/* Note: usage of AvailabilityMacros.h to detect whether we're
   building on OS X 10.3 does not work because the header #defines
   MAC_OS_X_VERSION_10_4 even though the machine is a 10.3 machine

#include <AvailabilityMacros.h>

#ifndef MAC_OS_X_VERSION_10_3
	#error building JOGL requires Mac OS X 10.3 or greater
#endif

#ifndef MAC_OS_X_VERSION_10_4
  #define NSOpenGLPFAColorFloat kCGLPFAColorFloat
  #define kCGLNoError 0
#endif
*/

#import <Cocoa/Cocoa.h>
#import <OpenGL/gl.h>
#import <OpenGL/CGLTypes.h>
#import <jni.h>
#import "ContextUpdater.h"

#import "macosx-window-system.h"

// see MacOSXPbufferGLContext.java createPbuffer
#define USE_GL_TEXTURE_RECTANGLE_EXT

#ifdef USE_GL_TEXTURE_RECTANGLE_EXT
    #ifndef GL_TEXTURE_RECTANGLE_EXT
            #define GL_TEXTURE_RECTANGLE_EXT 0x84F5
    #endif
#endif

// Workarounds for compiling on 10.3
#ifndef kCGLRGBA16161616Bit
#define kCGLRGBA16161616Bit 0x00800000  /* 64 argb bit/pixel,   R=63:48, G=47:32, B=31:16, A=15:0 */
#define kCGLRGBFloat64Bit   0x01000000  /* 64 rgb bit/pixel,    half float                        */
#define kCGLRGBAFloat64Bit  0x02000000  /* 64 argb bit/pixel,   half float                        */
#define kCGLRGBFloat128Bit  0x04000000  /* 128 rgb bit/pixel,   ieee float                        */
#define kCGLRGBAFloat128Bit 0x08000000  /* 128 argb bit/pixel,  ieee float                        */
#define kCGLRGBFloat256Bit  0x10000000  /* 256 rgb bit/pixel,   ieee double                       */
#define kCGLRGBAFloat256Bit 0x20000000  /* 256 argb bit/pixel,  ieee double                       */
#endif

struct _RendererInfo
{
	long id;				// kCGLRPRendererID
	long displayMask;		// kCGLRPDisplayMask
	
	long accelerated;		// kCGLRPAccelerated
	
	long window;			// kCGLRPWindow
	long fullscreen;		// kCGLRPFullScreen
	long multiscreen;		// kCGLRPMultiScreen
	long offscreen;			// kCGLRPOffScreen
	long floatPixels;		// see kCGLRPColorModes
	long stereo;			// kCGLRPBufferModes
	
	long auxBuffers;		// kCGLRPMaxAuxBuffers
	long sampleBuffers;		// kCGLRPMaxSampleBuffers
	long samples;			// kCGLRPMaxSamples
	long samplesModes;		// kCGLRPSampleModes
	long multiSample;		// see kCGLRPSampleModes
	long superSample;		// see kCGLRPSampleModes
	long alphaSample;		// kCGLRPSampleAlpha
	
	long colorModes;		// kCGLRPColorModes
	long colorRGBSizeMAX;
	long colorASizeMAX;
	long colorFloatRGBSizeMAX;
	long colorFloatASizeMAX;
	long colorFloatRGBSizeMIN;
	long colorFloatASizeMIN;
	long colorModesCount;
	long colorFloatModesCount;
	long depthModes;		// kCGLRPDepthModes
	long depthSizeMAX;
	long depthModesCount;
	long stencilModes;		// kCGLRPStencilModes
	long stencilSizeMAX;
	long stencilModesCount;
	long accumModes;		// kCGLRPAccumModes
	long accumRGBSizeMAX;
	long accumASizeMAX;
	long accumModesCount;
}
typedef RendererInfo;

