1 files changed, 80 insertions, 0 deletions
diff --git a/src/code/TwoHeadArena.c b/src/code/TwoHeadArena.c
new file mode 100644
index 000000000..8ca24c67e
--- /dev/null
+++ b/src/code/TwoHeadArena.c
@@ -0,0 +1,80 @@
+#include <ultra64.h>
+#include <global.h>
+
+void* THA_GetHead(TwoHeadArena* tha) {
+    return tha->head;
+}
+
+void THA_SetHead(TwoHeadArena* tha, void* start) {
+    tha->head = start;
+}
+
+void* THA_GetTail(TwoHeadArena* tha) {
+    return tha->tail;
+}
+
+void* THA_AllocStart(TwoHeadArena* tha, u32 size) {
+    void* start = tha->head;
+
+    tha->head = (u32)tha->head + size;
+    return start;
+}
+
+void* THA_AllocStart1(TwoHeadArena* tha) {
+    return THA_AllocStart(tha, 1);
+}
+
+void* THA_AllocEnd(TwoHeadArena* tha, u32 size) {
+    u32 mask;
+
+    if (size >= 0x10) {
+        mask = ~0xF;
+    } else if (size & 1) {
+        mask = -1;
+    } else if (size & 2) {
+        mask = ~0x1;
+    } else if (size & 4) {
+        mask = ~0x3;
+    } else {
+        mask = (size & 8) ? ~0x7 : -1;
+    }
+
+    tha->tail = (((u32)tha->tail & mask) - size) & mask;
+    return tha->tail;
+}
+
+void* THA_AllocEndAlign16(TwoHeadArena* tha, u32 size) {
+    u32 mask = ~0xF;
+
+    tha->tail = (((u32)tha->tail & mask) - size) & mask;
+    return tha->tail;
+}
+
+void* THA_AllocEndAlign(TwoHeadArena* tha, u32 size, u32 mask) {
+    tha->tail = (((u32)tha->tail & mask) - size) & mask;
+    return tha->tail;
+}
+
+s32 THA_GetSize(TwoHeadArena* tha) {
+    return (u32)tha->tail - (u32)tha->head;
+}
+
+u32 THA_IsCrash(TwoHeadArena* tha) {
+    return THA_GetSize(tha) < 0;
+}
+
+void THA_Init(TwoHeadArena* tha) {
+    tha->head = tha->bufp;
+    tha->tail = (u32)tha->bufp + tha->size;
+}
+
+void THA_Ct(TwoHeadArena* tha, void* ptr, u32 size) {
+    bzero(tha, sizeof(TwoHeadArena));
+    tha->bufp = ptr;
+    tha->size = size;
+    THA_Init(tha);
+}
+
+void THA_Dt(TwoHeadArena* tha) {
+    bzero(tha, sizeof(TwoHeadArena));
+}