ZennyViewDstImageViewController.m

//
//  ZennyViewDstImageViewController.m
//  CPU Dasher
//
//  Created by zenny_chen on 13-4-17.
//
//

#import "ZennyViewDstImageViewController.h"

@interface ZennyViewDstImageViewController ()

@end

@implementation ZennyViewDstImageViewController

- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
    self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
    if (self) {
        // Custom initialization
    }
    return self;
}

- (void)loadView
{
    CGRect screenBounds = [UIScreen mainScreen].bounds;
    CGFloat totalHeight = screenBounds.size.height - 20.0f;
    UIView *aView = [[UIView alloc] initWithFrame:CGRectMake(0.0f, 0.0f, screenBounds.size.width, totalHeight)];
    aView.backgroundColor = [UIColor blackColor];
    self.view = aView;
    [aView release];
}

- (void)viewDidLoad
{
    [super viewDidLoad];
	// Do any additional setup after loading the view.
    CGFloat height = self.view.bounds.size.height;
    CGFloat imageHeight = self.view.bounds.size.width;
    CGFloat y = (height - imageHeight) * 0.5f;
    
    UIImageView *imageView = [[UIImageView alloc] initWithFrame:CGRectMake(0.0f, y, self.view.bounds.size.width, imageHeight)];
    imageView.backgroundColor = [UIColor clearColor];
    imageView.contentScaleFactor = [UIScreen mainScreen].scale;
    UIImage *image = [ZennyViewDstImageViewController convertBitmapRGBA8ToUIImage:iImageBuffer withWidth:iImageWidth withHeight:iImageHeight];
    imageView.image = image;
    [self.view addSubview:imageView];
    [imageView release];
    
    UIButton *button = [[UIButton alloc] initWithFrame:self.view.bounds];
    button.backgroundColor = [UIColor clearColor];
    [button addTarget:self action:@selector(buttonTouched:) forControlEvents:UIControlEventTouchUpInside];
    [self.view addSubview:button];
    [button release];
}

- (void)buttonTouched:(id)sender
{
    [self dismissModalViewControllerAnimated:YES];
}

+ (UIImage *)convertBitmapRGBA8ToUIImage:(unsigned char*)buffer
                                withWidth:(int) width
                               withHeight:(int) height {
    
    
	size_t bufferLength = width * height * 4;
	CGDataProviderRef provider = CGDataProviderCreateWithData(NULL, buffer, bufferLength, NULL);
	size_t bitsPerComponent = 8;
	size_t bitsPerPixel = 32;
	size_t bytesPerRow = 4 * width;
    
	CGColorSpaceRef colorSpaceRef = CGColorSpaceCreateDeviceRGB();
	if(colorSpaceRef == NULL) {
		NSLog(@"Error allocating color space");
		CGDataProviderRelease(provider);
		return nil;
	}
    
	CGBitmapInfo bitmapInfo = kCGBitmapByteOrderDefault;
	CGColorRenderingIntent renderingIntent = kCGRenderingIntentDefault;
    
	CGImageRef iref = CGImageCreate(width,
                                    height,
                                    bitsPerComponent,
                                    bitsPerPixel,
                                    bytesPerRow,
                                    colorSpaceRef,
                                    bitmapInfo,
                                    provider,	// data provider
                                    NULL,		// decode
                                    YES,			// should interpolate
                                    renderingIntent);
    
	uint32_t* pixels = (uint32_t*)malloc(bufferLength);
    
	if(pixels == NULL) {
		NSLog(@"Error: Memory not allocated for bitmap");
		CGDataProviderRelease(provider);
		CGColorSpaceRelease(colorSpaceRef);
		CGImageRelease(iref);
		return nil;
	}
    
	CGContextRef context = CGBitmapContextCreate(pixels,
                                                 width,
                                                 height,
                                                 bitsPerComponent,
                                                 bytesPerRow,
                                                 colorSpaceRef,
                                                 kCGImageAlphaPremultipliedLast | kCGBitmapByteOrder32Big);
    
	if(context == NULL) {
		NSLog(@"Error context not created");
		free(pixels);
        pixels = NULL;
	}
    
    CGContextTranslateCTM(context, 0.0f, (CGFloat)height);
    CGContextScaleCTM(context, 1.0f, -1.0f);
    
	UIImage *image = nil;
	if(context) {
        
		CGContextDrawImage(context, CGRectMake(0.0f, 0.0f, width, height), iref);
        
		CGImageRef imageRef = CGBitmapContextCreateImage(context);
        
		// Support both iPad 3.2 and iPhone 4 Retina displays with the correct scale
		if([UIImage respondsToSelector:@selector(imageWithCGImage:scale:orientation:)]) {
			float scale = [[UIScreen mainScreen] scale];
			image = [UIImage imageWithCGImage:imageRef scale:scale orientation:UIImageOrientationUp];
		} else {
			image = [UIImage imageWithCGImage:imageRef];
		}
        
		CGImageRelease(imageRef);	
		CGContextRelease(context);	
	}
    
	CGColorSpaceRelease(colorSpaceRef);
	CGImageRelease(iref);
	CGDataProviderRelease(provider);
    
	if(pixels) {
		free(pixels);
	}	
	return image;
}

- (void)didReceiveMemoryWarning
{
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}

@end