Microchip Hardware LCD Plane Library
libplanes is a library that provides support for working with LCD controller hardware planes found on SAMA5 hardware. It directly uses libdrm to manipulate and control the hardware planes with support for using cairo for basic drawing primitives. It includes basic support for parsing a configuration file used to describe the layout and configuration of the planes, but this can also be done manually.
Also included are several applications that use libplanes to perform various tasks to exercise the hardware and library. These applications provide a set of examples and evaluation tests related to using hardware planes.
The general terminology used to describe hardware planes varies. The comparison is as follows:
- Primary Plane
- Overlay Plane
- Cursor Plane
- Base Layer
- Overlay Layer
- High End Overlay (HEO)
- libdrm >= 2.4.0
- cJSON >= 1.6.0
- lua >= 5.3.1
- cairo >= 1.14.6
- Python >= 2.7
- directfb >= 1.7.0 (optional)
Make sure you have the required dependencis listed above. To cross compile, put the cross gcc path in your environment PATH variable and use the appropriate prefix for --host on the configure line. For example:
./autogen.sh ./configure --host=arm-buildroot-linux-gnueabihf make
If you wish to statically link the applications, add the following to your configure line:
./configure --enable-static --disable-shared LDFLAGS="-static"
If you have doxygen installed, you can generate the API documentation by running:
The resulting documentation will be in the docs directory.
Full Python bindings are provided, generated with swig. You can find examples
Application that acts as a DRM master that takes a configuration and applies it to hardware planes and then will run a minimal engine to perform basic animation of the overlays.
./planes -v -c default.config
The config file is a simple JSON formatted file that specifies the configuration
of each plane. See
default.config for an example.
With this application running as a DRM master, other applications can then use the created GEM names to manipulate the plane framebuffers externally from another process.
Application that uses GEM names created by the planes app that can be passed to this process to write to a plane framebuffers independently. It supports setting a single background color or loading an image into the framebuffer. To run this, the planes app must already be running.
./render -n 1 -c 0xff0000ff --width 800 --height 480 ./render -n 1 -f ./frog.png --width 800 --height 480
Application that uses GEM names created by the planes app to capture and save the framebuffer as a PNG. To run this, the planes app must already be running.
./grab -n 1 -f capture.png --width 800 --height 480
Simple demo based on a DirectFB test that allocates hardware overlays using the DirectFB API and moves them around on the screen showing little CPU usage in the process.
libplanes is released under the terms of the
MIT license. See the
file for more information.