Moved OpenGLWidget into common folder so it can be used by other examples.

examples/common/OpenGLWidget.h

@@ -0,0 +1,122 @@
+/*******************************************************************************
+Copyright (c) 2005-2009 David Williams
+
+This software is provided 'as-is', without any express or implied
+warranty. In no event will the authors be held liable for any damages
+arising from the use of this software.
+
+Permission is granted to anyone to use this software for any purpose,
+including commercial applications, and to alter it and redistribute it
+freely, subject to the following restrictions:
+
+1. The origin of this software must not be misrepresented; you must not
+claim that you wrote the original software. If you use this software
+in a product, an acknowledgment in the product documentation would be
+appreciated but is not required.
+
+2. Altered source versions must be plainly marked as such, and must not be
+misrepresented as being the original software.
+
+3. This notice may not be removed or altered from any source
+distribution. 	
+*******************************************************************************/
+
+#ifndef __BasicExample_OpenGLWidget_H__
+#define __BasicExample_OpenGLWidget_H__
+
+#include "PolyVoxCore/Mesh.h"
+
+#include "glew/glew.h"
+
+#include <QGLWidget>
+#include <QGLShaderProgram>
+
+struct OpenGLMeshData
+{
+	GLuint noOfIndices;
+	GLuint indexBuffer;
+	GLuint vertexBuffer;
+	GLuint vertexArrayObject;
+	PolyVox::Vector3DInt32 translation;
+};
+
+class OpenGLWidget : public QGLWidget
+{
+public:
+	// Constructor
+	OpenGLWidget(QWidget *parent);
+
+	// Mouse handling
+	void mouseMoveEvent(QMouseEvent* event);
+	void mousePressEvent(QMouseEvent* event);
+
+	// The viewable region can be adjusted so that this example framework can be use for different volume sizes.
+	void setViewableRegion(PolyVox::Region viewableRegion);
+
+	// Convert a SurfaceMesh to OpenGL index/vertex buffers. Inlined because it's templatised.
+	template <typename MeshType>
+	void addMesh(const MeshType& surfaceMesh)
+	{
+		//Convienient access to the vertices and indices
+		const auto& vecIndices = surfaceMesh.getIndices();
+		const auto& vecVertices = surfaceMesh.getVertices();
+
+		// This struct holds the OpenGL properties (buffer handles, etc) which will be used
+		// to render our mesh. We copy the data from the PolyVox mesh into this structure.
+		OpenGLMeshData meshData;
+
+		//Create the VAO for the mesh
+		glGenVertexArrays(1, &(meshData.vertexArrayObject));
+		glBindVertexArray(meshData.vertexArrayObject);
+
+		//The GL_ARRAY_BUFFER will contain the list of vertex positions
+		glGenBuffers(1, &(meshData.vertexBuffer));
+		glBindBuffer(GL_ARRAY_BUFFER, meshData.vertexBuffer);
+		glBufferData(GL_ARRAY_BUFFER, vecVertices.size() * sizeof(CubicVertex<uint8_t>), vecVertices.data(), GL_STATIC_DRAW);
+
+		//and GL_ELEMENT_ARRAY_BUFFER will contain the indices
+		glGenBuffers(1, &(meshData.indexBuffer));
+		glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, meshData.indexBuffer);
+		glBufferData(GL_ELEMENT_ARRAY_BUFFER, vecIndices.size() * sizeof(uint32_t), vecIndices.data(), GL_STATIC_DRAW);
+
+		//We need to tell OpenGL how to understand the format of the vertex data
+		glEnableVertexAttribArray(0); //We're talking about shader attribute '0' 
+		glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, sizeof(CubicVertex<uint8_t>), 0); //take the first 3 floats from every sizeof(decltype(vecVertices)::value_type)
+
+		glBindVertexArray(0);
+
+		meshData.noOfIndices = vecIndices.size(); //Save this for the call to glDrawElements later
+
+		meshData.translation = surfaceMesh.m_Region.getLowerCorner();
+
+		mMeshData.push_back(meshData);
+	}
+
+protected:
+	
+
+	// Qt OpenGL functions
+	void initializeGL();
+	void resizeGL(int w, int h);
+	void paintGL();
+
+private:
+
+	void setupWorldToCameraMatrix();
+
+	// Index/vertex buffer data
+	std::vector<OpenGLMeshData> mMeshData;
+	
+	QGLShaderProgram shader;
+
+	// Mouse data
+	QPoint m_LastFrameMousePos;
+	QPoint m_CurrentMousePos;
+
+	// Camera setup
+	PolyVox::Region m_viewableRegion;
+	int m_xRotation;
+	int m_yRotation;
+};
+
+#endif //__BasicExample_OpenGLWidget_H__