I am trying to crop an area out of a UIImage to use with GLKTextureLoader. I can set the texture directly using the the UIImage with the following:
- (void)setTextureImage:(UIImage *)image
{
NSError *error;
texture = [GLKTextureLoader textureWithCGImage:image.CGImage options:nil error:&error];
if(error)
{
NSLog(@"Texture Error:%@", error);
} else {
self.textureCoordinates[0] = GLKVector2Make(1.0f, 1.0f);
self.textureCoordinates[1] = GLKVector2Make(1.0f, 0);
self.textureCoordinates[2] = GLKVector2Make(0, 0);
self.textureCoordinates[3] = GLKVector2Make(0, 1.0f);
}
}
However, if I try crop the image this way:
- (void)setTextureImage:(UIImage *)image
{
NSError *error;
CGImageRef imageRef = CGImageCreateWithImageInRect(image.CGImage, CGRectMake(0.0, 64.0f, 64.0f, 64.0f));
texture = [GLKTextureLoader textureWithCGImage:imageRef options:nil error:&error];
if(error)
{
NSLog(@"[SF] Texture Error:%@", error);
} else {
self.textureCoordinates[0] = GLKVector2Make(1.0f, 1.0f);
self.textureCoordinates[1] = GLKVector2Make(1.0f, 0);
self.textureCoordinates[2] = GLKVector2Make(0, 0);
self.textureCoordinates[3] = GLKVector2Make(0, 1.0f);
}
}
I get this error:
Texture Error:Error Domain=GLKTextureLoaderErrorDomain Code=12 "The operation couldn’t be completed. (GLKTextureLoaderErrorDomain error 12.)" UserInfo=0x6a6b550 {GLKTextureLoaderErrorKey=Image decoding failed}
How can I take a section of the UIImage to use as a texture with GLKTextureLoader?
In the end I got it to work with UIImagePNGRepresentation, I'm only learning OpenGL/GLKit at the moment - so not an expert but I'm guessing the CGImage was missing some colorspace or some other data that is required for textures.