From a93d09c96cf3e72e4962d004a4a416f5e2e15a10 Mon Sep 17 00:00:00 2001
From: Sara <sara@saragerretsen.nl>
Date: Sun, 18 Jun 2023 22:14:16 +0200
Subject: [PATCH] reworked most input listener types to use OS events instead
 of checking state on update

this allows for them to be more reliable with low framerates
---
 src/corelib/input.c | 93 +++++++++++++++++++++++----------------------
 1 file changed, 47 insertions(+), 46 deletions(-)

diff --git a/src/corelib/input.c b/src/corelib/input.c
index d4b5bf7..571de49 100644
--- a/src/corelib/input.c
+++ b/src/corelib/input.c
@@ -70,21 +70,6 @@ void input_init() {
 	g_key_states = SDL_GetKeyboardState(NULL);
 }
 
-static inline
-void _process_axis_listener(input_listener_t* listener) {
-	int val = 0;
-	if(g_key_states[listener->axis.negative]) {
-		val = -1;
-	}
-	if(g_key_states[listener->axis.positive]) {
-		val += 1;
-	}
-	if(val != listener->axis.last) {
-		listener->axis.last = val;
-		listener->axis.delegate(val);
-	}
-}
-
 static inline
 void _process_mouse_listener(input_listener_t* listener, float dx, float dy) {
 	if(dx != 0.0 && dy != 0.0) {
@@ -92,23 +77,6 @@ void _process_mouse_listener(input_listener_t* listener, float dx, float dy) {
 	}
 }
 
-static inline
-void _process_button_listener(input_listener_t* listener) {
-	uint32_t state = SDL_GetMouseState(NULL, NULL);
-	int is_down = (state & (listener->button.button)) != 0;
-	if(is_down != listener->button.last) {
-		listener->button.delegate(is_down);
-	}
-	listener->button.last = is_down;
-}
-
-static inline
-void _process_scroll_listener(input_listener_t* listener) {
-	if(_scroll_delta != 0) {
-		listener->scroll.delegate(_scroll_delta);
-	}
-}
-
 void update_input() {
 	float dx, dy;
 	int px, py;
@@ -118,19 +86,8 @@ void update_input() {
 	dx = (float)(px - _last_mouse_x)/width; dy = (float)(py - _last_mouse_y)/width;
 
 	for(input_listener_t* listener = g_key_listeners; listener != g_key_listeners_endptr; ++listener) {
-		switch(listener->type) {
-			case INPUT_LISTENER_AXIS:
-				_process_axis_listener(listener);
-				break;
-			case INPUT_LISTENER_MOUSE:
+		if(listener->type == INPUT_LISTENER_MOUSE) {
 				_process_mouse_listener(listener, dx, dy);
-				break;
-			case INPUT_LISTENER_SCROLL:
-				_process_scroll_listener(listener);
-				break;
-			case INPUT_LISTENER_BUTTON:
-				_process_button_listener(listener);
-				break;
 		}
 	}	
 
@@ -140,13 +97,57 @@ void update_input() {
 	_scroll_delta = 0;
 }
 
+static inline
+void _handle_key_event(const SDL_Event event) {
+	for(input_listener_t* listener = g_key_listeners; listener < g_key_listeners_endptr; ++listener) {
+		if(listener->type == INPUT_LISTENER_AXIS) {
+			if(listener->axis.positive == event.key.keysym.scancode
+			|| listener->axis.negative == event.key.keysym.scancode) {
+				const SDL_Scancode scode = event.key.keysym.scancode;
+				const int value = (event.type == SDL_KEYDOWN ? 1 : -1) * (scode == listener->axis.negative ? -1 : 1);
+				listener->axis.last += value;
+				listener->axis.delegate(listener->axis.last);
+			}
+		}
+	}
+}
+
+static inline
+void _handle_scroll_event(const SDL_Event event) {
+	_scroll_delta = event.wheel.y;
+	for(input_listener_t* listener = g_key_listeners; listener < g_key_listeners_endptr; ++listener) {
+		if(listener->type == INPUT_LISTENER_SCROLL) {
+			listener->scroll.delegate(_scroll_delta);
+		}
+	}
+}
+
+static inline
+void _handle_mousebutton_event(const SDL_Event event) {
+	for(input_listener_t* listener = g_key_listeners; listener < g_key_listeners_endptr; ++listener) {
+		if(listener->type == INPUT_LISTENER_BUTTON
+		|| listener->button.button == event.button.button) {
+			listener->button.last = event.button.state == SDL_PRESSED;
+			listener->button.delegate(listener->button.last);
+		}
+	}
+}
+
 void input_notify_event(SDL_Event event) {
 	switch(event.type) {
 		default:
 			return;
+		case SDL_KEYUP:
+		case SDL_KEYDOWN:
+			_handle_key_event(event);
+			return;
 		case SDL_MOUSEWHEEL:
-			_scroll_delta = event.wheel.y;
-			break;
+			_handle_scroll_event(event);
+			return;
+		case SDL_MOUSEBUTTONUP:
+		case SDL_MOUSEBUTTONDOWN:
+			_handle_mousebutton_event(event);
+			return;
 	}
 }