program sdl_p4;

{$mode objfpc}{$H+}

uses sdl, sdl_ttf, gl, glu;

var
  screen :pSDL_SURFACE;
  loopstop: boolean = FALSE;
  event: pSDL_EVENT;

  font : pointer;
  sFont: pSDL_SURFACE;
  color: pSDL_COLOR;

  text: array[0..3] of String = ('aaaaaaaaaaaa',
                    'bbbbbbbbbbbb',
                    'cccccccccccc',
                    'dddddddddddd');
  b: integer;
  cur: integer;
  all: String;
  i,i1: Integer;

procedure addchar;
begin
  if cur = 4 then Exit;
  if length(all)=length(text[cur]) then
  begin
       //writeln(length(all));
       //writeln(length(text[cur]));
       inc(cur);
       all:='';
       Exit;
  end;

  if cur<4 then
  begin
    all := all + text[cur][length(all)+1];
    //writeln(all);
  end;
end;

procedure RenderText(const message : PChar; r : GLubyte; g : GLubyte; b : GLubyte; x : Integer; y : Integer; size : Integer);
var
  texture: GLuint;
begin
    glGenTextures(1, @texture);
    glBindTexture(GL_TEXTURE_2D, texture);

    font := TTF_OpenFont('cour.ttf', size);

    new(color);

    color^.r:=r;
    color^.g:=g;
    color^.b:=b;

    sFont := TTF_RenderText_Blended(font, message, color^);

    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
    glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, sFont^.w, sFont^.h, 0, GL_RGBA, GL_UNSIGNED_BYTE, sFont^.pixels);

    glBegin(GL_QUADS);
     glTexCoord2f(0,1-0); glVertex2f(x, y);
     glTexCoord2f(1,1-0); glVertex2f(x + sFont^.w, y);
     glTexCoord2f(1,1-1); glVertex2f(x + sFont^.w, y + sFont^.h);
     glTexCoord2f(0,1-1); glVertex2f(x, y + sFont^.h);
    glEnd();

    glDeleteTextures(1, @texture);
    Dispose(color);

    TTF_CloseFont(font);
    SDL_FreeSurface(sFont);
end;

procedure DrawGLScene();
  var
    i: integer;
  begin

    glClear(GL_COLOR_BUFFER_BIT);

    glDisable(GL_DEPTH_TEST);
    glEnable(GL_TEXTURE_2D);
    glEnable(GL_BLEND);
    glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);

    inc(B);
    if b=20 then addchar;
    if b>20 then b:=0;

    //addchar;

    for i := 0 to cur - 1 do
    begin
         if cur = 4 then Exit;
         RenderText(PChar(text[i]), 255, 255, 255, 0, 448 - i*32, 32);
    end;

    if Length(all) <> 0 then RenderText(PChar(all), 255, 255, 255, 0, 448 - cur*32, 32);

    glDisable(GL_BLEND);
    glDisable(GL_TEXTURE_2D);
    glEnable(GL_DEPTH_TEST);
  end;
var
   m_Width, m_height: Integer;
   frame_rate: Integer = 30;
   frame_ms: Integer;
   start_ms: Integer;
   end_ms: Integer;
   delay_ms: Integer;

begin
     SDL_Init(SDL_INIT_VIDEO);

     screen := SDL_SetVideoMode(640, 480, 0, SDL_OPENGL);
     if screen = NIL then Halt;

     if Ttf_Init = -1 then Halt;

    glMatrixMode(GL_MODELVIEW);
    glPushMatrix();
    glLoadIdentity();

    m_Width := screen^.w;
    m_Height := screen^.h;

    gluOrtho2D(0, m_Width, 0, m_Height);
    glMatrixMode(GL_PROJECTION);
    glPushMatrix();
    glLoadIdentity();

     b:=0;
     cur:=0;
     all:='';

     new(event);

     frame_ms := 1000 div frame_rate;

     while loopstop = FALSE do
     begin

          if SDL_PollEvent(event) = 1 then
          begin
               case event^.type_ of
                    SDL_KEYDOWN:
                    begin
                         if event^.key.keysym.sym = 27 then loopstop := TRUE;
                    end;
                    SDL_QUITEV:
                    begin
                         loopstop := TRUE;
                    end;
               end;
          end;
          start_ms := sdl_getticks();
          DrawGLScene;
          end_ms := sdl_getticks();

          delay_ms := (end_ms - start_ms);

          writeln(delay_ms);

          SDL_GL_SWAPBUFFERS;

     end;

     Dispose(event);
     SDL_FreeSurface(screen);
     TTF_QUIT;
     SDL_QUIT;
end.