gfx2d sketch

src/core/core_ctx.h

@@ -2,6 +2,7 @@ typedef struct thread_ctx_t thread_ctx_t;
 struct thread_ctx_t {
     ma_arena_t scratch[3];
     ma_arena_t perm;
+    ma_arena_t *temp; // application specific arena
     logger_t log;
 };