I implemented the following solution in Openframeworks v0.7.4, working on Mac OS version 10.7.5, Xcode 4.6.3. It involves drawing the image to a framebuffer and then passing the texture ID for the framebuffer to CoreImage.
Note that the filename of "testApp.cpp" needs to be changed to "testApp.mm" and "main.cpp" to "main.mm". This changes these files to an Objective-C++ type, which can handle both C++ and Objective-C calls.
Note also that (apparently) the QuartzCore framework needs to be manually added to the Xcode project frameworks list.
N.B.: I have found that on occasional runs of this and similar code that occasionally (1 out of every 4-8 runs), the code generates a CoreImage: ROI is not tilable error, and the CI Filter doesn't run, even if the project is configured at a humble screen size like 800x600. I haven't been able to find a solution online, so if you know the solution, I'm all ears.
The "testApp.h" file:
The "testApp.mm" file, up through the draw() call:
Note that the filename of "testApp.cpp" needs to be changed to "testApp.mm" and "main.cpp" to "main.mm". This changes these files to an Objective-C++ type, which can handle both C++ and Objective-C calls.
Note also that (apparently) the QuartzCore framework needs to be manually added to the Xcode project frameworks list.
N.B.: I have found that on occasional runs of this and similar code that occasionally (1 out of every 4-8 runs), the code generates a CoreImage: ROI is not tilable error, and the CI Filter doesn't run, even if the project is configured at a humble screen size like 800x600. I haven't been able to find a solution online, so if you know the solution, I'm all ears.
The "testApp.h" file:
#pragma once
// *****************************************************************
// Demonstration of using Max OSX Core Image filters in an
// Open Frameworks 0.7.4 project
//
// Bret Battey / BatHatMedia.com
// August 4, 2013
// *****************************************************************
#include "ofMain.h"
#include "QuartzCore/QuartzCore.h" // One way to get the CI classes
class testApp : public ofBaseApp{
public:
void setup();
void update();
void draw();
void keyPressed (int key);
void keyReleased(int key);
void mouseMoved(int x, int y );
void mouseDragged(int x, int y, int button);
void mousePressed(int x, int y, int button);
void mouseReleased(int x, int y, int button);
void windowResized(int w, int h);
void dragEvent(ofDragInfo dragInfo);
void gotMessage(ofMessage msg);
// Basics
int outWidth, outHeight;
ofFbo sourceFbo;
// Core Image
CGLContextObj CGLContext;
NSOpenGLPixelFormatAttribute* attr;
NSOpenGLPixelFormat* pf;
CGColorSpaceRef genericRGB;
CIContext* glCIcontext;
CIImage* inputCIImage;
CIFilter* blurFilter;
CIImage* blurredCIImage;
CGSize texSize;
GLint tex;
CGRect outRect;
CGRect inRect;
};
The "testApp.mm" file, up through the draw() call:
// *****************************************************************
// Demonstration of using Max OSX Core Image filters in an
// Open Frameworks 0.7.4 project
//
// Note that this has to be a .mm file (Objective-C++), since it
// combines Objective-C and C++. >>> ALSO main.cpp needs to be changed
// to main.mm
//
// On Xcode, you must manually add the QuartzCore framework to the
// Project / Target / Summary list of frameworks for the build to
// succeed.
//
// Bret Battey / BatHatMedia.com
// August 4, 2013
// *****************************************************************
#include "testApp.h"
//--------------------------------------------------------------
void testApp::setup(){
ofSetFrameRate(30);
outWidth = ofGetViewportWidth();
outHeight = ofGetViewportHeight();
ofEnableSmoothing();
ofBackground(0);
ofNoFill();
ofSetLineWidth(4);
// Setup a framebuffer for the drawing. Perhaps there is some way to do this
// without a framebuffer, but this is the only way I could figure out how to
// enable grabbing an OpenGL texture to pass to the CoreImage filter
sourceFbo.allocate(outWidth, outHeight, GL_RGBA32F_ARB); //32-bit framebuffer for smoothness
// SETUP THE CORE IMAGE CONTEXT, FILTERS, ETC
// The appended .autorelease methods should auto cleanup the memory at exit.
// Use a generic RGB color space:
genericRGB = CGColorSpaceCreateWithName(kCGColorSpaceGenericRGB);
// Create the pixel format attributes... The Core Image Guide for processing images says:
// "It’s important that the pixel format for the context includes the NSOpenGLPFANoRecovery constant as an
// attribute. Otherwise Core Image may not be able to create another context that shares textures with this one."
NSOpenGLPixelFormatAttribute attr[] = {
NSOpenGLPFAAccelerated,
NSOpenGLPFANoRecovery,
NSOpenGLPFAColorSize, 32,
0
};
CGColorSpaceRelease(genericRGB);
// Setup the pixel format object:
pf=[[NSOpenGLPixelFormat alloc] initWithAttributes:attr].autorelease;
// Setup the core image context, tied to the OF Open GL context:
glCIcontext = [CIContext contextWithCGLContext: CGLGetCurrentContext()
pixelFormat: CGLPixelFormatObj(pf)
colorSpace: genericRGB
options: nil].autorelease;
// Setup a Gaussian Blur filter:
blurFilter = [CIFilter filterWithName:@"CIGaussianBlur"].autorelease;
// Supporting stuff
texSize = CGSizeMake(outWidth, outHeight);
inRect = CGRectMake(0,0,outWidth,outHeight);
outRect = CGRectMake(0,0,outWidth,outHeight);
}
//--------------------------------------------------------------
void testApp::update(){
sourceFbo.begin();
// For feedback fun, let's not clear the Fbo after the first frame
if(ofGetFrameNum()==1) {
ofClear(0);
}
// Draw circle
ofSetColor(20, 130, 250);
ofCircle(outWidth/2,outHeight/2,10+(ofGetFrameNum()%40)*6);
// Get the texture ID of the fbo:
tex = sourceFbo.getTextureReference().texData.textureID;
// set the CI Image to link with the Fbo texture
inputCIImage = [CIImage imageWithTexture:tex
size:texSize
flipped:NO
colorSpace:genericRGB];
// Blur filter
[blurFilter setValue:inputCIImage forKey:@"inputImage"];
[blurFilter setValue:[NSNumber numberWithFloat: 8] forKey:@"inputRadius"];
blurredCIImage = [blurFilter valueForKey:@"outputImage"];
// Draw it
ofSetColor(255);
[glCIcontext drawImage:blurredCIImage
inRect:outRect
fromRect:inRect];
sourceFbo.end();
}
//--------------------------------------------------------------
void testApp::draw(){
sourceFbo.draw(0,0);
}
