OpenGL Textures full code

{$apptype GUI}

uses Gl,Glu,Glut;

const width = 600;
      height = 600;

      res_y = 200;
      res_x = 200;

var torot, torot1, torot2: double;
    texture_id: GLuint;

procedure drawSphere;
  var sphere: PGLUquadricObj;
begin
  sphere := gluNewQuadric();
  gluQuadricTexture(sphere, GL_TRUE);
    gluSphere(sphere, 50.0, 20, 20);
  gluDeleteQuadric(sphere);
end;

procedure display(); cdecl;
begin
glClear(GL_COLOR_BUFFER_BIT or GL_DEPTH_BUFFER_BIT);
gLLoadIdentity();
glRotatef(torot, 0, 1, 0);

glBindTexture(GL_TEXTURE_2D, texture_id);
drawSphere();

glFlush();
glutSwapBuffers();
end;

function prepareTexture: GLuint;
    var texture_data: array [0..res_y - 1, 0..res_x - 1, 0..2] of byte;
            texture_id: GLuint;
            x, y: integer;
begin
  for y := 0 to res_y - 1 do begin
    for x := 0 to res_x - 1 do begin
      texture_data[y, x, 0] := random(256);
      texture_data[y, x, 1] := random(256);
      texture_data[y, x, 2] := random(256);
    end;
  end;
  glEnable(GL_TEXTURE_2D);
  glGenTextures(1, @texture_id);
  glBindTexture(GL_TEXTURE_2D, texture_id);
  glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
  glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
  glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
  glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
  glTexImage2D(GL_TEXTURE_2D, 0, 3, res_x, res_y, 0, GL_RGB, GL_UNSIGNED_BYTE, @texture_data);
  prepareTexture := texture_id;
end;

procedure initGl;
begin
glClearColor(0.0,0.0,0.0,0.0);
glMatrixMode(GL_projection);
glLoadIdentity;
glOrtho(-200, 200, -200, 200, -200, 200);
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
glClearDepth(1.0);
glEnable(GL_LEQUAL);
END;

procedure keyboard(code:byte;x,y:longint); cdecl;
begin
case code of
27:halt;
end;
end;

procedure initgLUT;
BEGIN
glutInitDisplayMode(GLUT_DOUBLE or GLUT_RGB);
glutInitWindowSize(width,height);
glutCreateWindow('DOLBOEB');
glutDisplayFunc(@display);
glutKeyboardFunc(@keyboard);
end;
begin
initGlut;initGL;
texture_id := preparetexture;
glutMainLoop();
end.