RendererInfo *gRenderers = NULL;
long gRenderersCount = 0;

long depthModes[] = {
					kCGL0Bit,
					kCGL1Bit,
					kCGL2Bit,
					kCGL3Bit,
					kCGL4Bit,
					kCGL5Bit,
					kCGL6Bit,
					kCGL8Bit,
					kCGL10Bit,
					kCGL12Bit,
					kCGL16Bit,
					kCGL24Bit,
					kCGL32Bit,
					kCGL48Bit,
					kCGL64Bit,
					kCGL96Bit,
					kCGL128Bit,
					0
					};
long depthModesBits[] = {0, 1, 2, 3, 4, 5, 6, 8, 10, 12, 16, 24, 32, 48, 64, 96, 128};
long colorModes[] = {
					kCGLRGB444Bit,
					kCGLARGB4444Bit,
					kCGLRGB444A8Bit,
					kCGLRGB555Bit,
					kCGLARGB1555Bit,
					kCGLRGB555A8Bit,
					kCGLRGB565Bit,
					kCGLRGB565A8Bit,
					kCGLRGB888Bit,
					kCGLARGB8888Bit,
					kCGLRGB888A8Bit,
					kCGLRGB101010Bit,
					kCGLARGB2101010Bit,
					kCGLRGB101010_A8Bit,
					kCGLRGB121212Bit,
					kCGLARGB12121212Bit,
					kCGLRGB161616Bit,
					kCGLRGBA16161616Bit,
					kCGLRGBFloat64Bit,
					kCGLRGBAFloat64Bit,
					kCGLRGBFloat128Bit,
					kCGLRGBAFloat128Bit,
					kCGLRGBFloat256Bit,
					kCGLRGBAFloat256Bit,
					0
					};
long colorModesBitsRGB[] =	{4, 4, 4, 5, 5, 5, 5, 5, 8, 8, 8, 10, 10, 10, 12, 12, 16, 16, 16, 16, 32, 32, 64, 64};
long colorModesBitsA[] =	{0, 4, 8, 0, 1, 8, 0, 8, 0, 8, 8,  0,  2,  8,  0, 12,  0, 16,  0, 16,  0, 32,  0, 64};

void getRendererInfo()
{
	if (gRenderersCount == 0)
	{		
		CGLRendererInfoObj info;
		CGLError err = CGLQueryRendererInfo(CGDisplayIDToOpenGLDisplayMask(kCGDirectMainDisplay), &info, &gRenderersCount);
		if (err == 0 /* kCGLNoError */)
		{
			// how many renderers are available?
			CGLDescribeRenderer(info, 0, kCGLRPRendererCount, &gRenderersCount);
			
			// allocate our global renderers info
			gRenderers = (RendererInfo*)malloc(gRenderersCount*sizeof(RendererInfo));
			memset(gRenderers, 0x00, gRenderersCount*sizeof(RendererInfo));
			
			// iterate through the renderers checking for their features
			long j;
			for (j=0; j<gRenderersCount; j++)
			{
				RendererInfo *renderer = &gRenderers[j];
				int i;
				
				CGLDescribeRenderer(info, j, kCGLRPRendererID, &(renderer->id));
				CGLDescribeRenderer(info, j, kCGLRPDisplayMask, &(renderer->displayMask));
				
				CGLDescribeRenderer(info, j, kCGLRPAccelerated, &(renderer->accelerated));
				
				CGLDescribeRenderer(info, j, kCGLRPWindow, &(renderer->window));
				CGLDescribeRenderer(info, j, kCGLRPFullScreen, &(renderer->fullscreen));
				CGLDescribeRenderer(info, j, kCGLRPMultiScreen, &(renderer->multiscreen));
				CGLDescribeRenderer(info, j, kCGLRPOffScreen, &(renderer->offscreen));
				CGLDescribeRenderer(info, j, kCGLRPColorModes, &(renderer->floatPixels));
				if ((renderer->floatPixels >= kCGLRGBFloat64Bit) != 0)
				{
					renderer->floatPixels = 1;
				}
				else
				{
					renderer->floatPixels = 0;
				}
				CGLDescribeRenderer(info, j, kCGLRPBufferModes, &(renderer->stereo));
				if ((renderer->stereo & kCGLStereoscopicBit) != 0)
				{
					renderer->stereo = 1;
				}
				else
				{
					renderer->stereo = 0;
				}
				
