Add FPS and Turbo controls; Simplify action inputs

src/linux/port.c

@@ -90,6 +90,10 @@ typedef struct {
     void* cart_data;
 } cart_info;
 
+typedef enum {
+    Flag_Turbo = 0b1,
+} Platform_Flags;
+
 typedef struct {
     nes* sys;
     cart_info cart;
@@ -101,6 +105,8 @@ typedef struct {
     SDL_Surface* screen;
     SDL_Rect view;
     Overlay overlay;
+    int fps_msg_id;
+    Platform_Flags flags;
 } platform_data;
 
 
@@ -115,6 +121,9 @@ typedef enum {
     Action_Save,
     Action_Menu,
     Action_Cancel,
+    Action_FPS,
+    Action_Turbo,
+    Action_Max
 } nese_Action;
 
 int nese_update_input(void* plat_data, nes_Input* input) {
@@ -122,12 +131,16 @@ int nese_update_input(void* plat_data, nes_Input* input) {
     return 0;
 }
 
+static const int sdl_action_keycodes[Action_Max] = {
+    [Action_Menu]  = SDLK_ESCAPE,
+    [Action_Reset] = SDLK_BACKSPACE,
+    [Action_Load]  = SDLK_F2,
+    [Action_Save]  = SDLK_F1,
+    [Action_FPS]   = SDLK_f,
+    [Action_Turbo] = SDLK_t,
+};
 
-#define sdl_save_key        (SDLK_F1)
-#define sdl_load_key        (SDLK_F2)
-#define sdl_alt_start_key   (SDLK_RETURN)
-
-static const int sdl_keycodes[nes_controller_num_buttons] = {
+static const int sdl_button_keycodes[nes_controller_num_buttons] = {
     SDLK_a,
     SDLK_s,
     SDLK_q,
@@ -138,21 +151,23 @@ static const int sdl_keycodes[nes_controller_num_buttons] = {
     SDLK_RIGHT,
 };
 
-static int button_index(int keycode, const int* codes) {
-    int index = nes_controller_num_buttons - 1;
+#define sdl_alt_start_key   (SDLK_RETURN)
+
+static int keycode_index(int keycode, const int* codes, int n_codes) {
+    int index = n_codes - 1;
     for ( ; index >= 0 && keycode != codes[index]; --index);
     return index;
 }
 
 // TODO: Return an action enum?
-static int process_events(nes* sys) {
-    int status = 0;
+static nese_Action process_events(nes* sys) {
+    nese_Action action = Action_OK;
     nes_Input* input = &sys->core.memory.input;
 
     SDL_Event event = {0};
-    while (0 == status && 0 != SDL_PollEvent(&event)) {
+    while (Action_OK == action && 0 != SDL_PollEvent(&event)) {
         if (SDL_QUIT == event.type) {
-            status = -1;
+            action = Action_Quit;
 
         } else if ( (   SDL_KEYDOWN == event.type ||
                         SDL_KEYUP == event.type) &&
@@ -160,9 +175,11 @@ static int process_events(nes* sys) {
                 ) {
             int index = (   sdl_alt_start_key ==
                             event.key.keysym.sym) ?
-                        Button_Start : button_index(
-                            event.key.keysym.sym,
-                            sdl_keycodes);
+                        Button_Start : keycode_index(
+                                event.key.keysym.sym,
+                                sdl_button_keycodes,
+                                nes_controller_num_buttons
+                            );
             if (index >= 0) {
                 uint8_t mask = (1 << index);
                 if (SDL_KEYDOWN == event.type) {
@@ -172,22 +189,17 @@ static int process_events(nes* sys) {
                 }
 
             } else if (SDL_KEYDOWN == event.type) {
-                switch (event.key.keysym.sym) {
-                case sdl_save_key:
-                    status = Action_Save;
-                    break;
-
-                case sdl_load_key:
-                    status = Action_Load;
-                    break;
-                }
+                index = keycode_index(
+                        event.key.keysym.sym,
+                        sdl_action_keycodes, Action_Max
+                    );
+                if (index >= 0) action = index;
             }
-            // TODO: Menu or other hotkeys
         }
         // TODO: Controller inputs
     }
 
-    return status;
+    return action;
 }
 
 
@@ -245,13 +257,13 @@ int nese_line_ready(void* plat_data, uint8_t* buffer, int line) {
 }
 
 
-#define NS_PER_S      (1000U * 1000U * 1000U)
+#define NS_PER_S      (1000L * 1000L * 1000L)
 #define FRAME_TIME_NS (16639267L)
 
 uint64_t time_now(void) {
   struct timespec ts_now = {0};
   clock_gettime(CLOCK_REALTIME, &ts_now);
-  return ((int64_t)ts_now.tv_sec * NS_PER_S) + ts_now.tv_nsec;
+  return (ts_now.tv_sec * NS_PER_S) + ts_now.tv_nsec;
 }
 
 int64_t time_sleep_until(int64_t t_target) {
@@ -318,27 +330,76 @@ int nese_frame_ready(void* plat_data) {
 
