random failure to load a texture from an image file

Question

I am working on an app that applies effects to live video using GPUimage.

One of the effects required an image to be loaded as a texture and then that image is is overplayed on the video.

All of the images are PNG files. the used can select one of the images from the list.

I use the following code to load the texture and it works 98% of the time, but randomly the texture does not load and i just get a black square. If the texture fails to load and I attempt to reload it with the same image it works. Again this failure to load is very random.

Any thought/ suggestions would be appreciated.

-(GLuint) loadTexture:(NSString *)fileName
{
    NSString *filePath =   [NSString stringWithFormat:@"%@/%@",[[NSBundle mainBundle] resourcePath],fileName];
    UIImage *image    = [UIImage imageWithContentsOfFile:filePath];

    GLuint width = image.size.width;
    GLuint height = image.size.height;

    if(width == 0 ){
        width = 64;
    }
    if(height == 0 )
    {
        height = 64;
    }

    CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();
    size_t cwidth = ceil( width );
    size_t cheight = ceil( height );
    size_t bytesPerRow = ( 4*cwidth + 15 ) & ~15;
    void *imageData = calloc( bytesPerRow, cheight );

    NSLog(@"texture : WIDTH %d HEIGHT %d\n", width, height);

    CGContextRef context = CGBitmapContextCreate( imageData, cwidth, cheight, 8, bytesPerRow, colorSpace, kCGImageAlphaPremultipliedLast |                                                                                                 kCGBitmapByteOrder32Big );

    CGColorSpaceRelease( colorSpace );

    CGContextClearRect( context, CGRectMake( 0, 0, cwidth, cheight ) );

    CGRect bounds=CGRectMake( 0, 0, cwidth, cheight );
    CGContextScaleCTM(context, 1, -1);
    bounds.size.height = bounds.size.height*-1;
    CGContextDrawImage(context, bounds, image.CGImage);


    GLuint lTextId;
    glGenTextures(1, &lTextId);
    glBindTexture(GL_TEXTURE_2D, lTextId);


    glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, (GLsizei)cwidth, (GLsizei)cheight, 0, GL_RGBA, GL_UNSIGNED_BYTE, imageData);

    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);

    glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
    glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);


    CGContextRelease(context);


    free(imageData);

    return( lTextId);
}

Answer 1

I am not sure it will help but I strongly suggest you to change

NSString *filePath =   [NSString stringWithFormat:@"%@/%@",[[NSBundle mainBundle] resourcePath],fileName];

to

NSString *filePath = [[NSBundle mainBundle] pathForResource:fileName ofType:nil];