static int luaB_unpack (lua_State *L) {
if (lua_gettop(L)==1 && lua_isvector3(L,1)) {
float x, y, z; lua_checkvector3(L, 1, &x, &y, &z);
lua_pushnumber(L,x);
lua_pushnumber(L,y);
lua_pushnumber(L,z);
return 3;
} else if (lua_gettop(L)==1 && lua_isquat(L,1)) {
float w, x, y, z; lua_checkquat(L, 1, &w, &x, &y, &z);
lua_pushnumber(L,w);
lua_pushnumber(L,x);
lua_pushnumber(L,y);
lua_pushnumber(L,z);
return 4;
} else {
int i, e, n;
luaL_checktype(L, 1, LUA_TTABLE);
i = luaL_optint(L, 2, 1);
e = luaL_opt(L, luaL_checkint, 3, luaL_getn(L, 1));
if (i > e) return 0; /* empty range */
n = e - i + 1; /* number of elements */
if (n <= 0 || !lua_checkstack(L, n)) /* n <= 0 means arith. overflow */
return luaL_error(L, "too many results to unpack");
lua_rawgeti(L, 1, i); /* push arg[i] (avoiding overflow problems) */
while (i++ < e) /* push arg[i + 1...e] */
lua_rawgeti(L, 1, i);
return n;
}
}
static int luaB_dot (lua_State *L) {
float x1, y1, z1, w1;
float x2, y2, z2, w2;
if (lua_gettop(L) != 2) luaL_error(L, "Invalid params, try dot(v,v)");
if (lua_isvector4(L,1)) {
lua_checkvector4(L, 1, &x1, &y1, &z1, &w1);
lua_checkvector4(L, 2, &x2, &y2, &z2, &w2);
lua_pushnumber(L,dot4(x1,y1,z1,w1, x2,y2,z2,w2));
} else if (lua_isvector3(L,1)) {
lua_checkvector3(L, 1, &x1, &y1, &z1);
lua_checkvector3(L, 2, &x2, &y2, &z2);
lua_pushnumber(L,dot3(x1,y1,z1, x2,y2,z2));
} else if (lua_isvector2(L,1)) {
lua_checkvector2(L, 1, &x1, &y1);
lua_checkvector2(L, 2, &x2, &y2);
lua_pushnumber(L,dot2(x1,y1, x2,y2));
}
return 1;
}
static int luaB_norm (lua_State *L) {
if (lua_gettop(L)==1 && lua_isvector3(L,1)) {
float x, y, z;
float len;
lua_checkvector3(L, 1, &x, &y, &z);
len = sqrtf(x*x + y*y + z*z);
lua_pushvector3(L,x/len,y/len,z/len);
return 1;
} else if (lua_gettop(L)==1 && lua_isquat(L,1)) {
float w, x, y, z;
float qlen;
lua_checkquat(L, 1, &w, &x, &y, &z);
qlen = sqrtf(w*w + x*x + y*y + z*z);
lua_pushquat(L,w/qlen,x/qlen,y/qlen,z/qlen);
return 1;
} else {
luaL_error(L, "Invalid params, try norm(v) norm(q)");
return 0;
}
}
static int luaB_norm (lua_State *L) {
if (lua_gettop(L)==1 && lua_isvector2(L,1)) {
float x, y;
float len;
lua_checkvector2(L, 1, &x, &y);
len = sqrtf(x*x + y*y);
if (len == 0)
luaL_error(L, "Cannot normalise vector2(0,0)");
lua_pushvector2(L,x/len,y/len);
return 1;
} else if (lua_gettop(L)==1 && lua_isvector3(L,1)) {
float x, y, z;
float len;
lua_checkvector3(L, 1, &x, &y, &z);
len = sqrtf(x*x + y*y + z*z);
if (len == 0)
