gistfile1.txt

- (void)loadShaderNamed:(NSString*)shaderName buffer:(const GLchar**)buffer length:(GLuint*)length{
    NSURL *url;
    NSString *shader;
    NSError  *error;
    NSDictionary *errorInfo;
        
    url = [self URLForResource:shaderName withExtension:nil subdirectory:@"Shaders"];
    shader = [NSString stringWithContentsOfURL:url encoding:NSUTF8StringEncoding error:&error];
    
    if (!shader) {
        errorInfo = [NSDictionary dictionaryWithObjectsAndKeys:
                     [NSString stringWithFormat:@"Shader \"%@\" could not be loaded.", shaderName],
                     NSLocalizedDescriptionKey,
                     [NSString stringWithFormat:@"Does \"%@\" exist?", shaderName],
                     NSLocalizedRecoverySuggestionErrorKey,
                     nil];
        error = [NSError errorWithDomain:@"com.dlukes.cglutil" code:1 userInfo:errorInfo];
        [NSApp presentError:error];
        return;
    }

    NSLog(@"%@", shader);
    
    *buffer = [shader UTF8String];
    *length = [shader lengthOfBytesUsingEncoding:NSUTF8StringEncoding];
}

version 110

attribute vec2 position;

varying vec2 texcoord;

void main()
{
gl_Position = vec4(position, 0.0, 1.0);
texcoord = position * vec2(0.5) + vec2(0.5);
}