iPhone – saving OpenGL ES content to the Photo Album

http://www.bit-101.com/blog/?p=1861

C:

1. -(UIImage *) glToUIImage {

2.     NSInteger myDataLength = 320 * 480 * 4;

4. // allocate array and read pixels into it.

5.     GLubyte *buffer = (GLubyte *) malloc(myDataLength);

6.     glReadPixels(0, 0, 320, 480, GL_RGBA, GL_UNSIGNED_BYTE, buffer);

8. // gl renders "upside down" so swap top to bottom into new array.

9. // there's gotta be a better way, but this works.

10.     GLubyte *buffer2 = (GLubyte *) malloc(myDataLength);

11. for(int y = 0; y <480; y++)

12. {

13. for(int x = 0; x <320 * 4; x++)

14. {

15.             buffer2[(479 - y) * 320 * 4 + x] = buffer[y * 4 * 320 + x];

16. }

17. }

19. // make data provider with data.

20.     CGDataProviderRef provider = CGDataProviderCreateWithData(NULL, buffer2, myDataLength, NULL);

22. // prep the ingredients

23. int bitsPerComponent = 8;

24. int bitsPerPixel = 32;

25. int bytesPerRow = 4 * 320;

26.     CGColorSpaceRef colorSpaceRef = CGColorSpaceCreateDeviceRGB();

27.     CGBitmapInfo bitmapInfo = kCGBitmapByteOrderDefault;

28.     CGColorRenderingIntent renderingIntent = kCGRenderingIntentDefault;

30. // make the cgimage

31.     CGImageRef imageRef = CGImageCreate(320, 480, bitsPerComponent, bitsPerPixel, bytesPerRow, colorSpaceRef, bitmapInfo, provider, NULL, NO, renderingIntent);

33. // then make the uiimage from that

34.     UIImage *myImage = [UIImage imageWithCGImage:imageRef];

35. return myImage;

36. }

38. -(void)captureToPhotoAlbum {

39.     UIImage *image = [self glToUIImage];

40.     UIImageWriteToSavedPhotosAlbum(image, self, nil, nil);

41. }