luaL_error(L, "Cannot normalise vector3(0,0,0)");
lua_pushvector3(L,x/len,y/len,z/len);
return 1;
} else if (lua_gettop(L)==1 && lua_isvector4(L,1)) {
float x, y, z, w;
float len;
lua_checkvector4(L, 1, &x, &y, &z, &w);
len = sqrtf(x*x + y*y + z*z + w*w);
if (len == 0)
luaL_error(L, "Cannot normalise vector4(0,0,0,0)");
lua_pushvector4(L,x/len,y/len,z/len,w/len);
return 1;
} else if (lua_gettop(L)==1 && lua_isquat(L,1)) {
float w, x, y, z;
float qlen;
lua_checkquat(L, 1, &w, &x, &y, &z);
qlen = sqrtf(w*w + x*x + y*y + z*z);
if (qlen == 0)
luaL_error(L, "Cannot normalise quat(0,0,0,0)");
lua_pushquat(L,w/qlen,x/qlen,y/qlen,z/qlen);
return 1;
} else {
return luaL_error(L, "Invalid arguments, try norm(v) or norm(q).");
}
}
static int luaB_quat (lua_State *L) {
if (lua_gettop(L)==4 && lua_isnumber(L,1) && lua_isnumber(L,2) && lua_isnumber(L,3) && lua_isnumber(L,4)) {
float w,x,y,z;
w = (float)lua_tonumber(L, 1);
x = (float)lua_tonumber(L, 2);
y = (float)lua_tonumber(L, 3);
z = (float)lua_tonumber(L, 4);
lua_pushquat(L, w,x,y,z);
return 1;
} else if (lua_gettop(L)==2 && lua_isnumber(L,1) && lua_isvector3(L,2)) {
float angle,x,y,z,ha,s;
angle = (float)lua_tonumber(L, 1);
lua_checkvector3(L, 2, &x, &y, &z);
ha = angle*(0.5f*PI/180.0f);
s = sinf(ha);
lua_pushquat(L, cosf(ha),s*x,s*y,s*z);
return 1;
} else if (lua_gettop(L)==2 && lua_isvector3(L,1) && lua_isvector3(L,2)) {
float x1, y1, z1;
float x2, y2, z2;
float l1,l2,d;
lua_checkvector3(L, 1, &x1, &y1, &z1);
lua_checkvector3(L, 2, &x2, &y2, &z2);
/* Based on Stan Melax's article in Game Programming Gems */
l1 = sqrtf(x1*x1 + y1*y1 + z1*z1);
l2 = sqrtf(x2*x2 + y2*y2 + z2*z2);
x1/=l1; y1/=l1; z1/=l1;
x2/=l2; y2/=l2; z2/=l2;
d = dot3(x1,y1,z1, x2,y2,z2);
/* If dot == 1, vectors are the same */
if (d >= 1.0f) {
lua_pushquat(L, 1,0,0,0);
return 1;
}
if (d < (1e-6f - 1.0f)) {
float ax, ay, az;
float len2, len;
cross3(1,0,0, x1,y1,z1, &ax, &ay, &az);
len2 = ax*ax + ay*ay + az*az;
if (len2 == 0) {
cross3(0,1,0, x1,y1,z1, &ax, &ay, &az);
len2 = ax*ax + ay*ay + az*az;
}
len = sqrtf(len2);
ax/=len; ay/=len; az/=len;
lua_pushquat(L, 0,ax,ay,az);
return 1;
} else {
float s = sqrtf((1+d)*2);
float ax, ay, az;
float qw, qlen;
cross3(x1,y1,z1, x2,y2,z2, &ax, &ay, &az);
ax/=s; ay/=s; az/=s;
qw = s*0.5f;
qlen = sqrtf(qw*qw + ax*ax + ay*ay + az*az);
lua_pushquat(L, qw/qlen,ax/qlen,ay/qlen,az/qlen);
return 1;
}
} else {
luaL_error(L, "Invalid params, try quat(n,n,n,n) quat(n,v3) quat(v3,v3)");
return 0;
}
}
