Magic Cube

///////////////////////////////////////////////////////////////////////////////////////////////////

// Copyright 2020 Leszek Koltunski                                                               //

//                                                                                               //

// This file is part of Magic Cube.                                                              //

//                                                                                               //

// Magic Cube is free software: you can redistribute it and/or modify                            //

// it under the terms of the GNU General Public License as published by                          //

// the Free Software Foundation, either version 2 of the License, or                             //

// (at your option) any later version.                                                           //

//                                                                                               //

// Magic Cube is distributed in the hope that it will be useful,                                 //

// but WITHOUT ANY WARRANTY; without even the implied warranty of                                //

// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the                                 //

// GNU General Public License for more details.                                                  //

//                                                                                               //

// You should have received a copy of the GNU General Public License                             //

// along with Magic Cube.  If not, see <http://www.gnu.org/licenses/>.                           //

///////////////////////////////////////////////////////////////////////////////////////////////////

package org.distorted.helpers;

import org.distorted.library.effect.MatrixEffectMove;

import org.distorted.library.effect.MatrixEffectQuaternion;

import org.distorted.library.effect.MatrixEffectScale;

import org.distorted.library.effect.VertexEffect;

import org.distorted.library.effect.VertexEffectDeform;

import org.distorted.library.mesh.MeshBase;

import org.distorted.library.mesh.MeshJoined;

import org.distorted.library.mesh.MeshPolygon;

import org.distorted.library.type.Static1D;

import org.distorted.library.type.Static3D;

import org.distorted.library.type.Static4D;

import java.util.ArrayList;

///////////////////////////////////////////////////////////////////////////////////////////////////

public class FactoryCubit

  {

  private static final Static1D RADIUS = new Static1D(1);

  private static FactoryCubit mThis;

  private static final double[] mBuffer = new double[3];

  private static final double[] mQuat1  = new double[4];

  private static final double[] mQuat2  = new double[4];

  private static final double[] mQuat3  = new double[4];

  private static final double[] mQuat4  = new double[4];

  private static class StickerCoords

    {

    double[] vertices;

    }

  private static class FaceTransform

    {

    int sticker;

    double vx,vy,vz;

    double scale;

    double qx,qy,qz,qw;

    boolean flip;

    }

  private static final ArrayList<FaceTransform> mNewFaceTransf = new ArrayList<>();

  private static final ArrayList<FaceTransform> mOldFaceTransf = new ArrayList<>();

  private static final ArrayList<StickerCoords> mStickerCoords = new ArrayList<>();

///////////////////////////////////////////////////////////////////////////////////////////////////

  private FactoryCubit()

    {

    }

///////////////////////////////////////////////////////////////////////////////////////////////////

  public static FactoryCubit getInstance()

    {

    if( mThis==null ) mThis = new FactoryCubit();

    return mThis;

    }

///////////////////////////////////////////////////////////////////////////////////////////////////

// H - height of the band in the middle

// alpha - angle of the edge  [0,90]

// dist - often in a polygon the distance from edge to center is not 1, but something else.

// This is the distance.

// K - where to begin the second, much more flat part of the band. [0,1]

// N - number of bands. N>=3

//

// theory: two distinct parts to the band:

// 1) (0,B) - steep

// 2) (B,1) - flat

//

// In first part, we have y = g(x) ; in second - y = g(f(x)) where

//

// g(x) = sqrt( R^2 - (x-D)^2 ) - R*cos(alpha)

// f(x) = ((D-B)/(1-B)*x + B*(1-D)/(1-B)

// h(x) = R*(sin(alpha) - sin(x))

// R = H/(1-cos(alpha))

// D = H*sin(alpha)

// B = h(K*alpha)

//

// The N points are taken at:

//

// 1) in the second part, there are K2 = (N-3)/3 such points

// 2) in the first - K1 = (N-3) - K2

// 3) also, the 3 points 0,B,1

//

// so we have the sequence A[i] of N points

//

// 0

// h((i+1)*(1-K)*alpha/(K1+1)) (i=0,1,...,K1-1)

// B

// (1-B)*(i+1)/(K2+1) + B   (i=0,i,...,K2-1)

// 1

///////////////////////////////////////////////////////////////////////////////////////////////////

  private float f(float D, float B, float x)

