永威國(guó)際道州本土游戲

永威國(guó)際道州本土游戲永威國(guó)際道州本土游戲第13章：HLSL基礎(chǔ)問(wèn)答答案1.?在HLSL中，如何獲取一個(gè)float4對(duì)象的第一個(gè)元素？?如果您想要獲取一個(gè)叫做color的float4對(duì)象中的第一個(gè)元素，您可以用數(shù)組符號(hào)（color[0]）或者您也可以使用顏色和位置的命名空間（color.r或者color.x）?2.?什么叫做混合（swizzling）？?Swizzling是指從顏色或位置的命名空間（如color.rb或color.xyz）取兩個(gè)或多個(gè)元素來(lái)獲取一個(gè)float4或類(lèi)似數(shù)據(jù)類(lèi)型的多個(gè)元素。?3.?在HLSL，如何規(guī)定使用頂點(diǎn)、像素著色器的哪一個(gè)版本？?在HLSL效果文件處理技巧中，您可以通過(guò)提供帶有著色器版本的compile關(guān)鍵字來(lái)指定一個(gè)VertexShader（頂點(diǎn)著色器）和/或PixelShader（像素著色器）。對(duì)于頂點(diǎn)著色器，您可以用vs_2_0句法，而對(duì)于像素著色器，您則可以用ps_2_0語(yǔ)法。?4.?若沒(méi)有HLSL，您不能實(shí)現(xiàn)哪些效果？?HLSL允許開(kāi)發(fā)人員連接到硬件功能，而XNA框架是不提供這些的。原因：圖形硬件變得越來(lái)越復(fù)雜，如果XNA框架被擴(kuò)展來(lái)處理所有顯卡（graphics?card）的話(huà)，XNA框架會(huì)變得很龐大。所以，HLSL與XNA協(xié)作，允許您為顯卡本身編寫(xiě)代碼。?5.?在HLSL，怎樣將那個(gè)兩個(gè)矩陣相乘？?HLSL中的mul函數(shù)可以將兩個(gè)矩陣相乘。?6.?語(yǔ)義（semantic）在HLSL扮演什么角色？?一個(gè)語(yǔ)義標(biāo)記一個(gè)變量的特定用途。對(duì)于輸入?yún)?shù)（input?parameters），語(yǔ)義意味著該參數(shù)會(huì)被自動(dòng)賦予由語(yǔ)義指定的一個(gè)值；對(duì)于輸出參數(shù)（output?parameters），語(yǔ)義是一種標(biāo)記特定391變量含有特定信息的方式，這種信息會(huì)在著色器（shader）執(zhí)行完之后被處理。?練習(xí)答案使用本章所創(chuàng)建的代碼，繪制一個(gè)六面體，用樹(shù)木圖像作為每面的紋理。在六面體的每面上，使用本章創(chuàng)建的四種紋理特效（一般紋理、模糊紋理、反相紋理、灰度紋理）的其中一種，每種效果必須被至少使用一次。?本練習(xí)和第9章的練習(xí)很相似，在那里您做了一個(gè)每個(gè)面紋理都不同的六面體。不同之處在于，您現(xiàn)在要對(duì)每個(gè)面應(yīng)用相同的紋理，再對(duì)那些面應(yīng)用不同的HLSL效果。?首先，根據(jù)本章所介紹的方法創(chuàng)建不同的效果文件，然后使用與下面類(lèi)似的代碼來(lái)創(chuàng)建這個(gè)六面體并為其應(yīng)用您所創(chuàng)建的效果：?usingusingusingusingusingusingusingusingusingusingSystem;System.Collections.Generic;System.Linq;Microsoft.Xna.Framework;Microsoft.Xna.Framework.Audio;Microsoft.Xna.Framework.Content;Microsoft.Xna.Framework.GamerServices;Microsoft.Xna.Framework.Graphics;Microsoft.Xna.Framework.Input;Microsoft.Xna.Framework.Media;namespace_3D_Madness{//////Thisisthemaintypeforyourgame.///publicclassGame1:Microsoft.Xna.Framework.Game{GraphicsDeviceManagergraphics;SpriteBatchspriteBatch;//GamecameraCameracamera;//VertexdataVertexPositionTexture[]verts;VertexBuffervertexBuffer;//EffectEffectnormalEffect;EffectblurEffect;EffectnegativeEffect;EffectgrayscaleEffect;//MovementandrotationstuffMatrixworldTranslation=Matrix.Identity;MatrixworldRotation=Matrix.Identity;//TextureinfoTexture2Dtexture;publicGame1(){graphics=newGraphicsDeviceManager(this);Content.RootDirectory="Content";}392??//////Allowsthegametoperformanyinitializationit///needstobeforestartingtorun.Thisiswhereitcanqueryfor///anyrequiredservicesandloadcontent.///protectedoverridevoidInitialize(){//Initializecameracamera=newCamera(this,newVector3(0,0,5),Vector3.Zero,Vector3.Up);Components.Add(camera);base.Initialize();}//////LoadContentwillbecalledoncepergameandistheplacetoload///allofyourcontent.