Add stack allocator

engine/breeze/memory/stack_alloc.c

@@ -0,0 +1,34 @@
+#include "stack_alloc.h"
+
+#include "memory.h"
+
+BzStackAlloc bzStackAllocCreate(size_t size) {
+    BzStackAlloc alloc = {
+            .memory=bzAlloc(size),
+            .size=size,
+            .allocated=0
+    };
+    BZ_ASSERT(alloc.memory);
+
+    return alloc;
+}
+
+void bzStackAllocDestroy(BzStackAlloc *alloc) {
+    bzFree(alloc->memory);
+    alloc->memory    = NULL;
+    alloc->size      = 0;
+    alloc->allocated = 0;
+}
+
+void *bzStackAlloc(BzStackAlloc *alloc, size_t numBytes) {
+    BZ_ASSERT(alloc->size + numBytes < alloc->size);
+    void *allocated = (u8 *) alloc->memory + alloc->allocated;
+    alloc->allocated += numBytes;
+    return allocated;
+}
+
+void bzStackAllocFree(BzStackAlloc *alloc, void *ptr) {
+    size_t byteOffset = (u8 *) ptr - (u8 *) alloc->memory;
+    BZ_ASSERT(byteOffset >= 0 && byteOffset < alloc->size);
+    alloc->allocated = byteOffset;
+}