Построение равностороннего треугольника и заполнение его некоторым цветом

{$mode objfpc}{$H+}
 
uses
  gl, glu, glut;
 
const
  AppWidth = 640;
  AppHeight = 480;
  mult = 2;
 
var
  tb:byte=0;
  tg:byte=0;
 
procedure InitializeGL;
begin
  glClearColor(0.0, 0.0, 0.9, 0);
end;
 
 
procedure DrawGLScene; cdecl;
begin
  glClear(GL_COLOR_BUFFER_BIT or GL_DEPTH_BUFFER_BIT);
 
  glLoadIdentity;
  glTranslatef(0, 0, -5);
 
  glBegin(GL_TRIANGLES);
    glColor3f(0, tg, tb);
 
    glVertex3f(-1* mult, 0, 0);
    glVertex3f(0, 1.73* mult, 0);
    glVertex3f(1* mult, 0, 0);
  glEnd;
 
  glutSwapBuffers;
end;
 
procedure ReSizeGLScene(Width, Height: Integer); cdecl;
begin
  if Height = 0 then
    Height := 1;
 
  glViewport(0, 0, Width, Height);
  glMatrixMode(GL_PROJECTION);
  glLoadIdentity;
  gluPerspective(90, Width / Height, 1, 1000);
 
  glMatrixMode(GL_MODELVIEW);
  glLoadIdentity;
end;
 
procedure GLKeyboard(Key: byte; X, Y: Longint); cdecl;
begin
  if Key = 27 then
    Halt(0);
  if key = $d then begin tg:=1; tb:=1; end;
end;
 
procedure glutInitPascal(ParseCmdLine: Boolean);
var
  Cmd: array of PChar;
  CmdCount, I: Integer;
begin
  if ParseCmdLine then
    CmdCount := ParamCount + 1
  else
    CmdCount := 1;
  SetLength(Cmd, CmdCount);
  for I := 0 to CmdCount - 1 do
    Cmd[I] := PChar(ParamStr(I));
  glutInit(@CmdCount, @Cmd);
end;
 
var
  ScreenWidth, ScreenHeight: Integer;
begin
  glutInitPascal(True);
  glutInitDisplayMode(GLUT_DOUBLE or GLUT_RGB or GLUT_DEPTH);
  glutInitWindowSize(AppWidth, AppHeight);
  ScreenWidth := glutGet(GLUT_SCREEN_WIDTH);
  ScreenHeight := glutGet(GLUT_SCREEN_HEIGHT);
  glutInitWindowPosition((ScreenWidth - AppWidth) div 2, (ScreenHeight - AppHeight) div 2);
  glutCreateWindow('test');
 
  InitializeGL;
 
  glutDisplayFunc(@DrawGLScene);
  glutReshapeFunc(@ReSizeGLScene);
  glutIdleFunc(@DrawGLScene);
  glutKeyboardFunc(@GLKeyboard);
 
  glutMainLoop;
 
end.

uses graph,wincrt;
const s = 'Press Enter';
var
  cx, cy, R, i : integer;
  pts : array[0 .. 3] of pointtype;
begin
  initgraph(cx, cy, '');
  cx := getmaxX div 2;
  cy := getmaxY div 2;
  R := cy - 100;
  setcolor(red);
  for i := 0 to 2 do
  begin
    pts[i].x := cx + trunc(R * cos(pi/2 + i * 2*pi/3));
    pts[i].y := cy - trunc(R * sin(pi/2 + i * 2*pi/3));
  end;
  pts[3] := pts[0];
 
  drawpoly(4, pts);
  outtextXY(cx - textwidth(s) div 2, 10, s);
  readln;
  setfillstyle(solidfill, red);
  fillpoly(4, pts);
  readln;
end.