Used __builtin_wasm_memory_size(0) instead of having the Javascript code call init_mem with the initial page count. Added a simple <div> below the canvas that can hold any number of labels that can be filled/updated through jsSetLabel which lives in a new file misc_functions.js.

std/src/std_mem.c

@@ -9,20 +9,19 @@ Description:
 
 extern unsigned char __heap_base;
 
-static void* heapBaseAddress = 0;
+static void* heapBaseAddress = nullptr;
 static size_t stdCurrentHeapSize = 0;
 static size_t stdCurrentPageCount = 0;
 
-WASM_EXPORT(init_mem) void init_mem(size_t numInitialPages)
-{
-	heapBaseAddress = (void*)&__heap_base;
-	stdCurrentPageCount = numInitialPages;
-}
-
 //These are our own std-like functions for interacting with WebAssembly memory
 void* grow_mem(size_t numBytes)
 {
-	assert_msg(heapBaseAddress != nullptr, "growmem called before initmem! Make sure initmem is being called by the Javascript code!");
+	if (heapBaseAddress == nullptr)
+	{
+		stdCurrentPageCount = __builtin_wasm_memory_size(0);
+		heapBaseAddress = (void*)&__heap_base;
+	}
+	
 	size_t memorySizeNeeded = ((size_t)heapBaseAddress) + stdCurrentHeapSize;
 	size_t numPagesNeeded = (memorySizeNeeded / WASM_MEMORY_PAGE_SIZE) + (((memorySizeNeeded % WASM_MEMORY_PAGE_SIZE) > 0) ? 1 : 0);
 	if (numPagesNeeded > WASM_MEMORY_MAX_NUM_PAGES)

std/stdlib.h

@@ -26,7 +26,6 @@ _Noreturn void abort_msg(const char* message);
 // void* aligned_alloc(size_t numBytes, size_t alignmentSize);
 
 //These are our own std-like functions for interacting with WebAssembly memory
-WASM_EXPORT(init_mem) void init_mem(size_t numInitialPages);
 void* grow_mem(size_t numBytes);
 size_t get_mem();