Merge commit '411251c6242b04119edc41ce83f09f0714e2d32b' as 'external/SDL'

external/SDL/src/SDL_list.c

@@ -0,0 +1,173 @@
+/*
+  Simple DirectMedia Layer
+  Copyright (C) 1997-2026 Sam Lantinga <slouken@libsdl.org>
+
+  This software is provided 'as-is', without any express or implied
+  warranty.  In no event will the authors be held liable for any damages
+  arising from the use of this software.
+
+  Permission is granted to anyone to use this software for any purpose,
+  including commercial applications, and to alter it and redistribute it
+  freely, subject to the following restrictions:
+
+  1. The origin of this software must not be misrepresented; you must not
+     claim that you wrote the original software. If you use this software
+     in a product, an acknowledgment in the product documentation would be
+     appreciated but is not required.
+  2. Altered source versions must be plainly marked as such, and must not be
+     misrepresented as being the original software.
+  3. This notice may not be removed or altered from any source distribution.
+*/
+#include "SDL_internal.h"
+
+#include "./SDL_list.h"
+
+// Append
+bool SDL_ListAppend(SDL_ListNode **head, void *ent)
+{
+    SDL_ListNode *cursor;
+    SDL_ListNode *node;
+
+    if (!head) {
+        return false;
+    }
+
+    node = (SDL_ListNode *)SDL_malloc(sizeof(*node));
+    if (!node) {
+        return false;
+    }
+    node->entry = ent;
+    node->next = NULL;
+
+    if (*head) {
+        cursor = *head;
+        while (cursor->next) {
+            cursor = cursor->next;
+        }
+        cursor->next = node;
+    } else {
+        *head = node;
+    }
+
+    return true;
+}
+
+bool SDL_ListInsertAtPosition(SDL_ListNode **head, int pos, void *ent)
+{
+    SDL_ListNode *cursor;
+    SDL_ListNode *node;
+    int i;
+
+    if (pos == -1) {
+        return SDL_ListAppend(head, ent);
+    }
+
+    if (!pos) {
+        node = (SDL_ListNode *)SDL_malloc(sizeof(*node));
+        if (!node) {
+            return false;
+        }
+        node->entry = ent;
+
+        if (*head) {
+            node->next = *head;
+        } else {
+            node->next = NULL;
+        }
+
+        *head = node;
+    }
+
+    cursor = *head;
+    for (i = 1; i < pos - 1 && cursor; i++) {
+        cursor = cursor->next;
+    }
+
+    if (!cursor) {
+        return SDL_ListAppend(head, ent);
+    }
+
+    node = (SDL_ListNode *)SDL_malloc(sizeof(*node));
+    if (!node) {
+        return false;
+    }
+    node->entry = ent;
+    node->next = cursor->next;
+    cursor->next = node;
+
+    return true;
+}
+
+// Push
+bool SDL_ListAdd(SDL_ListNode **head, void *ent)
+{
+    SDL_ListNode *node = (SDL_ListNode *)SDL_malloc(sizeof(*node));
+
+    if (!node) {
+        return false;
+    }
+
+    node->entry = ent;
+    node->next = *head;
+    *head = node;
+    return true;
+}
+
+// Pop from end as a FIFO (if add with SDL_ListAdd)
+void SDL_ListPop(SDL_ListNode **head, void **ent)
+{
+    SDL_ListNode **ptr = head;
+
+    // Invalid or empty
+    if (!head || !*head) {
+        return;
+    }
+
+    while ((*ptr)->next) {
+        ptr = &(*ptr)->next;
+    }
+
+    if (ent) {
+        *ent = (*ptr)->entry;
+    }
+
+    SDL_free(*ptr);
+    *ptr = NULL;
+}
+
+void SDL_ListRemove(SDL_ListNode **head, void *ent)
+{
+    SDL_ListNode **ptr = head;
+
+    while (*ptr) {
+        if ((*ptr)->entry == ent) {
+            SDL_ListNode *tmp = *ptr;
+            *ptr = (*ptr)->next;
+            SDL_free(tmp);
+            return;
+        }
+        ptr = &(*ptr)->next;
+    }
+}
+
+void SDL_ListClear(SDL_ListNode **head)
+{
+    SDL_ListNode *l = *head;
+    *head = NULL;
+    while (l) {
+        SDL_ListNode *tmp = l;
+        l = l->next;
+        SDL_free(tmp);
+    }
+}
+
+int SDL_ListCountEntries(SDL_ListNode **head)
+{
+    SDL_ListNode *node;
+    int count = 0;
+
+    for (node = *head; node; node = node->next) {
+        ++count;
+    }
+    return count;
+}