From 116ea7d0d756df2485a19c3d0d93027a8bd708a2 Mon Sep 17 00:00:00 2001
From: Maximilian Mader <max@bastelstu.be>
Date: Mon, 11 May 2020 00:05:59 +0200
Subject: [PATCH] [GTK3] Improve analog speed controls a bit

---
 gtk3/main.c | 60 +++++++++++++++++++++++++++++++++--------------------
 1 file changed, 38 insertions(+), 22 deletions(-)

diff --git a/gtk3/main.c b/gtk3/main.c
index 3fb05d9..2ad51cb 100644
--- a/gtk3/main.c
+++ b/gtk3/main.c
@@ -122,6 +122,7 @@ typedef struct GuiData {
 	bool turbo_down;
 	double clock_mutliplier;
 	double analog_clock_multiplier;
+	bool analog_clock_multiplier_valid;
 
 	// Input
 	uint8_t pressed_buttons;
@@ -164,6 +165,7 @@ static GuiData gui_data = {
 	.rewind_paused = false,
 	.turbo_down = false,
 	.clock_mutliplier = 1.0,
+	.analog_clock_multiplier = 1.0,
 };
 GB_gameboy_t gb;
 
@@ -269,6 +271,22 @@ static void replace_extension(const char *src, size_t length, char *dest, const
 	strcat(dest, ext);
 }
 
+static double clamp_double(double min, double max, double value) {
+	if (value < min) return min;
+	if (value > max) return max;
+	return value;
+}
+
+static double max_double(double a, double b) {
+	if (a > b) return a;
+	return b;
+}
+
+static double min_double(double a, double b) {
+	if (a < b) return a;
+	return b;
+}
+
 static uint32_t rgb_encode(GB_gameboy_t *gb, uint8_t r, uint8_t g, uint8_t b) {
 	return 0xFF000000 | (r << 16) | (g << 8) | b;
 }
@@ -1189,17 +1207,26 @@ static void vblank(GB_gameboy_t *gb) {
 
 	GB_set_pixels_output(gb, get_pixels());
 
-	if (config.analog_speed_controls && gui_data.analog_clock_multiplier != 0.0) {
-		GB_set_clock_multiplier(gb, gui_data.analog_clock_multiplier);
-	}
-	else if (gui_data.underclock_down && gui_data.clock_mutliplier > 0.5) {
-		gui_data.clock_mutliplier -= 1.0/16;
+	// Handle the speed modifiers:
+	// The binary slowdown is limited to half speed.
+	// The analog multiplier can go down to a third and up to three times full speed.
+	if (gui_data.underclock_down && gui_data.clock_mutliplier > 0.5) {
+		gui_data.clock_mutliplier -= 1.0 / 16;
+		//gui_data.clock_mutliplier = clamp_double(0.5, 1.0, gui_data.clock_mutliplier - 1.0 / 16);
 		GB_set_clock_multiplier(gb, gui_data.clock_mutliplier);
 	}
 	else if (!gui_data.underclock_down && gui_data.clock_mutliplier < 1.0) {
-		gui_data.clock_mutliplier += 1.0/16;
+		gui_data.clock_mutliplier += 1.0 / 16;
+		//gui_data.clock_mutliplier = clamp_double(0.5, 1.0, gui_data.clock_mutliplier + 1.0 / 16);
 		GB_set_clock_multiplier(gb, gui_data.clock_mutliplier);
 	}
+	else if (config.analog_speed_controls && gui_data.analog_clock_multiplier_valid) {
+		GB_set_clock_multiplier(gb, gui_data.analog_clock_multiplier);
+
+		if (gui_data.analog_clock_multiplier == 1.0) {
+			gui_data.analog_clock_multiplier_valid = false;
+		}
+	}
 
 	if (g_strcmp0("vram_viewer_tileset", gui_data.vram_viewer_active_tab) == 0) {
 		const gchar *palette_id = gtk_combo_box_get_active_id(builder_get(GTK_COMBO_BOX, "vram_viewer_tileset_palette_selector"));
@@ -1265,22 +1292,6 @@ static void vblank(GB_gameboy_t *gb) {
 	g_idle_add((GSourceFunc) on_vblank, NULL);
 }
 
-static double clamp_double(double min, double max, double value) {
-	if (value < min) return min;
-	if (value > max) return max;
-	return value;
-}
-
-static double max_double(double a, double b) {
-	if (a > b) return a;
-	return b;
-}
-
-static double min_double(double a, double b) {
-	if (a < b) return a;
-	return b;
-}
-
 static void handle_events(GB_gameboy_t *gb) {
 	SDL_GameControllerUpdate();
 
@@ -1302,9 +1313,11 @@ static void handle_events(GB_gameboy_t *gb) {
 
 			if (left_trigger > 0.0) {
 				analog_clock_multiplier = min_double(analog_clock_multiplier, clamp_double(1.0 / 3, 1.0, 1 - left_trigger + 0.2));
+				gui_data.analog_clock_multiplier_valid = true;
 			}
 			else if (right_trigger > 0.0) {
 				analog_clock_multiplier = max_double(analog_clock_multiplier, clamp_double(1.0, 3.0, right_trigger * 3 + 0.8));
+				gui_data.analog_clock_multiplier_valid = true;
 			}
 		}
 
@@ -1673,12 +1686,15 @@ static gboolean on_key_press(GtkWidget *w, GdkEventKey *event, gpointer data) {
 
 	if (event->keyval == key_map[INPUT_TURBO]) {
 		gui_data.turbo_down = event->type == GDK_KEY_PRESS;
+		gui_data.analog_clock_multiplier_valid = false;
+
 		GB_audio_clear_queue();
 		GB_set_turbo_mode(&gb, gui_data.turbo_down, gui_data.turbo_down && gui_data.rewind_down);
 	}
 
 	if (event->keyval == key_map[INPUT_SLOWDOWN]) {
 		gui_data.underclock_down = event->type == GDK_KEY_PRESS;
+		gui_data.analog_clock_multiplier_valid = false;
 	}
 
 	if (event->keyval == key_map[INPUT_FULLSCREEN]) {