1Skia Lua Bindings
2=================
3
4**Warning: The following has only been tested on Linux, but it will likely
5work for any Unix.**
6
7Prerequisites
8-------------
9
10This assumes one already has Skia building normally. If not, refer to the
11quick start guides. In addition to that, you will need Lua 5.2 installed on
12your system in order to use the bindings.
13
14Building lua requires the readline development library. If missing this can be installed (on Ubuntu) by executing:
15
16  * `apt-cache search libreadline` to see the available libreadline libraries
17  * `sudo apt-get install libreadline6 libreadline6-dev` to actually install the libraries
18
19Build
20-----
21
22The build process starts the same way as described in the quick starts, but
23before using gyp or make, do this instead:
24
25    $ export GYP_DEFINES="skia_shared_lib=1"
26    $ make tools
27
28This tells Skia to build as a shared library, which enables a build of another shared library called 'skia.so' that exposes Skia bindings to Lua.
29
30Try It Out
31----------
32
33Once the build is complete, use the same terminal:
34
35    $ cd out/Debug/
36    $ lua
37
38    Lua 5.2.0  Copyright (C) 1994-2011 Lua.org, PUC-Rio
39    > require 'skia'
40    > paint = Sk.newPaint()
41    > paint:setColor{a=1, r=1, g=0, b=0}
42    > doc = Sk.newDocumentPDF('test.pdf')
43    > canvas = doc:beginPage(72*8.5, 72*11)
44    > canvas:drawText('Hello Lua', 300, 300, paint)
45    > doc:close()
46
47The key part to loading the bindings is `require 'skia'` which tells lua to look
48for 'skia.so' in the current directory (among many others) and provides the
49bindings. 'skia.so' in turn will load 'libskia.so' from the current directory or
50in our case the lib.target directory. 'libskia.so' is what contains the native
51skia code. The script shown above uses skia to draw Hello Lua in red text onto
52a pdf that will be outputted into the current folder as 'test.pdf'. Go ahead and
53open 'test.pdf' to confirm that everything is working.
54
55