我知道这个问题得到了很多回答，但我的情况似乎有所不同。我正在尝试编写一个顶级函数，我可以随时截取我的应用程序的屏幕截图，无论是 openGLES 还是 UIKit，我将无法访问底层类来进行任何更改。
我一直在尝试的代码适用于 UIKit，但会为 OpenGLES 部件返回黑屏
CGSize imageSize = [[UIScreen mainScreen] bounds].size;
if (NULL != UIGraphicsBeginImageContextWithOptions)
UIGraphicsBeginImageContextWithOptions(imageSize, NO, 0);
else
UIGraphicsBeginImageContext(imageSize);
CGContextRef context = UIGraphicsGetCurrentContext();
// Iterate over every window from back to front
for (UIWindow *window in [[UIApplication sharedApplication] windows])
{
if (![window respondsToSelector:@selector(screen)] || [window screen] == [UIScreen mainScreen])
{
// -renderInContext: renders in the coordinate space of the layer,
// so we must first apply the layer's geometry to the graphics context
CGContextSaveGState(context);
// Center the context around the window's anchor point
CGContextTranslateCTM(context, [window center].x, [window center].y);
// Apply the window's transform about the anchor point
CGContextConcatCTM(context, [window transform]);
// Offset by the portion of the bounds left of and above the anchor point
CGContextTranslateCTM(context,
-[window bounds].size.width * [[window layer] anchorPoint].x,
-[window bounds].size.height * [[window layer] anchorPoint].y);
for (UIView *subview in window.subviews)
{
CAEAGLLayer *eaglLayer = (CAEAGLLayer *) subview.layer;
if([eaglLayer respondsToSelector:@selector(drawableProperties)]) {
NSLog(@"reponds");
/*eaglLayer.drawableProperties = @{
kEAGLDrawablePropertyRetainedBacking: [NSNumber numberWithBool:YES],
kEAGLDrawablePropertyColorFormat: kEAGLColorFormatRGBA8
};*/
UIImageView *glImageView = [[UIImageView alloc] initWithImage:[self snapshotx:subview]];
glImageView.transform = CGAffineTransformMakeScale(1, -1);
[glImageView.layer renderInContext:context];
//CGImageRef iref = [self snapshot:subview withContext:context];
//CGContextDrawImage(context, CGRectMake(0.0, 0.0, 640, 960), iref);
}
[[window layer] renderInContext:context];
// Restore the context
CGContextRestoreGState(context);
}
}
}
// Retrieve the screenshot image
UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return image;
和
- (UIImage*)snapshotx:(UIView*)eaglview
{
GLint backingWidth, backingHeight;
//glBindRenderbufferOES(GL_RENDERBUFFER_OES, _colorRenderbuffer);
//don't know how to access the renderbuffer if i can't directly access the below code
// Get the size of the backing CAEAGLLayer
glGetRenderbufferParameterivOES(GL_RENDERBUFFER_OES, GL_RENDERBUFFER_WIDTH_OES, &backingWidth);
glGetRenderbufferParameterivOES(GL_RENDERBUFFER_OES, GL_RENDERBUFFER_HEIGHT_OES, &backingHeight);
NSInteger x = 0, y = 0, width = backingWidth, height = backingHeight;
NSInteger dataLength = width * height * 4;
GLubyte *data = (GLubyte*)malloc(dataLength * sizeof(GLubyte));
// Read pixel data from the framebuffer
glPixelStorei(GL_PACK_ALIGNMENT, 4);
glReadPixels(x, y, width, height, GL_RGBA, GL_UNSIGNED_BYTE, data);
// Create a CGImage with the pixel data
// If your OpenGL ES content is opaque, use kCGImageAlphaNoneSkipLast to ignore the alpha channel
// otherwise, use kCGImageAlphaPremultipliedLast
CGDataProviderRef ref = CGDataProviderCreateWithData(NULL, data, dataLength, NULL);
CGColorSpaceRef colorspace = CGColorSpaceCreateDeviceRGB();
CGImageRef iref = CGImageCreate (
width,
height,
8,
32,
width * 4,
colorspace,
// Fix from Apple implementation
// (was: kCGBitmapByteOrder32Big | kCGImageAlphaPremultipliedLast).
kCGBitmapByteOrderDefault,
ref,
NULL,
true,
kCGRenderingIntentDefault
);
// OpenGL ES measures data in PIXELS
// Create a graphics context with the target size measured in POINTS
NSInteger widthInPoints, heightInPoints;
if (NULL != UIGraphicsBeginImageContextWithOptions)
{
// On iOS 4 and later, use UIGraphicsBeginImageContextWithOptions to take the scale into consideration
// Set the scale parameter to your OpenGL ES view's contentScaleFactor
// so that you get a high-resolution snapshot when its value is greater than 1.0
CGFloat scale = eaglview.contentScaleFactor;
widthInPoints = width / scale;
heightInPoints = height / scale;
UIGraphicsBeginImageContextWithOptions(CGSizeMake(widthInPoints, heightInPoints), NO, scale);
}
else {
// On iOS prior to 4, fall back to use UIGraphicsBeginImageContext
widthInPoints = width;
heightInPoints = height;
UIGraphicsBeginImageContext(CGSizeMake(widthInPoints, heightInPoints));
}
CGContextRef cgcontext = UIGraphicsGetCurrentContext();
// UIKit coordinate system is upside down to GL/Quartz coordinate system
// Flip the CGImage by rendering it to the flipped bitmap context
// The size of the destination area is measured in POINTS
CGContextSetBlendMode(cgcontext, kCGBlendModeCopy);
CGContextDrawImage(cgcontext, CGRectMake(0.0, 0.0, widthInPoints, heightInPoints), iref);
// Retrieve the UIImage from the current context
UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
// Clean up
free(data);
CFRelease(ref);
CFRelease(colorspace);
CGImageRelease(iref);
return image;
}
关于如何在不修改应用程序其余部分的类的情况下混合两者的任何建议？
谢谢！