int lh_iso(lua_State *L) {
checkArg(L, 2, "isoproject");
IsoParam *P = luaO(2, IsoParam);
int t0;
int ti = luaInt(1);
t0 = addFreeform(distill(ti, spIFloor), P->Floor);
t0 = addMerge(t0, addFreeform(addRecolor(distill(ti, spIWallL), 0xFF808080, recMult), P->WalL), false);
t0 = addMerge(t0, addFreeform(addRecolor(distill(ti, spIWallR), 0xFFC0C0C0, recMult), P->WalR), false);
//t0 = addMerge(t0, addFreeform(distill(ti, spIWallL), P->WalL), false);
//t0 = addMerge(t0, addFreeform(distill(ti, spIWallR), P->WalR), false);
t0 = addMerge(t0, addFreeform(distill(ti, spICeil), P->Ceil), false);
t0 = addMerge(t0, addFreeform(distill(ti, spIItem), P->Item), false);
return retInt(L, t0);
// return retInt(L, renderAsIso(luaInt(1), spIFloor | spIItem | spIWallL | spIWallR | spICeil, luaO(2, IsoParam)));
}
static void
_distill(void)
{
p2 = pop();
p1 = pop();
// is the entire expression constant?
if (find(p1, p2) == 0) {
push(p1);
//push(p1); // may need later for pushing both +a, -a
//negate();
return;
}
// sum?
if (isadd(p1)) {
distill_sum();
return;
}
// product?
if (car(p1) == symbol(MULTIPLY)) {
distill_product();
return;
}
// naive distill if not sum or product
p3 = cdr(p1);
while (iscons(p3)) {
push(car(p3));
push(p2);
distill();
p3 = cdr(p3);
}
}
void
distill_product(void)
{
int h;
// distill factors involving x
p3 = cdr(p1);
while (iscons(p3)) {
if (find(car(p3), p2)) {
push(car(p3));
push(p2);
distill();
}
p3 = cdr(p3);
}
// multiply together all constant factors
h = tos;
p3 = cdr(p1);
while (iscons(p3)) {
if (find(car(p3), p2) == 0)
push(car(p3));
p3 = cdr(p3);
}
if (tos - h) {
multiply_all(tos - h);
//p3 = pop(); // may need later for pushing both +a, -a
//push(p3);
//push(p3);
//negate();
}
}
void
distill_sum(void)
{
int h;
// distill terms involving x
p3 = cdr(p1);
while (iscons(p3)) {
if (find(car(p3), p2)) {
push(car(p3));
push(p2);
distill();
}
p3 = cdr(p3);
}
// add together all constant terms
h = tos;
p3 = cdr(p1);
while (iscons(p3)) {
if (find(car(p3), p2) == 0)
push(car(p3));
p3 = cdr(p3);
}
if (tos - h) {
add_all(tos - h);
p3 = pop();
push(p3);
push(p3);
negate(); // need both +a, -a for some integrals
}
}
