Launcher: Disable certain things when there's no external RAM

- Disable CRC caching
- Disable background images
- Disable previews

Many of those things already failed, this makes it more explicit. And it prevents wasting memory that's necessary for other basic operations.

I think all images should be disabled, really, but a text fallback must be added first...

README.md

@@ -155,6 +155,9 @@ You can configure automatic SRAM saving in the options menu. A longer delay will
 of losing data when powering down too quickly. Also note that when *resuming* a game, Retro-Go will give priority
 to a save state if present.
 
+### ZIP files
+Most Retro-Go applications now support ZIP files. ZIP archives should contain only one ROM file and nothing else. ZIP support also depends on available memory and larger ROMs may fail to load on some devices unfortunately.
+
 
 # Development
 If you wish to build or modify Retro-Go, you can find help in the following documents:

components/retro-go/rg_system.c

@@ -370,7 +370,7 @@ rg_app_t *rg_system_init(int sampleRate, const rg_handlers_t *handlers, const rg
         .frameskip = 1,
         .overclock = 0,
         .tickTimeout = 3000000,
-        .availableMemory = 0,
+        .lowMemoryMode = false,
         .enWatchdog = true,
         .isColdBoot = true,
         .isLauncher = false,
@@ -440,6 +440,9 @@ rg_app_t *rg_system_init(int sampleRate, const rg_handlers_t *handlers, const rg
     memset(&panicTrace, 0, sizeof(panicTrace));
     panicTraceCleared = true;
 
+    update_memory_statistics();
+    app.lowMemoryMode = statistics.totalMemoryExt == 0;
+
     rg_settings_init();
     app.configNs = rg_settings_get_string(NS_BOOT, SETTING_BOOT_NAME, app.name);
     app.bootArgs = rg_settings_get_string(NS_BOOT, SETTING_BOOT_ARGS, "");
@@ -467,13 +470,8 @@ rg_app_t *rg_system_init(int sampleRate, const rg_handlers_t *handlers, const rg
     profile->lock = rg_mutex_create();
 #endif
 
-    update_memory_statistics();
-    RG_LOGI("Available memory: %d/%d + %d/%d", statistics.freeMemoryInt / 1024, statistics.totalMemoryInt / 1024,
-            statistics.freeMemoryExt / 1024, statistics.totalMemoryExt / 1024);
-    app.availableMemory = statistics.freeMemoryInt + statistics.freeMemoryExt;
-
 #ifdef ESP_PLATFORM
-    if (statistics.totalMemoryExt == 0)
+    if (app.lowMemoryMode)
         rg_gui_alert("External memory not detected", "Boot will continue but it will surely crash...");
 
     if (app.bootFlags & RG_BOOT_ONCE)
@@ -484,6 +482,9 @@ rg_app_t *rg_system_init(int sampleRate, const rg_handlers_t *handlers, const rg
     rg_task_create("rg_sysmon", &system_monitor_task, NULL, 3 * 1024, RG_TASK_PRIORITY_5, -1);
     app.initialized = true;
 
+    update_memory_statistics();
+    RG_LOGI("Available memory: %d/%d + %d/%d", statistics.freeMemoryInt / 1024, statistics.totalMemoryInt / 1024,
+            statistics.freeMemoryExt / 1024, statistics.totalMemoryExt / 1024);
     RG_LOGI("Retro-Go ready.\n\n");
 
     return &app;

components/retro-go/rg_system.h

@@ -179,7 +179,7 @@ typedef struct
     int frameskip;
     int overclock;
     int tickTimeout;
-    int availableMemory;
+    bool lowMemoryMode;
     bool enWatchdog;
     bool isColdBoot;
     bool isLauncher;

launcher/main/applications.c

@@ -683,7 +683,6 @@ static void application(const char *desc, const char *name, const char *exts, co
 
 void applications_init(void)
 {
-    bool big_memory = rg_system_get_app()->availableMemory >= 0x600000;
     application("Nintendo Entertainment System", "nes", "nes fc fds nsf zip", "retro-core", 16);
     application("Super Nintendo", "snes", "smc sfc zip", "retro-core", 0);
     application("Nintendo Gameboy", "gb", "gb gbc zip", "retro-core", 0);
@@ -697,13 +696,14 @@ void applications_init(void)
     application("Coleco ColecoVision", "col", "col rom zip", "retro-core", 0);
     application("NEC PC Engine", "pce", "pce zip", "retro-core", 0);
     application("Atari Lynx", "lnx", "lnx zip", "retro-core", 64);
-    // application("Atari 2600", "a26", "a26", "stella-go", 0);
-    // application("Neo Geo Pocket Color", "ngp", "ngp ngc", "ngpocket-go", 0);
-    application("DOOM", "doom", big_memory ? "wad zip" : "wad", "prboom-go", 0);
+    // application("Atari 2600", "a26", "a26 zip", "stella-go", 0);
+    // application("Neo Geo Pocket Color", "ngp", "ngp ngc zip", "ngpocket-go", 0);
+    application("DOOM", "doom", "wad zip", "prboom-go", 0);
     application("MSX", "msx", "rom mx1 mx2 dsk", "fmsx", 0);
 
     // Special app to bootstrap native esp32 binaries from the SD card
     // application("Bootstrap", "apps", "bin elf", "bootstrap", 0);
 
-    crc_cache_init();
+    if (!rg_system_get_app()->lowMemoryMode)
+        crc_cache_init();
 }

launcher/main/gui.c

@@ -41,6 +41,8 @@ void gui_init(bool cold_boot)
     };
     // Auto: Show carousel on cold boot, browser on warm boot (after cleanly exiting an emulator)
     gui.browse = gui.start_screen == START_SCREEN_BROWSER || (gui.start_screen == START_SCREEN_AUTO && !cold_boot);
+    gui.http_lock = false;
+    gui.low_memory_mode = rg_system_get_app()->lowMemoryMode;
     gui.surface = rg_surface_create(gui.width, gui.height, RG_PIXEL_565_LE, MEM_SLOW);
     gui_update_theme();
 }
@@ -375,6 +377,14 @@ void gui_redraw(void)
 
 void gui_draw_background(tab_t *tab, int shade)
 {
+    // In low memory mode we can't fit an entire background in memory, flood a single color instead
+    // FIXME: The color should be themable...
+    if (gui.low_memory_mode)
+    {
+        rg_gui_draw_rect(0, 0, gui.width, gui.height, 0, C_BLACK, C_BLACK);
+        return;
+    }
+
     // We can't losslessly change shade, must reload!
     if (tab->background && tab->background_shade > 0 && tab->background_shade != shade)
     {
@@ -511,7 +521,7 @@ void gui_load_preview(tab_t *tab)
 
     gui_set_preview(tab, NULL);
 
-    if (!item || !item->arg)
+    if (!item || !item->arg || gui.low_memory_mode)
         return;
 
     switch (gui.show_preview)

launcher/main/gui.h

@@ -131,6 +131,7 @@ typedef struct {
     uint32_t idle_counter;
     uint32_t joystick;
     bool http_lock; // FIXME: should be a mutex...
+    bool low_memory_mode;
     rg_surface_t *surface;
 } retro_gui_t;