// AtlTangramGLVisual.cpp : Implementation of CAtlTangramGLVisual
//
// This is a part of the Active Template Library.
// Copyright (C) 1996-1998 Microsoft Corporation
// All rights reserved.
//
// This source code is only intended as a supplement to the
// Active Template Library Reference and related
// electronic documentation provided with the library.
// See these sources for detailed information regarding the
// Active Template Library product.

#include "stdafx.h"
#include "GLWorld.h"
#include "TanGLVis.h"
#include "event_i_i.c"
#include <windows.h>
#include <olectl.h>

// STL Interfaces
#include <new.h>
#include <algorithm>
#include <xmemory>
#include <list>
#include "util.h"
#include "util.cpp"
#include "CGL.h"
#include "CGL.cpp"
#include "CGL-Pal.cpp"

// Interfaces
#include "TanCanv_i.c"
#include "AtlModel.h"
#include "GdiWorld.h"
#include "GdiWorld_i.c"

// Sub-Components.
#include "AtlModel_i.c"

// Other
#include <math.h>
#include <gl/gl.h>
#include <gl/glu.h>

///////////////////////////////////////////////////////////
//
// Destructor
//
CAtlTangramGLVisual::~CAtlTangramGLVisual()
{

	// We keep a strong reference to the model.
	// Therefore, we need to release it here.
	m_pModel->Release();
	m_pModel = NULL;

	// We maintain a weak reference to GdiWorld to avoid
	// reference cycles. A weak reference means that we
	// do not need to Release m_pGdiWorld here.

	// Delete the vertex array.
	delete [] m_ptVertices;
}

///////////////////////////////////////////////////////////
//  ITangramVisual
// ITangramVisual::SetSelected Implementation.

HRESULT CAtlTangramGLVisual::SetSelected(BOOL bSelected)
{
	m_bSelected = bSelected;

	// Update the display.
	HRESULT hr = m_pWorld->Animate();
	ASSERT_HRESULT(hr);

	return S_OK;
}

///////////////////////////////////////////////////////////
// ITangramGLVisual::GetModel Implementation

HRESULT CAtlTangramGLVisual::GetModel(const IID& iid, IUnknown** ppI)
{
	if (!IsValidInterfaceOutParam(ppI))
	{
		ASSERT(0);
		return E_POINTER;
	}

	return m_pModel->QueryInterface(iid, (void**)ppI) ;
}

///////////////////////////////////////////////////////////
//  ITangramGLVisual
// ITangramGLVisual::Initialize Implementation

HRESULT __stdcall
CAtlTangramGLVisual::Initialize(IATLTangramModel* pModel,
	IAtlTangramGLWorld* pWorld)
{
	if (!IsValidInterface(pModel)|| !IsValidInterface(pWorld))
	{
		ASSERT(0);
		return E_POINTER;
	}

	if (m_pModel != NULL || m_pWorld != NULL)
	{
		// Cannot re-initialize.
		ASSERT(0);
		return E_FAIL;
	}

	// Keep a strong reference to the model.
	m_pModel = pModel;
	m_pModel->AddRef();

	// To avoid a cyclical reference count, we have a
	// weak reference to GLWorld. Therefore, we do
	// not AddRef this pointer.
	m_pWorld = pWorld;

	// Get the number of vertices in the model.
	HRESULT hr = m_pModel->GetNumberOfVertices(&m_cVertices);
	ASSERT_HRESULT(hr);

	// Create an array to hold the vertices.
	m_ptVertices = new TangramPoint2d[m_cVertices];

	//  Set up event sync
	// Create a sink object.
	TCHAR buf[128];
	wsprintf(buf, _T("Visual: m_dwRef = %d\n"), m_dwRef);
	ATLTRACE(buf);

	// Get the connection point container.
	IConnectionPointContainer* pContainer = NULL;
	hr = pModel->QueryInterface(IID_IConnectionPointContainer,
		(void**)&pContainer);
	ASSERT_HRESULT(hr);

	// Get our desired connection point. Cache the pointer so
	// we don't have to get it again.
	hr = pContainer->FindConnectionPoint(IID_IATLTangramModelEvent,
		&m_pIConnectionPoint);
	pContainer->Release();
	ASSERT_HRESULT(hr);

	IATLTangramModelEvent* pIATLTangramModelEvent;
	hr = GetUnknown()->QueryInterface(IID_IATLTangramModelEvent,
		(void**)&pIATLTangramModelEvent);
	wsprintf(buf, _T("Visual: m_dwRef = %d\n"), m_dwRef);
	ATLTRACE(buf);

	// Ask the visual to advise us of any changes.
	hr = m_pIConnectionPoint->Advise(pIATLTangramModelEvent, &m_dwCookie);
	ASSERT_HRESULT(hr);

	wsprintf(buf, _T("Visual: m_dwRef = %d\n"), m_dwRef);
	ATLTRACE(buf);

