capsulegenerator.cpp

// © Copyright 2010 - 2016 BlackTopp Studios Inc.
/* This file is part of The Mezzanine Engine.

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/*
 -----------------------------------------------------------------------------
 This source file is part of ogre-procedural

 For the latest info, see http://code.google.com/p/ogre-procedural/

 Copyright (c) 2010-2013 Michael Broutin

 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal
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 */
#ifndef _graphicsproceduralcapsulegenerator_cpp
#define _graphicsproceduralcapsulegenerator_cpp

#include "Graphics/Procedural/Mesh/capsulegenerator.h"

#include "MathTools/mathtools.h"
#include "exception.h"

namespace Mezzanine
{
    namespace Graphics
    {
        namespace Procedural
        {
            CapsuleGenerator::CapsuleGenerator(const Real Radius, const Real Height, const Whole Rings, const Whole SegCircle, const Whole SegHeight) :
                CapsuleRadius(Radius),
                CapsuleHeight(Height),
                NumRings(Rings),
                NumSegCircle(SegCircle),
                NumSegHeight(SegHeight)
                {  }

            CapsuleGenerator::~CapsuleGenerator()
                {  }

            ///////////////////////////////////////////////////////////////////////////////
            // Utility

            void CapsuleGenerator::AddToTriangleBuffer(TriangleBuffer& Buffer) const
            {
                Buffer.RebaseOffset();
                Buffer.EstimateVertexCount( ( 2 * this->NumRings + 2 ) * ( this->NumSegCircle + 1 ) + ( this->NumSegHeight - 1 ) * ( this->NumSegCircle + 1 ) );
                Buffer.EstimateIndexCount( ( 2 * this->NumRings + 1 ) * ( this->NumSegCircle + 1 ) * 6 + ( this->NumSegHeight - 1 ) * ( this->NumSegCircle + 1 ) * 6 );

                Real fDeltaRingAngle = ( MathTools::GetHalfPi() / this->NumRings );
                Real fDeltaSegAngle = ( MathTools::GetTwoPi() / this->NumSegCircle );

                Real sphereRatio = this->CapsuleRadius / ( 2 * this->CapsuleRadius + this->CapsuleHeight );
                Real cylinderRatio = this->CapsuleHeight / ( 2 * this->CapsuleRadius + this->CapsuleHeight );
                Integer Offset = 0;

                // Top half sphere
                // Generate the group of rings for the sphere
                for( Whole ring = 0 ; ring <= this->NumRings ; ring++ )
                {
                    Real r0 = this->CapsuleRadius * sinf( ring * fDeltaRingAngle );
                    Real y0 = this->CapsuleRadius * cosf( ring * fDeltaRingAngle );

                    // Generate the group of segments for the current ring
                    for( Whole seg = 0; seg <= this->NumSegCircle; seg++ )
                    {
                        Real x0 = r0 * cosf( seg * fDeltaSegAngle );
                        Real z0 = r0 * sinf( seg * fDeltaSegAngle );

                        // Add one vertex to the strip which makes up the sphere
                        this->AddPoint(Buffer, Vector3( x0, 0.5 * this->CapsuleHeight + y0, z0 ),
                                       Vector3( x0, y0, z0 ).GetNormal(),
                                       Vector2( (Real)seg / (Real)this->NumSegCircle, (Real)ring / (Real)this->NumRings * sphereRatio) );

                        // each vertex (except the last) has six indices pointing to it
                        Buffer.AddIndex( Offset + this->NumSegCircle + 1 );
                        Buffer.AddIndex( Offset + this->NumSegCircle );
                        Buffer.AddIndex( Offset );
                        Buffer.AddIndex( Offset + this->NumSegCircle + 1 );
                        Buffer.AddIndex( Offset );
                        Buffer.AddIndex( Offset + 1 );

                        Offset++;
                    }//for each segment
                }//for each ring

                // Cylinder part
                Real deltaAngle = ( MathTools::GetTwoPi() / this->NumSegCircle );
                Real deltaHeight = this->CapsuleHeight / (Real)this->NumSegHeight;

                for( Whole i = 1 ; i < this->NumSegHeight ; i++ )
                {
                    for( Whole j = 0 ; j <= this->NumSegCircle ; j++ )
                    {
                        Real x0 = this->CapsuleRadius * cosf( j * deltaAngle );
                        Real z0 = this->CapsuleRadius * sinf( j * deltaAngle );

