GLPaint save function (save current screen with background image)

Question

I am currently working with a GLpaint based graphics application. Saving the current screen becomes a pain for me. I have a ViewController. On top of the view controller, I loaded UIIMageView and UIView (PaintingView). Now it seems like I'm drawing on top of a UIImageView.

I managed to get my current drawing with this GLPaint question save the image . When I try to capture my current drawing, I get a drawing, but with a black screen. What I wanted was my background image (UIImageView). Should I overlay a UIView on a UIImageView?

Answer 1

OpenGL, UIKit ( UIImageView). OpenGLView , UIKit View .

, PaintingView, GLpaint, , .

Answer 2

OpenGL:

-(BOOL)iPhoneRetina{
    return ([[UIScreen mainScreen] respondsToSelector:@selector(displayLinkWithTarget:selector:)] && ([UIScreen mainScreen].scale == 2.0))?YES:NO;
}

void releasePixels(void *info, const void *data, size_t size) {
    free((void*)data);
}

-(UIImage *) glToUIImage{

    int imageWidth, imageHeight;

    int scale = [self iPhoneRetina]?2:1;

    imageWidth = self.frame.size.width*scale;
    imageHeight = self.frame.size.height*scale;

    NSInteger myDataLength = imageWidth * imageHeight * 4;

    // allocate array and read pixels into it.
    GLubyte *buffer = (GLubyte *) malloc(myDataLength);
    glReadPixels(0, 0, imageWidth, imageHeight, GL_RGBA, GL_UNSIGNED_BYTE, buffer);

    // make data provider with data.
    CGDataProviderRef provider = CGDataProviderCreateWithData(NULL, buffer, myDataLength, releasePixels);

    // prep the ingredients
    int bitsPerComponent = 8;
    int bitsPerPixel = 32;
    int bytesPerRow = 4 * imageWidth;
    CGColorSpaceRef colorSpaceRef = CGColorSpaceCreateDeviceRGB();
    CGBitmapInfo bitmapInfo =  kCGImageAlphaPremultipliedLast;
    CGColorRenderingIntent renderingIntent = kCGRenderingIntentDefault;

    // make the cgimage

    CGImageRef imageRef = CGImageCreate(imageWidth, imageHeight, bitsPerComponent, bitsPerPixel, bytesPerRow, colorSpaceRef, bitmapInfo, provider, NULL, NO, renderingIntent);

    UIImage *myImage = [UIImage imageWithCGImage:imageRef scale:scale orientation:UIImageOrientationDownMirrored]; //Render image flipped, since OpenGL data is mirrored

    CGImageRelease(imageRef);
    CGColorSpaceRelease(colorSpaceRef);

    CGDataProviderRelease(provider);

    return myImage;
}

, :

-(UIImage*)mergeImage:(UIImage*)image1 withImage:(UIImage*)image2{

    CGSize size = image1.size;

    UIGraphicsBeginImageContextWithOptions(size, NO, 0);

    [image1 drawAtPoint:CGPointMake(0.0f, 0.0f)];
    [image2 drawAtPoint:CGPointMake(0.0f, 0.0f)];

    UIImage *result = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();

    return result;
}

- :

finalImage = [self mergeImage: BackgroundImage withImage [self glToUIImage]];