path: root/src/game_tab/left_panel/board/BoardCanvas.cpp

#include "BoardCanvas.hpp"

#define TRANS(PT) { \
wxPoint2DDouble tmp((PT).x,(PT).y); \
tmp=rot_m.TransformPoint(tmp); \
(PT).x=tmp.m_x+xsrc;(PT).y=tmp.m_y+ysrc;}

#define TRANS2(PT) { \
(PT).x+=xsrc;(PT).y+=ysrc;}

wxDEFINE_EVENT(PLAY_MOVE_EVENT, wxCommandEvent);

BoardCanvas::BoardCanvas(wxFrame *parent)
    : wxPanel(parent), black_side(false), frozen(false),
      lock_square_size(false), t(new Theme()), t_captures(new Theme()) {
  color_arrows=wxColour(145, 233, 255);
  is_dragging = false;
  valid_drag = false;
  arrow_drag = false;
  arrows_offset = t->GetSquaresSizes()/2.5;
  arrow_thickness = t->GetSquaresSizes()/1.8;
  // Init animation data
  adata.duration=100;
  adata.duration_fast=50;
  adata.fps=60;
  adata.buffer=new wxBitmap(500,500,32);
  adata.animate=false;
  // Init game state
  gs.is_black_turn=false;
  gs.board = "rnbqkbnrpppppppp                                PPPPPPPPRNBQKBNR";
  gs.mat_black=false;
  gs.mat_white=false;
  // Init clocks
  SetClockTime(-1, -1, -1, false);
  SetClockTime(-1, -1, -1, true);
  // Init capture pieces
  t_captures->ResizePieces(t->GetPiecesSizes() * CAPTURE_FACTOR);
  // Load preferences
  ApplyPreferences();
  // The following should be called when using an EVT_PAINT handler
  SetBackgroundStyle(wxBG_STYLE_PAINT);
  // Let GameTableLeftPanel process keyboard events:
  Bind(wxEVT_KEY_DOWN, [p=this](wxKeyEvent &e){e.ResumePropagation(1);e.Skip();});
  Bind(wxEVT_KEY_UP, [p=this](wxKeyEvent &e){e.ResumePropagation(1);e.Skip();});
  Bind(wxEVT_PAINT, &BoardCanvas::OnPaint, this);
  // Mouse events:
  Bind(wxEVT_MOTION, &BoardCanvas::MouseEvent, this);
  Bind(wxEVT_LEFT_DOWN, &BoardCanvas::MouseEvent, this);
  Bind(wxEVT_LEFT_UP, &BoardCanvas::MouseEvent, this);
  Bind(wxEVT_RIGHT_DOWN, &BoardCanvas::MouseEvent, this);
  Bind(wxEVT_RIGHT_UP, &BoardCanvas::MouseEvent, this);
  Bind(wxEVT_RIGHT_DCLICK, &BoardCanvas::MouseEvent, this);
}

BoardCanvas::~BoardCanvas() {
  delete t;
  delete t_captures;
  if(adata.buffer!= nullptr)
    free(adata.buffer);
}

BoardCanvas::BoardCanvas(wxFrame *parent, std::uint32_t square_width,
                         bool frozen)
    : BoardCanvas(parent) {
  t->ResizeSquaresAndPieces(square_width);
  t_captures->ResizePieces(t->GetPiecesSizes() * CAPTURE_FACTOR);
  this->frozen = true;
  lock_square_size = true;
}

void BoardCanvas::OnPaint(wxPaintEvent &event) {
  wxBufferedPaintDC dc(this);
  dc.SetBackground(*wxWHITE_BRUSH);
  dc.Clear();
  