    {

    return ((D-B)*x + B*(1-D))/(1-B);

    }

///////////////////////////////////////////////////////////////////////////////////////////////////

  private float g(float R, float D, float x, float cosAlpha)

    {

    float d = x-D;

    return (float)(Math.sqrt(R*R-d*d)-R*cosAlpha);

    }

///////////////////////////////////////////////////////////////////////////////////////////////////

  private float h(float R, float sinAlpha, float x)

    {

    return R*(sinAlpha-(float)Math.sin(x));

    }

///////////////////////////////////////////////////////////////////////////////////////////////////

  private boolean areColinear(double[][] vertices, int index1, int index2, int index3)

    {

    double x1 = vertices[index1][0];

    double y1 = vertices[index1][1];

    double z1 = vertices[index1][2];

    double x2 = vertices[index2][0];

    double y2 = vertices[index2][1];

    double z2 = vertices[index2][2];

    double x3 = vertices[index3][0];

    double y3 = vertices[index3][1];

    double z3 = vertices[index3][2];

    double v1x = x2-x1;

    double v1y = y2-y1;

    double v1z = z2-z1;

    double v2x = x3-x1;

    double v2y = y3-y1;

    double v2z = z3-z1;

    double A = Math.sqrt( (v1x*v1x+v1y*v1y+v1z*v1z) / (v2x*v2x+v2y*v2y+v2z*v2z) );

    return (v1x==A*v2x && v1y==A*v2y && v1z==A*v2z);

    }

///////////////////////////////////////////////////////////////////////////////////////////////////

  private void computeNormalVector(double[][] vertices, int index1, int index2, int index3)

    {

    double x1 = vertices[index1][0];

    double y1 = vertices[index1][1];

    double z1 = vertices[index1][2];

    double x2 = vertices[index2][0];

    double y2 = vertices[index2][1];

    double z2 = vertices[index2][2];

    double x3 = vertices[index3][0];

    double y3 = vertices[index3][1];

    double z3 = vertices[index3][2];

    double v1x = x2-x1;

    double v1y = y2-y1;

    double v1z = z2-z1;

    double v2x = x3-x1;

    double v2y = y3-y1;

    double v2z = z3-z1;

    mBuffer[0] = v1y*v2z - v2y*v1z;

    mBuffer[1] = v1z*v2x - v2z*v1x;

    mBuffer[2] = v1x*v2y - v2x*v1y;

    double len = mBuffer[0]*mBuffer[0] + mBuffer[1]*mBuffer[1] + mBuffer[2]*mBuffer[2];

    len = Math.sqrt(len);

    mBuffer[0] /= len;

    mBuffer[1] /= len;

    mBuffer[2] /= len;

    }

///////////////////////////////////////////////////////////////////////////////////////////////////

// return quat1*quat2

  private static void quatMultiply( double[] quat1, double[] quat2, double[] result )

    {

    double qx = quat1[0];

    double qy = quat1[1];

    double qz = quat1[2];

    double qw = quat1[3];

    double rx = quat2[0];

    double ry = quat2[1];

    double rz = quat2[2];

    double rw = quat2[3];

    result[0] = rw*qx - rz*qy + ry*qz + rx*qw;

    result[1] = rw*qy + rz*qx + ry*qw - rx*qz;

    result[2] = rw*qz + rz*qw - ry*qx + rx*qy;

    result[3] = rw*qw - rz*qz - ry*qy - rx*qx;

    }

///////////////////////////////////////////////////////////////////////////////////////////////////

  private void fitInSquare(FaceTransform info, double[][] vert3D)

    {

    double minX = Double.MAX_VALUE;

    double maxX =-Double.MAX_VALUE;

    double minY = Double.MAX_VALUE;

    double maxY =-Double.MAX_VALUE;

    for (double[] vert : vert3D)

      {

      double x = vert[0];

      double y = vert[1];

      if (x > maxX) maxX = x;

      if (x < minX) minX = x;

      if (y > maxY) maxY = y;

      if (y < minY) minY = y;

