I am happy to share two b4xlibs that makes key parts of JTS (Java Topology Suite) easily accessible in B4J and B4A.
In addition, I am sharing two b4xlibs that make it easy to present JTS geometry on B4Xcanvas and in BitmapCreator, respectively.
The JTS Topology Suite is a Java library for creating and manipulating vector geometry.
Please provide feedback and suggestions.
This is the libraries:
JTSWrapper.b4xlib
This is the main wrapper library.
It depends on jna-5.14.0.jar. The jar must be in your additional libraries folder and the main module ned to reference it like this:
With this library you can:
This library depends on and are companion to JTSWrapper.b4xlib
With this library you can manipulate the geometries in more advanced wayes. You Build the desired transformation by chaining: Rotate, Scale, Translate, Shear, Reflect, Compose, ComposeBefore, SetTransformation, CreateFromControlVectors, or CreateFromBaseLines. Then you can use the transformation on one or more geometries.
JTSDrawer.b4xlib
This library depends on JTSWrapper.b4xlib
With this library you can define a drawing style and draw the geometries on a B4XCanvas.
You specify the coordinates for a viewport into JTS's world and coordinates for a target area on the b4xcanvas for drawing the geometry.
Then you can use the drawer to draw the geometry as you like.
JTSBCDrawer.b4xlib
This library depends on JTSWrapper.b4xlib and JTSDrawer.b4xlib (It shares the JTSStyle class that belongs to JTSDrawer)
[Edit]It also depends on version 4.74 of bitmapcreator. While you wait for new versions of B4J and B4A to be released, you can download latest version of bitmapcreator here.
The library uses the asynchronous drawing methods of bitmapcreator, but the interface has still been tried to be as similar as possible to JTSDrawer's.
JTSDemo.zip
I have made a demo app. I suggest that if you want to use these libraries you should study the demo app to understand how to use them.
[Edit]The demo app also depends on version 4.74 of bitmapcreator. While you wait for new versions of B4J and B4A to be released, you can download latest version of bitmapcreator here.
It is a B4Xpages project that runs on B4A and B4J. You must have all the b4Xlib files attached to this post and jna-5.14.0.jar. installed in your additional libraries folder
The gif animations below give a small taste of the demo app.
Interactive demo of using the libraries to animate geometries. It calculates fps and load on ui thread
Interactive demo of STRtree
In addition, I am sharing two b4xlibs that make it easy to present JTS geometry on B4Xcanvas and in BitmapCreator, respectively.
The JTS Topology Suite is a Java library for creating and manipulating vector geometry.
Please provide feedback and suggestions.
This is the libraries:
JTSWrapper.b4xlib
This is the main wrapper library.
It depends on jna-5.14.0.jar. The jar must be in your additional libraries folder and the main module ned to reference it like this:
B4X:
#AdditionalJar: jna-5.14.0.jarWith this library you can:
- create geometry in various ways
- retrieve wkb and wkt representation of the geometries
- manipulate the geometries in various ways
- examine interactions between 2 or more geometries (overlap, contain, etc.)
- combine 2 or more geometries in various ways (create collections, union, intersection, etc.)
- search for geometries that are within a defined rectangle (STRtree)
This library depends on and are companion to JTSWrapper.b4xlib
With this library you can manipulate the geometries in more advanced wayes. You Build the desired transformation by chaining: Rotate, Scale, Translate, Shear, Reflect, Compose, ComposeBefore, SetTransformation, CreateFromControlVectors, or CreateFromBaseLines. Then you can use the transformation on one or more geometries.
JTSDrawer.b4xlib
This library depends on JTSWrapper.b4xlib
With this library you can define a drawing style and draw the geometries on a B4XCanvas.
You specify the coordinates for a viewport into JTS's world and coordinates for a target area on the b4xcanvas for drawing the geometry.
Then you can use the drawer to draw the geometry as you like.
JTSBCDrawer.b4xlib
This library depends on JTSWrapper.b4xlib and JTSDrawer.b4xlib (It shares the JTSStyle class that belongs to JTSDrawer)
[Edit]It also depends on version 4.74 of bitmapcreator. While you wait for new versions of B4J and B4A to be released, you can download latest version of bitmapcreator here.
The library uses the asynchronous drawing methods of bitmapcreator, but the interface has still been tried to be as similar as possible to JTSDrawer's.
JTSDemo.zip
I have made a demo app. I suggest that if you want to use these libraries you should study the demo app to understand how to use them.
[Edit]The demo app also depends on version 4.74 of bitmapcreator. While you wait for new versions of B4J and B4A to be released, you can download latest version of bitmapcreator here.
It is a B4Xpages project that runs on B4A and B4J. You must have all the b4Xlib files attached to this post and jna-5.14.0.jar. installed in your additional libraries folder
The gif animations below give a small taste of the demo app.
Interactive demo of using the libraries to animate geometries. It calculates fps and load on ui thread
Interactive demo of STRtree
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