JavaScript string manipulation with certain logic in it

How would I make this code look less ugly?

// we are looping over an array of images
// width is a parameter passed to the current function 
//
// the resulting string looks like this: "30px 0"
// (it's a tool that returns coordinates for a CSS sprite)
// when iterating over the first item, we don't need 
// to add "-" and "px" to X coordinate
result.push(
    ( i === 0 ? "0" : "-" + i * ( ( is2PixelRatio ? width / 2 : width ) + 10 ) + "px" ) + " 0"
);

Minor upgrades, nice idea for the prepop result Raynos

result = ["0 0"]; // Outside of loop

// ...

if (is2PixelRatio) width /= 2;   
width += 10; // [Insert magik number explanation here]

result.push(  -(i * width) + "px 0"  ); // Negative numbers will convert to "-30"

StackExchange Code Review Q#3195, answer score: 5