api:dk11:java:tatukgis.jdk.tgis_layerpixel.loop_tgis_extent_double_tgis_shape_string_boolean
Table of Contents
TGIS_LayerPixel.Loop(TGIS_Extent, double, TGIS_Shape, java.lang.String, bool) method
DK11 for Java | tatukgis.jdk.TGIS_LayerPixel.Loop | Overloads | Constructors | Fields | Methods | Properties | Events
Prepares enumerator to iterate the layer (pixels are treated as points).
Syntax
// Java public TGIS_LayerPixelEnumeratorFactory Loop( TGIS_Extent _extent, double _pixelsize, TGIS_Shape _shape, java.lang.String _de9im, bool _writable );
// Oxygene public function Loop( _extent : TGIS_Extent; _pixelsize : Double; _shape : TGIS_Shape; _de9im : String; _writable : Boolean ) : TGIS_LayerPixelEnumeratorFactory; virtual;
Parameters
| Name | Type | Description |
|---|---|---|
| _extent | TGIS_Extent | extent of items to be found; expected _extent units are in the Layer coordinate space |
| _pixelsize | double Double | minimum requested size of image pixel; by providing 0, the maximum possible resolution will be used, which is also the fastest method if a layer is fully in-memory because, in such situation, a pointer to existing memory is used |
| _shape | TGIS_Shape | if not nil, then only pixels matching _de9im matrix with be found; |
| _de9im | java.lang.String String | DE-9IM matrix of comparison |
| _writable | bool Boolean | if true than layer will post back any changes in locked area; if write is not possible then TGIS_PixelItem.Writable will be set accordingly |
Result
| Type | Description |
|---|---|
| TGIS_LayerPixelEnumeratorFactory | Pixel item returned row by row, column by column. |
Remarks
_pixelsize
By providing _pixelsize=0, a native layer resolution is requested. This is also the fastest method if a layer is fully in-memory because, in such situation, a pointer to existing memory is used
Example
General way to query for terrain profile:
foreach (TatukGIS.NDK.TGIS_PixelItem px in lp.Loop(0, line, false)) { Memo.AppendText( String.Format("Distance: {0}, Height:{1}\r\n", px.Distance, px.Value) ); }
General way to query for pixels within polygon and modifying value:
foreach (TGIS_PixelItem px in lp.Loop(polygon.Extent, 0, polygon, "T", true)) { px.Color = TGIS_Color.Red; }
References
2022/11/16 01:47