source: trunk/src/lua/lua_glm.cc @ 74

// Copyright (C) 2012-2013 ChaosForge / Kornel Kisielewicz
// http://chaosforge.org/
//
// This file is part of NV Libraries.
// For conditions of distribution and use, see copyright notice in nv.hh

#include "nv/lua/lua_glm.hh"
#include "nv/types.hh"
#include "nv/string.hh"
#include <new>

static size_t nlua_swizzel_lookup[256];

inline bool nlua_is_swizzel( const char* str, size_t max )
{
        while (*str)
        {
                if (nlua_swizzel_lookup[*str] > max) return false;
                str++;
        }
        return true;
}

template < typename T, size_t k >
struct nlua_vec_constructor {
        static inline T construct( lua_State* L, int index ) {
                return T();
        }
};

template < typename T > struct nlua_vec_constructor< T, 1 > {
        static inline T construct( lua_State* L, int index ) {
                return T( lua_tonumber( L, index ) );
        }
};

template < typename T > struct nlua_vec_constructor< T, 2 > {
        static inline T construct( lua_State* L, int index ) {
                if ( lua_type( L, index ) == LUA_TUSERDATA )
                        return nlua_to_vec<T>( L, index );
                else
                        return T( lua_tonumber( L, index ), lua_tonumber( L, index + 1 ) );
        }
};

template < typename T > struct nlua_vec_constructor< T, 3 > {
        static inline T construct( lua_State* L, int index ) {
                typedef glm::detail::tvec2<T::value_type> vec2;
                if ( lua_type( L, index ) == LUA_TUSERDATA )
                {
                        if ( nlua_is_vec<T>( L, index ) )
                                return nlua_to_vec<T>( L, index );
                        else
                                return T( nlua_to_vec<vec2>( L, index ), lua_tonumber( L, index + 1 ) );
                }
                else
                {
                        if ( lua_type( L, index+1 ) == LUA_TUSERDATA )
                                return T( lua_tonumber( L, index ), nlua_to_vec<vec2>( L, index+1 ) );
                        else
                                return T( lua_tonumber( L, index ), lua_tonumber( L, index + 1 ), lua_tonumber( L, index + 2 ) );
                }
        }
};

template < typename T > struct nlua_vec_constructor< T, 4 > {
        static inline T construct( lua_State* L, int index ) {
                typedef glm::detail::tvec2<T::value_type> vec2;
                typedef glm::detail::tvec3<T::value_type> vec3;
                if ( lua_type( L, index ) == LUA_TUSERDATA )
                {
                        if ( nlua_is_vec<T>( L, index ) )
                                return nlua_to_vec<T>( L, index );
                        else
                        {
                                if ( nlua_is_vec<vec3>( L, index ) )
                                        return T( nlua_to_vec<vec3>( L, index ), lua_tonumber( L, index + 1 ) );
                                else
                                {
                                        if ( lua_type( L, index+1 ) == LUA_TUSERDATA )
                                                return T( nlua_to_vec<vec2>( L, index ), nlua_to_vec<vec2>( L, index + 1 ) );
                                        else
                                                return T( nlua_to_vec<vec2>( L, index ), lua_tonumber( L, index + 1 ), lua_tonumber( L, index + 2 ) );
                                }
                        }
                }
                else
                {
                        if ( lua_type( L, index+1 ) == LUA_TUSERDATA )
                        {
                                if ( nlua_is_vec<vec3>( L, index+1 ) )
                                        return T( lua_tonumber( L, index ), nlua_to_vec<vec3>( L, index+1 ) );
                                else
                                        return T( lua_tonumber( L, index ), nlua_to_vec<vec2>( L, index+1 ), lua_tonumber( L, index + 2 ) );
                        }
                        else
                        {
                                if ( lua_type( L, index+2 ) == LUA_TUSERDATA )
                                        return T( lua_tonumber( L, index ), lua_tonumber( L, index + 1 ), nlua_to_vec<vec2>( L, index+2 ) );
                                else
                                        return T( lua_tonumber( L, index ), lua_tonumber( L, index + 1 ), lua_tonumber( L, index + 2 ), lua_tonumber( L, index + 3 ) );
                        }
                }
        }
};

template< typename T >
int nlua_vec_new( lua_State* L )
{
        nlua_push_vec( L, nlua_vec_constructor<T,sizeof( T ) / sizeof( T::value_type )>::construct( L, 1 ) );
        return 1;
}

template< typename T >
int nlua_vec_call( lua_State* L )
{
        nlua_push_vec( L, nlua_vec_constructor<T,sizeof( T ) / sizeof( T::value_type )>::construct( L, 2 ) );
        return 1;
}

template< typename T >
static int nlua_vec_unm( lua_State* L )
{
        nlua_push_vec<T>( L, -nlua_to_vec<T>( L, 1 ) );
        return 1;
}

