Initial data commit

Task/Bitmap-Bresenhams-line-algorithm/UNIX-Shell/bitmap-bresenhams-line-algorithm.sh

@@ -0,0 +1,63 @@
+#! /bin/bash
+
+function line {
+  x0=$1
+  y0=$2
+  x1=$3
+  y1=$4
+
+  if (( x0 > x1 ))
+  then
+    (( dx = x0 - x1 ))
+    (( sx = -1 ))
+  else
+    (( dx = x1 - x0 ))
+    (( sx = 1 ))
+  fi
+
+  if (( y0 > y1 ))
+  then
+    (( dy = y0 - y1 ))
+    (( sy = -1 ))
+  else
+    (( dy = y1 - y0 ))
+    (( sy = 1 ))
+  fi
+
+  if (( dx > dy ))
+  then
+    (( err = dx ))
+  else
+    (( err = -dy ))
+  fi
+  (( err /= 2 ))
+  (( e2 = 0 ))
+
+  while :
+  do
+    echo -en "\e[${y0};${x0}H#\e[K"
+    (( x0 == x1 && y0 == y1 )) && return
+    (( e2 = err ))
+    if (( e2 > -dx ))
+    then
+      (( err -= dy ))
+      ((  x0 += sx ))
+    fi
+    if (( e2 < dy ))
+    then
+      (( err += dx ))
+      ((  y0 += sy ))
+    fi
+  done
+}
+
+# Draw a full screen diamond
+COLS=$( tput cols )
+LINS=$( tput lines )
+LINS=$((LINS-1))
+clear
+line $((COLS/2)) 1 $((COLS/4)) $((LINS/2))
+line $((COLS/4)) $((LINS/2)) $((COLS/2)) $LINS
+line $((COLS/2)) $LINS $((COLS/4*3)) $((LINS/2))
+line $((COLS/4*3)) $((LINS/2)) $((COLS/2)) 1
+echo -e "\e[${LINS}H"