Determining the X, Y co-ordinates in sprite sheets

Question

I am new to Android COCOS2D and developing a simple game to start with. I am developing a game for kids in which the kids shall spell out the names of the fruits they select. I have developed the sprite sheet consisting of pictures of several fruits. Kindly tell me how will the fruit on which the kid taps will get selected. How are the x and y co-ordinates in the sprite sheet determined??

I shall be thankful in case anyone can help me out with this. Thanks in advance

Answer 1

Depends on your spritesheet and how you'd like to refer to each sprite.

Horizontal Strip, Evenly Spaced

[0][1][2][3][4][5][6][7][8]

Coordinates for tile corresponding to position N:

X = N * TileWidth
Y = 0

Grid, Evenly Spaced, Single Index

[0][1][2]
[3][4][5]
[6][7][8]

Coordinates for tile corresponding to position N:

X = (N % Cols) * TileWidth
Y = floor(N / Cols) * TileHeight

In this example Cols equals 3.

Grid, Evenly Spaced, Double Index

[0,0][1,0][2,0]
[0,1][1,1][2,1]
[0,2][1,2][2,2]

Coordinates for tile corresponding to position NX and NY:

X = NX * TileWidth
Y = NY * TileHeight

Irregular Sprite Sheet

Store rectangle regions of each sprite in a seperate file. E.g.

0 0 30 60      // First sprite at (0,0) with size (30,60)
30 0 100 60    // Second sprite at (30,0) with size (100,60)
0 60 130 60    // Third sprite at (0,60) with size (130,60)