TwistyPuzzleLib

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

// 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/>.                           //

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

import android.graphics.Canvas;

import android.graphics.Paint;

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

public class FactorySticker

  {

  private static FactorySticker mThis;

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

  private FactorySticker()

    {

    }

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

  public static FactorySticker getInstance()

    {

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

    return mThis;

    }

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

  private float computeAngle(float dx, float dy)

    {

    double angle = Math.atan2(dy,dx);

    float ret = (float)(3*PI/2-angle);

    if( ret>2*PI ) ret-= 2*PI;

    return ret;

    }

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

  private float getAngle(float[] angles, int index)

    {

    return angles==null ? 0 : angles[index];

    }

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

    float ctg= 1.0f/((float)Math.tan(alpha));

    mOY = 0.5f*(y1+y2) + ctg*0.5f*(x1-x2);

    float dx = mOX-x1;

    float dy = mOY-y1;

    }

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

// circle1: center (x1,y1) radius r1; circle2: center (x2,y2) radius r2.

// Guaranteed to intersect in two points. Find the intersection. Which one? the one that's closer

// to (nearx,neary).

  private void findCircleIntersection(float x1,float y1, float r1, float x2, float y2, float r2, float nearx, float neary )

    {

    float dx = x2-x1;

    float dy = y2-y1;

    float d = (float)Math.sqrt(dx*dx+dy*dy);

    if( d>0 )

      {

      float Dx = dx/d;

      float Dy = dy/d;

      float cos = (r1*r1+d*d-r2*r2)/(2*r1*d);

      float sin = (float)Math.sqrt(1-cos*cos);

      float ox1 = x1 + r1*cos*Dx + r1*sin*Dy;

      float oy1 = y1 + r1*cos*Dy - r1*sin*Dx;

      float ox2 = x1 + r1*cos*Dx - r1*sin*Dy;

      float oy2 = y1 + r1*cos*Dy + r1*sin*Dx;

      dx = nearx-ox1;

      dy = neary-oy1;

      float d1 = dx*dx+dy*dy;

      dx = nearx-ox2;

      dy = neary-oy2;

      float d2 = dx*dx+dy*dy;

      if( d1<d2 )

        {

        mOX = ox1;

        mOY = oy1;

        }

      else

        {

        mOX = ox2;

        mOY = oy2;

        }

      }

    else

      {

      mOX = x1;

      mOY = y1;

      }

    }

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

    pX = (0.5f+pX)*TEXTURE_HEIGHT;

    pY = (0.5f-pY)*TEXTURE_HEIGHT;

    cX = (0.5f+cX)*TEXTURE_HEIGHT;

    cY = (0.5f-cY)*TEXTURE_HEIGHT;

      {

      float aX = pX-cX;

      float aY = pY-cY;

      float aLen = (float)Math.sqrt(aX*aX+aY*aY);

      aX /= aLen;

      aY /= aLen;

      // draw a little more - stroke*(aX,aY) more - so

      // that we draw over the rounded corners (Kilominx!)

    else

      {

      computeCircleCoords(pX,pY,cX,cY,pAngle);

      float ox = mOX;

      float oy = mOY;

      float r  = mR;

      float dy = oy-pY;

      float sweepA = 2*pAngle;

      sweepA *= 180/PI;

    }

// quotient==0 --> ret=curvature; quotient==1 --> ret=0.

