Make code sample less monolithic in component.

munificent · munificent · commit ba51580f5658 · 2014-08-03T23:08:54.000-07:00
diff --git a/asset/component-uml-processed.psd b/asset/component-uml-processed.psd
diff --git a/asset/component-uml-scan.psd b/asset/component-uml-scan.psd
diff --git a/book/component.markdown b/book/component.markdown
@@ -282,8 +282,11 @@ just "the next version of Photoshop."
 
 ^code 1
 
-`Bjorn` has an `update()` method that gets called once per frame by the game. It
-reads the joystick to determine how to accelerate the baker. Then it resolves
+`Bjorn` has an `update()` method that gets called once per frame by the game:
+
+^code monolithic-update
+
+It reads the joystick to determine how to accelerate the baker. Then it resolves
 its new position with the physics engine. Finally, it draws Bjørn onto the
 screen.
 
@@ -561,20 +564,20 @@ likely support more than one at the same time in your designs.
 
  *  **By referring directly to each other:**
 
-     *  The idea here is that components that need to talk will have direct
-        references to each other without having to go through the container
-        object at all.
+    The idea here is that components that need to talk will have direct
+    references to each other without having to go through the container
+    object at all.
 
-        Let's say we want to let Bjørn jump. The graphics code needs to know if
-        he should be drawn using a jump sprite or not. It can determine this by
-        asking the physics engine if he's currently on the ground. An easy way
-        to do this is by letting the graphics component know about the physics
-        component directly:
+    Let's say we want to let Bjørn jump. The graphics code needs to know if
+    he should be drawn using a jump sprite or not. It can determine this by
+    asking the physics engine if he's currently on the ground. An easy way
+    to do this is by letting the graphics component know about the physics
+    component directly:
 
-        ^code 18
+    ^code 18
 
-        When we construct Bjørn's `GraphicsComponent`, we'll give it a reference
-        to his corresponding `PhysicsComponent`.
+    When we construct Bjørn's `GraphicsComponent`, we'll give it a reference
+    to his corresponding `PhysicsComponent`.
 
      *  *It's simple and fast.* Communication is a direct method call from one
         object to another. The component can call any method that is supported
diff --git a/code/cpp/component.h b/code/cpp/component.h
@@ -77,40 +77,7 @@ namespace Monolithic
       x_(0), y_(0)
     {}
 
-    void update(World& world, Graphics& graphics)
-    {
-      // Apply user input to hero's velocity.
-      switch (Controller::getJoystickDirection())
-      {
-        case DIR_LEFT:
-          velocity_ -= WALK_ACCELERATION;
-          break;
-          
-        case DIR_RIGHT:
-          velocity_ += WALK_ACCELERATION;
-          break;
-          //^omit
-        case DIR_NONE: break; // Do nothing.
-          //^omit
-      }
-
-      // Modify position by velocity.
-      x_ += velocity_;
-      world.resolveCollision(volume_, x_, y_, velocity_);
-
-      // Draw the appropriate sprite.
-      Sprite* sprite = &spriteStand_;
-      if (velocity_ < 0)
-      {
-        sprite = &spriteWalkLeft_;
-      }
-      else if (velocity_ > 0)
-      {
-        sprite = &spriteWalkRight_;
-      }
-
-      graphics.draw(*sprite, x_, y_);
-    }
+    void update(World& world, Graphics& graphics);
 
   private:
     static const int WALK_ACCELERATION = 1;
@@ -125,6 +92,43 @@ namespace Monolithic
     Sprite spriteWalkRight_;
   };
   //^1
+    
+  //^monolithic-update
+  void Bjorn::update(World& world, Graphics& graphics)
+  {
+    // Apply user input to hero's velocity.
+    switch (Controller::getJoystickDirection())
+    {
+      case DIR_LEFT:
+      velocity_ -= WALK_ACCELERATION;
+      break;
+      
+      case DIR_RIGHT:
+      velocity_ += WALK_ACCELERATION;
+      break;
+      //^omit
+      case DIR_NONE: break; // Do nothing.
+      //^omit
+    }
+    
+    // Modify position by velocity.
+    x_ += velocity_;
+    world.resolveCollision(volume_, x_, y_, velocity_);
+    
+    // Draw the appropriate sprite.
+    Sprite* sprite = &spriteStand_;
+    if (velocity_ < 0)
+    {
+      sprite = &spriteWalkLeft_;
+    }
+    else if (velocity_ > 0)
+    {
+      sprite = &spriteWalkRight_;
+    }
+    
+    graphics.draw(*sprite, x_, y_);
+  }
+  //^monolithic-update
 }
 
 namespace SplitInputComponent
diff --git a/html/component.html b/html/component.html
@@ -272,37 +272,7 @@ <h3><a href="#a-monolithic-class" name="a-monolithic-class">A monolithic class</
     <span class="n">x_</span><span class="p">(</span><span class="mi">0</span><span class="p">),</span> <span class="n">y_</span><span class="p">(</span><span class="mi">0</span><span class="p">)</span>
   <span class="p">{}</span>
 