      }

    minX = minX<0 ? -minX:minX;

    maxX = maxX<0 ? -maxX:maxX;

    minY = minY<0 ? -minY:minY;

    maxY = maxY<0 ? -maxY:maxY;

    double max1 = Math.max(minX,minY);

    double max2 = Math.max(maxX,maxY);

    double max3 = Math.max(max1,max2);

    info.scale = max3/0.5;

    int len = vert3D.length;

    StickerCoords sInfo = new StickerCoords();

    sInfo.vertices = new double[2*len];

    for( int vertex=0; vertex<len; vertex++ )

      {

      sInfo.vertices[2*vertex  ] = vert3D[vertex][0] / info.scale;

      sInfo.vertices[2*vertex+1] = vert3D[vertex][1] / info.scale;

      }

    mStickerCoords.add(sInfo);

    info.sticker = mStickerCoords.size() -1;

    info.flip = false;

    }

///////////////////////////////////////////////////////////////////////////////////////////////////

  private FaceTransform constructNewTransform(final double[][] vert3D)

    {

    FaceTransform ft = new FaceTransform();

    // compute center of gravity

    ft.vx = 0.0f;

    ft.vy = 0.0f;

    ft.vz = 0.0f;

    int len = vert3D.length;

    for (double[] vert : vert3D)

      {

      ft.vx += vert[0];

      ft.vy += vert[1];

      ft.vz += vert[2];

      }

    ft.vx /= len;

    ft.vy /= len;

    ft.vz /= len;

    // move all vertices so that their center of gravity is at (0,0,0)

    for (int i=0; i<len; i++)

      {

      vert3D[i][0] -= ft.vx;

      vert3D[i][1] -= ft.vy;

      vert3D[i][2] -= ft.vz;

      }

    // find 3 non-colinear vertices

    int foundIndex = -1;

    for(int vertex=2; vertex<len; vertex++)

      {

      if( !areColinear(vert3D,0,1,vertex) )

        {

        foundIndex = vertex;

        break;

        }

      }

    // compute the normal vector

    if( foundIndex==-1 )

      {

      throw new RuntimeException("all vertices colinear");

      }

    computeNormalVector(vert3D,0,1,foundIndex);

    // rotate so that the normal vector becomes (0,0,1)

    double axisX, axisY, axisZ;

    if( mBuffer[0]!=0.0f || mBuffer[1]!=0.0f )

      {

      axisX = -mBuffer[1];

      axisY =  mBuffer[0];

      axisZ = 0.0f;

      double axiLen = axisX*axisX + axisY*axisY;

      axiLen = Math.sqrt(axiLen);

      axisX /= axiLen;

      axisY /= axiLen;

      axisZ /= axiLen;

      }

    else

      {

      axisX = 0.0f;

      axisY = 1.0f;

      axisZ = 0.0f;

      }

    double cosTheta = mBuffer[2];

    double sinTheta = Math.sqrt(1-cosTheta*cosTheta);

    double sinHalfTheta = computeSinHalf(cosTheta);

    double cosHalfTheta = computeCosHalf(sinTheta,cosTheta);

    mQuat1[0] = axisX*sinHalfTheta;

    mQuat1[1] = axisY*sinHalfTheta;

    mQuat1[2] = axisZ*sinHalfTheta;

    mQuat1[3] = cosHalfTheta;

    mQuat2[0] =-axisX*sinHalfTheta;

    mQuat2[1] =-axisY*sinHalfTheta;

    mQuat2[2] =-axisZ*sinHalfTheta;

    mQuat2[3] = cosHalfTheta;

    for (double[] vert : vert3D)

      {

      quatMultiply(mQuat1, vert  , mQuat3);

      quatMultiply(mQuat3, mQuat2, vert  );

      }

    // fit the whole thing in a square and remember the scale & 2D vertices

    fitInSquare(ft, vert3D);

    // remember the rotation

    ft.qx =-mQuat1[0];

    ft.qy =-mQuat1[1];

    ft.qz =-mQuat1[2];

    ft.qw = mQuat1[3];

    return ft;

    }

///////////////////////////////////////////////////////////////////////////////////////////////////

  private double computeCos(double oldX, double oldY, double newX, double newY, double len1, double len2)

    {

    double ret= (oldX*newX+oldY*newY) / (len1*len2);

    if( ret<-1.0 ) return -1.0;

    if( ret> 1.0 ) return  1.0;

    return ret;