  if(!adata.animate){
    // Setting up required attributes
    REFRESH_MOUSE_LOCATION();
    square_width = t->GetSquaresSizes();
    piece_width = t->GetPiecesSizes();
    canvas_size = this->GetSize();
    boardX = (canvas_size.x - (8 * square_width)) / 2;
    boardY = (canvas_size.y - (8 * square_width)) / 2;
    if (boardX > canvas_size.x)
      boardX = 0;
    if (boardY > canvas_size.y)
      boardY = 0;
    DrawBoard(dc);
  }
  else {
    // Reuse buffer and animate
    dc.DrawBitmap(*adata.buffer, 0, 0, true);
    double percent=adata.frame/adata.frames;
    // Draw moving piece
    dc.DrawBitmap(*t->Get(adata.piece_moved), 
    adata.src.x + adata.frame*(adata.transVect.x/adata.frames), 
    adata.src.y + adata.frame*(adata.transVect.y/adata.frames), false);
    // End drawing
    adata.frame++;
  }
}

void BoardCanvas::ApplyPreferences() {
  if (t != nullptr)
    delete t;
  if (t_captures != nullptr)
    delete t_captures;
  t = new Theme();
  t_captures = new Theme();

  CONFIG_OPEN(config);
  black_side = config->Read("board/black_by_default", false);
  if (lock_square_size) {
    t->ResizeSquaresAndPieces(square_width);
  } else {
    t->ResizeSquaresAndPieces(config->Read("board/square_size", 80));
  }
  t->SetSquareRadius(config->Read("board/corner_radius", 10));
  t_captures->ResizePieces(t->GetPiecesSizes() * CAPTURE_FACTOR);
  CONFIG_CLOSE(config);

  Refresh();
}

void BoardCanvas::SetupBoard(const GameState &new_gs) {
  gs=new_gs;
  Refresh();
}

void BoardCanvas::Animate(const GameState &new_gs, const std::string &src, const std::string &dst, bool faster){
  std::uint8_t pfile = src[0]-'a';
  std::uint8_t prank = src[1]-'1';
  adata.piece_moved = gs.board[pfile + 8 * (7-prank)]; // Piece to move
  
  // Now init adata.buffer and remove the piece that will be moved
  gs.board[pfile + 8 * (7-prank)]=' ';
  wxSize buffer_size=adata.buffer->GetSize();
  if(canvas_size!=buffer_size){
    wxLogDebug("Allocate a new animation buffer");
    free(adata.buffer);
    adata.buffer=new wxBitmap(canvas_size.x,canvas_size.y,32);
  }
  wxMemoryDC memDC(*adata.buffer);
  memDC.SetBackground(*wxWHITE_BRUSH);
  memDC.Clear();
  DrawBoard(memDC);

  // Now compute piece start position and translation vector
  std::uint32_t centrer_offset = (square_width - piece_width) / 2;
  if (!black_side) {
        prank = 7 - prank;
        pfile = 7 - pfile;
  }
  std::uint32_t x = boardX + (7 - pfile) * square_width;
  std::uint32_t y = boardY + prank * square_width;
  adata.src.x = x + centrer_offset;
  adata.src.y = y + centrer_offset;
  // Now dst:
  pfile = dst[0]-'a';
  prank = dst[1]-'1';
    if (!black_side) {
        prank = 7 - prank;
        pfile = 7 - pfile;
  }
  x = boardX + (7 - pfile) * square_width;
  y = boardY + prank * square_width;
  adata.transVect.x=x-adata.src.x+centrer_offset;
  adata.transVect.y=y-adata.src.y+centrer_offset;

  // Start animation:
  adata.animate=true;
  int duration_backup=adata.duration;
  adata.duration=faster ? adata.duration_fast : adata.duration;
  int frame_duration=(1000/adata.fps);
  adata.frame=0;
  adata.frames=adata.duration/frame_duration; // total number of frames
  int time_per_frame=adata.duration/adata.frames;
  wxStopWatch sw;
  for(int i=adata.frames;i>0;i--){
    Refresh();
    Update();
    int delay=frame_duration-sw.Time();
    if(delay>1){ // 1ms tolerance (max drift of fps each second that is fps*tolerance)
      wxMilliSleep(delay);
    }
    sw.Start(0);
  }
  adata.duration=faster ? duration_backup : duration_backup;
  adata.animate=false;
  SetupBoard(new_gs);
}

