Changing a sprite depending on variables

Question

I have code here which will change a sprite depending on the variables called gunUpgrade and moveUpgrade. Any way to make the code simpler or shorter? I'm using Unity 3D.

if (gunUpgrade > 0 && moveUpgrade > 0)
 {
 if (gunUpgrade == 1)
 {
 // For every moveupgrade, set the sprite to array number
 if (moveUpgrade == 1) { currentSprite = playerSprites[8]; }
 else if (moveUpgrade == 2) { currentSprite = playerSprites[9]; }
 else if (moveUpgrade == 3) { currentSprite = playerSprites[10]; }
 else if (moveUpgrade == 4) { currentSprite = playerSprites[11]; }
 }
 if (gunUpgrade == 2)
 {
 if (moveUpgrade == 1) { currentSprite = playerSprites[12]; }
 else if (moveUpgrade == 2) { currentSprite = playerSprites[13]; }
 else if (moveUpgrade == 3) { currentSprite = playerSprites[14]; }
 else if (moveUpgrade == 4) { currentSprite = playerSprites[15]; }
 }
 if (gunUpgrade == 3)
 {
 if (moveUpgrade == 1) { currentSprite = playerSprites[16]; }
 else if (moveUpgrade == 2) { currentSprite = playerSprites[17]; }
 else if (moveUpgrade == 3) { currentSprite = playerSprites[18]; }
 else if (moveUpgrade == 4) { currentSprite = playerSprites[19]; }
 }
 }

Answer 1

Use some math.

currentSprite = playerSprites[gunUpgrade*4+4+moveUpgrade-1];

Answer 2

I suggest writing it as

currentSprite = playerSprites[4 * (gunUpgrade + 1) + (moveUpgrade - 1)];

Consider laying out the elements of playerSprites so as to require fewer ±1 operations.

Note that you must ensure that gunUpgrade never exceeds 3, and moveUpgrade never exceeds 4.

• Bruno Costa: Sorry for the lack of a detailed answer but in the end this is the same as I suggested.
• DrakaSAN: @BrunoCosta: But he lack of a detailed answer make it so your code is "magic", and you leave a few important details such as the limitation of it, or how to scale it up.