dusklight/libs/dolphin/src/support/Tree.c

#include <charPipeline/structures/Tree.h>

void DSExtractBranch(DSTreePtr tree, Ptr obj) {
    DSBranchPtr branch = (DSBranchPtr)(obj + tree->Offset);
    Ptr cursor = branch->Children;
    Ptr next;

    while (cursor) {
        next = ((DSBranchPtr)(cursor + tree->Offset))->Next;
        DSInsertBranchBelow(tree, branch->Parent, cursor);
        cursor = next;
    }
    DSRemoveBranch(tree, obj);
}

void DSInitTree(DSTreePtr tree, Ptr obj, DSBranchPtr branch) {
    tree->Root = NULL;
    tree->Offset = (Ptr)branch - obj;
}

void DSInsertBranchBelow(DSTreePtr tree, Ptr cursor, Ptr obj) {
    DSBranchPtr branch;
    DSBranchPtr objBranch = (DSBranchPtr)(obj + tree->Offset);
    Ptr tail = NULL;

    if (cursor) {
        branch = (DSBranchPtr)(cursor + tree->Offset);
        if (branch->Children) {
            tail = branch->Children;
        } else {
            branch->Children = obj;
        }
    } else if (tree->Root) {
        tail = tree->Root;
    } else {
        tree->Root = obj;
    }

    if (tail) {
        while (((DSBranchPtr)(tail + tree->Offset))->Next) {
            tail = ((DSBranchPtr)(tail + tree->Offset))->Next;
        }
        ((DSBranchPtr)(tail + tree->Offset))->Next = obj;
        objBranch->Prev = tail;
    } else {
        objBranch->Prev = NULL;
    }

    objBranch->Next = NULL;
    objBranch->Parent = cursor;
}

void DSInsertBranchBeside(DSTreePtr tree, Ptr cursor, Ptr obj) {
    DSBranchPtr parent;
    DSBranchPtr branch;

    branch = (DSBranchPtr)(obj + tree->Offset);
    if (!cursor) {
        if (!tree->Root) {
            tree->Root = obj;
            branch->Next = NULL;
            branch->Prev = NULL;
            branch->Children = NULL;
            branch->Parent = NULL;
            return;
        }
        cursor = tree->Root;
    }

    while (((DSBranchPtr)(cursor + tree->Offset))->Next) {
        cursor = ((DSBranchPtr)(cursor + tree->Offset))->Next;
    }

    parent = (DSBranchPtr)(cursor + tree->Offset);
    parent->Next = obj;
    branch->Prev = cursor;
    branch->Next = NULL;
    branch->Parent = parent->Parent;
}

void DSRemoveBranch(DSTreePtr tree, Ptr obj) {
    DSBranchPtr branch;
    DSBranchPtr parent;

    branch = (DSBranchPtr)(obj + tree->Offset);
    if (branch->Parent) {
        parent = (DSBranchPtr)(branch->Parent + tree->Offset);
        if (parent->Children == obj) {
            parent->Children = branch->Next;
        }
    } else if (tree->Root == obj) {
        tree->Root = branch->Next;
    }

    if (branch->Prev) {
        ((DSBranchPtr)(branch->Prev + tree->Offset))->Next = branch->Next;
    }

    if (branch->Next) {
        ((DSBranchPtr)(branch->Next + tree->Offset))->Prev = branch->Prev;
    }

    branch->Prev = NULL;
    branch->Next = NULL;
    branch->Parent = NULL;
}