				CGLDescribeRenderer(info, j, kCGLRPMaxAuxBuffers, &(renderer->auxBuffers));
				CGLDescribeRenderer(info, j, kCGLRPMaxSampleBuffers, &(renderer->sampleBuffers));
				CGLDescribeRenderer(info, j, kCGLRPMaxSamples, &(renderer->samples));
				// The following queries are only legal on 10.4
				// FIXME: should figure out a way to enable them dynamically
#ifdef kCGLRPSampleModes
				CGLDescribeRenderer(info, j, kCGLRPSampleModes, &(renderer->samplesModes));
				if ((renderer->samplesModes & kCGLSupersampleBit) != 0)
				{
					renderer->multiSample = 1;
				}
				if ((renderer->samplesModes & kCGLMultisampleBit) != 0)
				{
					renderer->superSample = 1;
				}
				CGLDescribeRenderer(info, j, kCGLRPSampleAlpha, &(renderer->alphaSample));
#endif
				CGLDescribeRenderer(info, j, kCGLRPColorModes, &(renderer->colorModes));
				i=0;
				int floatPixelFormatInitialized = 0;
				while (colorModes[i] != 0)
				{
					if ((renderer->colorModes & colorModes[i]) != 0)
					{
						// non-float color model
						if (colorModes[i] < kCGLRGBFloat64Bit)
						{
							// look for max color and alpha values - prefer color models that have alpha
							if ((colorModesBitsRGB[i] >= renderer->colorRGBSizeMAX) && (colorModesBitsA[i] >= renderer->colorASizeMAX))
							{
								renderer->colorRGBSizeMAX = colorModesBitsRGB[i];
								renderer->colorASizeMAX = colorModesBitsA[i];
							}
							renderer->colorModesCount++;
						}
						// float-color model
						if (colorModes[i] >= kCGLRGBFloat64Bit)
						{
							if (floatPixelFormatInitialized == 0)
							{
								floatPixelFormatInitialized = 1;
								
								renderer->colorFloatASizeMAX = colorModesBitsA[i];
								renderer->colorFloatRGBSizeMAX = colorModesBitsRGB[i];
								renderer->colorFloatASizeMIN = colorModesBitsA[i];
								renderer->colorFloatRGBSizeMIN = colorModesBitsRGB[i];
							}
							// look for max color and alpha values - prefer color models that have alpha
							if ((colorModesBitsRGB[i] >= renderer->colorFloatRGBSizeMAX) && (colorModesBitsA[i] >= renderer->colorFloatASizeMAX))
							{
								renderer->colorFloatRGBSizeMAX = colorModesBitsRGB[i];
								renderer->colorFloatASizeMAX = colorModesBitsA[i];
							}
							// find min color
							if (colorModesBitsA[i] < renderer->colorFloatASizeMIN)
							{
								renderer->colorFloatASizeMIN = colorModesBitsA[i];
							}
							// find min alpha color
							if (colorModesBitsA[i] < renderer->colorFloatRGBSizeMIN)
							{
								renderer->colorFloatRGBSizeMIN = colorModesBitsRGB[i];
							}
							renderer->colorFloatModesCount++;
						}
					}
					i++;
				}
				CGLDescribeRenderer(info, j, kCGLRPDepthModes, &(renderer->depthModes));
				i=0;
				while (depthModes[i] != 0)
				{
					if ((renderer->depthModes & depthModes[i]) != 0)
					{
						renderer->depthSizeMAX = depthModesBits[i];
						renderer->depthModesCount++;
					}
					i++;
				}
				CGLDescribeRenderer(info, j, kCGLRPStencilModes, &(renderer->stencilModes));
				i=0;
				while (depthModes[i] != 0)
				{
					if ((renderer->stencilModes & depthModes[i]) != 0)
					{
						renderer->stencilSizeMAX = depthModesBits[i];
						renderer->stencilModesCount++;
					}
					i++;
				}
				CGLDescribeRenderer(info, j, kCGLRPAccumModes, &(renderer->accumModes));
				i=0;
				while (colorModes[i] != 0)
				{
					if ((renderer->accumModes & colorModes[i]) != 0)
					{
						if ((colorModesBitsRGB[i] >= renderer->accumRGBSizeMAX) && (colorModesBitsA[i] >= renderer->accumASizeMAX))
						{
							renderer->accumRGBSizeMAX = colorModesBitsRGB[i];
							renderer->accumASizeMAX = colorModesBitsA[i];
						}
						renderer->accumModesCount++;
					}
					i++;
				}
			}
		}
		CGLDestroyRendererInfo (info);
	}
	
