added a dynamic array header file

src/util/dynarr.h

@@ -0,0 +1,99 @@
+#ifndef DYNARR_H
+#define DYNARR_H
+#include <stddef.h>
+#include <stdint.h>
+#define DYNARR_COMB1(a, b) DYNARR_COMB2(a, b)
+#define DYNARR_COMB2(a, b) a##b
+#endif // DYNARR_H
+
+#ifdef DYNARR_TYPE
+#include <stdlib.h>
+
+// customising the linkage
+#ifndef DYNARR_LINKAGE
+#define DYNARR_LINKAGE static inline
+#endif
+
+// customising the name
+#ifndef DYNARR_NAME
+#define DYNARR_NAME DYNARR_COMB1(dynarr_, DYNARR_TYPE)
+#endif // DYNARR_NAME
+
+#define DYNARR_init   DYNARR_COMB1(DYNARR_NAME, _init)   // name of the initialization funcition
+#define DYNARR_add    DYNARR_COMB1(DYNARR_NAME, _add)    // name of the addition function
+#define DYNARR_remove DYNARR_COMB1(DYNARR_NAME, _remove) // name of the removal function
+#define DYNARR_free   DYNARR_COMB1(DYNARR_NAME, _free)   // name of the freeing function
+
+// define the dynamic array structure
+typedef struct {
+    DYNARR_TYPE* dat; // contains the data of the dynamic array
+    size_t count;     // contains the amount of elements of the dynamic array
+    size_t cap;       // contains the capacity of the dynamic array
+} DYNARR_NAME;
+
+// initializes the dynamic array with a specific capacity (dat may be null if malloc fails)
+DYNARR_LINKAGE DYNARR_NAME DYNARR_init(const size_t cap) {
+    return (DYNARR_NAME){
+        malloc(cap * sizeof(DYNARR_TYPE)),
+        0,
+        cap,
+    };
+}
+
+// adds an item to the dynamic array, doubles the capacity if the new count exceeds the maximum
+// returns 0 upon success, 1 upon failure
+DYNARR_LINKAGE uint8_t DYNARR_add(DYNARR_NAME* arr, DYNARR_TYPE item) {
+    size_t idx = arr->count;
+    arr->count++;
+
+    // resize the dynamic array if the new count has hit the max capacity
+    if (arr->cap == arr->count) {
+        arr->cap *= 2;
+        DYNARR_TYPE* nptr = realloc(arr->dat, arr->cap * sizeof(DYNARR_TYPE));
+
+        if (nptr == NULL)
+            return 1;
+
+        arr->dat = nptr;
+    }
+
+    arr->dat[idx] = item;
+    return 0;
+}
+
+// removes an item from the dynamic array from a certain index
+// returns 0 upon success, 1 upon failure
+DYNARR_LINKAGE uint8_t DYNARR_remove(DYNARR_NAME* arr, size_t idx) {
+    if (arr->count == 0 || idx >= arr->count) return 1;
+
+    // remove one from the count
+    arr->count--;
+
+    // update the subsequent items until the count (don't bother with the rest)
+    // will only run if there are subsequent items
+    for (size_t i = idx; i < arr->count; i++) {
+        arr->dat[i] = arr->dat[i + 1]; // +1 is fine, we know the last item exists because we removed 1
+    }
+
+    return 0;
+}
+
+// cleans up the resources associated with the array, do not use after this step. This is undefined behaviour
+DYNARR_LINKAGE void DYNARR_free(DYNARR_NAME* arr) {
+    free(arr->dat);
+    arr->dat = NULL;
+}
+
+// clean up all defined definitions so they can be used again later
+#undef DYNARR_NAME
+#undef DYNARR_init
+#undef DYNARR_add
+#undef DYNARR_remove
+#undef DYNARR_PREFIX
+#undef DYNARR_LINKAGE
+#undef DYNARR_TYPE
+#else
+#if __INCLUDE_LEVEL__ != 0
+#error define DYNARR_TYPE before including
+#endif // include level
+#endif // DYNARR_TYPE