C++ Examples – Getting Started (0)

C++ examples of Fade2D

Fade2D contains a collection of small, self-contained C++ examples, each of which demonstrates, step by step, how to apply the library practically for a certain topic.

For example, the goal of this very first example is to show you how to compile C++ source code with Fade2D and how to create and draw a triangulation. Furthermore you can find the other examples here:

• C++ Examples for 2D triangulations and Voronoi diagrams
• C++ Examples for 2.5D triangulations and meshing algorithms

“Note: All described example source codes are contained in the download.”

Point clouds: 2D and 2.5D vs. 3D

Before we jump into the source code, here’s a short clarification about the dimensions:

• Fade2D is a classic 2D Delaunay triangulation software for the xy-plane. It offers constraint edges, zones, boolean operations and more.
• Fade2.5D is like Fade 2D a Delaunay triangulation but for lifted points. More precisely, the library has
  • all functions of Fade2D plus
  • a z-coordinate and
  • additional algorithms from the field of land surveying.
• Fade3D is a Delaunay triangulation for 3D point clouds. But it is more precise to call it a 3D tetrahedralization because it creates tetrahedra, not triangles. If you want triangles instead, use WOF to reconstruct the surface of a 3D point cloud.

“The difference between 2.5D and 3D is that a 2.5D point cloud describes a surface f(x,y) where each coordinate pair (x,y) has only one z-coordinate. This is ideal for terrain data and other height fields, but a simple sphere is not 2.5D, for example.”

Example0: HelloTriangulation

The first C++ code example is equivalent to HelloWorld:

• It creates a Fade_2D object and 4 points.
• Then it inserts the points.
• Afterwards it draws the resulting triangulation.

// An empty triangulation
Fade_2D dt;
// 4 points
Point2 p0(0.0,0.0);
Point2 p1(1.0,0.0);
Point2 p2(0.5,2.0);
Point2 p3(0.5,0.5);
// Insert the points
dt.insert(p0);
dt.insert(p1);
dt.insert(p2);
dt.insert(p3);
// Draw as postscript graphic
dt.show("example0.ps");

“If you want to use Fade2.5D it might be helpful to look at the 2D examples as well, because they cover the basics that also apply to Fade2.5D.“

# Choose a matching distribution below:
# DISTRO :=../lib_centos6.4_${ARCHITECTURE}
# DISTRO :=../lib_ubuntu14.04_${ARCHITECTURE}
# DISTRO :=../lib_fedora24_${ARCHITECTURE}
DISTRO :=../lib_ubuntu20.04_${ARCHITECTURE}
# DISTRO :=../lib_APPLE
# DISTRO :=../lib_raspberry_armv6l
# DISTRO :=../lib_raspberry_armv7l

The next example benchmarks the performance of Fade on your computer.