stb_image: Document image size limits

Both the buffer size limits and the image dimension limits.

Fixes issue #672.
This commit is contained in:
Fabian Giesen 2021-07-02 22:52:15 -07:00
parent ba739e54ed
commit e795306bbc

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@ -187,6 +187,24 @@ RECENT REVISION HISTORY:
// // returns ok=1 and sets x, y, n if image is a supported format,
// // 0 otherwise.
//
// Note that stb_image pervasively uses ints in its public API for sizes,
// including sizes of memory buffers. This is now part of the API and thus
// hard to change without causing breakage. As a result, the various image
// loaders all have certain limits on image size; these differ somewhat
// by format but generally boil down to either just under 2GB or just under
// 1GB. When the decoded image would be larger than this, stb_image decoding
// will fail.
//
// Additionally, stb_image will reject image files that have any of their
// dimensions set to a larger value than the configurable STBI_MAX_DIMENSIONS,
// which defaults to 2**24 = 16777216 pixels. Due to the above memory limit,
// the only way to have an image with such dimensions load correctly
// is for it to have a rather extreme aspect ratio. Either way, the
// assumption here is that such larger images are likely to be malformed
// or malicious. If you do need to load an image with individual dimensions
// larger than that, and it still fits in the overall size limit, you can
// #define STBI_MAX_DIMENSIONS on your own to be something larger.
//
// ===========================================================================
//
// UNICODE: