WindowServer: Added configurable mouse acceleration and scroll length

The settings are also saved to the config file to survive reboots.

Base/etc/WindowServer/WindowServer.ini

@@ -5,6 +5,10 @@ Height=768
 [Theme]
 Name=Default
 
+[Mouse]
+AccelerationFactor=1.0
+ScrollStepSize=4
+
 [Cursor]
 Hidden=/res/cursors/hidden.png
 Arrow=/res/cursors/arrow.x2y2.png

Services/WindowServer/Screen.cpp

@@ -116,11 +116,23 @@ void Screen::set_buffer(int index)
     ASSERT(rc == 0);
 }
 
+void Screen::set_acceleration_factor(double factor)
+{
+    ASSERT(factor >= mouse_accel_min && factor <= mouse_accel_max);
+    m_acceleration_factor = factor;
+}
+
+void Screen::set_scroll_step_size(unsigned step_size)
+{
+    ASSERT(step_size >= scroll_step_size_min);
+    m_scroll_step_size = step_size;
+}
+
 void Screen::on_receive_mouse_data(const MousePacket& packet)
 {
     auto prev_location = m_cursor_location;
     if (packet.is_relative) {
-        m_cursor_location.move_by(packet.x, packet.y);
+        m_cursor_location.move_by(packet.x * m_acceleration_factor, packet.y * m_acceleration_factor);
 #ifdef WSSCREEN_DEBUG
         dbgprintf("Screen: New Relative mouse point @ X %d, Y %d\n", m_cursor_location.x(), m_cursor_location.y());
 #endif
@@ -154,7 +166,7 @@ void Screen::on_receive_mouse_data(const MousePacket& packet)
     }
 
     if (packet.z) {
-        auto message = make<MouseEvent>(Event::MouseWheel, m_cursor_location, buttons, MouseButton::None, m_modifiers, packet.z);
+        auto message = make<MouseEvent>(Event::MouseWheel, m_cursor_location, buttons, MouseButton::None, m_modifiers, packet.z * m_scroll_step_size);
         Core::EventLoop::current().post_event(WindowManager::the(), move(message));
     }
 

Services/WindowServer/Screen.h

@@ -35,6 +35,10 @@ struct MousePacket;
 
 namespace WindowServer {
 
+const double mouse_accel_max = 3.5;
+const double mouse_accel_min = 0.5;
+const unsigned scroll_step_size_min = 1;
+
 class Screen {
 public:
     Screen(unsigned width, unsigned height);
@@ -57,6 +61,12 @@ public:
     Gfx::IntPoint cursor_location() const { return m_cursor_location; }
     unsigned mouse_button_state() const { return m_mouse_button_state; }
 
+    double acceleration_factor() const { return m_acceleration_factor; }
+    void set_acceleration_factor(double);
+
+    unsigned scroll_step_size() const { return m_scroll_step_size; }
+    void set_scroll_step_size(unsigned);
+
     void on_receive_mouse_data(const MousePacket&);
     void on_receive_keyboard_data(::KeyEvent);
 
@@ -76,6 +86,8 @@ private:
     Gfx::IntPoint m_cursor_location;
     unsigned m_mouse_button_state { 0 };
     unsigned m_modifiers { 0 };
+    double m_acceleration_factor { 1.0 };
+    unsigned m_scroll_step_size { 1 };
 };
 
 inline Gfx::RGBA32* Screen::scanline(int y)

Services/WindowServer/WindowManager.cpp

@@ -163,6 +163,22 @@ Gfx::IntSize WindowManager::resolution() const
     return Screen::the().size();
 }
 
+void WindowManager::set_acceleration_factor(double factor)
+{
+    Screen::the().set_acceleration_factor(factor);
+    dbgln("Saving acceleration factor {} to config file at {}", factor, m_config->file_name());
+    m_config->write_entry("Mouse", "AccelerationFactor", String::formatted("{}", factor));
+    m_config->sync();
+}
+
+void WindowManager::set_scroll_step_size(unsigned step_size)
+{
+    Screen::the().set_scroll_step_size(step_size);
+    dbgln("Saving scroll step size {} to config file at {}", step_size, m_config->file_name());
+    m_config->write_entry("Mouse", "ScrollStepSize", String::number(step_size));
+    m_config->sync();
+}
+
 void WindowManager::add_window(Window& window)
 {
     bool is_first_window = m_windows_in_order.is_empty();

Services/WindowServer/WindowManager.h

@@ -145,6 +145,9 @@ public:
     bool set_resolution(int width, int height);
     Gfx::IntSize resolution() const;
 
+    void set_acceleration_factor(double);
+    void set_scroll_step_size(unsigned);
+
     Window* set_active_input_window(Window*);
     void restore_active_input_window(Window*);
     void set_active_window(Window*, bool make_input = true);

Services/WindowServer/main.cpp

@@ -91,6 +91,8 @@ int main(int, char**)
 
     WindowServer::Screen screen(wm_config->read_num_entry("Screen", "Width", 1024),
         wm_config->read_num_entry("Screen", "Height", 768));
+    screen.set_acceleration_factor(atof(wm_config->read_entry("Mouse", "AccelerationFactor", "1.0").characters()));
+    screen.set_scroll_step_size(wm_config->read_num_entry("Mouse", "ScrollStepSize", 4));
     WindowServer::Compositor::the();
     auto wm = WindowServer::WindowManager::construct(*palette);
     auto am = WindowServer::AppletManager::construct();