#if 0
	fprintf(stderr, "gRenderersCount=%ld\n", gRenderersCount);
	int j;
	for (j=0; j<gRenderersCount; j++)
	{
		RendererInfo *renderer = &gRenderers[j];
		fprintf(stderr, "	id=%ld\n", renderer->id);
		fprintf(stderr, "	displayMask=%ld\n", renderer->displayMask);
		
		fprintf(stderr, "		accelerated=%ld\n", renderer->accelerated);
		
		fprintf(stderr, "		window=%ld\n", renderer->window);
		fprintf(stderr, "		fullscreen=%ld\n", renderer->fullscreen);
		fprintf(stderr, "		multiscreen=%ld\n", renderer->multiscreen);
		fprintf(stderr, "		offscreen=%ld\n", renderer->offscreen);
		fprintf(stderr, "		floatPixels=%ld\n", renderer->floatPixels);
		fprintf(stderr, "		stereo=%ld\n", renderer->stereo);
		
		fprintf(stderr, "		auxBuffers=%ld\n", renderer->auxBuffers);
		fprintf(stderr, "		sampleBuffers=%ld\n", renderer->sampleBuffers);
		fprintf(stderr, "		samples=%ld\n", renderer->samples);
		fprintf(stderr, "		samplesModes=%ld\n", renderer->samplesModes);
		fprintf(stderr, "		multiSample=%ld\n", renderer->superSample);
		fprintf(stderr, "		superSample=%ld\n", renderer->superSample);
		fprintf(stderr, "		alphaSample=%ld\n", renderer->alphaSample);
		
		fprintf(stderr, "		colorModes=%ld\n", renderer->colorModes);
		fprintf(stderr, "			colorRGBSizeMAX=%ld\n", renderer->colorRGBSizeMAX);
		fprintf(stderr, "			colorASizeMAX=%ld\n", renderer->colorASizeMAX);
		fprintf(stderr, "			colorFloatRGBSizeMAX=%ld\n", renderer->colorFloatRGBSizeMAX);
		fprintf(stderr, "			colorFloatASizeMAX=%ld\n", renderer->colorFloatASizeMAX);
		fprintf(stderr, "			colorFloatRGBSizeMIN=%ld\n", renderer->colorFloatRGBSizeMIN);
		fprintf(stderr, "			colorFloatASizeMIN=%ld\n", renderer->colorFloatASizeMIN);
		fprintf(stderr, "			colorModesCount=%ld\n", renderer->colorModesCount);
		fprintf(stderr, "			colorFloatModesCount=%ld\n", renderer->colorFloatModesCount);
		fprintf(stderr, "		depthModes=%ld\n", renderer->depthModes);
		fprintf(stderr, "			depthSizeMAX=%ld\n", renderer->depthSizeMAX);
		fprintf(stderr, "			depthModesCount=%ld\n", renderer->depthModesCount);
		fprintf(stderr, "		stencilModes=%ld\n", renderer->stencilModes);
		fprintf(stderr, "			stencilSizeMAX=%ld\n", renderer->stencilSizeMAX);
		fprintf(stderr, "			stencilModesCount=%ld\n", renderer->stencilModesCount);
		fprintf(stderr, "		accumModes=%ld\n", renderer->accumModes);
		fprintf(stderr, "			accumRGBSizeMAX=%ld\n", renderer->accumRGBSizeMAX);
		fprintf(stderr, "			accumASizeMAX=%ld\n", renderer->accumASizeMAX);
		fprintf(stderr, "			accumModesCount=%ld\n", renderer->accumModesCount);
		fprintf(stderr, "\n");
	}
#endif
}

