source: trunk/src/lua/lua_math.cc @ 490

// Copyright (C) 2012-2015 ChaosForge Ltd
// http://chaosforge.org/
//
// This file is part of Nova libraries. 
// For conditions of distribution and use, see copying.txt file in root folder.

#include "nv/lua/lua_math.hh"

#include "nv/lua/lua_raw.hh"
#include "nv/core/random.hh"
#include "nv/stl/type_traits/common.hh"

static size_t nlua_swizzel_lookup[256];

using nv::lua::detail::is_vec;
using nv::lua::detail::to_vec;
using nv::lua::detail::to_pvec;
using nv::lua::detail::push_vec;

inline bool nlua_is_swizzel( const unsigned 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 unit() { return T(); }
        static inline T construct( lua_State*, int ) {
                return T();
        }
};

template < typename T > struct nlua_vec_constructor< T, 1 > {
        static inline T unit() { return 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 unit() { return T( 1, 1 ); }
        static inline T construct( lua_State* L, int index ) {
                if ( lua_type( L, index ) == LUA_TUSERDATA )
                        return 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 unit() { return T( 1, 1, 1 ); }
        static inline T construct( lua_State* L, int index ) {
                typedef nv::math::tvec2<typename T::value_type> vec2;
                if ( lua_type( L, index ) == LUA_TUSERDATA )
                {
                        if ( is_vec<T>( L, index ) )
                                return to_vec<T>( L, index );
                        else
                                return T( 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 ), 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 unit() { return T( 1, 1, 1, 1 ); }
        static inline T construct( lua_State* L, int index ) {
                typedef nv::math::tvec2<typename T::value_type> vec2;
                typedef nv::math::tvec3<typename T::value_type> vec3;
                if ( lua_type( L, index ) == LUA_TUSERDATA )
                {
                        if ( is_vec<T>( L, index ) )
                                return to_vec<T>( L, index );
                        else
                        {
                                if ( is_vec<vec3>( L, index ) )
                                        return T( to_vec<vec3>( L, index ), lua_tonumber( L, index + 1 ) );
                                else
                                {
                                        if ( lua_type( L, index+1 ) == LUA_TUSERDATA )
                                                return T( to_vec<vec2>( L, index ), to_vec<vec2>( L, index + 1 ) );
                                        else
                                                return T( 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 ( is_vec<vec3>( L, index+1 ) )
                                        return T( lua_tonumber( L, index ), to_vec<vec3>( L, index+1 ) );
                                else
                                        return T( lua_tonumber( L, index ), 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 ), 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 )
{
        push_vec<T>( L, nlua_vec_constructor<T,sizeof( T ) / sizeof( typename T::value_type )>::construct( L, 1 ) );
        return 1;
}

template< typename T >
int nlua_vec_random( lua_State* L )
{
        push_vec<T>( L, nv::random::get().range( to_vec<T>( L, 1 ), to_vec<T>( L, 2 ) ) );
        return 1;
}

template< typename T >
int nlua_vec_clone( lua_State* L )
{
        push_vec<T>( L, to_vec<T>( L, 1 ) );
        return 1;
}

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

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

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

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

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

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

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

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

template< typename T >
int nlua_vec_index( lua_State* L )
{
        T* v = to_pvec<T>( L, 1 );
        size_t len  = 0;
        size_t vlen = v->size();
        const unsigned char * key = reinterpret_cast<const unsigned char *>( 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 : push_vec( L, nv::math::tvec2<typename T::value_type>( (*v)[nlua_swizzel_lookup[key[0]]], (*v)[nlua_swizzel_lookup[key[1]]] ) ); return 1;
                case 3 : push_vec( L, nv::math::tvec3<typename 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 : push_vec( L, nv::math::tvec4<typename 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;
                }
        }

        luaL_getmetafield( L, 1, "__functions" );
        lua_pushvalue( L, 2 );
        lua_rawget( L, -2 );
        return 1;
}