template< typename T >
int nlua_vec_add( lua_State* L )
{
        if ( lua_type( L, 1 ) == LUA_TNUMBER )
                nlua_push_vec<T>( L, (T::value_type)(lua_tonumber( L, 1 )) + nlua_to_vec<T>( L, 2 ) );
        else
                if ( lua_type( L, 2 ) == LUA_TNUMBER )
                        nlua_push_vec<T>( L, nlua_to_vec<T>( L, 1 ) + (T::value_type)(lua_tonumber( L, 2 )) );
                else
                        nlua_push_vec<T>( L, nlua_to_vec<T>( L, 1 ) + nlua_to_vec<T>( L, 2 ) );
        return 1;
}

template< typename T >
int nlua_vec_sub( lua_State* L )
{
        if ( lua_type( L, 1 ) == LUA_TNUMBER )
                nlua_push_vec<T>( L, (T::value_type)(lua_tonumber( L, 1 )) - nlua_to_vec<T>( L, 2 ) );
        else
                if ( lua_type( L, 2 ) == LUA_TNUMBER )
                        nlua_push_vec<T>( L, nlua_to_vec<T>( L, 1 ) - (T::value_type)(lua_tonumber( L, 2 )) );
                else
                        nlua_push_vec<T>( L, nlua_to_vec<T>( L, 1 ) - nlua_to_vec<T>( L, 2 ) );
        return 1;
}

template< typename T >
int nlua_vec_mul( lua_State* L )
{
        if ( lua_type( L, 1 ) == LUA_TNUMBER )
                nlua_push_vec<T>( L, (T::value_type)(lua_tonumber( L, 1 )) * nlua_to_vec<T>( L, 2 ) );
        else
                if ( lua_type( L, 2 ) == LUA_TNUMBER )
                        nlua_push_vec<T>( L, nlua_to_vec<T>( L, 1 ) * (T::value_type)(lua_tonumber( L, 2 )) );
                else
                        nlua_push_vec<T>( L, nlua_to_vec<T>( L, 1 ) * nlua_to_vec<T>( L, 2 ) );
        return 1;
}

template< typename T >
int nlua_vec_div( lua_State* L )
{
        if ( lua_type( L, 1 ) == LUA_TNUMBER )
                nlua_push_vec<T>( L, (T::value_type)(lua_tonumber( L, 1 )) / nlua_to_vec<T>( L, 2 ) );
        else
                if ( lua_type( L, 2 ) == LUA_TNUMBER )
                        nlua_push_vec<T>( L, nlua_to_vec<T>( L, 1 ) / (T::value_type)(lua_tonumber( L, 2 )) );
                else
                        nlua_push_vec<T>( L, nlua_to_vec<T>( L, 1 ) / nlua_to_vec<T>( L, 2 ) );
        return 1;
}

template< typename T >
int nlua_vec_eq( lua_State* L )
{
        lua_pushboolean( L, nlua_to_vec<T>( L, 1 ) == nlua_to_vec<T>( L, 2 ) );
        return 1;
}

template< typename T >
int nlua_vec_get( lua_State* L )
{
        T v = nlua_to_vec<T>( L, 1 );
        for ( size_t i = 0; i < v.length(); ++i )
        {
                lua_pushnumber( L, v[i] );
        }
        return v.length();
}

template< typename T >
int nlua_vec_index( lua_State* L )
{
        T* v = nlua_to_pvec<T>( L, 1 );
        size_t len  = 0;
        size_t vlen = v->length();
        const char * key = lua_tolstring( L, 2, &len );
        size_t idx = 255;

        if( len == 1 )
        {
                idx = nlua_swizzel_lookup[ key[ 0 ] ];
                if ( idx < vlen )
                {
                        lua_pushnumber( L, (*v)[idx] );
                        return 1;
                }
        }
        else if ( len < 4 && nlua_is_swizzel(key,vlen-1) )
        {
                switch (len) {
                case 2 : nlua_push_vec( L, glm::detail::tvec2<T::value_type>( (*v)[nlua_swizzel_lookup[key[0]]], (*v)[nlua_swizzel_lookup[key[1]]] ) ); return 1;
                case 3 : nlua_push_vec( L, glm::detail::tvec3<T::value_type>( (*v)[nlua_swizzel_lookup[key[0]]], (*v)[nlua_swizzel_lookup[key[1]]], (*v)[nlua_swizzel_lookup[key[2]]] ) ); return 1;
                case 4 : nlua_push_vec( L, glm::detail::tvec4<T::value_type>( (*v)[nlua_swizzel_lookup[key[0]]], (*v)[nlua_swizzel_lookup[key[1]]], (*v)[nlua_swizzel_lookup[key[2]]], (*v)[nlua_swizzel_lookup[key[3]]] ) ); return 1;
                default: break;
                }
        }

        lua_getglobal( L, nv::get_type_name<T>() );
        lua_pushvalue( L, -2 );
        lua_rawget( L, -2 );

        return 1;
}

template< typename T >
int nlua_vec_newindex( lua_State* L )
{
        typedef glm::detail::tvec2<T::value_type> vec2;
        typedef glm::detail::tvec3<T::value_type> vec3;
        typedef glm::detail::tvec4<T::value_type> vec4;

