNormalScaleMax()

◆ GetNormalScaleMin()

◆ GetPubDate()

◆ GetRasterScaleFactor()

◆ GetSE()

◆ GetSize_X()

◆ GetSize_Y()

◆ GetSoundingsDatum()

◆ GetThumbnail()

◆ GetValidCanvasRegion()

◆ Init()

◆ IsReadyToRender()

◆ latlong_to_chartpix()

◆ RenderRegionView()

◆ SetColorScheme()

Member Data Documentation

◆ m_bReadyToRender

◆ m_Chart_Error_Factor

◆ m_Chart_Scale

◆ m_Chart_Skew

◆ m_ChartFamily

◆ m_ChartType

◆ m_datum_str

◆ m_depth_unit_id

◆ m_DepthUnits

◆ m_Description

◆ m_EdDate

◆ m_ExtraInfo

◆ m_FullPath

◆ m_ID

◆ m_Name

◆ m_projection

◆ m_PubYear

◆ m_SE

◆ m_SoundingsDatum