long validateParameter(NSOpenGLPixelFormatAttribute atttribute, long value)
{
	bool done = false;
	int i;
	for (i=0; i<gRenderersCount; i++)
	{
		RendererInfo renderer = gRenderers[i];
		if (renderer.accelerated != 0)
		{
			switch (atttribute)
			{
				case NSOpenGLPFAStencilSize:
					value = MIN(value, renderer.stencilSizeMAX);
					done = true;
					break;
				default:
					break;
			}
		}
		
		if (done == true)
		{
			break;
		}
	}
	
	return value;
}

void* createPixelFormat(int* iattrs, int niattrs, int* ivalues) {
  NSAutoreleasePool* pool = [[NSAutoreleasePool alloc] init];

  getRendererInfo();

  // http://developer.apple.com/documentation/Cocoa/Reference/ApplicationKit/ObjC_classic/Classes/NSOpenGLPixelFormat.html
  NSOpenGLPixelFormatAttribute attribs[256];

  int idx = 0;
  int i;
  for (i = 0; i < niattrs; i++) {
    int attr = iattrs[i];
    switch (attr) {
      case NSOpenGLPFAPixelBuffer:
        if (ivalues[i] != 0) {
          attribs[idx++] = NSOpenGLPFAPixelBuffer;
        }
        break;

      case kCGLPFAColorFloat:
        if (ivalues[i] != 0) {
          attribs[idx++] = kCGLPFAColorFloat;
        }
        break;
        
      case NSOpenGLPFADoubleBuffer:
        if (ivalues[i] != 0) {
          attribs[idx++] = NSOpenGLPFADoubleBuffer;
        }
        break;

      case NSOpenGLPFAStereo:
        if (ivalues[i] != 0) {
          attribs[idx++] = NSOpenGLPFAStereo;
        }
        break;

      case NSOpenGLPFAColorSize:
      case NSOpenGLPFAAlphaSize:
      case NSOpenGLPFADepthSize:
      case NSOpenGLPFAAccumSize:
      case NSOpenGLPFASampleBuffers:
      case NSOpenGLPFASamples:
        attribs[idx++] = attr;
        attribs[idx++] = ivalues[i];
        break;

      case NSOpenGLPFAStencilSize:
        attribs[idx++] = attr;
        attribs[idx++] = validateParameter(NSOpenGLPFAStencilSize, ivalues[i]);
        break;

      default:
        // Need better way to signal to caller
        return nil;
    }
  }

  // Zero-terminate
  attribs[idx++] = 0;

  NSOpenGLPixelFormat* fmt = [[NSOpenGLPixelFormat alloc] initWithAttributes:attribs];
  if (fmt == nil) {
    // should we fallback to defaults or not?
    fmt = [NSOpenGLView defaultPixelFormat];
  }

  [pool release];
  return fmt;
}

void queryPixelFormat(void* pixelFormat, int* iattrs, int niattrs, int* ivalues) {
  NSAutoreleasePool* pool = [[NSAutoreleasePool alloc] init];
  NSOpenGLPixelFormat* fmt = (NSOpenGLPixelFormat*) pixelFormat;
  long tmp;
  // FIXME: think about how specifying this might affect the API
  int virtualScreen = 0;

  int i;
  for (i = 0; i < niattrs; i++) {
    [fmt getValues: &tmp
         forAttribute: (NSOpenGLPixelFormatAttribute) iattrs[i]
         forVirtualScreen: virtualScreen];
    ivalues[i] = (int) tmp;
  }
  [pool release];
}
  
void deletePixelFormat(void* pixelFormat) {
  NSAutoreleasePool* pool = [[NSAutoreleasePool alloc] init];
  NSOpenGLPixelFormat* fmt = (NSOpenGLPixelFormat*) pixelFormat;
  [fmt release];
  [pool release];
}

void* createContext(void* shareContext,
                    void* view,
                    void* pixelFormat,
                    int* viewNotReady)
{
	getRendererInfo();
	