        T* v = nlua_to_pvec<T>( L, 1 );
        size_t len  = 0;
        size_t vlen = v->length();
        const char * key = lua_tolstring( L, 2, &len );
        size_t idx = 255;
        if( len == 1 )
        {
                idx = nlua_swizzel_lookup[ key[ 0 ] ];
                if ( idx < vlen )
                {
                        (*v)[idx] = (T::value_type)luaL_checknumber( L, 3 );
                        return 0;
                }
        }
        else if ( len < 4 && nlua_is_swizzel(key,vlen-1) )
        {
                switch (len) {
                case 2 : { vec2 v2 = nlua_to_vec<vec2>(L,3); for (size_t i = 0; i<len; ++i) (*v)[nlua_swizzel_lookup[key[i]]] = v2[i]; } return 0;
                case 3 : { vec3 v3 = nlua_to_vec<vec3>(L,3); for (size_t i = 0; i<len; ++i) (*v)[nlua_swizzel_lookup[key[i]]] = v3[i]; } return 0;
                case 4 : { vec4 v4 = nlua_to_vec<vec4>(L,3); for (size_t i = 0; i<len; ++i) (*v)[nlua_swizzel_lookup[key[i]]] = v4[i]; } return 0;
                default: break;
                }
        }
        return 0;
}

template< typename T >
static int nlua_vec_tostring( lua_State* L )
{
        T v = nlua_to_vec<T>( L, 1 );
        std::string s = "(";
        for ( size_t i = 0; i < v.length(); ++i )
        {
                if (i > 0) s += ",";
                s += nv::to_string(v[i]);
        }
        s+=")";
        lua_pushstring( L, s.c_str() );
        return 1;
}

template< typename T >
int luaopen_vec( lua_State * L )
{
        static const struct luaL_Reg nlua_vec_f [] = {
                { "new",            nlua_vec_new<T> },
                { "get",            nlua_vec_get<T> },
                {NULL, NULL}
        };

        static const struct luaL_Reg nlua_vec_fm [] = {
                { "__call",         nlua_vec_call<T> },
                {NULL, NULL}
        };

        static const struct luaL_Reg nlua_vec_m [] = {
                { "__add",      nlua_vec_add<T> },
                { "__sub",      nlua_vec_sub<T> },
                { "__unm",      nlua_vec_unm<T> },
                { "__mul",      nlua_vec_mul<T> },
                { "__div",      nlua_vec_div<T> },
                { "__eq",       nlua_vec_eq<T> },
                { "__index",    nlua_vec_index<T> },
                { "__newindex", nlua_vec_newindex<T> },
                { "__tostring", nlua_vec_tostring<T> },
                {NULL, NULL}
        };

        luaL_newmetatable( L, nv::get_type_name<T>() );
        luaL_setfuncs( L, nlua_vec_m, 0 );
        lua_pop(L,1);
        luaL_newlib(L, nlua_vec_f);
        lua_newtable( L );
        luaL_setfuncs( L, nlua_vec_fm, 0 );
        lua_setmetatable( L, -2 );
        return 1;
}

void nlua_register_glm( lua_State* L )
{ 
        for (size_t i = 0; i < 256; ++i ) nlua_swizzel_lookup[i] = 255;
        nlua_swizzel_lookup['x'] = 0;
        nlua_swizzel_lookup['r'] = 0;
        nlua_swizzel_lookup['s'] = 0;
        nlua_swizzel_lookup['0'] = 0;
        nlua_swizzel_lookup['y'] = 1;
        nlua_swizzel_lookup['g'] = 1;
        nlua_swizzel_lookup['t'] = 0;
        nlua_swizzel_lookup['1'] = 1;
        nlua_swizzel_lookup['z'] = 2;
        nlua_swizzel_lookup['b'] = 2;
        nlua_swizzel_lookup['u'] = 0;
        nlua_swizzel_lookup['2'] = 2;
        nlua_swizzel_lookup['w'] = 3;
        nlua_swizzel_lookup['a'] = 3;
        nlua_swizzel_lookup['v'] = 0;
        nlua_swizzel_lookup['3'] = 3;
        int stack = lua_gettop( L );
        luaL_requiref(L, "ivec2", luaopen_vec<glm::ivec2>, 1);
        luaL_requiref(L, "ivec3", luaopen_vec<glm::ivec3>, 1);
        luaL_requiref(L, "ivec4", luaopen_vec<glm::ivec4>, 1);
        luaL_requiref(L, "vec2", luaopen_vec<glm::vec2>, 1);
        luaL_requiref(L, "vec3", luaopen_vec<glm::vec3>, 1);
        luaL_requiref(L, "vec4", luaopen_vec<glm::vec4>, 1);
        lua_settop( L, stack );
}