From 486ab96ab2cc681ce1198cd03325051b97658395 Mon Sep 17 00:00:00 2001
From: Simon Gellis <simongellis@gmail.com>
Date: Thu, 31 Oct 2024 21:56:58 -0400
Subject: [PATCH] Stop rendering uninitialized memory

---
 emulation.c | 4 ++++
 emulation.h | 1 +
 ui.c        | 7 ++++---
 3 files changed, 9 insertions(+), 3 deletions(-)

diff --git a/emulation.c b/emulation.c
index 09d133d..6611a89 100644
--- a/emulation.c
+++ b/emulation.c
@@ -41,6 +41,10 @@ void emuReset(EmulationContext *emu) {
     vbReset(emu->sim);
 }
 
+bool emuIsGameLoaded(EmulationContext *emu) {
+    return vbGetCartROM(emu->sim, NULL) != NULL;
+}
+
 #define MAX_STEP_CLOCKS 20000000
 void emuTick(EmulationContext *emu) {
     uint32_t clocks = MAX_STEP_CLOCKS;
diff --git a/emulation.h b/emulation.h
index c931146..8721735 100644
--- a/emulation.h
+++ b/emulation.h
@@ -20,6 +20,7 @@ int emuInit(EmulationContext *emu);
 void emuDestroy(EmulationContext *emu);
 void emuLoadGame(EmulationContext *emu, uint8_t *rom, uint32_t romSize);
 void emuReset(EmulationContext *emu);
+bool emuIsGameLoaded(EmulationContext *emu);
 
 void emuTick(EmulationContext *emu);
 bool emuReadPixels(EmulationContext *emu, uint8_t *left, uint8_t *right);
diff --git a/ui.c b/ui.c
index c863718..c3cb86e 100644
--- a/ui.c
+++ b/ui.c
@@ -106,9 +106,10 @@ typedef enum status_t {
 } status_t;
 
 int uiRun(UIContext *ui, bool running) {
-    static uint8_t leftEye[384*224];
-    static uint8_t rightEye[384*224];
+    static uint8_t leftEye[384*224] = {0};
+    static uint8_t rightEye[384*224] = {0};
     status_t status = running ? status_running : status_paused;
+    windowUpdate(&ui->win, leftEye, rightEye);
 
     while (1) {
         struct nk_context *ctx;
@@ -163,7 +164,7 @@ int uiRun(UIContext *ui, bool running) {
                 }
                 if (nk_menu_item_label(ctx, "Reset", NK_TEXT_ALIGN_LEFT)) {
                     emuReset(&ui->emu);
-                    status = status_running;
+                    status = emuIsGameLoaded(&ui->emu) ? status_running : status_paused;
                 }
                 nk_menu_end(ctx);
             }