polyvox/examples/OpenGL/main.cpp

/*******************************************************************************
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. 	
*******************************************************************************/

#include "PolyVox/FilePager.h"
#include "PolyVox/MarchingCubesSurfaceExtractor.h"
#include "PolyVox/MaterialDensityPair.h"
#include "PolyVox/LowPassFilter.h"
#include "PolyVox/RawVolume.h"
#include "PolyVox/Mesh.h"
#include "PolyVox/Impl/Utility.h"

#include "Shapes.h"

#include "OpenGLWidget.h"

#ifdef WIN32
#include <windows.h>   // Standard Header For Most Programs
#endif

#include <QApplication>
#include <QTime>

//Some namespaces we need
using namespace std;
using namespace PolyVox;
using namespace std;

const int32_t g_uVolumeSideLength = 128;

class OpenGLExample : public OpenGLWidget
{
public:
	OpenGLExample(QWidget *parent)
		:OpenGLWidget(parent)
	{
	}

protected:
	void initialize() 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);

		//Make our volume contain a sphere in the center.
		int32_t minPos = 0;
		int32_t midPos = g_uVolumeSideLength / 2;
		int32_t maxPos = g_uVolumeSideLength - 1;

		cout << "Creating sphere 1" << std::endl;
		createSphereInVolume(volData, 60.0f, 5);
		cout << "Creating sphere 2" << std::endl;
		createSphereInVolume(volData, 50.0f, 4);
		cout << "Creating sphere 3" << std::endl;
		createSphereInVolume(volData, 40.0f, 3);
		cout << "Creating sphere 4" << std::endl;
		createSphereInVolume(volData, 30.0f, 2);
		cout << "Creating sphere 5" << std::endl;
		createSphereInVolume(volData, 20.0f, 1);

		cout << "Creating cubes" << std::endl;
		createCubeInVolume(volData, Vector3DInt32(minPos, minPos, midPos + 1), Vector3DInt32(midPos - 1, midPos - 1, maxPos), 0);
		createCubeInVolume(volData, Vector3DInt32(midPos + 1, midPos + 1, midPos + 1), Vector3DInt32(maxPos, maxPos, maxPos), 0);
		createCubeInVolume(volData, Vector3DInt32(minPos, midPos + 1, minPos), Vector3DInt32(midPos - 1, maxPos, midPos - 1), 0);
		createCubeInVolume(volData, Vector3DInt32(midPos + 1, minPos, minPos), Vector3DInt32(maxPos, midPos - 1, midPos - 1), 0);

		createCubeInVolume(volData, Vector3DInt32(1, midPos - 10, midPos - 10), Vector3DInt32(maxPos - 1, midPos + 10, midPos + 10), MaterialDensityPair44::getMaxDensity());
		createCubeInVolume(volData, Vector3DInt32(midPos - 10, 1, midPos - 10), Vector3DInt32(midPos + 10, maxPos - 1, midPos + 10), MaterialDensityPair44::getMaxDensity());
		createCubeInVolume(volData, Vector3DInt32(midPos - 10, midPos - 10, 1), Vector3DInt32(midPos + 10, midPos + 10, maxPos - 1), MaterialDensityPair44::getMaxDensity());

		QSharedPointer<QGLShaderProgram> shader(new QGLShaderProgram);

		if (!shader->addShaderFromSourceFile(QGLShader::Vertex, ":/openglexample.vert"))
		{
			std::cerr << shader->log().toStdString() << std::endl;
			exit(EXIT_FAILURE);
		}

		if (!shader->addShaderFromSourceFile(QGLShader::Fragment, ":/openglexample.frag"))
		{
			std::cerr << shader->log().toStdString() << std::endl;
			exit(EXIT_FAILURE);
		}

		setShader(shader);

		QTime time;
		time.start();
		//openGLWidget.setVolume(&volData);
		cout << endl << "Time taken = " << time.elapsed() / 1000.0f << "s" << endl << endl;

		const int32_t extractedRegionSize = 32;
		int meshCounter = 0;

		for (int32_t z = 0; z < volData.getDepth(); z += extractedRegionSize)
		{
			for (int32_t y = 0; y < volData.getHeight(); y += extractedRegionSize)
			{
				for (int32_t x = 0; x < volData.getWidth(); x += extractedRegionSize)
				{
					// Specify the region to extract based on a starting position and the desired region sze.
					PolyVox::Region regToExtract(x, y, z, x + extractedRegionSize, y + extractedRegionSize, z + extractedRegionSize);

					// If you uncomment this line you will be able to see that the volume is rendered as multiple seperate meshes.
					//regToExtract.shrink(1);

					// Perform the extraction for this region of the volume
					auto mesh = extractMarchingCubesMesh(&volData, regToExtract);

					// The returned mesh needs to be decoded to be appropriate for GPU rendering.
					auto decodedMesh = decodeMesh(mesh);

					// Pass the surface to the OpenGL window. Note that we are also passing an offset in this multi-mesh example. This is because
					// the surface extractors return a mesh with 'local space' positions to reduce storage requirements and precision problems.
					addMesh(decodedMesh, decodedMesh.getOffset());

					meshCounter++;
				}
			}
		}

		cout << "Rendering volume as " << meshCounter << " seperate meshes" << endl;

		setCameraTransform(QVector3D(150.0f, 150.0f, 150.0f), -(PI / 4.0f), PI + (PI / 4.0f));
	}
};

int main(int argc, char *argv[])
{
	//Create and show the Qt OpenGL window
	QApplication app(argc, argv);
	OpenGLExample openGLWidget(0);
	openGLWidget.show();

	//Run the message pump.
	return app.exec();
}