-  <span class="kt">void</span> <span class="n">update</span><span class="p">(</span><span class="n">World</span><span class="o">&amp;</span> <span class="n">world</span><span class="p">,</span> <span class="n">Graphics</span><span class="o">&amp;</span> <span class="n">graphics</span><span class="p">)</span>
-  <span class="p">{</span>
-    <span class="c1">// Apply user input to hero&#39;s velocity.</span>
-    <span class="k">switch</span> <span class="p">(</span><span class="n">Controller</span><span class="o">::</span><span class="n">getJoystickDirection</span><span class="p">())</span>
-    <span class="p">{</span>
-      <span class="k">case</span> <span class="n">DIR_LEFT</span>:
-        <span class="n">velocity_</span> <span class="o">-=</span> <span class="n">WALK_ACCELERATION</span><span class="p">;</span>
-        <span class="k">break</span><span class="p">;</span>
-
-      <span class="k">case</span> <span class="n">DIR_RIGHT</span>:
-        <span class="n">velocity_</span> <span class="o">+=</span> <span class="n">WALK_ACCELERATION</span><span class="p">;</span>
-        <span class="k">break</span><span class="p">;</span>
-    <span class="p">}</span>
-
-    <span class="c1">// Modify position by velocity.</span>
-    <span class="n">x_</span> <span class="o">+=</span> <span class="n">velocity_</span><span class="p">;</span>
-    <span class="n">world</span><span class="p">.</span><span class="n">resolveCollision</span><span class="p">(</span><span class="n">volume_</span><span class="p">,</span> <span class="n">x_</span><span class="p">,</span> <span class="n">y_</span><span class="p">,</span> <span class="n">velocity_</span><span class="p">);</span>
-
-    <span class="c1">// Draw the appropriate sprite.</span>
-    <span class="n">Sprite</span><span class="o">*</span> <span class="n">sprite</span> <span class="o">=</span> <span class="o">&amp;</span><span class="n">spriteStand_</span><span class="p">;</span>
-    <span class="k">if</span> <span class="p">(</span><span class="n">velocity_</span> <span class="o">&lt;</span> <span class="mi">0</span><span class="p">)</span>
-    <span class="p">{</span>
-      <span class="n">sprite</span> <span class="o">=</span> <span class="o">&amp;</span><span class="n">spriteWalkLeft_</span><span class="p">;</span>
-    <span class="p">}</span>
-    <span class="k">else</span> <span class="k">if</span> <span class="p">(</span><span class="n">velocity_</span> <span class="o">&gt;</span> <span class="mi">0</span><span class="p">)</span>
-    <span class="p">{</span>
-      <span class="n">sprite</span> <span class="o">=</span> <span class="o">&amp;</span><span class="n">spriteWalkRight_</span><span class="p">;</span>
-    <span class="p">}</span>
-
-    <span class="n">graphics</span><span class="p">.</span><span class="n">draw</span><span class="p">(</span><span class="o">*</span><span class="n">sprite</span><span class="p">,</span> <span class="n">x_</span><span class="p">,</span> <span class="n">y_</span><span class="p">);</span>
-  <span class="p">}</span>
+  <span class="kt">void</span> <span class="n">update</span><span class="p">(</span><span class="n">World</span><span class="o">&amp;</span> <span class="n">world</span><span class="p">,</span> <span class="n">Graphics</span><span class="o">&amp;</span> <span class="n">graphics</span><span class="p">);</span>
 
 <span class="nl">private:</span>
   <span class="k">static</span> <span class="k">const</span> <span class="kt">int</span> <span class="n">WALK_ACCELERATION</span> <span class="o">=</span> <span class="mi">1</span><span class="p">;</span>
@@ -319,8 +289,42 @@ <h3><a href="#a-monolithic-class" name="a-monolithic-class">A monolithic class</
 </pre></div>
 