void BoardCanvas::DrawBoard(wxDC &dc) {
  std::uint32_t centrer_offset = (square_width - piece_width) / 2;
  wxSize numbers_size=dc.GetTextExtent("0");

  bool DrawDraggingPiece = false;
  char dp = 'p';
  std::uint32_t dpx = 0, dpy = 0;
  for (std::int8_t file = 7; file >= 0; file--) {
    for (std::uint8_t rank = 0; rank <= 7; rank++) {
      std::uint32_t x = boardX + (7 - file) * square_width;
      std::uint32_t y = boardY + rank * square_width;
      if ((file + rank) % 2 == 0) {
        if (file == 0 && rank == 0) {
          dc.DrawBitmap(*t->Get('1'), x, y, true);
        } else if (file == 7 && rank == 7) {
          dc.DrawBitmap(*t->Get('2'), x, y, true);
        } else {
          dc.DrawBitmap(*t->Get('s'), x, y, true);
        }
      } else {
        if (file == 7 && rank == 0) {
          dc.DrawBitmap(*t->Get('0'), x, y, true);
        } else if (file == 0 && rank == 7) {
          dc.DrawBitmap(*t->Get('3'), x, y, true);
        } else {
          dc.DrawBitmap(*t->Get('S'), x, y, true);
        }
      }

      // Draw highlighted squares
      for(int i=0;i<(gs.squares_hl.size()+squares_hl.size());i++){
          const GameState::Square &s=i<gs.squares_hl.size() ? gs.squares_hl[i] : squares_hl[i-gs.squares_hl.size()];
          std::uint8_t sfile = s.square[0]-'a';
          std::uint8_t srank = s.square[1]-'1';
          if (!black_side) {
            srank = 7 - srank;
            sfile = 7 - sfile;
          }
          if(srank == rank && sfile==file){
            dc.SetPen(wxNullPen);
            if(s.color!=wxNullColour)
              dc.SetBrush(s.color);
            else
              dc.SetBrush(wxColour(255, 102, 122));
            dc.DrawRectangle(wxRect(x,y,square_width,square_width));
          }
      }

      // Draw numbers
      dc.SetFont(wxFont(*wxNORMAL_FONT).MakeBold());
      if(file==7){ // Right numbers
        dc.DrawText(wxString((char)('1'+7-rank)),
        x-numbers_size.x*1.5,y+square_width/2-numbers_size.y/2);
      }
      if(rank==7){ // Bottom numbers
        dc.DrawText(wxString((char)('a'+7-file)),
        x+square_width/2-numbers_size.x/2,y+square_width);
      }    

      // Draw pieces
      std::uint8_t prank = rank;
      std::uint8_t pfile = file;
      if (black_side) {
        prank = 7 - rank;
        pfile = 7 - file;
      }
      std::uint32_t px = x + centrer_offset;
      std::uint32_t py = y + centrer_offset;
      char piece =  gs.board[(7 - pfile) + 8 * prank];
      if (is_dragging && (7 - pfile) == active_square.x &&
          (7 - prank) == active_square.y) {
        dp = piece;
        dpx = px - (lastClickX - mouseX);
        dpy = py - (lastClickY - mouseY);
        DrawDraggingPiece = true;
        continue;
      }
      if (piece != ' ') {
        dc.DrawBitmap(*t->Get(piece), px, py, false);
        if((piece == 'k' && gs.mat_black) || (piece == 'K' && gs.mat_white))
          dc.DrawBitmap(*t->Get('#'), x+square_width/2+centrer_offset, y+centrer_offset, false);
      }
    }
  }

