More work splitting example framework into two pieces.

examples/Basic/main.cpp

@@ -75,7 +75,7 @@ public:
 	}
 
 protected:
-	void initialize() override
+	void initializeExample() override
 	{
 		// Create an empty volume and then place a sphere in it
 		PagedVolume<uint8_t> volData(PolyVox::Region(Vector3DInt32(0, 0, 0), Vector3DInt32(63, 63, 63)));

examples/DecodeOnGPU/main.cpp

@@ -75,7 +75,7 @@ public:
 	}
 
 protected:
-	void initialize() override
+	void initializeExample() override
 	{
 		QSharedPointer<QGLShaderProgram> shader(new QGLShaderProgram);
 

examples/OpenGL/main.cpp

@@ -56,7 +56,7 @@ public:
 	}
 
 protected:
-	void initialize() override
+	void initializeExample() override
 	{
 		FilePager<MaterialDensityPair88>* pager = new FilePager<MaterialDensityPair88>(".");
 		PagedVolume<MaterialDensityPair88> volData(PolyVox::Region(Vector3DInt32(0, 0, 0), Vector3DInt32(g_uVolumeSideLength - 1, g_uVolumeSideLength - 1, g_uVolumeSideLength - 1)), pager);

examples/Paging/main.cpp

@@ -148,7 +148,7 @@ public:
 	}
 
 protected:
-	void initialize() override
+	void initializeExample() override
 	{
 		PerlinNoisePager* pager = new PerlinNoisePager();
 		PagedVolume<MaterialDensityPair44> volData(PolyVox::Region::MaxRegion(), pager, 64);

examples/SmoothLOD/main.cpp

@@ -77,7 +77,7 @@ public:
 	}
 
 protected:
-	void initialize() override
+	void initializeExample() override
 	{
 		//Create an empty volume and then place a sphere in it
 		PagedVolume<uint8_t> volData(PolyVox::Region(Vector3DInt32(0, 0, 0), Vector3DInt32(63, 63, 63)));

examples/common/OpenGLWidget.cpp

@@ -17,11 +17,6 @@ OpenGLWidget::OpenGLWidget(QWidget *parent)
 {
 }
 
-void OpenGLWidget::setShader(QSharedPointer<QGLShaderProgram> shader)
-{
-	mShader = shader;
-}
-
 void OpenGLWidget::setCameraTransform(QVector3D position, float pitch, float yaw)
 {
 	mCameraPosition = position;
@@ -92,38 +87,6 @@ void OpenGLWidget::initializeGL()
 	glDepthFunc(GL_LEQUAL);
 	glDepthRange(0.0, 1.0);
 
-	mShader = QSharedPointer<QGLShaderProgram>(new QGLShaderProgram);
-	
-	// This is basically a simple fallback vertex shader which does the most basic rendering possible.  
-	// PolyVox examples are able to provide their own shaders to demonstrate certain effects if desired. 
-	if (!mShader->addShaderFromSourceFile(QGLShader::Vertex, ":/example.vert"))
-	{
-		std::cerr << mShader->log().toStdString() << std::endl;
-		exit(EXIT_FAILURE);
-	}
-	
-	// This is basically a simple fallback fragment shader which does the most basic rendering possible.  
-	// PolyVox examples are able to provide their own shaders to demonstrate certain effects if desired. 
-	if (!mShader->addShaderFromSourceFile(QGLShader::Fragment, ":/example.frag"))
-	{
-		std::cerr << mShader->log().toStdString() << std::endl;
-		exit(EXIT_FAILURE);
-	}
-	
-	// Bind the position semantic - this is defined in the vertex shader above.
-	mShader->bindAttributeLocation("position", 0);
-
-	// Bind the other semantics. Note that these don't actually exist in our example shader above! However, other
-	// example shaders may choose to provide them and having the binding code here does not seem to cause any problems.
-	mShader->bindAttributeLocation("normal", 1);
-	mShader->bindAttributeLocation("material", 2);
-	
-	if (!mShader->link())
-	{
-		std::cerr << mShader->log().toStdString() << std::endl;
-		exit(EXIT_FAILURE);
-	}
-
 	initialize();
 
