Added rewind and underclocking support to the SDL port. Joystick controls to be done.

SDL/gui.c

@@ -62,10 +62,15 @@ configuration_t configuration =
         SDL_SCANCODE_RETURN,
         SDL_SCANCODE_SPACE
     },
+    .keys_2 = {
+        SDL_SCANCODE_TAB,
+        SDL_SCANCODE_LSHIFT,
+    },
     .color_correction_mode = GB_COLOR_CORRECTION_EMULATE_HARDWARE,
     .highpass_mode = GB_HIGHPASS_ACCURATE,
     .scaling_mode = GB_SDL_SCALING_INTEGER_FACTOR,
     .blend_frames = true,
+    .rewind_length = 60 * 2,
     .model = MODEL_CGB
 };
 
@@ -282,8 +287,55 @@ const char *current_model_string(unsigned index)
         [configuration.model];
 }
 
+static const uint32_t rewind_lengths[] = {0, 10, 30, 60, 60 * 2, 60 * 5, 60 * 10};
+static const char *rewind_strings[] = {"Disabled",
+                                       "10 Seconds",
+                                       "30 Seconds",
+                                       "1 Minute",
+                                       "2 Minutes",
+                                       "5 Minutes",
+                                       "10 Minutes",
+};
+
+static void cycle_rewind(unsigned index)
+{
+    for (unsigned i = 0; i < sizeof(rewind_lengths) / sizeof(rewind_lengths[0]) - 1; i++) {
+        if (configuration.rewind_length == rewind_lengths[i]) {
+            configuration.rewind_length = rewind_lengths[i + 1];
+            GB_set_rewind_length(&gb, configuration.rewind_length);
+            return;
+        }
+    }
+    configuration.rewind_length = rewind_lengths[0];
+    GB_set_rewind_length(&gb, configuration.rewind_length);
+}
+
+static void cycle_rewind_backwards(unsigned index)
+{
+    for (unsigned i = 1; i < sizeof(rewind_lengths) / sizeof(rewind_lengths[0]); i++) {
+        if (configuration.rewind_length == rewind_lengths[i]) {
+            configuration.rewind_length = rewind_lengths[i - 1];
+            GB_set_rewind_length(&gb, configuration.rewind_length);
+            return;
+        }
+    }
+    configuration.rewind_length = rewind_lengths[sizeof(rewind_lengths) / sizeof(rewind_lengths[0]) - 1];
+    GB_set_rewind_length(&gb, configuration.rewind_length);
+}
+
+const char *current_rewind_string(unsigned index)
+{
+    for (unsigned i = 0; i < sizeof(rewind_lengths) / sizeof(rewind_lengths[0]); i++) {
+        if (configuration.rewind_length == rewind_lengths[i]) {
+            return rewind_strings[i];
+        }
+    }
+    return "Custom";
+}
+
 static const struct menu_item emulation_menu[] = {
     {"Emulated Model:", cycle_model, current_model_string, cycle_model_backwards},
+    {"Rewind Length:", cycle_rewind, current_rewind_string, cycle_rewind_backwards},
     {"Back", return_to_root_menu},
     {NULL,}
 };
@@ -486,16 +538,15 @@ static void enter_audio_menu(unsigned index)
     current_menu = audio_menu;
     current_selection = 0;
 }
-static const char *key_name(unsigned index)
-{
-    return SDL_GetScancodeName(configuration.keys[index]);
-}
 
 static void modify_key(unsigned index)
 {
     gui_state = WAITING_FOR_KEY;
 }
 
+static void enter_controls_menu_2(unsigned index);
+static const char *key_name(unsigned index);
+
 static const struct menu_item controls_menu[] = {
     {"Right:", modify_key, key_name,},
     {"Left:", modify_key, key_name,},
@@ -505,17 +556,42 @@ static const struct menu_item controls_menu[] = {
     {"B:", modify_key, key_name,},
     {"Select:", modify_key, key_name,},
     {"Start:", modify_key, key_name,},
-    {"Turbo:", modify_key, key_name,},
+    {"Next Page", enter_controls_menu_2},
     {"Back", return_to_root_menu},
     {NULL,}
 };
 
+static const struct menu_item controls_menu_2[] = {
+    {"Turbo:", modify_key, key_name,},
+    {"Rewind:", modify_key, key_name,},
+    {"Slow-Motion:", modify_key, key_name,},
+    {"Back", return_to_root_menu},
+    {NULL,}
+};
+
+static const char *key_name(unsigned index)
+{
+    if (current_menu == controls_menu_2) {
+        if (index == 0) {
+            return SDL_GetScancodeName(configuration.keys[8]);
+        }
+        return SDL_GetScancodeName(configuration.keys_2[index - 1]);
+    }
+    return SDL_GetScancodeName(configuration.keys[index]);
+}
+
 static void enter_controls_menu(unsigned index)
 {
     current_menu = controls_menu;
     current_selection = 0;
 }
 
+static void enter_controls_menu_2(unsigned index)
+{
+    current_menu = controls_menu_2;
+    current_selection = 0;
+}
+
 static unsigned joypad_index = 0;
 SDL_Joystick *joystick = NULL;
 SDL_GameController *controller = NULL;
@@ -906,7 +982,17 @@ void run_gui(bool is_running)
                     should_render = true;
                 }
                 else if (gui_state == WAITING_FOR_KEY) {
-                    configuration.keys[current_selection] = event.key.keysym.scancode;
+                    if (current_menu == controls_menu_2) {
+                        if (current_selection == 0) {
+                            configuration.keys[8] = event.key.keysym.scancode;
+                        }
+                        else {
+                            configuration.keys_2[current_selection - 1] = event.key.keysym.scancode;
+                        }
+                    }
+                    else {
+                        configuration.keys[current_selection] = event.key.keysym.scancode;
+                    }
                     gui_state = SHOWING_MENU;
                     should_render = true;
                 }

