Алгоритм Бризенхема

program most;
uses GraphABC;
 
 
procedure drawLine(x1, y1, x2, y2: integer);
var
  
  errorX, errorY: integer;
  d, dx, dy, incX, incY: integer;
begin
  dx := x2 - x1;
  dy := y2 - y1;
  errorX := 0;
  errorY := 0;
 
  if(dx > 0) then incX := 1
    else if(dx = 0) then incX := 0
      else incX := -1;
 
  if(dy > 0) then incY := 1
    else if(dy = 0) then incY := 0
      else incY := -1;
 
  dx := abs(dx);
  dy := abs(dy);
 
  if(dy > dx) then d := dy
    else d := dx;
 
  
  SetPixel(X1, Y1, clred);
  while((X1 <> x2) OR (Y1 <> y2)) do
  begin
    errorX := errorX + dx;
    errorY := errorY + dy;
    if(errorX >= d) then
    begin
         errorX := errorX - d;
         X1 := X1 + incX;
    end;
    if(errorY >= d) then
    begin
         errorY := errorY - d;
         Y1 := Y1 + incY;
    end;
    SetPixel(X1, Y1, clred);
  end;
end;
var
x1,y1,x2,y2:integer;
begin
x1:=10;
y1:=10;
 
x2:=100;
y2:=100;
 
 drawLine(x1, y1, x2, y2);
end.

program ets;
uses graphabc;
var
x1,y1,x2,y2:integer;
begin
x1:=10;
y1:=10;
 
x2:=100;
y2:=100;
 
while(x1<>x2) or (y1<>y2) do
begin
 
setpixel(x1,y1,clred);
x1:=x1+1;
y1:=y1+1;
 
 
end;
end.