     SDL_RenderPresent(plat->renderer);
 
-    status = process_events(plat->sys);
 
-    if (Action_Save == status) {
+    nese_Action action = process_events(plat->sys);
+    switch (action) {
+    case Action_Menu:
+    case Action_Quit:
+        status = -1;
+        break;
+
+    case Action_Save:
         status = save_state(plat->sys, plat->cart.filename);
-    } else if (Action_Load == status) {
+        break;
+
+    case Action_Load:
         status = load_state(plat->sys, plat->cart.filename);
+        break;
+
+    case Action_FPS:
+        if (plat->fps_msg_id <= 0) {
+            plat->fps_msg_id = overlay_add_message(&plat->overlay, "", 0);
+        } else {
+            overlay_clear_message(&plat->overlay, plat->fps_msg_id);
+            plat->fps_msg_id = 0;
+        }
+        break;
+
+    case Action_Turbo:
+        plat->flags ^= Flag_Turbo;
+        break;
+
+    default:
     }
 
     // TODO: Perform more actions
 
-#ifndef NESE_TURBO
     if (0 == status) {
         plat->t_target += FRAME_TIME_NS;
-        int64_t slept_ns = time_sleep_until(plat->t_target);
-        if (slept_ns <= -FRAME_TIME_NS) {
-            // We're way out of sync.
-            plat->t_target = time_now();
-            printf("Out of sync: %d\n", (int)slept_ns);
+        int64_t slept_ns = 0;
+        if (plat->flags & Flag_Turbo) {
+            int64_t now = time_now();
+            slept_ns = plat->t_target - now;
+            plat->t_target = now;
+        } else {
+            slept_ns = time_sleep_until(plat->t_target);
+            if (slept_ns <= -FRAME_TIME_NS) {
+                // We're way out of sync.
+                plat->t_target = time_now();
+                printf("Out of sync: %d\n", (int)slept_ns);
+            }
         }
+
+        static int frame = 0;
+        static int64_t slept_total = 0;
+        slept_total += slept_ns;
+        if (60 == ++frame) {
+            if (plat->fps_msg_id > 0) {
+                int64_t game_elapsed = frame * FRAME_TIME_NS;
+                int64_t cpu_elapsed = game_elapsed - slept_total;
+                float fps = (double)(NS_PER_S * frame) / cpu_elapsed;
+
+                char message[32];
+                snprintf(message, sizeof(message), "%.1f fps", fps);
+                overlay_update_message(&plat->overlay, plat->fps_msg_id, message);
+            }
+
+            slept_total = 0;
+            frame = 0;
+        }
+
     }
-#endif // NESE_TURBO
+
 
     return status;
 }

src/nes.c

@@ -3,7 +3,7 @@
 #include "nes.h"
 #include "port.h"
 
-#define NESE_DEBUG "NES"
+//#define NESE_DEBUG "NES"
 #include "log.h"
 
 

src/overlay.c

@@ -178,7 +178,7 @@ typedef struct Overlay_message_t {
 
 int overlay_init(Overlay* overlay, SDL_Renderer* rend) {
     overlay->messages = NULL;
-    overlay->next_id = 0;
+    overlay->next_id = 1;
     overlay_font_init(&overlay->font, rend);
     return 0;
 }
@@ -203,6 +203,32 @@ void overlay_done(Overlay* overlay) {
     overlay_font_done(&overlay->font);
 }
 
+static Overlay_message* overlay_find_message(Overlay* overlay, int id) {
+    Overlay_message* message = overlay->messages;
+    for (   ;
+            NULL != message && message->id != id;
+            message = message->next
+        );
+    return message;
+}
+
+int overlay_update_message(Overlay* overlay, int id, const char* string) {
+    Overlay_message* msg = overlay_find_message(overlay, id);
+    if (NULL != msg) {
+        free(msg->string);
+        msg->string = strdup(string);
+    }
+    return (NULL == msg) ? -1 : 0;
+}
+
+int overlay_update_expiry(Overlay* overlay, int id, int expiry) {
+    Overlay_message* msg = overlay_find_message(overlay, id);
+    if (NULL != msg) {
+        msg->expiry = expiry;
+    }
+    return (NULL == msg) ? -1 : 0;
+}
+
 int overlay_clear_message(Overlay* overlay, int id) {
     int result = -1;
     Overlay_message* last = NULL;

src/overlay.h

@@ -35,6 +35,8 @@ int overlay_init(Overlay*, SDL_Renderer*);
 void overlay_done(Overlay*);
 
 int overlay_add_message(Overlay*, const char*, int expiry);
+int overlay_update_message(Overlay*, int id, const char*);
+int overlay_update_expiry(Overlay*, int id, int expiry);
 int overlay_clear_message(Overlay*, int id);
 int overlay_clear(Overlay*);