This preview shows page 1. Sign up to view the full content.
Unformatted text preview: . The protocol.BgnRecord and protocol.PopRecord classes contain the names
of all the imporatant fields; they also contain comments describing from
where these fields are filled. You should read these comments before
implementing the parsing for these records. We have already provided you
with a complete parser for the population records; you must implement
parsers for BGN and the TIGER datatypes. If you are confused about how to execute a join, refer to Barry Brumitt's slides (posted
on the course web site). Rendering
The primary component of this assignment is the tile renderer. Tile rendering is done by
subclasses of the TileRenderer abstract class. You must implement a concrete subtype
of this class that renders important geographic features on tiles.
We have provided you with an example of how to implement this with the
FakeTileRenderer class. The FakeTileRenderer will draw the same picture on every tile,
regardless of its input features. The purpose of this class is to familiarize you with the
graphics primitives necessary to perform the drawing. This renderer will render a line, a
polygon, and a text object; it shows you how to change colors and fonts. When you are
stuck on how to do something, refer to the example uses in this file, and of course,
always refer to the Java API documentation online for specific methods to use and types
The TileRenderer is used in a Reducer. The Reducer receives all shape object records for
a given Tile Set. The Mapper should read in all shape object records, determine which
tile or tiles they cover, and emit them to the reducers for the Tile Sets containing the tile
IDs in question.
When features are read in by the Reducer, they are added to the collection seen by the
TileRenderer with the addRecord() method. After buffering all its features, the Reducer
invokes the TileRenderer repeatedly to render every Tile in its Tile Set. The setTile()
method is used to set the tile extent which should be rendered. Feature records which
are visible (partially or fully) within this tile should then be rendered on to the output
buffer when renderTile() is called. Y...
View Full Document
This homework help was uploaded on 04/02/2014 for the course CSE 490 taught by Professor Staff during the Fall '08 term at University of Washington.
- Fall '08