Trying to use stbi_load_from_memory to obtain texture file from a glb file.

[dc2032]

The NASA webite has fantastic 3D models of all nine planets, which I have downloaded. I am trying to develop a game for my 14 year old grandson where you fly a spaceship through the solar system. The models are downloaded in GLTF format, with a PNG file imbedded. I have successfully used cgltf.h to load all of the model data into memory, including the PNG file. I am trying to build an openGL texture file using stbi_load_from_memory. I'm calling it like this:
unsigned char* data = stbi_load_from_memory((unsigned char*)image, size, &width, &height, &channels, 0);
On return from the call, in which I do not get any error messages, data points to a buffer containing all xCC. Single stepping through the Visual Studio 2022 debugger, the buffer appears to get corrupted in stbi__parse_png_file, but I have been unable to trap the exact point. I know the PNG file is valid, because I can access the buffer and write it out to a file and then read it using Windows Photo viewer. All I'm looking for is some guidance on what could be wrong with the file in memory and perhaps what I could do about it.

[nothings]

if you write it out to a file, can you then load it with stbi_load? if that corrupts in exactly the same way, please post that file.

[dc2032]

The version of stb_image I have is 2.27 and I've been compiling for 64-bit.

[dc2032]

I decided to try the solution suggested in the discussion David referred to earlier and put in the #define STB_IMAGE_STATIC. But when I do that I get unresolved references to stb_load_from_memory and stb_load_from_file. I'm also not making much headway trying it on linux. It appears I have a version problem, gcc is looking for glibc 2.27 but I have 2.28 installed. I'm still researching that one.

[nothings]

For reference, I doubt STB_IMAGE_STATIC is the issue, but it's a tool that allows multiple instances of stb_image in the same project without name collisions. If you use it, it makes the functions private to the c/cpp file with the implementation, so you have to write your own wrappers in that file to allow it to be called externally.

[nothings]

Also, you should try loading the file-written image yourself in the same program just using stbi_load and see if it has the same problem or not. If that works ok, then try stbi_load_from_memory but loading it from the file. If that's ok, then you should triangulate what's different in the call that works and the call that fails--are you using the wrong 'size', etc.

All of this should be straightforward and simpler and more direct to figuring out what's going wrong in stb_image than trying to build another program on another operating system.

[dc2032]

When I try the file, I get the same corruption. At one point I had converted the PNG file produced to a JPG and I just tried stbi_load with it and had the same problem. It looks like I may have a Visual Studio problem because sometimes as I'm single stepping in the debugger, it will exit my program without generating an exception.