Add proper button function

src/types.rs

@@ -1,30 +1,79 @@
-#[derive(Clone, Copy, Debug, Deserialize, Serialize)]
+#[derive(Clone, Copy, Debug, Default, Deserialize, Serialize)]
 pub struct Vec2 {
     pub x: f32,
     pub y: f32,
 }
 
-#[derive(Clone, Copy, Debug, Deserialize, Serialize)]
+#[derive(Clone, Copy, Debug, Default, Deserialize, Serialize)]
 pub struct Rect {
     pub pos: Vec2,
     pub size: Vec2,
 }
 
 impl Rect {
-    pub fn contains(&self, p: &Vec2) -> bool {
+    pub fn contains(&self, p: Vec2) -> bool {
         self.pos.x <= p.x
             && p.x <= self.pos.x + self.size.x
             && self.pos.y <= p.y
             && p.y <= self.pos.y + self.size.y
     }
+
+    pub fn center(&self) -> Vec2 {
+        Vec2 {
+            x: self.pos.x + self.size.x / 2.0,
+            y: self.pos.y + self.size.y / 2.0,
+        }
+    }
 }
 
-#[derive(Clone, Copy, Debug, Deserialize)]
-pub struct Input {
-    pub screen_size: Vec2,
+// ----------------------------------------------------------------------------
+
+/// What the integration gives to the gui.
+#[derive(Clone, Copy, Debug, Default, Deserialize)]
+pub struct RawInput {
+    /// Is the button currently down?
+    pub mouse_down: bool,
+
+    /// Current position of the mouse in points.
     pub mouse_pos: Vec2,
+
+    /// Size of the screen in points.
+    pub screen_size: Vec2,
 }
 
+/// What the gui maintains
+#[derive(Clone, Copy, Debug)]
+pub struct GuiInput {
+    /// Is the button currently down?
+    pub mouse_down: bool,
+
+    /// The mouse went from !down to down
+    pub mouse_clicked: bool,
+
+    /// The mouse went from down to !down
+    pub mouse_released: bool,
+
+    /// Current position of the mouse in points.
+    pub mouse_pos: Vec2,
+
+    /// Size of the screen in points.
+    pub screen_size: Vec2,
+}
+
+impl GuiInput {
+    pub fn from_last_and_new(last: &RawInput, new: &RawInput) -> GuiInput {
+        GuiInput {
+            mouse_down: new.mouse_down,
+            mouse_clicked: !last.mouse_down && new.mouse_down,
+            mouse_released: last.mouse_down && !new.mouse_down,
+            mouse_pos: new.mouse_pos,
+            screen_size: new.screen_size,
+        }
+    }
+}
+
+// ----------------------------------------------------------------------------
+
 #[derive(Clone, Copy, Debug, Serialize)]
 #[serde(rename_all = "snake_case")]
 pub enum TextAlign {