Update

line.md

@@ -1,17 +1,17 @@
 # Line
 
-Line is one of the most basic geometric shapes, it is straight, continuous, infinitely long and infinitely thin. A finite continuous part of a line is called **line segment**, though in practice we sometimes call line segments also just *lines*. Shortest path between any two points always lies on a line. { At least I hope :D ~drummyfish }
+Line is one of the most basic geometric shapes, it is straight, continuous, infinitely long and infinitely thin. A finite continuous part of a line is called **line segment**, though in practice we sometimes call line segments also just *lines*. In flat, non-curved geometries shortest path between any two points always lies on a line.
 
-Line is a one [dimensional](dimension.md) shape, i.e. any of its points can be identified by a single straightforward number (signed distance from a certain point on the line). But of course a line itself may exist in more than one dimensional spaces (just as a two dimensional sheet of paper can exist in our three dimensional space etc.).
+Line is a one [dimensional](dimension.md) shape, i.e. any of its points can be directly identified by a single number -- the signed distance from a certain point on the line. But of course a line itself may exist in more than one dimensional spaces (just as a two dimensional sheet of paper can exist in our three dimensional space etc.).
 
 ```
-   /               |     \
-  /   ________     |      \
- /                 |       \
-/                  |        \
+   /               |     \            .'
+  /   ________     |      \         .'
+ /                 |       \      .'
+/                  |        \   .'
 ```
 
-*some lines, in case you haven't see one yet*
+*some lines, in case you haven't seen one yet*
 
 ## Equations
 
@@ -46,4 +46,31 @@ Now for whatever *t* we plug into these equations we get the *[x,y]* coordinates
 
 ## Line Drawing Algorithms
 
-TODO
+Drawing lines with computers is a subject of [computer graphics](graphics.md). On specific devices such as [vector monitors](vector_monitor.md) this may be a trivial task, however as most display devices nowadays work with [raster graphics](raster_graphics.md), let's from now on focus only on such devices.
+
+There are many [algorithms](algorithm.md) for line [rasterization](rasterization.md). They differ in attributes such as:
+
+- complexity of implementation
+- speed/efficiency (some algorithms avoid the use of [floating point](float.md) which requires special [hardware](hardware.md))
+- support of [antialiasing](antialiasing.md) ("smooth" vs "pixelated" lines)
+- [subpixel](subpixel.md) precision (whether start and end point of the line has to lie exactly on integer pixel coordinates; subpixel precision makes for smoother animation)
+- support for different width lines (and additionally e.g. the shape of line segment ends etc.)
+- ...
+
+```
+                                                 .
+             XXX               XX             .aXa
+           XX                XX             lXa.
+         XX                XX            .lXl
+      XXX               XXX            .aal
+    XX                XX             lXa.
+  XX               XXX            .aXl
+XX               XX               a.
+
+      pixel         subpixel     subpixel accuracy
+     accuracy       accuracy      + anti-aliasing
+```
+
+One of the most basic line rasterization algorithms is the [DDA](dda.md) (Digital differential analyzer), however it is usually better to use at least the [Bresenham's line algorithm](bresenham.md) which is still simple and considerably improves on DDA.
+
+TODO: more algorithms, code example, general form (dealing with different direction etc.)