 
-<p><code>Bjorn</code> has an <code>update()</code> method that gets called once per frame by the game. It
-reads the joystick to determine how to accelerate the baker. Then it resolves
+<p><code>Bjorn</code> has an <code>update()</code> method that gets called once per frame by the game:</p>
+<div class="codehilite"><pre><span class="kt">void</span> <span class="n">Bjorn</span><span class="o">::</span><span class="n">update</span><span class="p">(</span><span class="n">World</span><span class="o">&amp;</span> <span class="n">world</span><span class="p">,</span> <span class="n">Graphics</span><span class="o">&amp;</span> <span class="n">graphics</span><span class="p">)</span>
+<span class="p">{</span>
+  <span class="c1">// Apply user input to hero&#39;s velocity.</span>
+  <span class="k">switch</span> <span class="p">(</span><span class="n">Controller</span><span class="o">::</span><span class="n">getJoystickDirection</span><span class="p">())</span>
+  <span class="p">{</span>
+    <span class="k">case</span> <span class="n">DIR_LEFT</span>:
+    <span class="n">velocity_</span> <span class="o">-=</span> <span class="n">WALK_ACCELERATION</span><span class="p">;</span>
+    <span class="k">break</span><span class="p">;</span>
+
+    <span class="k">case</span> <span class="n">DIR_RIGHT</span>:
+    <span class="n">velocity_</span> <span class="o">+=</span> <span class="n">WALK_ACCELERATION</span><span class="p">;</span>
+    <span class="k">break</span><span class="p">;</span>
+  <span class="p">}</span>
+
+  <span class="c1">// Modify position by velocity.</span>
+  <span class="n">x_</span> <span class="o">+=</span> <span class="n">velocity_</span><span class="p">;</span>
+  <span class="n">world</span><span class="p">.</span><span class="n">resolveCollision</span><span class="p">(</span><span class="n">volume_</span><span class="p">,</span> <span class="n">x_</span><span class="p">,</span> <span class="n">y_</span><span class="p">,</span> <span class="n">velocity_</span><span class="p">);</span>
+
+  <span class="c1">// Draw the appropriate sprite.</span>
+  <span class="n">Sprite</span><span class="o">*</span> <span class="n">sprite</span> <span class="o">=</span> <span class="o">&amp;</span><span class="n">spriteStand_</span><span class="p">;</span>
+  <span class="k">if</span> <span class="p">(</span><span class="n">velocity_</span> <span class="o">&lt;</span> <span class="mi">0</span><span class="p">)</span>
+  <span class="p">{</span>
+    <span class="n">sprite</span> <span class="o">=</span> <span class="o">&amp;</span><span class="n">spriteWalkLeft_</span><span class="p">;</span>
+  <span class="p">}</span>
+  <span class="k">else</span> <span class="k">if</span> <span class="p">(</span><span class="n">velocity_</span> <span class="o">&gt;</span> <span class="mi">0</span><span class="p">)</span>
+  <span class="p">{</span>
+    <span class="n">sprite</span> <span class="o">=</span> <span class="o">&amp;</span><span class="n">spriteWalkRight_</span><span class="p">;</span>
+  <span class="p">}</span>
+
+  <span class="n">graphics</span><span class="p">.</span><span class="n">draw</span><span class="p">(</span><span class="o">*</span><span class="n">sprite</span><span class="p">,</span> <span class="n">x_</span><span class="p">,</span> <span class="n">y_</span><span class="p">);</span>
+<span class="p">}</span>
+</pre></div>
+
+
+<p>It reads the joystick to determine how to accelerate the baker. Then it resolves
 its new position with the physics engine. Finally, it draws Bj&oslash;rn onto the
 screen.</p>
 <p>The sample implementation here is trivially simple. There&#8217;s no gravity,
@@ -817,11 +821,9 @@ <h3><a href="#how-do-components-communicate-with-each-other" name="how-do-compon
 </li>
 <li>
 <p><strong>By referring directly to each other:</strong></p>
-<ul>
-<li>
 <p>The idea here is that components that need to talk will have direct
-    references to each other without having to go through the container
-    object at all.</p>
+references to each other without having to go through the container
+object at all.</p>
 <p>Let&#8217;s say we want to let Bj&oslash;rn jump. The graphics code needs to know if
 he should be drawn using a jump sprite or not. It can determine this by
 asking the physics engine if he&#8217;s currently on the ground. An easy way
@@ -862,7 +864,7 @@ <h3><a href="#how-do-components-communicate-with-each-other" name="how-do-compon
 
 <p>When we construct Bj&oslash;rn&#8217;s <code>GraphicsComponent</code>, we&#8217;ll give it a reference
 to his corresponding <code>PhysicsComponent</code>.</p>
-</li>
+<ul>
 <li>
 <p><em>It&#8217;s simple and fast.</em> Communication is a direct method call from one
     object to another. The component can call any method that is supported
diff --git a/note/log.txt b/note/log.txt
@@ -1,3 +1,5 @@
+2014-08-02 - layout component
+2014-08-01 - merge component changes
 2014-07-28 - email
 2014-07-27 - layout type object
 2014-07-26 - merge type object changes

Original file line number	Diff line number	Diff line change
`@@ -1,3 +1,5 @@`
	`1`	`+2014-08-02 - layout component`
	`2`	`+2014-08-01 - merge component changes`
`1`	`3`	`2014-07-28 - email`
`2`	`4`	`2014-07-27 - layout type object`
`3`	`5`	`2014-07-26 - merge type object changes`