Game Development Reference
In-Depth Information
using
Microsoft.Xna.Framework;
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class
JewelJamGameWorld : GameObjectList
{
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public
JewelJamGameWorld()
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{
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this
.Add(
new
SpriteGameObject("spr_background"));
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8
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GameObjectList playingField =
new
GameObjectList(1);
playingField.Position =
new
Vector2(85, 150);
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this
.Add(playingField);
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JewelGrid grid =
new
JewelGrid(10, 5, 0);
playingField.Add(grid);
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15
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playingField.Add(
new
RowSelectGameObject(grid, 1));
}
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}
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Listing 15.2
The class for representing the game world in the
JewelJam
game
15.3 Accessing the Game World
In the
JewelJam
game, we do not have a separate
GameWorld
class anymore. This
is because the
GameObjectList
class is now basically the basis for creating the game
world consisting of a hierarchy of game objects that are drawn in a certain order.
However, creating all the game objects is now done in the
JewelJam
class because
of that. This is not a very nice software design, because now the basic initialization
tasks are mingled with the game-specific object creation tasks. We can separate them
by creating a new class called
JewelJamGameWorld
which will be a subclass of the
GameObjectList
class. In the constructor of this class, we write all the instructions for
filling the game world. Now we only have to make an instance of that class in the
JewelJam
class, and call the game loop methods on the
JewelJamGameWorld
object.
The complete
JewelJamGameWorld
class can be found in Listing
15.2
. You can find
the new version of the
JewelJam
class in the
JewelJam4
program belonging to this
chapter.
15.4 Game Objects Using the Asset Manager
15.4.1 The
SpriteGameObject
Class
Since we want our objects to retrieve their assets themselves, we do not want to
pass a
Texture2D
object anymore as a parameter. For example, the sprite game ob-