  // Draw captures (+player names) first for white then for black
  std::uint32_t captures_size = t_captures->GetPiecesSizes();
  std::uint8_t padding = 10;
  std::uint32_t offsetX = 0;
  std::uint32_t offsetY = -(captures_size + padding);
  std::uint32_t offsetYPlayerName=offsetY-captures_size-padding; // For top player name we
  // add -padding at the end (ortherwise bottom of the letters
  // are to close to captured pieces)
  // White (black's captures):
  if (black_side) {
    offsetY = 8 * square_width + padding + numbers_size.y;
    offsetYPlayerName = offsetY+captures_size;
  }
  for (char p : {'P', 'N', 'B', 'R', 'Q'}) {
    if (gs.captures.find(p) != gs.captures.end()) {
      for (std::uint8_t i = 0; i < gs.captures[p]; i++) {
        dc.DrawBitmap(*t_captures->Get(p), boardX + offsetX, boardY + offsetY);
        offsetX += captures_size / 2;
      }
      offsetX += captures_size / 2;
    }
  }
  dc.DrawText(wxString(gs.black),boardX,boardY + offsetYPlayerName);
  // Black (white's captures):
  offsetX = 0;
  if (black_side) {
    offsetY = -(captures_size + padding);
    offsetYPlayerName = offsetY-captures_size-padding; // Same for -padding (cf. for black's captures)
  } else {
    offsetY = 8 * square_width + padding + numbers_size.y;
    offsetYPlayerName = offsetY+captures_size;
  }
  for (char p : {'p', 'n', 'b', 'r', 'q'}) {
    if (gs.captures.find(p) != gs.captures.end()) {
      for (std::uint8_t i = 0; i < gs.captures[p]; i++) {
        dc.DrawBitmap(*t_captures->Get(p), boardX + offsetX, boardY + offsetY);
        offsetX += captures_size / 2;
      }
      offsetX += captures_size / 2;
    }
  }
  dc.DrawText(wxString(gs.white),boardX,boardY + offsetYPlayerName);

  // Draw dragging piece
  if (DrawDraggingPiece) {
    dc.DrawBitmap(*t->Get(dp), dpx, dpy, false);
  }

  // Draw numbers
  for (char l = 'a'; l < 'a' + 8; l++) {
    dc.DrawText(wxString(l), wxPoint(boardX + l - 'a' * square_width,
                                     boardY + 8 * square_width + 10));
  }

  // Draw Clocks
  if (std::get<0>(gs.black_time) >= 0) {
    wxFont font = dc.GetFont();
    ClockTime clock = black_side ? gs.white_time : gs.black_time;
    wxString time =
        wxString::Format("%ds", std::get<1>(clock), std::get<2>(clock));
    if (std::get<0>(clock) > 0) {
      time = wxString::Format("%d:%d", std::get<0>(clock), std::get<1>(clock));
    } else if (std::get<1>(clock) > 0) {
      time = wxString::Format("%d:%ds", std::get<1>(clock), std::get<2>(clock));
    }
    dc.SetFont(font.Scale(1.5).MakeBold());
    wxCoord width, height;
    dc.GetTextExtent(time, &width, &height);
    dc.DrawText(time,
                wxPoint(boardX + square_width * 8 - width, boardY - height - numbers_size.y*2));
    clock = black_side ? gs.black_time : gs.white_time;
    time = wxString::Format("%ds", std::get<1>(clock), std::get<2>(clock));
    if (std::get<0>(clock) > 0) {
      time = wxString::Format("%d:%d", std::get<0>(clock), std::get<1>(clock));
    } else if (std::get<1>(clock) > 0) {
      time = wxString::Format("%d:%ds", std::get<1>(clock), std::get<2>(clock));
    }
    dc.GetTextExtent(time, &width, &height);
    dc.DrawText(time, wxPoint(boardX + square_width * 8 - width,
                              boardY + square_width * 8 + numbers_size.y*2));
  }
  // Draw arrows
 for(int i=0;i<(gs.arrows.size()+arrows.size());i++){
    const GameState::Arrow &arrow= i<gs.arrows.size() ? gs.arrows[i] : arrows[i-gs.arrows.size()];
    std::uint8_t sfile = arrow.src[0]-'a';
    std::uint8_t srank = arrow.src[1]-'1';
    std::uint8_t dfile = arrow.dst[0]-'a';
    std::uint8_t drank = arrow.dst[1]-'1';
    if (!black_side) {
      srank = 7 - srank;
      sfile = 7 - sfile;
      drank = 7 - drank;
      dfile = 7 - dfile;
    }
    std::uint32_t sx = boardX + (7 - sfile) * square_width + square_width/2;
    std::uint32_t sy = boardY + srank * square_width + square_width/2;
    std::uint32_t dx = boardX + (7 - dfile) * square_width + square_width/2;
    std::uint32_t dy = boardY + drank * square_width + square_width/2;

