#include "macofflinegl.h"
#include <traster.h>
#include <tconvert.h>

#include "tthread.h"

namespace
{

#if defined(powerpc)
void rightRotateBits(UCHAR *buf, int bufferSize)
{
	UINT *buffer = (UINT *)buf;
	register UINT app;
	for (int i = 0; i < bufferSize; i++, buffer++) {
		app = *buffer;
		*buffer = app >> 8 | app << 24;
	}
}
#else
void rightRotateBits(UCHAR *buf, int bufferSize)
{
	UINT *buffer = (UINT *)buf;
	register UINT app;
	for (int i = 0; i < bufferSize; i++, buffer++) {
		app = *buffer;
		*buffer = (app >> 16 & 0x000000ff) | (app << 16 & 0x00ff0000) | (app & 0xff00ff00);
	}
}
#endif

} // namespace

GLubyte *memBuffer;

//=============================================================================
// MacOfflineGL : implem. offlineGL usando Pixel Buffer (tramite AGL)
//-----------------------------------------------------------------------------

MacOfflineGL::MacOfflineGL(TDimension rasterSize, const TOfflineGL::Imp *shared)
	: TOfflineGL::Imp(rasterSize.lx, rasterSize.ly), m_context(0), m_oldContext(0)
{
	createContext(rasterSize, shared);
}

//-----------------------------------------------------------------------------

MacOfflineGL::~MacOfflineGL()
{
	aglDestroyContext(m_context);
}

//-----------------------------------------------------------------------------

void MacOfflineGL::createContext(TDimension rasterSize, const TOfflineGL::Imp *shared)
{

	GLint attribs[20], cnt = 0;

	//NOTE: AGL_OFFSCREEN *must* be selected - or it seems that gl surfaces are never destructed correctly!
	//This may lead to a kernel panic!

	attribs[cnt++] = AGL_RGBA;
	attribs[cnt++] = GL_TRUE;
	attribs[cnt++] = AGL_PIXEL_SIZE;
	attribs[cnt++] = 32;
	attribs[cnt++] = AGL_BUFFER_SIZE;
	attribs[cnt++] = 32;
	attribs[cnt++] = AGL_STENCIL_SIZE;
	attribs[cnt++] = 8;
	attribs[cnt++] = AGL_DEPTH_SIZE;
	attribs[cnt++] = 24;
	attribs[cnt++] = AGL_OFFSCREEN;
	attribs[cnt++] = AGL_ALPHA_SIZE;
	attribs[cnt++] = 8;
	attribs[cnt] = AGL_NONE;

	AGLPixelFormat fmt = aglChoosePixelFormat(0, 0, attribs);

	if (fmt == NULL) {
		GLenum err = aglGetError();
		std::cout << "Unable to create a pixel format, AGLError =  " << err << std::endl;
	}

	m_context = aglCreateContext(fmt, NULL);
	if (!m_context) {
		GLenum err = aglGetError();
		/*		
		AGL_NO_ERROR                 0 
		AGL_BAD_ATTRIBUTE        10000
		AGL_BAD_PROPERTY         10001
		AGL_BAD_PIXELFMT         10002
		AGL_BAD_RENDINFO         10003
		AGL_BAD_CONTEXT          10004
		AGL_BAD_DRAWABLE         10005
		AGL_BAD_GDEV             10006
		AGL_BAD_STATE            10007
		AGL_BAD_VALUE            10008
		AGL_BAD_MATCH            10009
		AGL_BAD_ENUM             10010
		AGL_BAD_OFFSCREEN        10011
		AGL_BAD_FULLSCREEN       10012
		AGL_BAD_WINDOW           10013
		AGL_BAD_POINTER          10014
		AGL_BAD_MODULE           10015
		AGL_BAD_ALLOC            10016
		AGL_BAD_CONNECTION       10017
	*/
		std::cout << "Unable to create an OpenGL Context, AGLError = " << err << std::endl;
	}

	makeCurrent();

	// Creo il pixel buffer

	GLboolean ret;

	AGLPbuffer pbuffer;

	ret = aglCreatePBuffer(rasterSize.lx, rasterSize.ly, GL_TEXTURE_RECTANGLE_EXT, GL_RGBA, 0, &pbuffer);
	if (!ret) {
		GLenum err = aglGetError();
		std::cout << "Unable to create a PBuffer, AGLError = " << err << std::endl;
	}

	//memBuffer = new GLubyte[rasterSize.lx*rasterSize.ly*4];

	ret = aglSetOffScreen(m_context, rasterSize.lx, rasterSize.ly, rasterSize.lx * 4, memBuffer);

	ret = aglSetPBuffer(m_context, pbuffer, 0, 0, 0);
	if (!ret) {
		GLenum err = aglGetError();
		std::cout << "Unable to set a PBuffer, AGLError = " << err << std::endl;
	}

	// Non serve piu'
	aglDestroyPixelFormat(fmt);
}

//-----------------------------------------------------------------------------

void MacOfflineGL::makeCurrent()
{
	if (m_context) {
		bool ret = aglSetCurrentContext(m_context);
		if (ret == GL_FALSE) {
			GLenum err = aglGetError();
			std::cout << "Unable to set current OpenGL Context, AGLError = " << err << std::endl;
		}
	} else
		m_oldContext = 0;
}

//-----------------------------------------------------------------------------

void MacOfflineGL::doneCurrent()
{
	if (aglGetCurrentContext() != m_context)
		return;
	aglSetCurrentContext(0);
}

//-----------------------------------------------------------------------------

void MacOfflineGL::saveCurrentContext()
{
	m_oldContext = aglGetCurrentContext();
}

//-----------------------------------------------------------------------------

void MacOfflineGL::restoreCurrentContext()
{
	if (m_oldContext)
		aglSetCurrentContext(m_oldContext);
	m_oldContext = 0;
}

//-----------------------------------------------------------------------------

void MacOfflineGL::getRaster(TRaster32P raster)
{
	makeCurrent();
	glFinish();

	int lx = raster->getLx();
	int ly = raster->getLy();

	raster->lock();

	glReadPixels(0, 0, lx, ly, GL_RGBA, GL_UNSIGNED_BYTE, raster->getRawData());

	rightRotateBits(raster->getRawData(), lx * ly);

	raster->unlock();
}