Map Drawer (Shapes, Lines & Polygons)
Draw custom polygons, lines, circles, and markers on a map with full undo/redo history, area/distance calculations, and multi-format vector export.
The Map Drawer provides a vector sketching canvas to draw custom polygons, multi-segment lines, boundary buffers, circle radii, marker pins, and text annotations on an interactive map. It calculates enclosed area and perimeter lengths in real time and exports finished drawings as GeoJSON, KML, and SVG.
Drawing Tools
Stroke & Fill Color
Map Drawer Technical Specifications & Standards
WGS84 (EPSG:4326)
Standard global ellipsoidal coordinate reference system
Vector Geodesics
Sub-millimeter calculation accuracy
GeoJSON · KML · CSV · SVG
Compatible with QGIS, ArcGIS, Google Earth & CAD
100% Client-Side
Calculations run in-browser. Zero coordinate logging.
How to Use the Map Drawer (Shapes, Lines & Polygons)
Follow this step-by-step procedure to execute precise spatial measurements and export results.
- 1Select drawing tool: Choose Polygon (area), LineString (distance path), Circle (radius buffer), or Point (marker pin) from the toolbar.
- 2Click on map to sketch: Click sequential points on the map to construct lines and polygons. Double-click to complete the shape.
- 3Customize styles & colors: Select fill colors, border thickness, opacity, and stroke color for individual shapes or layers.
- 4Inspect geodetic measurements: Review real-time computed surface area (acres, hectares, sq ft) and path lengths (miles, km).
- 5Export vector drawing: Click "Export" to download your complete drawing as GeoJSON, KML (for Google Earth), or SVG vector format.
Geodesic Precision vs. Competitor Mapping Approaches
Most legacy mapping utilities (such as CalcMaps and FreeMapTools) rely on planar Web Mercator projections or spherical approximations, causing significant mathematical distortion at higher latitudes. GeoMap Suite computes exact ellipsoidal geodesics on the WGS84 reference ellipsoid.
| Calculation Model | Mathematical Basis | Distortion on WGS84 | Standard Tools | Practical Application |
|---|---|---|---|---|
| Planar (Web Mercator) | Cartesian dx² + dy² | 10% to 200%+ error | CalcMaps / Simple map tools | Distorts drastically away from equator. Inaccurate for true distance. |
| Spherical Great-Circle | Haversine (R = 6,371 km) | Up to 0.5% (~5 km/1,000 km) | Basic Google Maps wrappers | Ignores Earth's polar flattening. Reasonable for rough estimates. |
| GeoMap Suite Ellipsoidal | Karney Direct/Inverse WGS84 | < 15 nanometers (<0.0001%) | GeoMap Suite | Geodetic surveying, maritime, flight paths & legal boundary analysis. |
Worked Example: Sketching a Construction Site Plan & Perimeter
A civil site contractor sketches a 5-acre construction laydown yard with security fence lines.
Input Parameters
- Shapes
- 1 Boundary Polygon, 2 Access Lines, 4 Marker Pins
- Units
- Acres, Feet, Square Feet
Computed Outputs
- Site Area
- 5.24 Acres (228,254 sq ft)
- Fence Perimeter
- 1,940 Linear Feet
- Export File
- Site_Plan.kml / Site_Plan.geojson
Step-by-Step Mathematical Process
- Select Polygon tool and draw 4-sided laydown yard.
- Tool computes enclosed area: 5.24 Acres (228,254 sq ft) and perimeter: 1,940 ft.
- Select Line tool to draw access road from main highway (1,250 ft).
- Add Point pins at security gate entrances.
Understanding Your Results & Practical Interpretation
Multi-Layer Vector Annotation Support
You can combine points, lines, circles, and polygons on the same map canvas. Each geometry retains its independent styling, label properties, and measurements.
Practical Applications & Real-World Use Cases
Site Planning, Event Layouts & Festival Mapping
Draw parking zones, emergency access corridors, tent perimeters, and stage locations on satellite basemaps.
Mathematical Methodology & Geodetic Accuracy
Vector Topology & WGS84 Geodesic Measurement
Drawn geometries are stored in GeoJSON FeatureCollection structures with real-time Karney ellipsoidal geodesic distance and area calculations.
FeatureCollection: [Polygon(Karney_Area), LineString(Karney_Length), Point]Limitations & Boundary Conditions
- •Drawings are saved locally in browser localStorage until exported.
Authoritative Reference Standards
Troubleshooting & Geographic Edge Cases
How do I finish drawing a polygon or line?
Double-click on your final point, or click the first point to close the polygon.
Frequently Asked Questions
Yes. Export your drawing as a GeoJSON or KML file. You can drag and drop that file back into the Map Drawer at any time to resume editing, adjust boundary vertices, and add new shapes.