      {

      double sinC = Math.sin(curvature);

      float arcsin = (float)Math.asin(quotient*sinC);

      return curvature-arcsin;

      }

    return curvature;

    }

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

  private float computeSideAngle(float vX, float vY, float radius, float curvature)

    {

    float quotient = radius/(float)Math.sqrt(vX*vX + vY*vY);

    float ret = computeAngle(vX,-vY)-computeQuotientOfCurvature(quotient,curvature);

    if( ret<0     ) ret += 2*PI;

    }

    {

    float diff = angle2-angle1;

    if( diff<0 ) diff = -diff;

    float avg = (angle1+angle2)/2;

      {

      avg -= PI;

      if( avg<0 ) avg += 2*PI;

      }

    }

                              float radius, float cX, float cY, float pA, float cA)

    cY = (0.5f-cY)*TEXTURE_HEIGHT;

      {

      stopA  = pA;

      if( stopA >2*PI ) stopA  -= 2*PI;

      centerA= angleMidpoint(pA,cA) - PI/2;

      if( centerA<0 ) centerA += 2*PI;

      float diff = cA-centerA;

      if( diff<0 ) diff += 2*PI;

      alpha = diff> PI/2 ? PI-diff : diff;

      D = (float)(R/Math.sin(alpha));

      {

      stopA  = cA + PI;

      if( centerA>=2*PI ) centerA -= 2*PI;

      float diff = centerA-cA;

      if( diff<0 ) diff += 2*PI;

      alpha = diff> PI/2 ? PI-diff : diff;

      D = (float)((R-stroke)/Math.sin(alpha));

    float sinA = (float)(Math.sin(centerA));

    float cosA = (float)(Math.cos(centerA));

    float oY= cY + D*cosA;

    startA *= 180/PI;

    sweepA *= 180/PI;

    if( !isConvex ) paint.setColor(color);

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

// PUBLIC

    float stroke = sticker.getStroke();

    float[] vertices = sticker.getCoords();

    float[] angles = sticker.getCurvature();

    float[] radii = sticker.getRadii();

    stroke *= TEXTURE_HEIGHT;

    paint.setAntiAlias(true);

    paint.setStrokeWidth(stroke);

    paint.setColor(color);

    paint.setStyle(Paint.Style.FILL);

    canvas.drawRect(left,bottom-TEXTURE_HEIGHT,left+TEXTURE_HEIGHT,bottom,paint);

    int length = vertices.length;

    int numVertices = length/2;

    float prevX = vertices[length-2];

    float prevY = vertices[length-1];

    float currX = vertices[0];

    float currY = vertices[1];

    float nextX = vertices[2];

    float nextY = vertices[3];

    float prevA = getAngle(angles,numVertices-1);

    float currA = getAngle(angles,0);

    for(int vert=0; vert<numVertices; vert++)

      {

      prevY = currY;

      currX = nextX;

      currY = nextY;

      prevA = currA;

      currA = getAngle(angles, vert==numVertices-1 ? 0 : vert+1);

      if( 2*(vert+2)+1 < length )

        {

        nextX = vertices[2*(vert+2)  ];

        nextY = vertices[2*(vert+2)+1];

        }

      else

        {

        nextX = vertices[0];

        nextY = vertices[1];

        }

      }

    prevX = vertices[length-2];

    prevY = vertices[length-1];

    currX = vertices[0];

    currY = vertices[1];

    nextX = vertices[2];

    nextY = vertices[3];

    prevA = getAngle(angles,numVertices-1);

    currA = getAngle(angles,0);

    for(int vert=0; vert<numVertices; vert++)

      {

      float prevAngle = computeSideAngle(currX-prevX,currY-prevY,radii[prev],-prevA);

      float currAngle = computeSideAngle(nextX-currX,nextY-currY,radii[vert],+currA);

      drawRoundCorner(canvas,paint,color,left,bottom,stroke,radii[vert],currX,currY,prevAngle,currAngle);

      prevX = currX;

      prevY = currY;

      currX = nextX;

      currY = nextY;

      prevA = currA;

      currA = getAngle(angles, vert==numVertices-1 ? 0 : vert+1);

      if( 2*(vert+2)+1 < length )

        {

        nextX = vertices[2*(vert+2)  ];

        nextY = vertices[2*(vert+2)+1];

        }

      else

        {

        nextX = vertices[0];

        nextY = vertices[1];

        }

      }

    canvas.restore();

  }