如何使用GLKTextureLoader从Web URL加载立方体贴图

Question

Unsure how to use an image loaded from the web as an asset in a GLKit skybox (like the old apple/google maps streetview) There are 2 methods for loading cubemaps with GLKTextureLoader: cubeMapWithContentsOfFile and cubeMapWithContentsOfUrl

If I grab the image locally it works fine:

NSString *path = [[NSBundle mainBundle] pathForResource:@"pano" ofType:@"jpg"];
GLKTextureInfo *skyboxCubemap =  [GLKTextureLoader cubeMapWithContentsOfFile:imgPath options:options error:&error];

So is there a way to get a path from an image loaded from the web and use it here?

Answer 1

I ended up loading the image from the web like so:

- (void) cacheImage: (NSURL *) ImageURL : (NSString *)imageName
{
    NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
    NSString *dir = [paths objectAtIndex: 0];
    NSString *file = [docDir stringByAppendingPathComponent: imageName];

    if(![[NSFileManager defaultManager] fileExistsAtPath: file])
    {
        NSData *data = [[NSData alloc] initWithContentsOfURL: ImageURL];
        UIImage *image = [[UIImage alloc] initWithData: data];
        [UIImageJPEGRepresentation(image, 100) writeToFile: docFile atomically: YES];
    }
}

caching and returning the file url via :

- (NSString *) getCachedImage : (NSString *)imageName
{
    NSArray *paths = NSSearchPathForDirectoriesInDomains
    (NSDocumentDirectory, NSUserDomainMask, YES);
    NSString *documentsDirectory = [paths objectAtIndex:0];
    NSString* cachedPath = [documentsDirectory stringByAppendingPathComponent:imageName];
    NSString *path;
    if([[NSFileManager defaultManager] fileExistsAtPath: cachedPath])
    {
        path = cachedPath;
    }
    return path;
}

and loading the file via

NSString *cached = [self getCachedImage:@"cacheKey"];
self.skyboxCubemap =  [GLKTextureLoader cubeMapWithContentsOfFile:cached options:options error:&error];