 	// Start a timer to drive the main rendering loop.
@@ -190,21 +153,6 @@ void OpenGLWidget::paintGL()
 	{
 		mCameraPosition -= cameraRight * deltaTime * mCameraMoveSpeed;
 	}
-	// Move backward
-	/*if ((glfwGetKey(mWindow, GLFW_KEY_DOWN) == GLFW_PRESS) || (glfwGetKey(mWindow, GLFW_KEY_S) == GLFW_PRESS))
-	{
-		mCameraPosition -= cameraForward * deltaTime * mCameraMoveSpeed;
-	}
-	// Strafe right
-	if ((glfwGetKey(mWindow, GLFW_KEY_RIGHT) == GLFW_PRESS) || (glfwGetKey(mWindow, GLFW_KEY_D) == GLFW_PRESS))
-	{
-		mCameraPosition += cameraRight * deltaTime * mCameraMoveSpeed;
-	}
-	// Strafe left
-	if ((glfwGetKey(mWindow, GLFW_KEY_LEFT) == GLFW_PRESS) || (glfwGetKey(mWindow, GLFW_KEY_A) == GLFW_PRESS))
-	{
-		mCameraPosition -= cameraRight * deltaTime * mCameraMoveSpeed;
-	}*/
 
 	worldToCameraMatrix.setToIdentity();
 	worldToCameraMatrix.lookAt(
@@ -216,32 +164,7 @@ void OpenGLWidget::paintGL()
 	//Clear the screen
 	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
 
-	// Our example framework only uses a single shader for the scene (for all meshes).
+	renderOneFrame();
-	mShader->bind();
-
-	// These two matrices are constant for all meshes.
-	mShader->setUniformValue("worldToCameraMatrix", worldToCameraMatrix);
-	mShader->setUniformValue("cameraToClipMatrix", cameraToClipMatrix);
-
-	// Iterate over each mesh which the user added to our list, and render it.
-	for (OpenGLMeshData meshData : mMeshData)
-	{
-		//Set up the model matrrix based on provided translation and scale.
-		QMatrix4x4 modelToWorldMatrix;
-		modelToWorldMatrix.translate(meshData.translation); 
-		modelToWorldMatrix.scale(meshData.scale);
-		mShader->setUniformValue("modelToWorldMatrix", modelToWorldMatrix);
-
-		// Bind the vertex array for the current mesh
-		glBindVertexArray(meshData.vertexArrayObject);
-		// Draw the mesh
-		glDrawElements(GL_TRIANGLES, meshData.noOfIndices, meshData.indexType, 0);
-		// Unbind the vertex array.
-		glBindVertexArray(0);
-	}
-	
-	 // We're done with the shader for this frame.
-	mShader->release();
 	
 	// Check for errors.
 	GLenum errCode = glGetError();

examples/common/OpenGLWidget.h

@@ -34,19 +34,6 @@ distribution.
 #include <QOpenGLVertexArrayObject>
 #include <QOpenGLBuffer>
 
-// This structure holds all the data required
-// to render one of our meshes through OpenGL. 
-struct OpenGLMeshData
-{
-	GLuint noOfIndices;
-	GLenum indexType;
-	GLuint indexBuffer;
-	GLuint vertexBuffer;
-	GLuint vertexArrayObject;
-	QVector3D translation;
-	float scale;
-};
-
 // Our OpenGLWidget is used by all the examples to render the extracted meshes. It is
 // fairly specific to our needs (you probably won't want to use it in your own project)
 // but should provide a useful illustration of how PolyVox meshes can be rendered.
@@ -56,73 +43,6 @@ public:
 	// Constructor
 	OpenGLWidget(QWidget *parent);
 
-	// Convert a PolyVox mesh to OpenGL index/vertex buffers. Inlined because it's templatised.
-	template <typename MeshType>
-	void addMesh(const MeshType& surfaceMesh, const PolyVox::Vector3DInt32& translation = PolyVox::Vector3DInt32(0, 0, 0), float scale = 1.0f)
-	{
-		// 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(typename MeshType::VertexType), 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(typename MeshType::IndexType), vecIndices.data(), GL_STATIC_DRAW);
-
-		// Every surface extractor outputs valid positions for the vertices, so tell OpenGL how these are laid out
-		glEnableVertexAttribArray(0); // Attrib '0' is the vertex positions
-		glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, sizeof(typename MeshType::VertexType), (GLvoid*)(offsetof(typename MeshType::VertexType, position))); //take the first 3 floats from every sizeof(decltype(vecVertices)::value_type)
-
-		// Some surface extractors also generate normals, so tell OpenGL how these are laid out. If a surface extractor
-		// does not generate normals then nonsense values are written into the buffer here and sghould be ignored by the
-		// shader. This is mostly just to simplify this example code - in a real application you will know whether your
-		// chosen surface extractor generates normals and can skip uploading them if not.
-		glEnableVertexAttribArray(1); // Attrib '1' is the vertex normals.
-		glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, sizeof(typename MeshType::VertexType), (GLvoid*)(offsetof(typename MeshType::VertexType, normal)));
-
-		// Finally a surface extractor will probably output additional data. This is highly application dependant. For this example code 
-		// we're just uploading it as a set of bytes which we can read individually, but real code will want to do something specialised here.
-		glEnableVertexAttribArray(2); //We're talking about shader attribute '2'
-		GLint size = (std::min)(sizeof(typename MeshType::VertexType::DataType), size_t(4)); // Can't upload more that 4 components (vec4 is GLSL's biggest type)
-		glVertexAttribIPointer(2, size, GL_UNSIGNED_BYTE, sizeof(typename MeshType::VertexType), (GLvoid*)(offsetof(typename MeshType::VertexType, data)));
-
-		// We're done uploading and can now unbind.
-		glBindVertexArray(0);
-
-		// A few additional properties can be copied across for use during rendering.
-		meshData.noOfIndices = vecIndices.size();
-		meshData.translation = QVector3D(translation.getX(), translation.getY(), translation.getZ());
-		meshData.scale = scale;
-
-		// Set 16 or 32-bit index buffer size.
-		meshData.indexType = sizeof(typename MeshType::IndexType) == 2 ? GL_UNSIGNED_SHORT : GL_UNSIGNED_INT;
-
-		// Now add the mesh to the list of meshes to render.
-		addMeshData(meshData);
-	}
-
-	void addMeshData(OpenGLMeshData meshData)
-	{
-		mMeshData.push_back(meshData);
-	}
-
-	// For our purposes we use a single shader for the whole volume, and
-	// this example framework is only meant to show a single volume at a time
-	void setShader(QSharedPointer<QGLShaderProgram> shader);
-
 	void setCameraTransform(QVector3D position, float pitch, float yaw);
 
