Image.GetSurface() and Image.GetSurfaceRegion()

[skn3]

Added two methods to the monkey Image class so module developers can have more access to images. GetSurface() just returns the images surface object GetSurfaceRegion(frame:int=0) returns the x,y,width,height the image/frame takes up in the images surface.

These two are very useful methods and I have used for for stuff like saving images to photo gallery on iOS. For example I could convert a monkey image to UIImage with something like:

Local region := image.GetSurfaceRegion()
SaveNativeFunction(image.GetSurface(), region[0],region[1],region[2],region[3],"blah.png")

//allocate read in array
NSInteger dataLength = surfaceWidth * surfaceHeight * 4;
GLubyte *buffer = (GLubyte *) malloc(dataLength);

//remember old frame buffer
GLint oldFrameBuffer;
glGetIntegerv(GL_FRAMEBUFFER_BINDING, &oldFrameBuffer);

//setup temp frame buffer
GLuint frameBuffer;
glGenFramebuffers(1, &frameBuffer);
glBindFramebuffer(GL_FRAMEBUFFER, frameBuffer);
glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, surface->texture, 0);

glViewport(surfaceX, surfaceY, surfaceWidth, surfaceHeight);
glReadPixels(surfaceX, surfaceY, surfaceWidth, surfaceHeight, GL_RGBA, GL_UNSIGNED_BYTE, buffer);

//restore frame buffer
glBindFramebuffer(GL_FRAMEBUFFER, oldFrameBuffer);

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

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

//make the cgimage
CGImageRef imageRef = CGImageCreate(surfaceWidth, surfaceHeight, bitsPerComponent, bitsPerPixel, bytesPerRow, colorSpaceRef, bitmapInfo, provider, NULL, NO, renderingIntent);

//make the uiimage
UIImage *image = [UIImage imageWithCGImage:imageRef];

//free it
CGImageRelease(imageRef);
CGColorSpaceRelease(colorSpaceRef);
CGDataProviderRelease(provider);
free(buffer);