/koreader-base

Base framework offering a Lua scriptable environment for creating document readers

Primary LanguageLuaGNU Affero General Public License v3.0AGPL-3.0

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This is the base framework for creating document readers like KOReader, an e-ink device oriented reader application for various document formats.

It uses the MuPDF library (see http://mupdf.com/), djvulibre library, CREngine library, libk2pdfopt library and it is scripted using Lua (see http://www.lua.org/). To gain good speed at that, it uses the LuaJIT compiler.

It all started as the KindlePDFviewer application, which has since been greatly enhanced and now reflects this in having a new name, KOReader.

The code is distributed under the GNU AGPL v3 license (read the COPYING file).

Building

Follow these steps:

  • automatically fetch thirdparty sources with Makefile:

    • make sure you have patch, wget, unzip, git and svn installed
    • run make fetchthirdparty.

  • run make TARGET=kindlepw2 For Kindle models >= Paperwhite 2.

  • run make TARGET=kindle For Kindle models >= Kindle 4 < Paperwhite 2.

  • run make TARGET=kindle-legacy for Kindle DXG/2/3 devices.

  • or run make TARGET=kobo for Kobo devices.

  • or run make TARGET=pocketbook for PocketBook devices.

  • or run make TARGET=cervantes for BQ Cervantes devices.

  • or run make TARGET=android for Android devices.

  • or run make TARGET=win32 for Windows.

  • or run make TARGET=generic-arm for generic ARM devices.

  • or run make TARGET=ubuntu-touch for Ubuntu Touch.

  • or run make TARGET=appimage for the desktop AppImage.

  • or run make TARGET=debian, debian-armel or debian-armhf for a Debian package.

  • or run make KODEBUG=1 to build with debugging symbols.

  • or run make for the emulator on Linux.

Use ccache

Ccache can speed up recompilation by caching previous compilations and detecting when the same compilation is being repeated. In other words, it will decrease build time when the sources have already been built. Ccache support has been added to KOReader's build system. Before using it, you will need to install a ccache in your system.

  • in Ubuntu use:sudo apt-get install ccache
  • in Fedora use:sudo yum install ccache
  • install from source:
  • to disable ccache, use export USE_NO_CCACHE=1 before make.
  • for more detail about ccache. visit:

http://ccache.samba.org

Device emulation

The code also features a device emulation. You need SDL headers and library for this. It allows to develop on a standard PC and saves precious development time. It might also create a suboptimal desktop PDF viewer, depending on your view.

If you are using Fedora Core Linux, run yum install SDL2 SDL2-devel. If you are using Debian or Ubuntu, install the libsdl2-dev package.

By default, the build system builds in "emulation mode", so following is all you need to build the emulator:

make

The emulator uses 800x600 as the default resolution. It can be changed at runtime by changing the following environment variables:

EMULATE_READER_W=746 EMULATE_READER_H=1024

The emulator uses a default DPI of 160. This can also be changed with an environment variable:

EMULATE_READER_DPI=300

KOReader supports "viewports", i.e. displaying only in a rectangular excerpt of the screen. This is useful on devices where the framebuffer is larger than the area that is actually visible. In order to simulate such a viewport using the emulator, specify a specially crafted environment variable:

EMULATE_READER_VIEWPORT="{x=50,w=600,y=10,h=680}"

You can also simulate e-ink refresh with the emulator. When active, only refreshed areas of the screen are actually updated and you also get a visual inverse flash feedback. In order to activate that mode, set an environment variable to the number of milliseconds you want the flash to endure:

EMULATE_READER_FLASH=100