Easy method of obtaining texture coordinates for sprite sheet

In my (OpenGL ES 2.0 Android) game, I use 2 types of Sprite Sheets. In one type all sprites/frames are of equal size and in the other they are all different shapes and sizes.

It is the latter one to which this question pertains. Basically, I've created a sprite sheet and I currently use Paint.net to find the coordinates a particular frame sits at. I then have to work out the texture coordinates by dividing the pixel by the width (for X) or height (for Y) so, if my image is 2048 x 2048 and a particular frame is at 300, 500, I work it out like so:

300/2048 = 0.146484375
500/2048 = 0.244140625


So, my X (or S) is 0.146484375 and my Y (or T) is 0.244140625.

I use the same method to work out the width and height.

I then code this using a method like so:

setTexCoords(0.146484375f, 0.244140625f, 0.048828125f, 0.048828125f);  //X, Y, Width, Height


When working with lots of sprites, this is a very tedious process.

The main problem however, is if I, at a later date, want to add sprites to the sheet and make it bigger to accommodate the extra sprites, I have to revisit every sprite and work out it's new texture coords based on the new bitmap size.

Is there any method I can use to make this process easier?

Even if it's just a program where I can hover the mouse over a bitmap and it tells me the texture coordinate (between 0-1). Even that would take a little of the work out of it.

Any suggestions welcomed.

I have read a similar question on here however, none of the answers really helped

• At the very least use setTexCoords(300/2048f, 500/2048f, and so on) – user253751 Sep 6 '15 at 6:50

Here's a really simple improvement:

Define a method that sets the texture coordinates as pixels. Something like:

void setTexCoordsI(int x, int y, int w, int h) {
float TEXTURE_SIZE = 2048.0f;
setTexCoords(x/TEXTURE_SIZE, y/TEXTURE_SIZE, w/TEXTURE_SIZE, h/TEXTURE_SIZE);
}


Then call:

setTexCoordsI(300, 500, 100, 100);


setTexCoords(0.146484375f, 0.244140625f, 0.048828125f, 0.048828125f);