    }

///////////////////////////////////////////////////////////////////////////////////////////////////

// sin of (signed!) angle between vectors 'old' and 'new', counterclockwise!

  private double computeSin(double oldX, double oldY, double newX, double newY, double len1, double len2)

    {

    double ret= (newX*oldY-oldX*newY) / (len1*len2);

    if( ret<-1.0 ) return -1.0;

    if( ret> 1.0 ) return  1.0;

    return ret;

    }

///////////////////////////////////////////////////////////////////////////////////////////////////

  private void rotateAllVertices(double[] result, int len, double[] vertices, double sin, double cos)

    {

    for(int i=0; i<len; i++)

      {

      result[2*i  ] = vertices[2*i  ]*cos - vertices[2*i+1]*sin;

      result[2*i+1] = vertices[2*i  ]*sin + vertices[2*i+1]*cos;

      }

    }

///////////////////////////////////////////////////////////////////////////////////////////////////

  private double computeScale(double[] v1, double[] v2, int v1i, int v2i)

    {

    double v1x = v1[2*v1i];

    double v1y = v1[2*v1i+1];

    double v2x = v2[2*v2i];

    double v2y = v2[2*v2i+1];

    double lenSq1 = v1x*v1x + v1y*v1y;

    double lenSq2 = v2x*v2x + v2y*v2y;

    return Math.sqrt(lenSq2/lenSq1);

    }

///////////////////////////////////////////////////////////////////////////////////////////////////

// valid for 0<angle<2*PI

  private double computeSinHalf(double cos)

    {

    return Math.sqrt((1-cos)/2);

    }

///////////////////////////////////////////////////////////////////////////////////////////////////

// valid for 0<angle<2*PI

  private double computeCosHalf(double sin, double cos)

    {

    double cosHalf = Math.sqrt((1+cos)/2);

    return sin<0 ? -cosHalf : cosHalf;

    }

///////////////////////////////////////////////////////////////////////////////////////////////////

  private int computeRotatedIndex(int oldVertex, int len, int rotatedVertex, boolean inverted)

    {

    int v = (rotatedVertex + (inverted? -oldVertex : oldVertex));

    if( v>=len ) v-=len;

    if( v< 0   ) v+=len;

    return v;

    }

///////////////////////////////////////////////////////////////////////////////////////////////////

  private boolean isScaledVersionOf(double[] newVert, double[] oldVert, int len, int vertex, boolean inverted)

    {

    int newZeroIndex = computeRotatedIndex(0,len,vertex,inverted);

    double EPSILON = 0.001;

    double scale = computeScale(newVert,oldVert,newZeroIndex,0);

    for(int i=1; i<len; i++)

      {

      int index = computeRotatedIndex(i,len,vertex,inverted);

      double horz = oldVert[2*i  ] - scale*newVert[2*index  ];

      double vert = oldVert[2*i+1] - scale*newVert[2*index+1];

      if( horz>EPSILON || horz<-EPSILON || vert>EPSILON || vert<-EPSILON ) return false;

      }

    return true;

    }

///////////////////////////////////////////////////////////////////////////////////////////////////

  private void mirrorAllVertices(double[] output, int len, double[] input)

    {

    for(int vertex=0; vertex<len; vertex++)

      {

      output[2*vertex  ] = input[2*vertex  ];

      output[2*vertex+1] =-input[2*vertex+1];

      }

    }

///////////////////////////////////////////////////////////////////////////////////////////////////

  private void correctInfo(FaceTransform info, double scale, double sin, double cos, int oldSticker, boolean flip)

    {

    mStickerCoords.remove(info.sticker);

    info.flip    = flip;

    info.sticker = oldSticker;

    info.scale  *= scale;

    mQuat1[0] = info.qx;

    mQuat1[1] = info.qy;

    mQuat1[2] = info.qz;

    mQuat1[3] = info.qw;

    double sinHalf = computeSinHalf(cos);

    double cosHalf = computeCosHalf(sin,cos);

    if( flip )

