gamemain.cs

说明如何使用托管 Direct3D Mobile 创建一个简单的二维游戏。

                mode = ModeSwitch.None;

                // Store the tick at which this frame started
                Int64 startTick = sw.CurrentTick();

                // Check if the user pressed the exit key
                if (gi.KeyPressed((int)gi.HardwareKeys[Player.ButtonMap()[
                    (int)Player.Buttons.Quit]]))
                {
                    done = true;
                }
                else if (levelLoaded && (level.Done || gi.KeyPressed(
                    (int)gi.HardwareKeys[Player.ButtonMap()[
                    (int)Player.Buttons.ResetLevel]])))
                {
                    Reset();
                    Application.DoEvents();
                    continue;
                }

                // Update the game
                update();

                // Check for pending events from the OS
                Application.DoEvents();

                // Lock the framerate...
                Int64 deltaMS = sw.DeltaTimeMilliseconds(sw.CurrentTick(), startTick);
                Int64 minMS = (Int64)(1000.0F * MinSecondsPerFrame);
                Int64 maxMS = (Int64)(1000.0F * MaxSecondsPerFrame);

                // Check if the frame time was fast enough
                if (deltaMS <= minMS)
                {
                    // Loop until the frame time is met
                    do
                    {
                        if (gi.KeyPressed((int)gi.HardwareKeys[
                            Player.ButtonMap()[(int)Player.Buttons.Quit]]))
                        {
                            done = true;
                            break;
                        }

                        // Thread.Sleep(0);
                        Application.DoEvents();
                        deltaMS = sw.DeltaTimeMilliseconds(sw.CurrentTick(),
                            startTick);

                    } while (deltaMS < minMS);
                }

                // Increment the number of frames
                numFrames++;
                // Increment the overall time for these frames
                if (deltaMS < maxMS)
                    secondsElapsedForCurrentFrames += deltaMS / 1000.0F;
                else
                    secondsElapsedForCurrentFrames += maxMS / 1000.0F;

                // Make sure enough time has elapsed since the last check
                if (level != null && secondsElapsedForCurrentFrames >
                    level.FrameRateCheckRate)
                {
                    currentSecondsPerFrame =
                        secondsElapsedForCurrentFrames / numFrames;
                    numFrames = 0;
                    secondsElapsedForCurrentFrames = 0;
                }
            }
        }

        /// <summary>
        /// Breaks the run loop and causes the game to exit
        /// </summary>
        public void Stop()
        {
            done = true;
        }

        /// <summary>
        /// Load the introduction to the level.
        /// </summary>
        public void LoadIntro()
        {
            DataSet dsIntro = new DataSet();

            Debug.Assert(dsIntro != null,
                "GameMain.LoadIntro: Failed to initialize intro DataSet");

            dsIntro.Locale = CultureInfo.InvariantCulture;

            // Load the intro xml file
            dsIntro.ReadXml(GetFullPath(@"Data\Intro\intro.xml"));

            // Load the intr resources specified in the xml file
            intro = new Intro(dsIntro, graphics);
            Debug.Assert(intro != null,
                "GameMain.LoadIntro: Failed to initialize Intro");

            // The intro is loaded at this point
            introLoaded = true;
        }

        /// <summary>
        /// Load the current level.  For this demo there is only one.
        /// </summary>
        public void LoadLevel()
        {
            DataSet dsLevel = new DataSet();
            Debug.Assert(dsLevel != null,
                "GameMain.LoadLevel: Failed to initialize level DataSet");

            dsLevel.Locale = CultureInfo.InvariantCulture;

            // Load the level xml file
            dsLevel.ReadXml(GetFullPath(@"Data\Level\level.xml"));

            // Load the level resources specified in the xml file
            level = new Level(dsLevel, graphics);
            Debug.Assert(level != null,
                "GameMain.LoadLevel: Failed to initialize level");

            // The level is loaded at this point
            levelLoaded = true;
        }

        /// <summary>
        /// Update the level.  This method is called during level gameplay.
        /// </summary>
        public void UpdateLevel()
        {
            // Update
            level.Update(gi);
            ui.Update(level);

            // Draw
            level.Draw();
            ui.Draw(graphics);

            // Flip the back buffer
            graphics.Flip();
        }

        /// <summary>
        /// Update the count down that is displayed before gameplay starts.
        /// </summary>
        public void UpdateCountdown()
        {
            if (startCountDown)
            {
                // Decrement the count
                countDown -= currentSecondsPerFrame;

                // Check if the count down is done
                if (countDown <= 0.0F)
                {
                    // Start updating the level
                    mode = ModeSwitch.UpdateLevel;
                    return;
                }
            }

            // Update UI
            ui.Update(level);

            // Draw
            level.Draw();
            ui.Draw(graphics);