 	// Mouse handling
@@ -135,22 +55,15 @@ public:
 
 protected:
 
-	const float PI = 3.14159265358979f;
-
 	// Qt OpenGL functions
 	void initializeGL();
 	void resizeGL(int w, int h);
 	void paintGL();
 
-	virtual void initialize()
+	virtual void initialize() {}
-	{
+	virtual void renderOneFrame() {}
-	}
 
-private:
+protected:
-	// Index/vertex buffer data
-	std::vector<OpenGLMeshData> mMeshData;
-	
-	QSharedPointer<QGLShaderProgram> mShader;
 
 	// Matrices
 	QMatrix4x4 worldToCameraMatrix;

examples/common/PolyVoxExample.cpp

@@ -1 +1,6 @@
 #include "PolyVoxExample.h"
+
+void PolyVoxExample::setShader(QSharedPointer<QGLShaderProgram> shader)
+{
+	mShader = shader;
+}

examples/common/PolyVoxExample.h

@@ -26,6 +26,19 @@ distribution.
 
 #include "OpenGLWidget.h"
 
+// This structure holds all the data required
+// to render one of our meshes through OpenGL. 
+struct OpenGLMeshData
+{
+	GLuint noOfIndices;
+	GLenum indexType;
+	GLuint indexBuffer;
+	GLuint vertexBuffer;
+	GLuint vertexArrayObject;
+	QVector3D translation;
+	float scale;
+};
+
 class PolyVoxExample : public OpenGLWidget
 {
 public:
@@ -33,6 +46,152 @@ public:
 		:OpenGLWidget(parent)
 	{
 	}
+
+	// For our purposes we use a single shader for the whole volume, and
+	// this example framework is only meant to show a single volume at a time
+	void setShader(QSharedPointer<QGLShaderProgram> shader);
+
+	// Convert a PolyVox mesh to OpenGL index/vertex buffers. Inlined because it's templatised.
+	template <typename MeshType>
+	void addMesh(const MeshType& surfaceMesh, const PolyVox::Vector3DInt32& translation = PolyVox::Vector3DInt32(0, 0, 0), float scale = 1.0f)
+	{
+		// 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(typename MeshType::VertexType), 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(typename MeshType::IndexType), vecIndices.data(), GL_STATIC_DRAW);
+
+		// Every surface extractor outputs valid positions for the vertices, so tell OpenGL how these are laid out
+		glEnableVertexAttribArray(0); // Attrib '0' is the vertex positions
+		glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, sizeof(typename MeshType::VertexType), (GLvoid*)(offsetof(typename MeshType::VertexType, position))); //take the first 3 floats from every sizeof(decltype(vecVertices)::value_type)
+
+		// Some surface extractors also generate normals, so tell OpenGL how these are laid out. If a surface extractor
+		// does not generate normals then nonsense values are written into the buffer here and sghould be ignored by the
+		// shader. This is mostly just to simplify this example code - in a real application you will know whether your
+		// chosen surface extractor generates normals and can skip uploading them if not.
+		glEnableVertexAttribArray(1); // Attrib '1' is the vertex normals.
+		glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, sizeof(typename MeshType::VertexType), (GLvoid*)(offsetof(typename MeshType::VertexType, normal)));
+
+		// Finally a surface extractor will probably output additional data. This is highly application dependant. For this example code 
+		// we're just uploading it as a set of bytes which we can read individually, but real code will want to do something specialised here.
+		glEnableVertexAttribArray(2); //We're talking about shader attribute '2'
+		GLint size = (std::min)(sizeof(typename MeshType::VertexType::DataType), size_t(4)); // Can't upload more that 4 components (vec4 is GLSL's biggest type)
+		glVertexAttribIPointer(2, size, GL_UNSIGNED_BYTE, sizeof(typename MeshType::VertexType), (GLvoid*)(offsetof(typename MeshType::VertexType, data)));