      {

      mQuat3[0] = 0.0f;

      mQuat3[1] = 0.0f;

      mQuat3[2] = sinHalf;

      mQuat3[3] = cosHalf;

      mQuat4[0] = 1.0;

      mQuat4[1] = 0.0;

      mQuat4[2] = 0.0;

      mQuat4[3] = 0.0;

      quatMultiply( mQuat3, mQuat4, mQuat2 );

      }

    else

      {

      mQuat2[0] = 0.0f;

      mQuat2[1] = 0.0f;

      mQuat2[2] = sinHalf;

      mQuat2[3] = cosHalf;

      }

    quatMultiply( mQuat1, mQuat2, mQuat3 );

    info.qx = mQuat3[0];

    info.qy = mQuat3[1];

    info.qz = mQuat3[2];

    info.qw = mQuat3[3];

    }

///////////////////////////////////////////////////////////////////////////////////////////////////

  private void printVert(double[] buffer)

    {

    int len = buffer.length/2;

    String str = "";

    for(int i=0; i<len; i++)

      {

      str += (" ("+buffer[2*i]+" , "+buffer[2*i+1]+" ) ");

      }

    android.util.Log.d("D", str);

    }

///////////////////////////////////////////////////////////////////////////////////////////////////

  private boolean foundVertex(FaceTransform info, double[] buffer, int len, double[] newVert,

                              double[] oldVert, double lenFirstOld, int oldSticker, boolean inverted)

    {

    for(int vertex=0; vertex<len; vertex++)

      {

      double newX = newVert[2*vertex  ];

      double newY = newVert[2*vertex+1];

      double lenIthNew = Math.sqrt(newX*newX + newY*newY);

      double cos = computeCos( oldVert[0], oldVert[1], newX, newY, lenIthNew, lenFirstOld);

      double sin = computeSin( oldVert[0], oldVert[1], newX, newY, lenIthNew, lenFirstOld);

      rotateAllVertices(buffer,len,newVert,sin,cos);

      if( isScaledVersionOf(buffer,oldVert,len,vertex,inverted) )

        {

        int newZeroIndex = computeRotatedIndex(0,len,vertex,inverted);

        double scale = computeScale(oldVert,newVert,0,newZeroIndex);

        correctInfo(info,scale,sin,cos,oldSticker,inverted);

        return true;

        }

      }

    return false;

    }

///////////////////////////////////////////////////////////////////////////////////////////////////

  private boolean successfullyCollapsedStickers(final FaceTransform newInfo, final FaceTransform oldInfo)

    {

    StickerCoords sNewInfo = mStickerCoords.get(newInfo.sticker);

    StickerCoords sOldInfo = mStickerCoords.get(oldInfo.sticker);

    double[] newVert = sNewInfo.vertices;

    double[] oldVert = sOldInfo.vertices;

    int oldLen = oldVert.length;

    int newLen = newVert.length;

    if( oldLen == newLen )

      {

      int oldSticker = oldInfo.sticker;

      double[] buffer1 = new double[oldLen];

      double lenFirstOld = Math.sqrt(oldVert[0]*oldVert[0] + oldVert[1]*oldVert[1]);

      if( foundVertex(newInfo, buffer1, oldLen/2, newVert, oldVert, lenFirstOld, oldSticker, false) ) return true;

      double[] buffer2 = new double[oldLen];

      mirrorAllVertices(buffer2, newLen/2, newVert);

      if( foundVertex(newInfo, buffer1, oldLen/2, buffer2, oldVert, lenFirstOld, oldSticker, true ) ) return true;

      }

    return false;

    }

///////////////////////////////////////////////////////////////////////////////////////////////////

  private double[][] constructVert(double[][] vertices, int[] index)

    {

    int len = index.length;

    double[][] ret = new double[len][4];

    for(int i=0; i<len; i++)

      {

      ret[i][0] = vertices[index[i]][0];

      ret[i][1] = vertices[index[i]][1];

      ret[i][2] = vertices[index[i]][2];

      ret[i][3] = 1.0f;

      }

    return ret;

    }

///////////////////////////////////////////////////////////////////////////////////////////////////

  private void prepareAndRoundCorners(MeshBase mesh, double[][] vertices,

                                      float[][] corners, int[] cornerIndexes,

                                      float[][] centers, int[] centerIndexes )

    {

    int lenV = vertices.length;

    Static3D[] staticVert = new Static3D[1];