SDL/gui.h

@@ -6,6 +6,7 @@
 #include <stdbool.h> 
 #include "shader.h"
 
+extern GB_gameboy_t gb;
 
 extern SDL_Window *window;
 extern SDL_Renderer *renderer;
@@ -51,6 +52,10 @@ typedef struct {
         MODEL_AGB,
         MODEL_MAX,
     } model;
+    
+    /* v0.11 */
+    uint32_t rewind_length;
+    SDL_Scancode keys_2[2]; /* Rewind and underclock */
 } configuration_t;
 
 extern configuration_t configuration;

SDL/main.c

@@ -1,6 +1,7 @@
 #include <stdbool.h>
 #include <stdio.h>
 #include <signal.h>
+#include <unistd.h>
 #include <SDL2/SDL.h>
 #include <Core/gb.h>
 #include "utils.h"
@@ -25,6 +26,8 @@ GB_gameboy_t gb;
 static bool paused = false;
 static uint32_t pixel_buffer_1[160*144], pixel_buffer_2[160*144];
 static uint32_t *active_pixel_buffer = pixel_buffer_1, *previous_pixel_buffer = pixel_buffer_2;
+static bool underclock_down = false, rewind_down = false, do_rewind = false, rewind_paused = false, turbo_down = false;
+static double clock_mutliplier = 1.0;
 
 static char *filename = NULL;
 static bool should_free_filename = false;
@@ -143,7 +146,8 @@ static void handle_events(GB_gameboy_t *gb)
                     GB_set_key_state(gb, GB_KEY_RIGHT, event.type == SDL_JOYBUTTONDOWN);
                 }
                 else if (event.jbutton.button & 1) {
-                    GB_set_turbo_mode(gb, event.type == SDL_JOYBUTTONDOWN, false);
+                    turbo_down = event.type == SDL_JOYBUTTONDOWN;
+                    GB_set_turbo_mode(gb, turbo_down, turbo_down && rewind_down);
                 }
                 
                 else {
@@ -152,9 +156,6 @@ static void handle_events(GB_gameboy_t *gb)
                         SDL_PauseAudioDevice(device_id, 1);
                     }
                     run_gui(true);
-                    if (!audio_playing) {
-                        SDL_PauseAudioDevice(device_id, 0);
-                    }
                     GB_set_color_correction_mode(gb, configuration.color_correction_mode);
                     GB_set_highpass_filter_mode(gb, configuration.highpass_mode);
                 }
@@ -268,7 +269,18 @@ static void handle_events(GB_gameboy_t *gb)
                 }
             case SDL_KEYUP: // Fallthrough
                 if (event.key.keysym.scancode == configuration.keys[8]) {
-                    GB_set_turbo_mode(gb, event.type == SDL_KEYDOWN, false);
+                    turbo_down = event.type == SDL_KEYDOWN;
+                    GB_set_turbo_mode(gb, turbo_down, turbo_down && rewind_down);
+                }
+                else if (event.key.keysym.scancode == configuration.keys_2[0]) {
+                    rewind_down = event.type == SDL_KEYDOWN;
+                    if (event.type == SDL_KEYUP) {
+                        rewind_paused = false;
+                    }
+                    GB_set_turbo_mode(gb, turbo_down, turbo_down && rewind_down);
+                }
+                else if (event.key.keysym.scancode == configuration.keys_2[1]) {
+                    underclock_down = event.type == SDL_KEYDOWN;
                 }
                 else {
                     for (unsigned i = 0; i < GB_KEY_MAX; i++) {
@@ -286,6 +298,14 @@ static void handle_events(GB_gameboy_t *gb)
 
 static void vblank(GB_gameboy_t *gb)
 {
+    if (underclock_down && clock_mutliplier > 0.5) {
+        clock_mutliplier -= 0.1;
+        GB_set_clock_multiplier(gb, clock_mutliplier);
+    }
+    else if (!underclock_down && clock_mutliplier < 1.0) {
+        clock_mutliplier += 0.1;
+        GB_set_clock_multiplier(gb, clock_mutliplier);
+    }
     if (configuration.blend_frames) {
         render_texture(active_pixel_buffer, previous_pixel_buffer);
         uint32_t *temp = active_pixel_buffer;
@@ -296,6 +316,7 @@ static void vblank(GB_gameboy_t *gb)
     else {
         render_texture(active_pixel_buffer, NULL);
     }
+    do_rewind = rewind_down;
     handle_events(gb);
 }
 
@@ -381,6 +402,7 @@ restart:
         GB_set_sample_rate(&gb, have_aspec.freq);
         GB_set_color_correction_mode(&gb, configuration.color_correction_mode);
         GB_set_highpass_filter_mode(&gb, configuration.highpass_mode);
+        GB_set_rewind_length(&gb, configuration.rewind_length);
     }
     
     bool error = false;
@@ -410,11 +432,21 @@ restart:
     
     /* Run emulation */
     while (true) {
-        if (paused) {
+        if (paused || rewind_paused) {
             SDL_WaitEvent(NULL);
             handle_events(&gb);
         }
         else {
+            if (do_rewind) {
+                GB_rewind_pop(&gb);
+                if (turbo_down) {
+                    GB_rewind_pop(&gb);
+                }
+                if (!GB_rewind_pop(&gb)) {
+                    rewind_paused = true;
+                }
+                do_rewind = false;
+            }
             GB_run(&gb);
         }