	NSAutoreleasePool* pool = [[NSAutoreleasePool alloc] init];

	NSView *nsView = (NSView*)view;

	if (nsView != NULL)
	{
		Bool viewReady = true;

		if ([nsView lockFocusIfCanDraw] == NO)
		{
			viewReady = false;
		}
		else
		{
			NSRect frame = [nsView frame];
			if ((frame.size.width == 0) || (frame.size.height == 0))
			{
				[nsView unlockFocus];		
				viewReady = false;
			}
		}

		if (!viewReady)
		{
			if (viewNotReady != NULL)
			{
				*viewNotReady = 1;
			}

			// the view is not ready yet
			[pool release];
			return NULL;
		}
	}
	
	NSOpenGLContext* nsContext = [[NSOpenGLContext alloc]
                                       initWithFormat: (NSOpenGLPixelFormat*) pixelFormat
                                       shareContext:   (NSOpenGLContext*) shareContext];
		
	if (nsView != nil)
	{
		[nsContext setView:nsView];
		[nsView unlockFocus];		
	}

	[pool release];
	return nsContext;
}

Bool makeCurrentContext(void* context) {
  NSOpenGLContext *nsContext = (NSOpenGLContext*)context;
	
  NSAutoreleasePool* pool = [[NSAutoreleasePool alloc] init];
  [nsContext makeCurrentContext];
  [pool release];
  return true;
}

Bool clearCurrentContext(void* context) {
  NSAutoreleasePool* pool = [[NSAutoreleasePool alloc] init];
  [NSOpenGLContext clearCurrentContext];
  [pool release];
  return true;
}

Bool deleteContext(void* context) {
  NSOpenGLContext *nsContext = (NSOpenGLContext*)context;
	
  NSAutoreleasePool* pool = [[NSAutoreleasePool alloc] init];
  [nsContext clearDrawable];
  [nsContext release];
  [pool release];
  return true;
}

Bool flushBuffer(void* context) {
  NSOpenGLContext *nsContext = (NSOpenGLContext*)context;
	
  NSAutoreleasePool* pool = [[NSAutoreleasePool alloc] init];
  [nsContext flushBuffer];
  [pool release];
  return true;
}

void updateContext(void* context) {
  NSOpenGLContext *nsContext = (NSOpenGLContext*)context;
	
  NSAutoreleasePool* pool = [[NSAutoreleasePool alloc] init];
  [nsContext update];
  [pool release];
}

void* updateContextRegister(void* context, void* view) {
  NSOpenGLContext *nsContext = (NSOpenGLContext*)context;
  NSView *nsView = (NSView*)view;
	
  NSAutoreleasePool* pool = [[NSAutoreleasePool alloc] init];
  ContextUpdater *contextUpdater = [[ContextUpdater alloc] init];
  [contextUpdater registerFor:nsContext with:nsView];
  [pool release];
  return NULL;
}

void updateContextUnregister(void* context, void* view, void* updater) {
  ContextUpdater *contextUpdater = (ContextUpdater *)updater;
	
  NSAutoreleasePool* pool = [[NSAutoreleasePool alloc] init];
  [contextUpdater release];
  [pool release];
}

void* createPBuffer(int renderTarget, int internalFormat, int width, int height) {
  NSAutoreleasePool* pool = [[NSAutoreleasePool alloc] init];
  NSOpenGLPixelBuffer* pBuffer = [[NSOpenGLPixelBuffer alloc]
                                   initWithTextureTarget:renderTarget
                                   textureInternalFormat:internalFormat
                                   textureMaxMipMapLevel:0
                                   pixelsWide:width
                                   pixelsHigh:height];
  [pool release];
  return pBuffer;
}

