RoamingBlockBuster

Introduction

Joel shows how you can write a shooter game in Smart Mobile Studio with a moderate amount of code. Use the wasd or arrow keys to move and q or the space bar to fire (in the direction of your last movement) at the pink targets. The targets move randomly in a mesmerising manner and are not easy to hit. In this version of the game you can see how many blocks you can bust until, say, the time reaches 50. You may like to introduce your own scoring system and make the game either easier or more difficult to play.

The code follows the game in action.

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The Code

unit RoamingBlockBuster;  
{
    Copyright (c) 2014 Joel Sutcliffe

    Licensed under the Apache License, Version 2.0 (the "License"); you may not
    use this file except in compliance with the License, as described at
    http://www.apache.org/licenses/ and http://www.pp4s.co.uk/licenses/
}
interface

uses
  W3System, W3Components, W3Application, W3Game, W3GameApp, W3Graphics;

type
  TApplication = class(TW3CustomGameApplication)
  protected
    procedure  ApplicationStarting; override;
    procedure  ApplicationClosing; override;
    procedure  PaintView(Canvas: TW3Canvas); override;
    procedure  KeyDownEvent(mCode : Integer);
  end;

  TTarget = class(TObject)
  public
    X, Y, Dir, Dircount : Integer;
    constructor Create();
    procedure Move;
  end;

implementation
var
  Redcode, Greencode, Bluecode, Face, bulletX, BulletY, TargetX, TargetY,
    timecount, count, i, score, mobspeed, bullspeed, time, MobY, MobX: integer;
  Fire, Right, Left, Up, Down: Boolean;
  Target: array[0..10] of TTarget;

procedure TTarget.Move;
begin
  inc(Dircount);
  if Dircount = 10 then
    begin
      Dir := Randomint(4) + 1;
      Dircount := 0;           //chooses direction to move in for 5 frames
    end;
  case Dir of
    1: begin
         if X < 299 then
           inc(X)
         else
           dec(i);
       end;
    2: begin
         if X > 0 then
           dec(X)
         else
           dec(i);
       end;
   3: begin
        if Y < 299 then
          inc(Y)
        else
          dec(i);
      end;
   4: begin
        if Y > 0 then
          dec(Y)
        else
          dec(i);
      end;
  end;
end;

constructor TTarget.create;
begin
  //Create target at starting location
  X := Randomint(295) + 5;
  Y := Randomint(295) + 5;
  Dircount := 0;
end;

procedure TApplication.KeyDownEvent(mCode : integer);
begin
  case mCode of
    //move up
    38, 87: begin
              MobY := MobY - Mobspeed;
              Face := 1;
            end;
    //move down
    40, 83: begin
              MobY := MobY + Mobspeed;
              Face := 2;
            end;
    //move right
    39, 68: begin
              MobX := MobX + Mobspeed;
              Face := 3;
            end;
    //move left
    37, 65: begin
              MobX := MobX - Mobspeed;
              Face := 4;
            end;
    32: begin
          if fire = false then  //allows only one bullet at a time
            begin
              fire := true;
              count := 0;
            end;
        end;
  end;
end;

procedure TApplication.ApplicationStarting;
begin
  inherited;
  asm
    window.onkeydown=function(e)
    {
    TApplication.KeyDownEvent(Self,e.keyCode);
    }
  end;
  KeyDownEvent(0);
  MobX := 0;
  MobY := 0;
  i := 0;
  score := 0;
  repeat
    Target[i] := TTarget.Create();      //create the initial targets
    inc(i);
  until i = 10;
  Mobspeed := 2;
  Bullspeed := 2;
  Time := 0;
  TimeCount := 0;
  GameView.Delay := 20;
  GameView.StartSession(True);
end;

procedure TApplication.ApplicationClosing;
begin
  GameView.EndSession;
  inherited;
end;

procedure TApplication.PaintView(Canvas: TW3Canvas);
begin
  // Clear background
  Canvas.FillStyle := 'rgb(0, 0, 0)';
  Canvas.FillRectF(0, 0, GameView.Width, GameView.Height);
  //Randomise colour for bullet
  Redcode := Randomint(255);
  Greencode := Randomint(255);
  Bluecode := Randomint(255);
  Canvas.Fillstyle := 'rgb(255, 255, 255)';
  Canvas.FillRect(MobX, MobY, 5, 5);
  // Draw the score
  Canvas.Font := '10pt verdana';
  Canvas.FillStyle := 'rgb(255, 255, 255)';
  Canvas.FillTextF('Score:' + IntToStr(Score), 300, 300, MAX_INT);
  //Draw time
  Canvas.Font := '10pt verdana';
  Canvas.FillStyle := 'rgb(255, 255, 255)';
  Canvas.FillTextF('Time:' + IntToStr(Time), 10, 20, MAX_INT);
  //Draw targets
  i := 0;
  repeat
    Target[i].Move;
    inc(i);
  until i = 10;
  i := 0;
  repeat
    Canvas.Fillstyle := 'pink';
    Canvas.FillRect(Target[i].X, Target[i].Y, 5, 5);
    inc(i);
  until i = 10;
  i := 0;
  //Randomise colour for bullet
  Redcode := Randomint(255);
  Greencode := Randomint(255);
  Bluecode := Randomint(255);
  Canvas.Fillstyle := 'rgb(' + InttoStr(Redcode)+ ',' + InttoStr(Greencode) +
                           ',' + InttoStr(Bluecode) +')';
  if fire = true then
    begin
      inc(count);
      if count = 1 then
        begin
          case face of           // decides direction to fire
            1: begin
                 up := true;
                 down := false;
                 left := false;
                 right := false;
               end;
            2: begin
                 down := true;
                 up := false;
                 left := false;
                 right := false;
               end;
            3: begin
                 right := true;
                 left := false;
                 down := false;
                 up := false;
               end;
            4: begin
                 left := true;
                 right := false;
                 down := false;
                 up := false;
               end;
          end;
          BulletX := MobX + 2;      //spawns bullet
          BulletY := MobY + 2;
        end
      else if count = 41 then
        begin
          fire := false;
        end
      else
        begin
          if up = true then                        //moves bullet
            BulletY := BulletY - Bullspeed;
          if down = true then
            BulletY := BulletY + Bullspeed;
          if left = true then
            BulletX := BulletX - Bullspeed;
          if right = true then
            BulletX := BulletX + Bullspeed;
        end;
      //draw bullet
      Canvas.FillRect(BulletX - 1, BulletY - 1, 3, 3);
    end;
  repeat
    if (BulletX < target[i].X + 5) and (BulletX > target[i].X) and
       (BulletY < target[i].Y + 5) and (BulletY > target[i].Y) then
      begin
        Canvas.fillstyle := 'yellow';                   //destroy target effect
        Canvas.fillrect(BulletX - 5, BulletY - 5, 15, 15);
        Target[i].X := randomint(295) + 5;               //spawns new target
        Target[i].Y := randomint(295) + 5;
        inc(score);
      end;
    inc(i);
  until i = 10;
  i := 0;
  inc(timecount);
  if timecount = 100 then
    begin
      inc(time);
      timecount := 0;
    end;
end;

end.