	// We don't need to keep a reference to the sink.
	pIATLTangramModelEvent->Release();
	wsprintf(buf, _T("Visual: m_dwRef = %d\n"), m_dwRef);
	ATLTRACE(buf);
	return S_OK;
}


///////////////////////////////////////////////////////////
// ITangramGLVisual::DrawOn Implementation

HRESULT CAtlTangramGLVisual::DrawOn(IAtlTangramCanvas* pCanvas)
{
	// Preconditions.
	if (!m_bFirstEvent)
	{
		// We have not received a model change event to initialize use.
		return S_FALSE;
	}

	if (!IsValidInterface(pCanvas))
	{
		ASSERT(0);
		return E_POINTER;
	}

	double thickness = 0.01;

	if (m_bSelected)
		glPolygonMode(GL_FRONT_AND_BACK, GL_LINE);

	// Bottom
	glNormal3d(0.0, 0.0, -1.0);
	glBegin(GL_TRIANGLE_FAN);
		for (int i = 0; i < m_cVertices; i++)
			glVertex2d(m_ptVertices[i].x, m_ptVertices[i].y);

	glEnd();

	// Top
	glNormal3d(0.0, 0.0, 1.0);
	glBegin(GL_TRIANGLE_FAN);
		for (i = 0; i < m_cVertices; i++)
			glVertex3d(m_ptVertices[i].x, m_ptVertices[i].y, thickness);
	glEnd();

	// Sides
	for (i = 0; i < m_cVertices; i++)
	{
		int iNextIndex = (i+1) % m_cVertices;

		// Compute Normal [v1 - v2] X [v2 - v3] see page 58 of RedBook

		// V1 = v1 - v2
		double X1 = m_ptVertices[i].x - m_ptVertices[iNextIndex].x;
		double Y1 = m_ptVertices[i].y - m_ptVertices[iNextIndex].y;
		double Z1 = 0.0; // 0.0f - 0.0f;

		// V2 = v2 - v3
		double X2 = 0.0; //m_ptVertices[iNextIndex].x - m_ptVertices[iNextIndex].x;
		double Y2 = 0.0; //m_ptVertices[iNextIndex].y - m_ptVertices[iNextIndex].y;
		double Z2 = -thickness; // 0.0 - thickness;

		// V = V1 X V2
		double X = Y1 * Z2; //Y1*Z2 - Z1*Y2  = Y1*Z2 - 0.0*0.0;
		double Y = -X1 * Z2; //Z1*X2 - X1*Z2 = 0.0*0.0 - X1*Z2
		//double Z = 0.0; //X1*Y2 - Y1*X2;

		// Normalize
		double d = sqrt(X*X + Y*Y /*+ Z*Z*/);
		ASSERT( d != 0.0);
		X /= d;
		Y /= d;
		//Z /= d;

		glNormal3d(X, Y, 0.0/*Z*/);

		glBegin(GL_QUADS);
			glVertex3d(m_ptVertices[i].x, m_ptVertices[i].y, 0.0);
			glVertex3d(m_ptVertices[iNextIndex].x,
				m_ptVertices[iNextIndex].y, 0.0);
			glVertex3d(m_ptVertices[iNextIndex].x,
				m_ptVertices[iNextIndex].y, thickness);
			glVertex3d(m_ptVertices[i].x, m_ptVertices[i].y, thickness);
		glEnd();
	}

	if (m_bSelected)
		glPolygonMode(GL_FRONT_AND_BACK, GL_FILL);

	return S_OK;
}

///////////////////////////////////////////////////////////
//  ITangramModelEvent
// ITangramModelEvent::OnModelChange

HRESULT __stdcall CAtlTangramGLVisual::OnModelChange()
{
	// Create an array to hold the new vertices.
	TangramPoint2d* pointds = new TangramPoint2d[m_cVertices];

	// Get the vertices from the model.
	HRESULT hr = m_pModel->GetVertices(m_cVertices, pointds);
	ASSERT_HRESULT(hr);

	// Convert the vertices to our coordinates.
	for (int i = 0; i < m_cVertices; i++)
	{
		hr = m_pWorld->ModelToDevice(pointds[i], &m_ptVertices[i]);
		ASSERT_HRESULT(hr);
	}

	// Cleanup;
	delete [] pointds;

	// We are in sync.
	m_bFirstEvent = TRUE;

	// Update the display.
	hr = m_pWorld->Animate();
	ASSERT_HRESULT(hr);

	return S_OK;
}

STDMETHODIMP CAtlTangramGLVisual::ReleaseConnectionPoint()
{
	HRESULT hr = S_OK;
	// Release the event source component.
	if (m_pIConnectionPoint != NULL)
	{
		// We no longer need to be enformed of events
		HRESULT hr = m_pIConnectionPoint->Unadvise(m_dwCookie);
		ASSERT_HRESULT(hr);
		m_pIConnectionPoint->Release();
	}
	return hr;
}