Bool destroyPBuffer(void* context, void* buffer) {
  /* FIXME: not clear whether we need to perform the clearDrawable below */
  /* FIXME: remove the context argument -- don't need it any more */
  /*  NSOpenGLContext *nsContext = (NSOpenGLContext*)context; */
  NSOpenGLPixelBuffer *pBuffer = (NSOpenGLPixelBuffer*)buffer;
	
  NSAutoreleasePool* pool = [[NSAutoreleasePool alloc] init];
  /*
  if (nsContext != NULL) {
    [nsContext clearDrawable];
  }
  */
  [pBuffer release];
  [pool release];
	
  return true;
}

void setContextPBuffer(void* context, void* buffer) {
  NSOpenGLContext *nsContext = (NSOpenGLContext*)context;
  NSOpenGLPixelBuffer *pBuffer = (NSOpenGLPixelBuffer*)buffer;

  NSAutoreleasePool* pool = [[NSAutoreleasePool alloc] init];
  [nsContext setPixelBuffer: pBuffer
             cubeMapFace: 0
             mipMapLevel: 0
             currentVirtualScreen: [nsContext currentVirtualScreen]];
  [pool release];
}

void setContextTextureImageToPBuffer(void* context, void* buffer, int colorBuffer) {
  NSOpenGLContext *nsContext = (NSOpenGLContext*)context;
  NSOpenGLPixelBuffer *pBuffer = (NSOpenGLPixelBuffer*)buffer;

  NSAutoreleasePool* pool = [[NSAutoreleasePool alloc] init];
  [nsContext setTextureImageToPixelBuffer: pBuffer
             colorBuffer: (unsigned long) colorBuffer];
  [pool release];
}

#include <mach-o/dyld.h>
Bool imagesInitialized = false;
static char libGLStr[] = "/System/Library/Frameworks/OpenGL.framework/Libraries/libGL.dylib";
static char libGLUStr[] = "/System/Library/Frameworks/OpenGL.framework/Libraries/libGLU.dylib";
static const struct mach_header *libGLImage;
static const struct mach_header *libGLUImage;
void* getProcAddress(const char *procname) {
  if (imagesInitialized == false) {
    imagesInitialized = true;
    unsigned long options = NSADDIMAGE_OPTION_RETURN_ON_ERROR;
    libGLImage = NSAddImage(libGLStr, options);
    libGLUImage = NSAddImage(libGLUStr, options);
  }
	
  unsigned long options = NSLOOKUPSYMBOLINIMAGE_OPTION_BIND | NSLOOKUPSYMBOLINIMAGE_OPTION_RETURN_ON_ERROR;
  char underscoreName[512] = "_";
  strcat(underscoreName, procname);
	
  if (NSIsSymbolNameDefinedInImage(libGLImage, underscoreName) == YES) {
    NSSymbol sym = NSLookupSymbolInImage(libGLImage, underscoreName, options);
    return NSAddressOfSymbol(sym);
  }
	
  if (NSIsSymbolNameDefinedInImage(libGLUImage, underscoreName) == YES)	{
    NSSymbol sym = NSLookupSymbolInImage(libGLUImage, underscoreName, options);
    return NSAddressOfSymbol(sym);
  }
	
  if (NSIsSymbolNameDefinedWithHint(underscoreName, "GL")) {
    NSSymbol sym = NSLookupAndBindSymbol(underscoreName);
    return NSAddressOfSymbol(sym);
  }
  
  return NULL;
}

void setSwapInterval(void* context, int interval) {
  NSOpenGLContext *nsContext = (NSOpenGLContext*)context;
  long swapInterval = interval;
  [nsContext setValues: &swapInterval forParameter: NSOpenGLCPSwapInterval];
}

Bool setGammaRamp(int tableSize, float* redRamp, float* greenRamp, float* blueRamp) {
  CGDisplayErr err = CGSetDisplayTransferByTable(kCGDirectMainDisplay, tableSize, redRamp, greenRamp, blueRamp);
  return (err == CGDisplayNoErr);
}

void resetGammaRamp() {
  CGDisplayRestoreColorSyncSettings();
}