在 cocos2d 中将屏幕内容截取为图片

这个方法忘了从哪里抄来的了，但非常好用。要实现保存当前屏幕显示之类的功能时，一个方法调用就搞定。

不说废话，贴代码：

01.+ (UIImage*) screenshotUIImage

02.{

03.    CGSize displaySize  = [[CCDirector sharedDirector] displaySizeInPixels];

04.    CGSize winSize      = [[CCDirector sharedDirector] winSizeInPixels];

05.  

06.    //Create buffer for pixels

07.    GLuint bufferLength = displaySize.width * displaySize.height * 4;

08.    GLubyte* buffer = (GLubyte*)malloc(bufferLength);

09.  

10.    //Read Pixels from OpenGL

11.    glReadPixels(0, 0, displaySize.width, displaySize.height, GL_RGBA, GL_UNSIGNED_BYTE, buffer);

12.    //Make data provider with data.

13.    CGDataProviderRef provider = CGDataProviderCreateWithData(NULL, buffer, bufferLength, NULL);

14.  

15.    //Configure image

16.    int bitsPerComponent = 8;

17.    int bitsPerPixel = 32;

18.    int bytesPerRow = 4 * displaySize.width;

19.    CGColorSpaceRef colorSpaceRef = CGColorSpaceCreateDeviceRGB();

20.    CGBitmapInfo bitmapInfo = kCGBitmapByteOrderDefault;

21.    CGColorRenderingIntent renderingIntent = kCGRenderingIntentDefault;

22.    CGImageRef iref = CGImageCreate(displaySize.width, displaySize.height, bitsPerComponent, bitsPerPixel, bytesPerRow, colorSpaceRef, bitmapInfo, provider, NULL, NO, renderingIntent);

23.  

24.    uint32_t* pixels = (uint32_t*)malloc(bufferLength);

25.    CGContextRef context = CGBitmapContextCreate(pixels, winSize.width, winSize.height, 8, winSize.width * 4, CGImageGetColorSpace(iref), kCGImageAlphaPremultipliedLast | kCGBitmapByteOrder32Big);

26.  

27.    CGContextTranslateCTM(context, 0, displaySize.height);

28.    CGContextScaleCTM(context, 1.0f, -1.0f);

29.  

30.    switch ([CCDirector sharedDirector].deviceOrientation)

31.    {

32.        case CCDeviceOrientationPortrait: break;

33.        case CCDeviceOrientationPortraitUpsideDown:

34.            CGContextRotateCTM(context, CC_DEGREES_TO_RADIANS(180));

35.            CGContextTranslateCTM(context, -displaySize.width, -displaySize.height);

36.            break;

37.        case CCDeviceOrientationLandscapeLeft:

38.            CGContextRotateCTM(context, CC_DEGREES_TO_RADIANS(-90));

39.            CGContextTranslateCTM(context, -displaySize.height, 0);

40.            break;

41.        case CCDeviceOrientationLandscapeRight:

42.            CGContextRotateCTM(context, CC_DEGREES_TO_RADIANS(90));

43.            CGContextTranslateCTM(context, displaySize.height-displaySize.width, -displaySize.height);

44.            break;

45.    }

46.  

47.    CGContextDrawImage(context, CGRectMake(0.0f, 0.0f, displaySize.width, displaySize.height), iref);

48.    CGImageRef imageRef = CGBitmapContextCreateImage(context);

49.    UIImage *outputImage = [[[UIImage alloc] initWithCGImage:imageRef] autorelease];

50.  

51.    //Dealloc

52.    CGImageRelease(imageRef);

53.    CGDataProviderRelease(provider);

54.    CGImageRelease(iref);

55.    CGColorSpaceRelease(colorSpaceRef);

56.    CGContextRelease(context);

57.    free(buffer);

58.    free(pixels);

59.  

60.    return outputImage;

61.}

这个方法返回 UIImage 对象，因此保存为文件，或者构造为材质都可以。