b2Draw

An OpenGL implementation of Box2D's DebugDraw.

Dependencies

For building and using the library, install:

• Box2D v2.3.2 (github);
• a modern OpenGL implementation;
• GLEW.

Additionally, to build and run the demo, you'll need:

• SDL2;
• GLM (github).

Building

Configure as with a normal CMake project. CMake package finders will be used for locating Box2D, GLEW, OpenGL and SDL2 where required.

Example

Assuming dependencies are installed in places where the compiler will find them:

mkdir build
cd build
cmake ..
cmake --build .

You can then optionally install by running e.g. make install (as usual, the install prefix can be modified by setting -DCMAKE_INSTALL_PREFIX when invoking cmake; see the CMake documentation for details).

Consuming

CMake projects

Either install as above and use find_package(b2draw), or if, for example, using Git submodules, you can add_subdirectory(path/to/b2draw). In either case, linking against the b2draw::b2draw library should provide dependants with the correct include dirctories and link libraries.

Non-CMake projects

Either install as above, or build in-place to include in your build; the details will depend on your toolchain.

In the source

Create a debug draw:

// Configuration...
DebugDraw debugDraw(...);
debugDraw.SetFlags(0xff); // Draw everything.
b2World world;
world.SetDebugDraw(&debugDraw);

When you update the Box2D world, make sure to buffer the debug draw data:

// Logic loop:
debugDraw.Clear(); // Clears the previous geometry set.
world.DrawDebugData(); // Adds world geometry to the DebugDraw.
debugDraw.BufferData(); // Sends geometry to the GPU.

Finally, when rendering, call DebugDraw::Render():

// Render loop:
debugDraw.Render();

Demo

To run the demo, build as above but ensure to define b2draw_BUILD_DEMO, and that GLM and SDL2 can be found. Once built, run $BUILD_DIR/demo/demo, where BUILD_DIR is the path to your build directory.

Example

mkdir build
cd build
cmake -Db2draw_BUILD_DEMO=ON ..