Initial commit of VolumeResampler and LOD demo.

examples/SmoothLOD/OpenGLWidget.cpp

@@ -0,0 +1,154 @@
+#include "OpenGLWidget.h"
+
+#include <QMouseEvent>
+
+using namespace PolyVox;
+using namespace std;
+
+OpenGLWidget::OpenGLWidget(QWidget *parent)
+	:QGLWidget(parent)
+	,m_xRotation(0)
+	,m_yRotation(0)
+{
+}
+
+void OpenGLWidget::setSurfaceMeshToRender(const PolyVox::SurfaceMesh<PositionMaterialNormal>& surfaceMesh)
+{
+	//Convienient access to the vertices and indices
+	const vector<uint32_t>& vecIndices = surfaceMesh.getIndices();
+	const vector<PositionMaterialNormal>& vecVertices = surfaceMesh.getVertices();
+
+	//Build an OpenGL index buffer
+	glGenBuffers(1, &indexBuffer);
+	glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, indexBuffer);
+	const GLvoid* pIndices = static_cast<const GLvoid*>(&(vecIndices[0]));		
+	glBufferData(GL_ELEMENT_ARRAY_BUFFER, vecIndices.size() * sizeof(uint32_t), pIndices, GL_STATIC_DRAW);
+
+	//Build an OpenGL vertex buffer
+	glGenBuffers(1, &vertexBuffer);
+	glBindBuffer(GL_ARRAY_BUFFER, vertexBuffer);
+	const GLvoid* pVertices = static_cast<const GLvoid*>(&(vecVertices[0]));	
+	glBufferData(GL_ARRAY_BUFFER, vecVertices.size() * sizeof(PositionMaterialNormal), pVertices, GL_STATIC_DRAW);
+
+	m_uBeginIndex = 0;
+	m_uEndIndex = vecIndices.size();
+}
+
+void OpenGLWidget::initializeGL()
+{
+	//We need GLEW to access recent OpenGL functionality
+	std::cout << "Initialising GLEW...";
+	GLenum result = glewInit();
+	if (result == GLEW_OK)
+	{
+	  std::cout << "success" << std::endl;
+	}
+	else
+	{
+		/* Problem: glewInit failed, something is seriously wrong. */
+		std::cout << "failed" << std::endl;
+		std::cout << "Initialising GLEW failed with the following error: " << glewGetErrorString(result) << std::endl;
+		exit(EXIT_FAILURE);
+	}
+	
+	//Print out some information about the OpenGL implementation.
+	std::cout << "OpenGL Implementation Details:" << std::endl;
+	if(glGetString(GL_VENDOR))
+	  std::cout << "\tGL_VENDOR: " << glGetString(GL_VENDOR) << std::endl;
+	if(glGetString(GL_RENDERER))
+	  std::cout << "\tGL_RENDERER: " << glGetString(GL_RENDERER) << std::endl;
+	if(glGetString(GL_VERSION))
+	  std::cout << "\tGL_VERSION: " << glGetString(GL_VERSION) << std::endl;
+	if(glGetString(GL_SHADING_LANGUAGE_VERSION))
+	  std::cout << "\tGL_SHADING_LANGUAGE_VERSION: " << glGetString(GL_SHADING_LANGUAGE_VERSION) << std::endl;
+	
+	//Check our version of OpenGL is recent enough.
+	//We need at least 1.5 for vertex buffer objects,
+	if (!GLEW_VERSION_1_5)
+	{
+	  std::cout << "Error: You need OpenGL version 1.5 to run this example." << std::endl;
+	  exit(EXIT_FAILURE);
+	}
+
+	//Set up the clear colour
+	glClearColor(0.0f, 0.0f, 0.0f, 0.0f);		
+	glClearDepth(1.0f);		
+
+	//Enable the depth buffer
+	glEnable(GL_DEPTH_TEST);					
+	glDepthFunc(GL_LEQUAL);						
+
+	//Anable smooth lighting
+	glEnable(GL_LIGHTING);
+	glEnable(GL_LIGHT0);
+	glShadeModel(GL_SMOOTH);
+
+	//We'll be rendering with index/vertex arrays
+	glEnableClientState(GL_VERTEX_ARRAY);
+	glEnableClientState(GL_NORMAL_ARRAY);
+
+	glPolygonMode( GL_FRONT_AND_BACK, GL_LINE );
+}
+
+void OpenGLWidget::resizeGL(int w, int h)
+{
+	//Setup the viewport
+	glViewport(0, 0, w, h);
+
+	//Set up the projection matrix
+	glMatrixMode(GL_PROJECTION);
+	glLoadIdentity();
+	float frustumSize = 32.0f; //Half the volume size
+	float aspect = static_cast<float>(width()) / static_cast<float>(height());
+	glOrtho(frustumSize*aspect, -frustumSize*aspect, frustumSize, -frustumSize, 1.0, 1000);
+}
+
+void OpenGLWidget::paintGL()
+{
+	//Clear the screen
+	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
+
+	//Set up the viewing transformation
+	glMatrixMode(GL_MODELVIEW); 
+	glLoadIdentity();
+	glTranslatef(0.0f,0.0f,-100.0f); //Centre volume and move back
+	glRotatef(-m_xRotation, 0.0f, 1.0f, 0.0f);
+	glRotatef(-m_yRotation, 1.0f, 0.0f, 0.0f);
+	glTranslatef(-32.0f,-32.0f,-32.0f); //Centre volume and move back
+
+	//Bind the index buffer
+	glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, indexBuffer);
+
+	//Bind the vertex buffer
+	glBindBuffer(GL_ARRAY_BUFFER, vertexBuffer);
+	glVertexPointer(3, GL_FLOAT, sizeof(PositionMaterialNormal), 0);
+	glNormalPointer(GL_FLOAT, sizeof(PositionMaterialNormal), (GLvoid*)12);
+
+	glDrawRangeElements(GL_TRIANGLES, m_uBeginIndex, m_uEndIndex-1, m_uEndIndex - m_uBeginIndex, GL_UNSIGNED_INT, 0);
+	
+	GLenum errCode = glGetError();
+	if(errCode != GL_NO_ERROR)
+	{
+	  //What has replaced getErrorString() in the latest OpenGL?
+	  std::cout << "OpenGL Error: " << errCode << std::endl;
+	}
+}
+
+void OpenGLWidget::mousePressEvent(QMouseEvent* event)
+{
+	m_CurrentMousePos = event->pos();
+	m_LastFrameMousePos = m_CurrentMousePos;
+
+	update();
+}
+
+void OpenGLWidget::mouseMoveEvent(QMouseEvent* event)
+{
+	m_CurrentMousePos = event->pos();
+	QPoint diff = m_CurrentMousePos - m_LastFrameMousePos;
+	m_xRotation += diff.x();
+	m_yRotation += diff.y();
+	m_LastFrameMousePos = m_CurrentMousePos;
+
+	update();
+}