    // Parse arrow for metadata (maybe having a datatype is better)
    if(arrow.color!=wxNullColour)
      dc.SetBrush(arrow.color);
    else
      dc.SetBrush(color_arrows);
    if(((abs(drank-srank) == 2) && (abs(dfile-sfile) == 1))||
    ((abs(drank-srank) == 1) && (abs(dfile-sfile) == 2))){
      if(abs(drank-srank) == 1){
        DrawLArrow(dc,sx,sy,dx,dy,false,arrow_thickness*arrow.scale);
      }
      else {
        DrawLArrow(dc,sx,sy,dx,dy,true,arrow_thickness*arrow.scale);
      }
    } else {
      DrawArrow(dc,sx,sy,dx,dy,arrow_thickness*arrow.scale);
    }
  }
  // Ask for promotion
  if(gs.promotion.size()==2){
    std::uint8_t sfile = gs.promotion[0]-'a';
    std::uint8_t srank = gs.promotion[1]-'1';
    bool is_black_promotion=gs.promotion[1]=='1';
    if (!black_side) {
      srank = 7 - srank;
      sfile = 7 - sfile;
    }
    std::uint32_t PX = boardX + (7 - sfile) * square_width;
    std::uint32_t PY = boardY + srank * square_width;

    short offset=0,border=5;
    char s=is_black_promotion ? 's' : 'S';

    for (char p : {'q', 'r', 'b', 'n'}) {
      p=is_black_promotion ? p : std::toupper(p);
      // Background
      dc.SetPen(wxNullPen);
      dc.SetBrush(*wxLIGHT_GREY);
      dc.DrawCircle(PX+square_width/2,PY + offset*square_width+square_width/2,square_width/2);
      dc.SetBrush(wxColour(219, 161, 0));
      dc.DrawCircle(PX+square_width/2,PY + offset*square_width+square_width/2,square_width/2-border);
      // Piece
      dc.DrawBitmap(*t->Get(p), PX + centrer_offset, PY + centrer_offset + offset*square_width);
      if((is_black_promotion && !black_side) || (!is_black_promotion && black_side))
        offset--;
      else
        offset++;
    }
  }

  // Draw engine evaluation bar
  if(gs.show_evalbar){
    short w=35,p=20,range=20,border=8;
    short bar_height=8*square_width-2*border;
    float visible_px=10; // Part of the bar that will always be visible no matter the evaluation
    float eval=gs.eval;
    float eval_norm=range/2+std::min(std::max((-(float)range/2),eval),(float)range/2);
    float evalbar_height=(eval_norm/(float)range)*bar_height;
    evalbar_height=std::min(std::max(visible_px,evalbar_height),bar_height-visible_px);
    wxLogDebug("%f",((float)eval_norm/(float)(range/2)));
    dc.SetPen(wxNullPen);
    dc.SetBrush(*wxBLACK_BRUSH);
    dc.DrawRectangle(wxRect(boardX+8*square_width+p,boardY,w,8*square_width));
    dc.SetBrush(*wxWHITE_BRUSH);
    if(!black_side){
      dc.DrawRectangle(wxRect(boardX+8*square_width+p+border,boardY+border+bar_height-evalbar_height,w-2*border,evalbar_height));
    }else {
      dc.DrawRectangle(wxRect(boardX+8*square_width+p+border,boardY+border,w-2*border,evalbar_height));
    }
    // Convert eval to string:
    char buffer[20];  // maximum expected length of the float
    std::snprintf(buffer, 20, "%.1f", eval);
    wxString evalstr(buffer);
    if(eval>0)
      evalstr="+"+evalstr;

