From 5c52afe1f40f542dcf259a8b2ac4e8afb4ff00a4 Mon Sep 17 00:00:00 2001
From: Ritchie Cunningham <ritchie@ritchiecunningham.co.uk>
Date: Sat, 25 Oct 2025 19:19:02 +0100
Subject: [PATCH] [Add] Better scrolling/snap to botom for terminal.

---
 client/src/terminal.cpp | 35 ++++++++++++++++++++++++++++-------
 client/src/terminal.h   |  2 +-
 2 files changed, 29 insertions(+), 8 deletions(-)

diff --git a/client/src/terminal.cpp b/client/src/terminal.cpp
index a02f12f..ac04b0b 100644
--- a/client/src/terminal.cpp
+++ b/client/src/terminal.cpp
@@ -62,7 +62,7 @@ uint32_t Terminal::get_session_id(void) const {
   return _session_id;
 }
 
-void Terminal::_on_ret_press(void) {
+void Terminal::_on_ret_press(int content_height) {
   std::string command = _input_buffer.get_line(0);
   if(!command.empty()) {
     _command_history.push_back(command);
@@ -90,6 +90,13 @@ void Terminal::_on_ret_press(void) {
 
   _history.push_back(_prompt + "> " + command);
   _game_state->send_network_command(_session_id, command);
+
+  /* After processing a command, always snap to the bottom. */
+  float line_height = 20.0f;
+  int visible_lines = content_height / line_height;
+  int max_scroll = (_history.size()+1) - visible_lines;
+  if(max_scroll < 0) max_scroll = 0;
+  _scroll_offset = max_scroll;
 }
 
 void Terminal::handle_input(SDL_Event* event, int window_x, int window_y, int window_gl_y,
@@ -115,10 +122,25 @@ void Terminal::handle_input(SDL_Event* event, int window_x, int window_y, int wi
         }
         break;
       default:
-        if(_input_view->handle_event(event, content_height)) { _on_ret_press(); }
+      float line_height = 20.0f;
+      int visible_lines = content_height / line_height;
+      int max_scroll = (_history.size()+1) - visible_lines;
+      if(max_scroll < 0) max_scroll = 0;
+
+      if(_input_view->handle_event(event, content_height)) { _on_ret_press(content_height); }
+      else {
+        _scroll_offset = max_scroll; /* Always snap to bottom on key press. */
+      }
+    }
+  } else if(event->type == SDL_EVENT_TEXT_INPUT) {
+    if(_input_view->handle_event(event, content_height)) { _on_ret_press(content_height); }
+    else {
+      float line_height = 20.0f;
+      int visible_lines = content_height / line_height;
+      int max_scroll = (_history.size()+1) - visible_lines;
+      if(max_scroll < 0) max_scroll = 0;
+      _scroll_offset = max_scroll; /* Always snap to bottom on text input. */
     }
-  } else {
-    if(_input_view->handle_event(event, content_height)) { _on_ret_press(); }
   }
 }
 
@@ -186,12 +208,11 @@ void Terminal::render(const RenderContext& context, int x, int y_screen, int y_g
 
   context.ui_renderer->flush_text();
 
-  /* Disable scissor test. */
-  glDisable(GL_SCISSOR_TEST);
-
   if(context.show_cursor) {
     context.ui_renderer->begin_shapes();
     _input_view->render_cursor(context.ui_renderer, theme, input_x_pos, prompt_line_y, input_width, line_height);
     context.ui_renderer->flush_shapes();
   }
+  /* Disable scissor test. */
+  glDisable(GL_SCISSOR_TEST);
 }
diff --git a/client/src/terminal.h b/client/src/terminal.h
index f841b8a..4fa8f1d 100644
--- a/client/src/terminal.h
+++ b/client/src/terminal.h
@@ -31,7 +31,7 @@ public:
   uint32_t get_session_id(void) const;
 
 private:
-  void _on_ret_press(void);
+  void _on_ret_press(int content_height);
 
   bool _should_close;
   std::vector<std::string> _command_history;