Game Development Reference
In-Depth Information
for (var rowCtr:int = 0; rowCtr < mapRowCount; rowCtr++) {
for (var colCtr:int = 0; colCtr < mapColumnCount; colCtr++) {
tileNum = spriteMap[rowCtr][colCtr];
switch(tileSheetData[tileNum]) {
case SPRITE_PLAYER:
player.animationLoop = false;
playerStartRow= rowCtr;
playerStartCol= colCtr;
player.currRow = rowCtr;
player.currCol = colCtr;
player.currentDirection = MOVE_STOP;
break;
}
}
}
}
This function is used to parse the 2D array of data in the
levelData.spriteMap
variable. As you
might recall, this variable was assigned
readBackGroundData
function in the original
GameDemo.as
file. Here is a breakdown of what is happening in this function.
We will loop through this data using a nested loop structure. A nested loop structure contains an
outer loop that will iterate though the rows in our sprite data, and inside each row, we will iterate
through each column. This inside loop through the column data for each row is the
nested loop
.
1.
We create a local variable called
tileNum
. This will hold the current tile
id
for the
[row][column]
on our sprite layer when we iterate through the level sprite data.
2.
We assign the
spriteMap
class variable the value of the
levelData.spriteMap
contents.
3.
We start our outer loop using the local
rowCtr
variable (starting at
0
) while it is less
than the
mapRowCount
amount (
15
).
4.
The inner, or nested, loop through each column in the current row begins by using the
colCtr
variable to start at
0
and loop through all of the columns while it is less than
mapColumnCount
(
20
).
5.
The current
tileNum
is the value in the array at
[rowCtr][colCtr]
.
6.
That
tileNum
is plugged into the
tileSheetData
single dimensional array to find the
type of sprite that is in that location. If you recall, the i
nitTileSheetData
function
parsed the data in the
TileSheeDataXML.as
file as assigned a constant to the value of
each sprite in the t
ileSheetData
array.
7.
We start a
switch:case
statement based on the constant.
8.
The player variable is assigned with its starting values.
The player begins with its
animationLoop
variable set to
false
. The tank is stopped
(
player.currDir=MOVE_STOP
) when the level begins. We don't want the tank treads to animate
while the tank is stopped, so we set this to
false
.