                        this->AddPoint(Buffer, Vector3( x0, 0.5 * this->CapsuleHeight - i * deltaHeight, z0 ),
                                       Vector3( x0, 0, z0 ).GetNormal(),
                                       Vector2( j / (Real)this->NumSegCircle, i / (Real)this->NumSegHeight * cylinderRatio + sphereRatio));

                        Buffer.AddIndex( Offset + this->NumSegCircle + 1 );
                        Buffer.AddIndex( Offset + this->NumSegCircle );
                        Buffer.AddIndex( Offset );
                        Buffer.AddIndex( Offset + this->NumSegCircle + 1 );
                        Buffer.AddIndex( Offset );
                        Buffer.AddIndex( Offset + 1 );

                        Offset++;
                    }
                }

                // Bottom half sphere
                // Generate the group of rings for the sphere
                for( Whole ring = 0 ; ring <= this->NumRings ; ring++ )
                {
                    Real r0 = this->CapsuleRadius * sinf( MathTools::GetHalfPi() + ring * fDeltaRingAngle );
                    Real y0 = this->CapsuleRadius * cosf( MathTools::GetHalfPi() + ring * fDeltaRingAngle );

                    // Generate the group of segments for the current ring
                    for( Whole seg = 0 ; seg <= this->NumSegCircle ; seg++ )
                    {
                        Real x0 = r0 * cosf( seg * fDeltaSegAngle );
                        Real z0 = r0 * sinf( seg * fDeltaSegAngle );

                        // Add one vertex to the strip which makes up the sphere
                        this->AddPoint(Buffer, Vector3( x0, -0.5 * this->CapsuleHeight + y0, z0 ),
                                       Vector3( x0, y0, z0 ).GetNormal(),
                                       Vector2( (Real)seg / (Real)this->NumSegCircle, (Real)ring / (Real)this->NumRings * sphereRatio + cylinderRatio + sphereRatio) );

                        if( ring != this->NumRings ) {
                            // each vertex (except the last) has six indices pointing to it
                            Buffer.AddIndex( Offset + this->NumSegCircle + 1 );
                            Buffer.AddIndex( Offset + this->NumSegCircle );
                            Buffer.AddIndex( Offset );
                            Buffer.AddIndex( Offset + this->NumSegCircle + 1 );
                            Buffer.AddIndex( Offset );
                            Buffer.AddIndex( Offset + 1 );
                        }
                        Offset++;
                    }//for each segment
                }//for each ring
            }

            ///////////////////////////////////////////////////////////////////////////////
            // Configuration

            CapsuleGenerator& CapsuleGenerator::SetRadius(const Real Radius)
            {
                if( Radius <= 0.0 )
                    MEZZ_EXCEPTION(ExceptionBase::PARAMETERS_EXCEPTION,"Radius for a generated capsule mesh must be greater than zero.");

                this->CapsuleRadius = Radius;
                return *this;
            }

            CapsuleGenerator& CapsuleGenerator::SetHeight(const Real Height)
            {
                if( Height <= 0.0 )
                    MEZZ_EXCEPTION(ExceptionBase::PARAMETERS_EXCEPTION,"Height for a generated capsule mesh must be greater than zero.");
                this->CapsuleHeight = Height;
                return *this;
            }

            CapsuleGenerator& CapsuleGenerator::SetNumRings(const Whole Rings)
            {
                if( Rings == 0 )
                    MEZZ_EXCEPTION(ExceptionBase::PARAMETERS_EXCEPTION,"Number of rings for generated capsule mesh must be greater than zero.");

                this->NumRings = Rings;
                return *this;
            }

            CapsuleGenerator& CapsuleGenerator::SetNumSegCircle(const Whole SegCircle)
            {
                if( SegCircle == 0 )
                    MEZZ_EXCEPTION(ExceptionBase::PARAMETERS_EXCEPTION,"Number of segments for generated capsule mesh must be greater than zero.");

                this->NumSegCircle = SegCircle;
                return *this;
            }

            CapsuleGenerator& CapsuleGenerator::SetNumSegHeight(const Whole SegHeight)
            {
                if( SegHeight == 0 )
                    MEZZ_EXCEPTION(ExceptionBase::PARAMETERS_EXCEPTION,"Number of segments for generated capsule mesh must be greater than zero.");

                this->NumSegHeight = SegHeight;
                return *this;
            }
        }//Procedural
    }//Graphics
}//Mezzanine

#endif