///protectedoverridevoidLoadContent(){//CreateanewSpriteBatch,whichcanbeusedtodrawtextures.spriteBatch=newSpriteBatch(GraphicsDevice);//initializeverticesverts=newVertexPositionTexture[24];//FRONTverts[0]=newVertexPositionTexture(newVector3(-1,1,1),newVector2(0,0));verts[1]=newVertexPositionTexture(newVector3(1,1,1),newVector2(1,0));verts[2]=newVertexPositionTexture(newVector3(-1,-1,1),newVector2(0,1));verts[3]=newVertexPositionTexture(newVector3(1,-1,1),newVector2(1,1));//BACKverts[4]=newVertexPositionTexture(newVector3(1,1,-1),newVector2(0,0));verts[5]=newVertexPositionTexture(newVector3(-1,1,-1),newVector2(1,0));verts[6]=newVertexPositionTexture(newVector3(1,-1,-1),newVector2(0,1));verts[7]=newVertexPositionTexture(newVector3(-1,-1,-1),newVector2(1,1));//LEFTverts[8]=newVertexPositionTexture(newVector3(-1,1,-1),newVector2(0,0));verts[9]=newVertexPositionTexture(newVector3(-1,1,1),newVector2(1,0));verts[10]=newVertexPositionTexture(newVector3(-1,-1,-1),newVector2(0,1));verts[11]=newVertexPositionTexture(newVector3(-1,-1,1),newVector2(1,1));//RIGHTverts[12]=newVertexPositionTexture(newVector3(1,1,1),newVector2(0,0));verts[13]=newVertexPositionTexture(newVector3(1,1,-1),newVector2(1,0));verts[14]=newVertexPositionTexture(newVector3(1,-1,1),newVector2(0,1));verts[15]=newVertexPositionTexture(?393newVector3(1,-1,-1),newVector2(1,1));//TOPverts[16]=newVertexPositionTexture(newVector3(-1,1,-1),newVector2(0,0));verts[17]=newVertexPositionTexture(newVector3(1,1,-1),newVector2(1,0));verts[18]=newVertexPositionTexture(newVector3(-1,1,1),newVector2(0,1));verts[19]=newVertexPositionTexture(newVector3(1,1,1),newVector2(1,1));//BOTTOMverts[20]=newVertexPositionTexture(newVector3(-1,-1,1),newVector2(0,0));verts[21]=newVertexPositionTexture(newVector3(1,-1,1),newVector2(1,0));verts[22]=newVertexPositionTexture(newVector3(-1,-1,-1),newVector2(0,1));verts[23]=newVertexPositionTexture(newVector3(1,-1,-1),newVector2(1,1));//SetvertexdatainVertexBuffervertexBuffer=newVertexBuffer(GraphicsDevice,typeof(VertexPositionTexture),verts.Length,BufferUsage.None);vertexBuffer.SetData(verts);//LoadeffectnormalEffect=Content.Load<Effect>(@"effects\Red");grayscaleEffect=Content.Load<Effect>(@"effects\Grayscale");negativeEffect=Content.Load<Effect>(@"effects\Negative");blurEffect=Content.Load<Effect>(@"effects\Blur");//Loadtexturetexture=Content.Load<Texture2D>(@"Textures\trees");}//////UnloadContentwillbecalledoncepergameandis///theplacetounloadallcontent.///protectedoverridevoidUnloadContent(){//TODO:Unloadanynon-ContentManagercontenthere}//////Allowsthegametorunlogicsuchasupdatingtheworld,///checkingforcollisions,gatheringinput,andplayingaudio.//////Providesasnapshotoftimingvalues.protectedoverridevoidUpdate(GameTimegameTime){//Allowsthegametoexitif(GamePad.GetState(PlayerIndex.One).Buttons.Back==ButtonState.Pressed)this.Exit();//TranslationKeyboardStatekeyboardState=Keyboard.GetState();if(keyboardState.IsKeyDown(Keys.Left))worldTranslation*=Matrix.CreateTranslation(-.01f,0,0);if(keyboardState.IsKeyDown(Keys.Right))394??worldTranslation*=Matrix.CreateTranslation(.01f,0,0);//RotationworldRotation*=Matrix.CreateFromYawPitchRoll(MathHelper.PiOver4/60,0,0);base.Update(gameTime);}//////Thisiscalledwhenthegameshoulddrawitself.//////Providesasnapshotoftimingvalues.///protectedoverridevoidDraw(GameTimegameTime){GraphicsDevice.Clear(Color.CornflowerBlue);//SetthevertexbufferontheGraphicsDeviceGraphicsDevice.SetVertexBuffer(vertexBuffer);//DrawfrontDrawVerts(normalEffect,0,2);//DrawbackDraw