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

        T* v = to_pvec<T>( L, 1 );
        size_t len  = 0;
        size_t vlen = v->size();
        const unsigned char * key = reinterpret_cast<const unsigned char *>( lua_tolstring( L, 2, &len ) );
        size_t idx = 255;
        if( len == 1 )
        {
                idx = nlua_swizzel_lookup[ key[ 0 ] ];
                if ( idx < vlen )
                {
                        (*v)[idx] = static_cast<typename 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 = 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 = 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 = 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 = to_vec<T>( L, 1 );
        bool fl = nv::is_floating_point<typename T::value_type>::value;
        switch ( v.size() )
        {
        case 1: lua_pushfstring( L, ( fl ? "(%f)"          : "(%d)" ),          v[0] ); break;
        case 2: lua_pushfstring( L, ( fl ? "(%f,%f)"       : "(%d,%d)" ),       v[0], v[1] ); break;
        case 3: lua_pushfstring( L, ( fl ? "(%f,%f,%f)"    : "(%d,%d,%d)" ),    v[0], v[1], v[2] ); break;
        case 4: lua_pushfstring( L, ( fl ? "(%f,%f,%f,%f)" : "(%d,%d,%d,%d)" ), v[0], v[1], v[2], v[3] ); break;
        default:
                lua_pushliteral( L, "(vector?)" ); break;
        }
        return 1;
}

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

        static const struct luaL_Reg nlua_vec_f [] = {
                { "clone",          nlua_vec_clone<T> },
                { "get",            nlua_vec_get<T> },
                { "tostring",       nlua_vec_tostring<T> },
                {NULL, NULL}
        };

        static const struct luaL_Reg nlua_vec_sm [] = {
                { "__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::lua::pass_traits<T>::metatable() );
        nlua_register( L, nlua_vec_m, -1 );
        lua_createtable( L, 0, 0 );
        nlua_register( L, nlua_vec_f, -1 );
        lua_setfield(L, -2, "__functions" );
        lua_pop( L, 1 );

        lua_createtable( L, 0, 0 );
        nlua_register( L, nlua_vec_sf, -1 );
        lua_createtable( L, 0, 0 );
        nlua_register( L, nlua_vec_sm, -1 );
        lua_setmetatable( L, -2 );

        nv::lua::detail::push_vec( L, T() );
        lua_setfield( L, -2, "ZERO" );
        nv::lua::detail::push_vec( L, nlua_vec_constructor<T,sizeof( T ) / sizeof( typename T::value_type )>::unit() );
        lua_setfield( L, -2, "UNIT" );
        return 1;
}

void nv::lua::register_math( lua_State* L )
{ 
        for (size_t i = 0; i < 256; ++i ) nlua_swizzel_lookup[i] = 255;
        using nv::uchar8;
        nlua_swizzel_lookup[uchar8( 'x' )] = 0;
        nlua_swizzel_lookup[uchar8( 'r' )] = 0;
        nlua_swizzel_lookup[uchar8( 's' )] = 0;
        nlua_swizzel_lookup[uchar8( '0' )] = 0;
        nlua_swizzel_lookup[uchar8( 'y' )] = 1;
        nlua_swizzel_lookup[uchar8( 'g' )] = 1;
        nlua_swizzel_lookup[uchar8( 't' )] = 0;
        nlua_swizzel_lookup[uchar8( '1' )] = 1;
        nlua_swizzel_lookup[uchar8( 'z' )] = 2;
        nlua_swizzel_lookup[uchar8( 'b' )] = 2;
        nlua_swizzel_lookup[uchar8( 'u' )] = 0;
        nlua_swizzel_lookup[uchar8( '2' )] = 2;
        nlua_swizzel_lookup[uchar8( 'w' )] = 3;
        nlua_swizzel_lookup[uchar8( 'a' )] = 3;
        nlua_swizzel_lookup[uchar8( 'v' )] = 0;
        nlua_swizzel_lookup[uchar8( '3' )] = 3;
        int stack = lua_gettop( L );

        nlua_requiref(L, "coord", luaopen_vec<nv::ivec2>, 1);
        nlua_requiref(L, "ivec2", luaopen_vec<nv::ivec2>, 1);
        nlua_requiref(L, "ivec3", luaopen_vec<nv::ivec3>, 1);
        nlua_requiref(L, "ivec4", luaopen_vec<nv::ivec4>, 1);
        nlua_requiref(L, "vec2", luaopen_vec<nv::vec2>, 1);
        nlua_requiref(L, "vec3", luaopen_vec<nv::vec3>, 1);
        nlua_requiref(L, "vec4", luaopen_vec<nv::vec4>, 1);
        lua_settop( L, stack );
}