From 65fe7f2f9c1dcc6f602b5c9d53e62263951c4fcb Mon Sep 17 00:00:00 2001
From: Maximilian Mader <max@bastelstu.be>
Date: Mon, 4 May 2020 03:30:10 +0200
Subject: [PATCH] [GTK3] Add analog speed controls

---
 gtk3/main.c | 52 +++++++++++++++++++++++++++++++++++++++++++++-------
 1 file changed, 45 insertions(+), 7 deletions(-)

diff --git a/gtk3/main.c b/gtk3/main.c
index 5ca2cde..f4c69ce 100644
--- a/gtk3/main.c
+++ b/gtk3/main.c
@@ -118,6 +118,7 @@ typedef struct GuiData {
 	bool rewind_paused;
 	bool turbo_down;
 	double clock_mutliplier;
+	double analog_clock_multiplier;
 
 	// Input
 	uint8_t pressed_buttons;
@@ -1179,7 +1180,10 @@ static void vblank(GB_gameboy_t *gb) {
 
 	GB_set_pixels_output(gb, get_pixels());
 
-	if (gui_data.underclock_down && gui_data.clock_mutliplier > 0.5) {
+	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;
 		GB_set_clock_multiplier(gb, gui_data.clock_mutliplier);
 	}
@@ -1252,31 +1256,63 @@ 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();
 
 	uint8_t controller_state = 0;
+	double analog_clock_multiplier = 1.0;
 
 	for (unsigned i = 0; i < gui_data.controller_count; i++) {
 		struct Controller_t *s = &gui_data.controllers[i];
 
-		int16_t x_axis = SDL_GameControllerGetAxis(s->controller, SDL_CONTROLLER_AXIS_LEFTX);
-		int16_t y_axis = SDL_GameControllerGetAxis(s->controller, SDL_CONTROLLER_AXIS_LEFTY);
+		int16_t left_x_axis = SDL_GameControllerGetAxis(s->controller, SDL_CONTROLLER_AXIS_LEFTX);
+		int16_t left_y_axis = SDL_GameControllerGetAxis(s->controller, SDL_CONTROLLER_AXIS_LEFTY);
 
-		if (x_axis >= JOYSTICK_HIGH) {
+		int16_t right_x_axis = SDL_GameControllerGetAxis(s->controller, SDL_CONTROLLER_AXIS_RIGHTX);
+		int16_t right_y_axis = SDL_GameControllerGetAxis(s->controller, SDL_CONTROLLER_AXIS_RIGHTY);
+
+		if (config.analog_speed_controls) {
+			double left_trigger  = (double) SDL_GameControllerGetAxis(s->controller, SDL_CONTROLLER_AXIS_TRIGGERLEFT)  / (double) 32767;
+			double right_trigger = (double) SDL_GameControllerGetAxis(s->controller, SDL_CONTROLLER_AXIS_TRIGGERRIGHT) / (double) 32767;
+
+			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));
+			}
+			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));
+			}
+		}
+
+		if (left_x_axis >= JOYSTICK_HIGH || right_x_axis >= JOYSTICK_HIGH) {
 			gui_data.last_used_controller = s;
 			controller_state |= BUTTON_MASK_RIGHT;
 		}
-		else if (x_axis <= -JOYSTICK_HIGH) {
+		else if (left_x_axis <= -JOYSTICK_HIGH || right_x_axis <= -JOYSTICK_HIGH) {
 			gui_data.last_used_controller = s;
 			controller_state |= BUTTON_MASK_LEFT;
 		}
 
-		if (y_axis >= JOYSTICK_HIGH) {
+		if (left_y_axis >= JOYSTICK_HIGH || right_y_axis >= JOYSTICK_HIGH) {
 			gui_data.last_used_controller = s;
 			controller_state |= BUTTON_MASK_DOWN;
 		}
-		else if (y_axis <= -JOYSTICK_HIGH) {
+		else if (left_y_axis <= -JOYSTICK_HIGH || right_y_axis <= -JOYSTICK_HIGH) {
 			gui_data.last_used_controller = s;
 			controller_state |= BUTTON_MASK_UP;
 		}
@@ -1322,6 +1358,8 @@ static void handle_events(GB_gameboy_t *gb) {
 		}
 	}
 
+	gui_data.analog_clock_multiplier = analog_clock_multiplier;
+
 	GB_set_key_state(gb, GB_KEY_RIGHT,  (gui_data.pressed_buttons & BUTTON_MASK_RIGHT)  | (controller_state & BUTTON_MASK_RIGHT));
 	GB_set_key_state(gb, GB_KEY_LEFT,   (gui_data.pressed_buttons & BUTTON_MASK_LEFT)   | (controller_state & BUTTON_MASK_LEFT));
 	GB_set_key_state(gb, GB_KEY_UP,     (gui_data.pressed_buttons & BUTTON_MASK_UP)     | (controller_state & BUTTON_MASK_UP));