拍攝快照的CCGLView

我想拍攝我的viewController中的CCGLView中的內容的快照，並在相同的viewController中顯示結果圖像。拍攝快照的CCGLView

現在，我使用下面的方法可以這樣做：

-(UIImage *) drawableToCGImage{ 
    GLint backingWidth2, backingHeight2; 
    //backingHeight2=self.glView.frame.size.height; 
    //backingWidth2=self.glView.frame.size.width; 
    //Bind the color renderbuffer used to render the OpenGL ES view 
    // If your application only creates a single color renderbuffer which is already bound at this point, 
    // this call is redundant, but it is needed if you're dealing with multiple renderbuffers. 
    // Note, replace "_colorRenderbuffer" with the actual name of the renderbuffer object defined in your class. 

    glBindRenderbufferOES(GL_RENDERBUFFER_OES, self.glView.colorRenderBuffer); 

    // Get the size of the backing CAEAGLLayer 
    glGetRenderbufferParameterivOES(GL_RENDERBUFFER_OES, GL_RENDERBUFFER_WIDTH_OES, &backingWidth2); 
    glGetRenderbufferParameterivOES(GL_RENDERBUFFER_OES, GL_RENDERBUFFER_HEIGHT_OES, &backingHeight2); 

    NSInteger x = self.glView.frame.origin.x, y = self.glView.frame.origin.y, width2 = backingWidth2, height2 = backingHeight2; 
    NSInteger dataLength = width2 * height2 * 4; 
    GLubyte *data = (GLubyte*)malloc(dataLength * sizeof(GLubyte)); 

    // Read pixel data from the framebuffer 
    glPixelStorei(GL_PACK_ALIGNMENT, 4); 
    glReadPixels(x, y, width2, height2, 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(width2, height2, 8, 32, width2 * 4, colorspace, kCGBitmapByteOrder32Big | kCGImageAlphaPremultipliedLast, 
            ref, NULL, true, kCGRenderingIntentDefault); 

    // OpenGL ES measures data in PIXELS 
    // Create a graphics context with the target size measured in POINTS 
    NSInteger widthInPoints, heightInPoints; 

    // 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 = self.glView.contentScaleFactor; 
    widthInPoints = width2/scale; 
    heightInPoints = height2/scale; 
    UIGraphicsBeginImageContextWithOptions(CGSizeMake(widthInPoints, heightInPoints), NO, scale); 


    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; 
}

但它只能在模擬器和設備時，我測試了一下，我沒有得到CCGLView的內容。爲什麼這種方法不能提供設備中的快照？或者有沒有其他的方式來完成它？

來源

2014-10-27 Chengappa C D

我不知道爲什麼以前的方法不起作用，但我知道了另一種方式做它，並且它也更便宜:)。我使用下面的方法：

- (UIImage *)snapshot:(UIView *)view{ 
UIGraphicsBeginImageContextWithOptions(view.bounds.size, YES, 0); 
[view drawViewHierarchyInRect:view.bounds afterScreenUpdates:YES]; 
UIImage *image = UIGraphicsGetImageFromCurrentImageContext(); 
UIGraphicsEndImageContext(); 

return image;

}

更多信息請訪問以下鏈接：https://developer.apple.com/library/ios/qa/qa1817/_index.html

來源

2014-10-27 12:44:06

拍攝快照的CCGLView

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