CUR, ANI, and the pixel that makes a click land

CUR is a still Windows cursor

A .cur file looks similar to an icon file, but it carries one extra piece of information that matters every time you click: the hotspot. A well-built CUR file can contain the same pointer artwork at several resolutions so Windows can choose an appropriate size for the current display scale.

Renaming a PNG or ICO file to .cur does not create a working cursor. The file needs the cursor directory structure, image data, and hotspot coordinates Windows expects.

ANI is an animated Windows cursor

An .ani file stores a sequence of cursor frames plus timing information. Windows uses ANI for moving pointers such as an animated busy indicator. Each frame still needs a reliable hotspot so the apparent click point does not jump as the animation plays.

GIF and APNG are image-animation formats, not native Windows cursor formats. Cursed decodes their frames and writes the corresponding ANI cursor files locally.

The hotspot is the actual click point

The hotspot is a pair of pixel coordinates inside the cursor. An arrow normally clicks from its sharp tip; a crosshair normally clicks from its center. If the artwork looks correct but every click lands a few pixels away, the hotspot is probably misplaced.

Hotspots should scale with the artwork. Reusing one absolute coordinate across several cursor sizes can make only one size feel accurate. Cursed stores the chosen point proportionally and writes the correct coordinate for each output size.

Why multiple sizes matter

Windows display scaling changes how large interface elements appear on high-density screens. A cursor with several built-in resolutions gives Windows suitable artwork to choose from instead of stretching one small bitmap. Cursed produces still cursors at 32, 48, 64, 96, 128, 192, and 256 pixels.

Animated cursor files do not carry the same multi-resolution directory as CUR files, so Cursed creates a separate ANI for each target size and selects the closest one when applying the pointer.

What about ICO, PNG, GIF, and APNG?

• ICO is a Windows icon format. Cursed can read it as artwork, but a cursor still needs hotspot information.
• PNG, JPEG, WebP, BMP, and TIFF are still image sources that can become CUR files.
• GIF and APNG are animation sources that can become ANI files.
• CUR and ANI are the native cursor files Windows applies.

Quick diagnosis: if the cursor is sharp but clicks in the wrong place, check the hotspot. If it clicks correctly but looks blurry at some display scales, check the resolutions stored in the file.