    wxSize evalstr_size=dc.GetTextExtent(evalstr);
    dc.DrawText(evalstr,boardX+8*square_width+p+(w/2-evalstr_size.x/2),boardY-evalstr_size.y);
  }
}

void BoardCanvas::MouseEvent(wxMouseEvent &event) {
  // Disable mouse events if BoardCanvas is frozen:
  if(frozen)
    return;

  // If ask for promotion just wait for the user reply
  if(gs.promotion.size()==2){
    if(event.LeftDown()){
      REFRESH_MOUSE_LOCATION();
      INIT_CURRENT_SQUARE();
      if (IsCurrentSquareValid) {
        if((char)('a' + file)==gs.promotion[0]){
          std::uint8_t prank=abs((int)gs.promotion[1]-(int)(char)('1' + rank));
          if(prank<=3){
            wxCommandEvent event(PLAY_MOVE_EVENT, GetId());
            event.SetEventObject(this);
            if(prank==1)
              event.SetInt((int)'r');
            else if(prank==2)
              event.SetInt((int)'b');
            else if(prank==3)
              event.SetInt((int)'n');
            else
              event.SetInt((int)'q');
            ProcessEvent(event);
          }
        }
      }
    }
    return;
  }

  // Just redraw if a piece is currently being moved:
  if (event.Dragging() && valid_drag) {
    is_dragging = true;
    Refresh();
    return;
  }
  
  if ((event.LeftDown() || event.RightDown()) && !is_dragging) {
    // Start dragging (either piece or arrows drawing)
    SetFocus();
    REFRESH_MOUSE_LOCATION();
    lastClickX = mouseX;
    lastClickY = mouseY;
    INIT_CURRENT_SQUARE();
    if (IsCurrentSquareValid) {
      active_square.x = file;
      active_square.y = rank;
      if(event.LeftDown()){
        if (gs.board[(7 - rank) * 8 + file] != ' ') {
          wxLogDebug("Drag start on square (%d,%d)", file, rank);
          valid_drag = true;
        }
      }
      else {
        wxLogDebug("Arrow start on square (%d,%d)", file, rank);
        arrow_drag = true;
      }
    }
  } else if(event.LeftUp()) {
    if(valid_drag){
      // Handle drop
      REFRESH_MOUSE_LOCATION();
      INIT_CURRENT_SQUARE();

      if (IsCurrentSquareValid) {
        wxLogDebug("Drag end on square (%d,%d)", file, rank);
        /// Play the move
        wxCommandEvent event(PLAY_MOVE_EVENT, GetId());
        event.SetEventObject(this);
        std::string move = ((char)('a' + active_square.x)) +
                            std::to_string(+active_square.y + 1) +
                            ((char)('a' + file)) + std::to_string(rank + 1);
        event.SetString(move);
        event.SetInt((int)'q'); // Promote to queen by default
        ProcessEvent(event);
      } else {
        // If square not valid just redraw (place piece back to its square)
        Refresh(); // Note that there will be 2 Refresh() this one and the next after clear() of arrows and squares_hl but it is clearer like this
      }
    }
    arrows.clear();
    squares_hl.clear();
    Refresh();
    // In any left up, reset dragging variables
    valid_drag = false;
    is_dragging = false;
  } else if(event.RightUp()){
    if(arrow_drag){
      // Handle drop
      REFRESH_MOUSE_LOCATION();
      INIT_CURRENT_SQUARE();
      if (IsCurrentSquareValid) {
        std::string src=((char)('a' + active_square.x)) +
                          std::to_string(+active_square.y + 1);
        std::string dst=((char)('a' + file)) + std::to_string(rank + 1);
        if(src!=dst){
          arrows.push_back(DEFAULT_ARROW(src,dst));
          wxLogDebug("Draw arrow %s",src+dst);
        }
        else {
          int id=0;
          bool removed=false;
          for(GameState::Square &s:squares_hl){
            if(s.square==src){
              squares_hl.erase(squares_hl.begin()+id);
              removed=true;
              break;
            }
            id++;
          }
          if(!removed){
            squares_hl.push_back(DEFAULT_SQUARE(src));
            wxLogDebug("Highlight square %s",src);
          }
        }
        Refresh();
      }
    }
    // In any right up, reset dragging variables
    is_dragging = false;
    arrow_drag = false;
  } else {
    // Let GameTableLeftPanel process mouse wheel events:
    if (event.GetWheelRotation() != 0) {
      event.ResumePropagation(1);event.Skip();
    }
  }
}