+
+		// We're done uploading and can now unbind.
+		glBindVertexArray(0);
+
+		// A few additional properties can be copied across for use during rendering.
+		meshData.noOfIndices = vecIndices.size();
+		meshData.translation = QVector3D(translation.getX(), translation.getY(), translation.getZ());
+		meshData.scale = scale;
+
+		// Set 16 or 32-bit index buffer size.
+		meshData.indexType = sizeof(typename MeshType::IndexType) == 2 ? GL_UNSIGNED_SHORT : GL_UNSIGNED_INT;
+
+		// Now add the mesh to the list of meshes to render.
+		addMeshData(meshData);
+	}
+
+	void addMeshData(OpenGLMeshData meshData)
+	{
+		mMeshData.push_back(meshData);
+	}
+
+protected:
+	const float PI = 3.14159265358979f;
+
+	virtual void initializeExample() {};
+
+	void initialize() override
+	{
+		mShader = QSharedPointer<QGLShaderProgram>(new QGLShaderProgram);
+
+		// This is basically a simple fallback vertex shader which does the most basic rendering possible.  
+		// PolyVox examples are able to provide their own shaders to demonstrate certain effects if desired. 
+		if (!mShader->addShaderFromSourceFile(QGLShader::Vertex, ":/example.vert"))
+		{
+			std::cerr << mShader->log().toStdString() << std::endl;
+			exit(EXIT_FAILURE);
+		}
+
+		// This is basically a simple fallback fragment shader which does the most basic rendering possible.  
+		// PolyVox examples are able to provide their own shaders to demonstrate certain effects if desired. 
+		if (!mShader->addShaderFromSourceFile(QGLShader::Fragment, ":/example.frag"))
+		{
+			std::cerr << mShader->log().toStdString() << std::endl;
+			exit(EXIT_FAILURE);
+		}
+
+		// Bind the position semantic - this is defined in the vertex shader above.
+		mShader->bindAttributeLocation("position", 0);
+
+		// Bind the other semantics. Note that these don't actually exist in our example shader above! However, other
+		// example shaders may choose to provide them and having the binding code here does not seem to cause any problems.
+		mShader->bindAttributeLocation("normal", 1);
+		mShader->bindAttributeLocation("material", 2);
+
+		if (!mShader->link())
+		{
+			std::cerr << mShader->log().toStdString() << std::endl;
+			exit(EXIT_FAILURE);
+		}
+
+		// Now do any initialization for the specific example.
+		initializeExample();
+	}
+
+	void renderOneFrame() override
+	{
+		// Our example framework only uses a single shader for the scene (for all meshes).
+		mShader->bind();
+
+		// These two matrices are constant for all meshes.
+		mShader->setUniformValue("worldToCameraMatrix", worldToCameraMatrix);
+		mShader->setUniformValue("cameraToClipMatrix", cameraToClipMatrix);
+
+		// Iterate over each mesh which the user added to our list, and render it.
+		for (OpenGLMeshData meshData : mMeshData)
+		{
+			//Set up the model matrrix based on provided translation and scale.
+			QMatrix4x4 modelToWorldMatrix;
+			modelToWorldMatrix.translate(meshData.translation);
+			modelToWorldMatrix.scale(meshData.scale);
+			mShader->setUniformValue("modelToWorldMatrix", modelToWorldMatrix);
+
+			// Bind the vertex array for the current mesh
+			glBindVertexArray(meshData.vertexArrayObject);
+			// Draw the mesh
+			glDrawElements(GL_TRIANGLES, meshData.noOfIndices, meshData.indexType, 0);
+			// Unbind the vertex array.
+			glBindVertexArray(0);
+		}
+
+		// We're done with the shader for this frame.
+		mShader->release();
+	}
+
+private:
+	// Index/vertex buffer data
+	std::vector<OpenGLMeshData> mMeshData;
+
+	QSharedPointer<QGLShaderProgram> mShader;
 };
 
 #endif //__PolyVoxExample_H__