From f1a54fd165251b1f2296f5845d31198f9b0198d9 Mon Sep 17 00:00:00 2001
From: Loic Guegan <manzerbredes@mailbox.org>
Date: Mon, 9 Jan 2023 09:55:20 +0100
Subject: [PATCH] Improve arrow drawing

---
 src/game_tab/left_panel/board/BoardCanvas.cpp | 23 ++++++++++++++++---
 src/game_tab/left_panel/board/BoardCanvas.hpp |  2 ++
 2 files changed, 22 insertions(+), 3 deletions(-)

diff --git a/src/game_tab/left_panel/board/BoardCanvas.cpp b/src/game_tab/left_panel/board/BoardCanvas.cpp
index aab3c45..a31b0c6 100644
--- a/src/game_tab/left_panel/board/BoardCanvas.cpp
+++ b/src/game_tab/left_panel/board/BoardCanvas.cpp
@@ -13,9 +13,11 @@ 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;
   valid_arrow = false;
+  arrows_offset = t->GetSquaresSizes()/2.5;
   // Init animation data
   adata.duration=100;
   adata.duration_fast=100;
@@ -409,6 +411,7 @@ void BoardCanvas::DrawBoard(wxDC &dc) {
     std::uint32_t dx = boardX + (7 - dfile) * square_width + square_width/2;
     std::uint32_t dy = boardY + drank * square_width + square_width/2;
 
+  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){
@@ -538,6 +541,14 @@ void BoardCanvas::DrawArrow(wxDC &dc, int xsrc, int ysrc, int xdst, int ydst){
   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 thickness=50;
   std::uint8_t tip_height=sqrt(3)/2*thickness;
@@ -557,7 +568,6 @@ void BoardCanvas::DrawArrow(wxDC &dc, int xsrc, int ysrc, int xdst, int ydst){
 
   // Draw
   dc.SetPen(wxNullPen);
-  dc.SetBrush(wxColour(255,0,0));
   dc.DrawPolygon(3,tip);
   dc.DrawPolygon(4,tail);
 }
@@ -572,6 +582,15 @@ void BoardCanvas::DrawLArrow(wxDC &dc, int xsrc, int ysrc, int xdst, int ydst, b
     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
     std::uint8_t thickness=50;
@@ -589,7 +608,6 @@ void BoardCanvas::DrawLArrow(wxDC &dc, int xsrc, int ysrc, int xdst, int ydst, b
 
     // Draw
     dc.SetPen(wxNullPen);
-    dc.SetBrush(wxColour(255,0,0));
     dc.DrawPolygon(4,tail1);
     dc.DrawPolygon(4,tail2);
     dc.DrawPolygon(3,tip);
@@ -610,7 +628,6 @@ void BoardCanvas::DrawLArrow(wxDC &dc, int xsrc, int ysrc, int xdst, int ydst, b
 
     // Draw
     dc.SetPen(wxNullPen);
-    dc.SetBrush(wxColour(255,0,0));
     dc.DrawPolygon(4,tail1);
     dc.DrawPolygon(4,tail2);
     dc.DrawPolygon(3,tip);
diff --git a/src/game_tab/left_panel/board/BoardCanvas.hpp b/src/game_tab/left_panel/board/BoardCanvas.hpp
index 24c469c..f387c22 100644
--- a/src/game_tab/left_panel/board/BoardCanvas.hpp
+++ b/src/game_tab/left_panel/board/BoardCanvas.hpp
@@ -76,6 +76,8 @@ class BoardCanvas : public wxPanel {
   // *t is theme for board+pieces and
   // *t_captures is theme for captured pieces (scale down version of t)
   Theme *t, *t_captures;
+  wxColour color_arrows;
+  int arrows_offset;
   // Board to draw (char version)
   std::string board;
   std::string white_player,black_player;