§14.2游戏屏幕

/// <summary>

/// Render splash screen

/// </summary>

public bool Render()

{

// This starts both menu and in game post screen shader!

BaseGame.UI.PostScreenMenuShader.Start();

// Render background and black bar

BaseGame.UI.RenderMenuBackground();

BaseGame.UI.RenderBlackBar(352, 61);

// Show Press Start to continue.

if ((int)(BaseGame.TotalTime / 0.375f) % 3 != 0)

BaseGame.UI.Logos.RenderOnScreen( BaseGame.CalcRectangleCenteredWithGivenHeight( 512, 352 + 61 / 2, 26, UIRenderer.PressStartGfxRect), UIRenderer.PressStartGfxRect);

// Show logos BaseGame.UI.RenderLogos();

// Clicking or pressing start will go to the menu

return Input.MouseLeftButtonJustPressed || Input.KeyboardSpaceJustPressed || Input.KeyboardEscapeJustPressed || Input.GamePadStartPressed;

} // Render()

// [From RenderMenuTrackBackground(), which is called by

// RenderMenuBackground(), both located in the UIRenderer class]

// [Some code to calculate carPos, carMatrix, etc.]

// Put camera behind car

RacingGame.Player.SetCameraPosition( carPos + carMatrix.Forward * 9 - carMatrix.Up * 2.3f);

// For rendering rotate car to stay correctly on the road

carMatrix = Matrix.CreateRotationX(MathHelper.Pi / 2.0f) * Matrix.CreateRotationZ(MathHelper.Pi) * carMatrix;

RacingGame.Landscape.Render();

RacingGame.CarModel.RenderCar( randomCarNumber, randomCarColor, carMatrix);

/// <summary>

/// Current button sizes for scaling up/down smooth effect.

/// </summary>

float[] currentButtonSizes = new float[NumberOfButtons] { 1, 0, 0, 0, 0, 0 };

然后在Rnnder方法中处理按钮选择和缩放。为了确保你会在同时悬浮在一个以上的按钮，这里为鼠标使用了一个辅助变量。如果不使用鼠标选取菜单按钮，这个变量将不会被使用。

// Little helper to keep track if mouse is actually over a button.

// Required because buttons are selected even when not hovering over

// them for GamePad support, but we still want the mouse only to

// be applied when we are actually over the button.

int mouseIsOverButton = -1;

// [a little later in the code ...]

for (int num = 0; num < NumberOfButtons; num++)

{

// Is this button currently selected?

bool selected = num == selectedButton;

// Increase size if selected, decrease otherwise

currentButtonSizes[num] += (selected ? 1 : -1) * BaseGame.MoveFactorPerSecond * 2;

if (currentButtonSizes[num] < 0)

currentButtonSizes[num] = 0;

if (currentButtonSizes[num] > 1)

currentButtonSizes[num] = 1;

// Use this size to build rect

Rectangle thisRect = InterpolateRect(activeRect, inactiveRect, currentButtonSizes[num]);

Rectangle renderRect = new Rectangle( xPos, yPos - (thisRect.Height - inactiveRect.Height) / 2, thisRect.Width, thisRect.Height); BaseGame.UI.Buttons.RenderOnScreen(renderRect, ButtonRects[num],

// Make button gray if not selected selected ? Color.White : new Color(192, 192, 192, 192));

// Add border effect if selected if (selected)

BaseGame.UI.Buttons.RenderOnScreen(renderRect, UIRenderer.MenuButtonSelectionGfxRect);

// Also check if the user hovers with the mouse over this button

if (Input.MouseInBox(renderRect))

mouseIsOverButton = num;

// [etc.]

} // for (num)

if (mouseIsOverButton >= 0)

selectedButton = mouseIsOverButton;

/// <summary>

/// Render game screen. Called each frame.

/// </summary>

public bool Render()

{

if (BaseGame.AllowShadowMapping)

{

// Generate shadows

ShaderEffect.shadowMapping.GenerateShadows(

delegate

{

RacingGame.Landscape.GenerateShadow();

RacingGame.CarModel.GenerateShadow( RacingGame.Player.CarRenderMatrix);

}

); // Render shadows

ShaderEffect.shadowMapping.RenderShadows(

delegate

{

RacingGame.Landscape.UseShadow();

RacingGame.CarModel.UseShadow( RacingGame.Player.CarRenderMatrix);

}

);

} // if (BaseGame.AllowShadowMapping)

// This starts both menu and in game post screen shader!

BaseGame.UI.PostScreenGlowShader.Start();

// Render background sky and lensflare.

BaseGame.UI.RenderGameBackground();

// Render landscape with track and all objects

RacingGame.Landscape.Render();

// Render car with matrix we got from CarPhysics

RacingGame.CarModel.RenderCar( RacingGame.currentCarNumber, RacingGame.CarColor, RacingGame.Player.CarRenderMatrix);

// And flush all models to be rendered

BaseGame.MeshRenderManager.Render();

// Show shadows we calculated above

if (BaseGame.AllowShadowMapping)

{

ShaderEffect.shadowMapping.ShowShadows();

} // if (BaseGame.AllowShadowMapping)

// Apply post screen shader here before doing the UI

BaseGame.UI.PostScreenGlowShader.Show();

// Play motor sound Sound.UpdateGearSound(RacingGame.Player.Speed, RacingGame.Player.Acceleration);

// Show on screen UI for the game.

BaseGame.UI.RenderGameUI( (int)RacingGame.Player.GameTimeMiliseconds,

// Best time and current lap

(int)RacingGame.Player.BestTimeMs, RacingGame.Player.CurrentLap+1, RacingGame.Player.Speed * CarPhysics.MeterPerSecToMph,

// Gear logic with sound (could be improved ^^) 1+(int)(5*RacingGame.Player.Speed/CarPhysics.MaxSpeed),

// Motormeter

0.5f*RacingGame.Player.Speed/CarPhysics.MaxSpeed +

// This could be improved

0.5f*RacingGame.Player.Acceleration, RacingGame.Landscape.CurrentTrackName, Highscore.GetTop5Highscores());

if (Input.KeyboardEscapeJustPressed || Input.GamePadBackJustPressed)

{

// Stop motor sound

Sound.StopGearSound();

// Play menu music again

Sound.Play(Sound.Sounds.MenuMusic);

// Return to menu

return true;

} // if (Input.KeyboardEscapeJustPressed)

return false;

} // Render()

// Go through all highscores

for (int num = 0; num < NumOfHighscores; num++)

{

// Show player in white if mouse is over line or else use gray color

Rectangle lineRect = new Rectangle( 0, yPos, BaseGame.Width, lineHeight);

Color col = Input.MouseInBox(lineRect) ? Color.White : new Color(200, 200, 200);

// Fill in text for this line

BaseGame.UI.WriteText(xPos1, yPos, (1 + num) + ".", col);

BaseGame.UI.WriteText(xPos2, yPos, highscores[selectedLevel, num].name, col);

BaseGame.UI.WriteGameTime(xPos3, yPos, highscores[selectedLevel, num].timeMs, Color.Yellow);

yPos += lineHeight;

} // for (num)