Add initial manual section on creating lights

doc/manual.adoc

@@ -508,3 +508,27 @@ properties of the sound shader itself, such as volume.
 *Player start (info_player_start)*:: This entity tells the game engine where to
 place the player when a map is first loaded. A map without such an entity will
 not be playable.
+
+==== Creating lights
+
+To create a light, *Right click* in the 2D view and choose *Create light…*.
+The position and size of the light volume depends on the current selection:
+
+- If _nothing_ is selected, then a light volume will be created at the clicked
+  position with a default size.
+- If a _single brush_ is selected, the brush will be deleted and the light
+  volume will match the size and position of the brush.
+- If _several brushes_ are selected, then all selected brushes will be deleted
+  and the light volume will be sized according to the bounding box of the
+  brushes (i.e. the smallest box that would contain all of the brushes).
+
+Unselected lights are shown in the 2D view as small boxes, while selected lights
+also show the boundaries of the light volume.
+
+.Light entity selected (left) and unselected (right)
+image::LightSelectedAndUnselected.png[align="center"]
+
+A selected light entity can be moved by dragging inside the small center box,
+and it can be resized by dragging outside the edge of the light volume. Unlike
+brushes, light volumes will by default resize symmetrically, so that the center
+point does not move during the resize.

doc/manual.html

@@ -457,7 +457,11 @@ <h1>DarkRadiant User Guide</h1>
 <li><a href="#_applying_textures_to_brushes">Applying textures to brushes</a></li>
 </ul>
 </li>
-<li><a href="#_working_with_entities">Working with entities</a></li>
+<li><a href="#_working_with_entities">Working with entities</a>
+<ul class="sectlevel3">
+<li><a href="#_creating_lights">Creating lights</a></li>
+</ul>
+</li>
 </ul>
 </li>
 </ul>
@@ -1257,13 +1261,53 @@ <h3 id="_working_with_entities">Working with entities</h3>
 </dd>
 </dl>
 </div>
+<div class="sect3">
+<h4 id="_creating_lights">Creating lights</h4>
+<div class="paragraph">
+<p>To create a light, <strong>Right click</strong> in the 2D view and choose <strong>Create light…</strong>.
+The position and size of the light volume depends on the current selection:</p>
+</div>
+<div class="ulist">
+<ul>
+<li>
+<p>If <em>nothing</em> is selected, then a light volume will be created at the clicked
+position with a default size.</p>
+</li>
+<li>
+<p>If a <em>single brush</em> is selected, the brush will be deleted and the light
+volume will match the size and position of the brush.</p>
+</li>
+<li>
+<p>If <em>several brushes</em> are selected, then all selected brushes will be deleted
+and the light volume will be sized according to the bounding box of the
+brushes (i.e. the smallest box that would contain all of the brushes).</p>
+</li>
+</ul>
+</div>
+<div class="paragraph">
+<p>Unselected lights are shown in the 2D view as small boxes, while selected lights
+also show the boundaries of the light volume.</p>
+</div>
+<div class="imageblock" style="text-align: center">
+<div class="content">
+<img src="img/LightSelectedAndUnselected.png" alt="LightSelectedAndUnselected">
+</div>
+<div class="title">Figure 4. Light entity selected (left) and unselected (right)</div>
+</div>
+<div class="paragraph">
+<p>A selected light entity can be moved by dragging inside the small center box,
+and it can be resized by dragging outside the edge of the light volume. Unlike
+brushes, light volumes will by default resize symmetrically, so that the center
+point does not move during the resize.</p>
+</div>
+</div>
 </div>
 </div>
 </div>
 </div>
 <div id="footer">
 <div id="footer-text">
-Last updated 2018-08-07 21:18:13 BST
+Last updated 2018-08-08 21:01:26 BST
 </div>
 </div>
 </body>