    Static3D center = new Static3D(0,0,0);

    for(int v=0; v<lenV; v++)

      {

      staticVert[0] = new Static3D( (float)vertices[v][0], (float)vertices[v][1], (float)vertices[v][2]);

      int cent = centerIndexes[v];

      if( cent>=0 )

        {

        center.set( centers[cent][0], centers[cent][1], centers[cent][2]);

        int corn = cornerIndexes[v];

        float strength = corners[corn][0];

        float radius   = corners[corn][1];

        roundCorners(mesh, center, staticVert, strength, radius);

        }

      }

    }

///////////////////////////////////////////////////////////////////////////////////////////////////

  private void correctComponents(MeshBase mesh, int numComponents)

    {

    int numTexToBeAdded = numComponents-mesh.getNumTexComponents();

    mesh.mergeEffComponents();

    for(int i=0; i<numTexToBeAdded; i++ ) mesh.addEmptyTexComponent();

    }

///////////////////////////////////////////////////////////////////////////////////////////////////

  private void printTransform(FaceTransform f)

    {

    android.util.Log.e("D", "q=("+f.qx+", "+f.qy+", "+f.qz+", "+f.qw+") v=("

                       +f.vx+", "+f.vy+", "+f.vz+") scale="+f.scale+" sticker="+f.sticker);

    }

///////////////////////////////////////////////////////////////////////////////////////////////////

// PUBLIC

  public float[] computeBands(float H, int alpha, float dist, float K, int N)

    {

    float[] bands = new float[2*N];

    bands[0] = 1.0f;

    bands[1] = 0.0f;

    float beta = (float)Math.atan(dist*Math.tan(Math.PI*alpha/180));

    float sinBeta = (float)Math.sin(beta);

    float cosBeta = (float)Math.cos(beta);

    float R = cosBeta<1.0f ? H/(1.0f-cosBeta) : 0.0f;

    float D = R*sinBeta;

    float B = h(R,sinBeta,K*beta);

    if( D>1.0f )

      {

      for(int i=1; i<N; i++)

        {

        bands[2*i  ] = (float)(N-1-i)/(N-1);

        bands[2*i+1] = H*(1-bands[2*i]);

        }

      }

    else

      {

      int K2 = (int)((N-3)*K);

      int K1 = (N-3)-K2;

      for(int i=0; i<=K1; i++)

        {

        float angle = K*beta + (1-K)*beta*(K1-i)/(K1+1);

        float x = h(R,sinBeta,angle);

        bands[2*i+2] = 1.0f - x;

        bands[2*i+3] = g(R,D,x,cosBeta);

        }

      for(int i=0; i<=K2; i++)

        {

        float x = (1-B)*(i+1)/(K2+1) + B;

        bands[2*K1+2 + 2*i+2] = 1.0f - x;

        bands[2*K1+2 + 2*i+3] = g(R,D,f(D,B,x),cosBeta);

        }

      }

    bands[2*N-2] = 0.0f;

    bands[2*N-1] =    H;

    return bands;

    }

///////////////////////////////////////////////////////////////////////////////////////////////////

  public void roundCorners(MeshBase mesh, Static3D center, Static3D[] vertices, float strength, float regionRadius)

    {

    Static4D reg= new Static4D(0,0,0,regionRadius);

    float centX = center.get0();

    float centY = center.get1();

    float centZ = center.get2();

    for (Static3D vertex : vertices)

      {

      float x = strength*(centX - vertex.get0());

      float y = strength*(centY - vertex.get1());

      float z = strength*(centZ - vertex.get2());

      VertexEffect effect = new VertexEffectDeform(new Static3D(x,y,z), RADIUS, vertex, reg);

      mesh.apply(effect);

      }

    }

///////////////////////////////////////////////////////////////////////////////////////////////////

  public void printStickerCoords()

    {

    int stickers = mStickerCoords.size();

    android.util.Log.d("D", "---- STICKER COORDS ----");

    for(int s=0; s<stickers; s++)

      {

      String ver = "{ ";

      StickerCoords info = mStickerCoords.get(s);

      int len = info.vertices.length/2;

      for(int i =0; i<len; i++)

        {

        if( i!=0 ) ver += ", ";