probably the quickest way to draw pixels on OSX in C. catch: compiles only with -m32 (32 bit arch). :|

osx_framebuffer

#include <Carbon/Carbon.h>
#include <CoreGraphics/CoreGraphics.h>

uint32_t framebuffer[FB_W*FB_H];

WindowRef osx_window;
CGContextRef osx_window_context;
CGContextRef osx_bitmap_context;

void updateFrameBuffer() {
	//printf("updateFrameBuffer\n");
	CGImageRef img = CGBitmapContextCreateImage(osx_bitmap_context);
    CGContextDrawImage(osx_window_context, CGRectMake(0,0,FB_W,FB_H), img);
    CGContextFlush(osx_window_context);
  	CGImageRelease(img);
}

void destroyFrameBuffer() {
  	QDEndCGContext(GetWindowPort(osx_window), &osx_window_context);
}

void createFrameBuffer() {
	Rect rect = {100,100,100+FB_H,100+FB_W};

	OSStatus err = CreateNewWindow(
		kDocumentWindowClass,
		kWindowStandardDocumentAttributes,
		&rect, &osx_window);

	osx_bitmap_context = CGBitmapContextCreate(framebuffer,
   		FB_W,
   		FB_H,
   		FB_D,
   		FB_W*4,
		CGColorSpaceCreateDeviceRGB(),
		kCGBitmapByteOrder32Big | kCGImageAlphaPremultipliedFirst);

	for (int i=0; i<FB_W*FB_H; i++) {
		framebuffer[i] = 0x000000ff;
	}

	ShowWindow(osx_window);
	SetPortWindowPort(osx_window);
	QDBeginCGContext(GetWindowPort(osx_window), &osx_window_context);

	updateFrameBuffer();
}

void putPixel(uint32_t x,uint32_t y,uint32_t color) {
	framebuffer[x+y*FB_W] = color;
}

Do you know of a more modern way to use this, with a 64-bit OSX?