void BoardCanvas::Zoom(std::int32_t zoom) {
  if(!t->Zoom(zoom))
    return;
  t_captures->ResizePieces(t->GetPiecesSizes() * CAPTURE_FACTOR);
  arrow_thickness = t->GetSquaresSizes()/1.8;
  Refresh();
}

void BoardCanvas::Swap() {
  black_side = !black_side;
  Refresh();
}

void BoardCanvas::SetClockTime(short hours, short min, short sec,
                               bool IsBlack) {
  if (IsBlack) {
    gs.black_time = std::make_tuple(hours, min, sec);
  } else {
    gs.white_time = std::make_tuple(hours, min, sec);
  }
}

void BoardCanvas::DrawArrow(wxDC &dc, int xsrc, int ysrc, int xdst, int ydst, std::uint8_t thickness){
  // Compute arrow length and angle
  wxPoint vect(xdst-xsrc,ydst-ysrc);
  double length=ceil(sqrt(pow(vect.x,2)+pow(vect.y,2)));
  double angle=acos(vect.x/length);
  angle= (vect.y>0) ? angle=angle : -angle;

  // Translate starting point (xsrc,ysrc) about arrows_offset px to not start on the center of the square (less confusing visually)
  double k=arrows_offset/length;
  xsrc=xsrc+(xdst-xsrc)*k;
  ysrc=ysrc+(ydst-ysrc)*k;
  vect.x=(xdst-xsrc);
  vect.y=(ydst-ysrc);
  length=ceil(sqrt(pow(vect.x,2)+pow(vect.y,2)));

  // Compute metrics
  std::uint8_t tip_height=sqrt(3)/2*thickness;
  std::uint32_t tail_length=length-tip_height;

  // Setup transform matrix
  wxAffineMatrix2D rot_m;
  rot_m.Rotate(angle);
  wxLogDebug("Angle is %d,%d",(int)vect.x,(int)vect.y);
  // Init polygons
  wxPoint tip[]={wxPoint(tail_length,-thickness/2),wxPoint(tail_length,thickness/2),wxPoint(tail_length+tip_height,0)};
  wxPoint tail[]={wxPoint(0,-thickness/4),wxPoint(tail_length,-thickness/4),wxPoint(tail_length,thickness/4),wxPoint(0,thickness/4)};

  // Transform points
  TRANS(tip[0]);TRANS(tip[1]);TRANS(tip[2]);
  TRANS(tail[0]);TRANS(tail[1]);TRANS(tail[2]);TRANS(tail[3]);

  // Draw
  dc.SetPen(wxNullPen);
  dc.DrawPolygon(3,tip);
  dc.DrawPolygon(4,tail);
}

void BoardCanvas::DrawLArrow(wxDC &dc, int xsrc, int ysrc, int xdst, int ydst, bool flip, std::uint8_t thickness){
  double X=xdst-xsrc;
  double Y=ydst-ysrc;