            // Display the time left until the game starts. If the time is 
            // less than 1/2 second then flash
            if (startCountDown && (countDown > 0.5F ||
                (countDown <= 0.5F && (numFrames % 2 == 0))))
            {
                // Display "Start" for the last 1/2 second
                graphics.DrawText(graphics.ScreenWidth >> 1, 
                    graphics.ScreenHeight >> 1,
                    countDown > 0.5F ? string.Format(CultureInfo.InvariantCulture,
                    "{0}",
                    (int)(countDown + .49F)) : "Start",
                    Color.White, ui.Font, FontDrawOptions.DrawTextCenter);
            }

            if (!startCountDown)
            {
                int fireId = Player.ButtonMap()[(int)Player.Buttons.FireShot]
                    + 1;
                int quitId = Player.ButtonMap()[(int)Player.Buttons.Quit] + 1;
                int resetId = Player.ButtonMap()[
                    (int)Player.Buttons.ResetLevel] + 1;
                int x = graphics.ScreenWidth >> 1;
                int y = (graphics.ScreenHeight >> 1) - 60;

                graphics.DrawText(x, y, "<- -> to move player", Color.Yellow,
                    ui.Font, FontDrawOptions.DrawTextCenter);

#if (SMARTPHONE || MAINSTONE || DESKTOP)

                y += 20;
                graphics.DrawText(x, y, string.Format(
                    CultureInfo.InvariantCulture,
                    "Button {0} to fire",
                    fireId), Color.Yellow, ui.Font,
                    FontDrawOptions.DrawTextCenter);

                y += 20;
                graphics.DrawText(x, y, string.Format(
                    CultureInfo.InvariantCulture,
                    "Button {0} to Quit",
                    quitId), Color.Yellow, ui.Font,
                    FontDrawOptions.DrawTextCenter);

                y += 20;
                graphics.DrawText(x, y, string.Format(
                    CultureInfo.InvariantCulture,
                    "Button {0} to Reset",
                    resetId), Color.Yellow, ui.Font,
                    FontDrawOptions.DrawTextCenter);

#else // PPC

                y += 20;
                graphics.DrawText(x, y, 
                    "Action button to fire", 
                    Color.Yellow, ui.Font,
                    FontDrawOptions.DrawTextCenter);

                y += 20;
                graphics.DrawText(x, y, 
                    "Click the upper right", 
                    Color.Yellow, ui.Font,
                    FontDrawOptions.DrawTextCenter);

                y += 20;
                graphics.DrawText(x, y, 
                    "corner GMan to quit", 
                    Color.Yellow, ui.Font,
                    FontDrawOptions.DrawTextCenter);

#endif

                y += 20;
                graphics.DrawText(x, y, "Press any key to start", Color.Red,
                    ui.Font, FontDrawOptions.DrawTextCenter);

                if (gi.AnyKeyPressed())
                    startCountDown = true;
            }

            // Flip the back buffer
            graphics.Flip();
        }

        /// <summary>
        /// Update the intro that leads into the current level.
        /// </summary>
        public void UpdateIntro()
        {
            // If the level has finished loading and the intro is done
            // playing then start the count down
            if (levelLoaded && intro.Done)
            {
                mode = ModeSwitch.UpdateCountdown;
                return;
            }

            // Update the intro
            intro.Update(graphics);

            // Draw the intro
            intro.Draw(graphics);

            // Flip the back buffers
            graphics.Flip();
        }

        /// <summary>
        /// Update the splash screen.
        /// </summary>
        public void UpdateSplash()
        {

            // Calculate the upper-left corner of the splash screen image
            int x = (graphics.ScreenWidth - splash.Width) >> 1;
            int y = (graphics.ScreenHeight - splash.Height) >> 1;

            // The source region is the entire image
            src.X = 0;
            src.Y = 0;
            src.Width = splash.Width;
            src.Height = splash.Height;

            // Draw the splash screen
            graphics.DrawBitmap(x, y, src, splash);

            // Flip the back buffers
            graphics.Flip();

            // Store the tick at which this frame started
            Timer.Stopwatch sw = new Timer.Stopwatch();
            Int64 startTick = sw.CurrentTick();

            // Draw the splash screen
            graphics.DrawBitmap(x, y, src, splash);

            // Draw a "Loading" message as this might take a while
            graphics.DrawText(graphics.ScreenWidth >> 1, 
                graphics.ScreenHeight - 50,
                "Loading...",
                Color.White, ui.Font, FontDrawOptions.DrawTextCenter);

            // Flip the back buffers
            graphics.Flip();

            if (!introLoaded) LoadIntro();

            // delay if the splash screen hasn't been up long enough
            while (sw.DeltaTimeMilliseconds(sw.CurrentTick(), startTick)
                < TotalSplashTime * 1000.0F)
                Thread.Sleep(0);

            mode = ModeSwitch.UpdateIntro;
        }

        /// <summary>
        /// Clean up the game's resources.
        /// </summary>
        public void Dispose()
        {
            if (intro != null)
                intro.Dispose();

            if (ui != null)
                ui.Dispose();

            if (level != null)
                level.Dispose();

            if (graphics != null)
                graphics.Dispose();
        }
    }
}