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| author | scuri <scuri> | 2008-10-17 06:10:33 +0000 |
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| committer | scuri <scuri> | 2008-10-17 06:10:33 +0000 |
| commit | 7b52cc13af4e85f1ca2deb6b6c77de9c95ea0dcf (patch) | |
| tree | d0857278bde2eff784227c57dcaf930346ceb7ac /html/en/cdlua.html | |
First commit - moving from LuaForge to SourceForge
Diffstat (limited to 'html/en/cdlua.html')
| -rw-r--r-- | html/en/cdlua.html | 117 |
1 files changed, 117 insertions, 0 deletions
diff --git a/html/en/cdlua.html b/html/en/cdlua.html new file mode 100644 index 0000000..9cfb965 --- /dev/null +++ b/html/en/cdlua.html @@ -0,0 +1,117 @@ +<html> + +<head> +<meta http-equiv="Content-Language" content="en-us"> +<title>Lua Binding</title> +<link rel="stylesheet" type="text/css" href="../style.css"> +</head> + +<body> + +<h1>Lua Binding</h1> +<h3><a name="Overview">Overview</a></h3> + + <p>CDLua was developed to make all functionalities of the CD library available to Lua programmers. To use the CDLua + bindings, your executable must be linked with the CDLua library, and you must call the initialization function <strong> + <font face="Courier New">cdlua_open</font></strong> declared in the header file <strong><font face="Courier New">cdlua</font><font size="2" face="Courier New">.</font><font face="Courier New">h</font></strong>, + as seen in the example below:</p> + + <div align="center"> + <center> + <table border="1" cellpadding="10" cellspacing="0" style="border-collapse: collapse" bordercolor="#111111" id="AutoNumber1"> + <tr> + <th> + <p align="center">in Lua5</th> + </tr> + <tr> + <td> + <pre>#include <lua.h> +#include <lualib.h> +#include <lauxlib.h> +<b><font color="#FF0000">#include <cdlua.h></font></b></pre> + <pre>void main(void) +{ + lua_State *L = lua_open(); + + luaopen_string(L); + luaopen_math(L); + luaopen_io(L); + +<b> <font color="#FF0000">cdlua_open(L);</font> +</b> + lua_dofile("myprog.lua"); + + <b><font color="#FF0000">cdlua_close(L);</font></b> + lua_close(L); +}</pre> + </td> + </tr> + </table> + </center> + </div> + + <p>The <font face="Courier New"><strong>cdlua_open</strong>()</font> function registers all CD functions and constants + your Lua program will need. The use of the CDLua functions in Lua is generally identical to their equivalents in C. + Nevertheless, there are several exceptions due to differences between the two languages. Notice that, as opposed to C, + in which the flags are<i> </i>combined with the bitwise operator OR, in Lua the flags are added arithmetically. </p> + <p>The CDLua dynamic libraries are also compatible with the Lua 5 "loadlib" function.<span lang="en-us"> + </span>Here is an example on how to dynamically load CD + in Lua 5<span lang="en-us">.1</span>:</p> +<pre>local cdlua_open = package.loadlib("cdlua51.dll", "cdlua_open") +cdlua_open()</pre> +<p><strong>Lua</strong> 5.1 "require" can be used for all the <strong> +CDLua</strong> +libraries. You can use <b>require</b>"<b>cdlua</b>" and so on, but the LUA_CPATH +must also contains the following: </p> + +<pre>"./lib?51.so;" [in UNIX] + +".\\?51.dll;" [in Windows] +</pre> +<p>The LuaBinaries distribution already includes these modifications on the +default search path.</p> +<p>The simplest form <b>require</b>"<b>cd</b>" +and so on, can not be used because there are CD dynamic libraries with names +that will conflict with the names used by <b>require</b> during search.</p> + +<h3><a name="New Functions">Function Names and Definitions</a></h3> + + <p>In Lua, because of the name space "cd" all the functions and definitions have their names prefix changed. The + general rule is quite simple:</p> + + <pre>cdXxx -> cd.Xxx +wdXxx -> cd.wXxx +CD_XXX -> cd.XXX</pre> + + +<h3>Modifications to the API</h3> + + <p>New functions (without equivalents in C) were implemented to create and + destroy objects that do not exist in C. For instance functions were developed + to create and destroy images, pattern, stipple and palette. All the + metatables have the "tostring" method implemented to help debuging.</p> + + <p>Some functions were modified to receive those objects as parameters.</p> + <p>Also the functions which receive values by reference in C were modified. Generally, the values of + parameters that would have their values modified are now returned by the function in the same order.</p> + + +<h3>Garbage Collection</h3> + + <p>All the objects are garbage collected by the Lua garbage collector, except + the canvas because there can be different Lua canvases pointing to the same + C canvas. The tostring method of the Lua canvas will print both values, Lua + and C. The equal method will compare the C canvas value.</p> + +<h3>Exchanging Values between C and Lua</h3> + + <p>Because of some applications that interchange the use of CD canvases in Lua and C, we build a + few C functions that are available in "cdlua.h":</p> + +<pre>cdCanvas* cdlua_checkcanvas(lua_State* L, int pos); +void cdlua_pushcanvas(lua_State* L, cdCanvas* canvas);</pre> + + +</body> + +</html>
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