  // Check if L arrows are required
  if(X==0 || Y==0){
    DrawArrow(dc, xsrc, ysrc, xdst, ydst);
    return;
  }

  // Translate starting point (xsrc,ysrc) about arrows_offset px to not start on the center of the square (less confusing visually)
  if(!flip)
    xsrc+= (xdst-xsrc) > 0 ? arrows_offset : -arrows_offset;
  else
    ysrc+= (ydst-ysrc) > 0 ? arrows_offset : -arrows_offset;
  X=xdst-xsrc;
  Y=ydst-ysrc;

  // Draw L shaped arrows
  if(flip){
    // Compute metrics
    double tip_height=sqrt(3)/2*thickness;
    double yoffset=Y<0 ? -thickness/4 : thickness/4; // Y tail should be longer to form a right angle (corner of tail joins)
    double xoffset=X<0 ? -thickness/4 : thickness/4; // X tail's starting point should be translated to form a right angle (corner of tail joins)
    if(X<0){tip_height=-tip_height;}
    wxPoint tip[]={wxPoint(X-tip_height,-thickness/2+Y),wxPoint(X,Y),wxPoint(X-tip_height,thickness/2+Y)};
    wxPoint tail1[]={wxPoint(-thickness/4,0),wxPoint(thickness/4,0),wxPoint(thickness/4,Y+yoffset),wxPoint(-thickness/4,Y+yoffset)};
    wxPoint tail2[]={wxPoint(xoffset,Y-thickness/4),wxPoint(X-tip_height,Y-thickness/4),wxPoint(X-tip_height,Y+thickness/4),wxPoint(xoffset,Y+thickness/4)};

    // Apply transforms
    TRANS2(tip[0]);TRANS2(tip[1]);TRANS2(tip[2]);
    TRANS2(tail1[0]);TRANS2(tail1[1]);TRANS2(tail1[2]);TRANS2(tail1[3]);
    TRANS2(tail2[0]);TRANS2(tail2[1]);TRANS2(tail2[2]);TRANS2(tail2[3]);

    // Draw
    dc.SetPen(wxNullPen);
    dc.DrawPolygon(4,tail1);
    dc.DrawPolygon(4,tail2);
    dc.DrawPolygon(3,tip);
  } else {
    // Compute metrics
    double tip_height=sqrt(3)/2*thickness;
    double xoffset=X<0 ? -thickness/4 : thickness/4; // X tail should be longer to form a right angle (corner of tail joins)
    double yoffset=Y<0 ? -thickness/4 : thickness/4; // Y tail's starting point should be translated to form a right angle (corner of tail joins)
    if(Y<0){tip_height=-tip_height;}
    wxPoint tip[]={wxPoint(-thickness/2 + X,Y-tip_height),wxPoint(thickness/2 + X ,Y-tip_height),wxPoint(X,Y)};
    wxPoint tail1[]={wxPoint(0,-thickness/4),wxPoint(X+xoffset,-thickness/4),wxPoint(X+xoffset,thickness/4),wxPoint(0,thickness/4)};
    wxPoint tail2[]={wxPoint(X-thickness/4,yoffset),wxPoint(X+thickness/4,yoffset),wxPoint(X+thickness/4,Y-tip_height),wxPoint(X-thickness/4,Y-tip_height)};

    // Apply transforms
    TRANS2(tip[0]);TRANS2(tip[1]);TRANS2(tip[2]);
    TRANS2(tail1[0]);TRANS2(tail1[1]);TRANS2(tail1[2]);TRANS2(tail1[3]);
    TRANS2(tail2[0]);TRANS2(tail2[1]);TRANS2(tail2[2]);TRANS2(tail2[3]);

    // Draw
    dc.SetPen(wxNullPen);
    dc.DrawPolygon(4,tail1);
    dc.DrawPolygon(4,tail2);
    dc.DrawPolygon(3,tip);
  }
}