1 high level shader language (hlsl) chapter 11. 2 what is hlsl? the previous vertex and pixel shader...

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High Level Shader Language (HLSL)

Chapter 11

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What is HLSL?The previous vertex and pixel shader programming is to use assembly language to write instructions, which can de directly executed by GPU Graphical Processing Unit.

HLSL, which refers to High Level Shader Language, is a C style programming language in GPU. However, in order to make HLSL working, the GPU of video card must have ability to compile HLSL into assembly instructions. The minimal requirement for GPU is to fit the shader version 2.

Some tested GPU chips are:

ATI Radeon Xpress 200 or high.nVIDIA GeForce 5200 or high

Intel GMA 945 is failed to execute IndexBuffer

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Check video card shader VersionCaps DevCaps = Manager.GetDeviceCaps(0,

DeviceType.Hardware);DeviceType DevType = D3D.DeviceType.Reference;CreateFlags DevFlags = CreateFlags.SoftwareVertexProcessing;if ((DevCaps.VertexShaderVersion >= new Version(2, 0)) &&

(DevCaps.PixelShaderVersion >= new Version(2, 0))) {

DevType =DeviceType.Hardware; if (DevCaps.DeviceCaps.SupportsHardwareTransformAndLight){

DevFlags = CreateFlags.HardwareVertexProcessing;if (DevCaps.DeviceCaps.SupportsPureDevice){

DevFlags |= CreateFlags.PureDevice;}

} }

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Class EffectHLSL code is written in text file with extension *.fx. First we need to load is to an Effect object .

public static Effect FromFile( Device device, string fileName, Include includeFile, // use null ShaderFlags flags, EffectPool pool // use null )

Example

Effect effect = Effect.FromFile(device, "rotation.fx", null, ShaderFlags.None, null);

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Structure of HLSL codeHLSL code has four parts:

1. Variables that get values from application2. Input and Output structure (optional)3. Functions4. Techniques and passes.

One HLSL file could have more techniques. One technique can have multiple passes. Lets see the following example

struct VS_OUPUT{ float4 pos : POSITION; float4 color : COLOR0;};

float4x4 WorldViewProj : WORLDVIEWPROJECTION;

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VS_OUTPUT Rotation(in float4 position : POSITION , in float4 color: COLOR0)

{ VS_OUTPUT Out = (VS_OUTPUT)0; Out.pos = mul(position, WorldViewProj); // Set position Out.color = color; // Set color return Out;

}

technique Transformation{ pass Pass0 { VertexShader = compile vs_1_1 Rotation(); PixelShader = NULL; }}

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VertexDeclaration decl;

VertexElement[] velements = new VertexElement[] { new VertexElement(0, 0, DeclarationType.Float3,

DeclarationMethod.Default, DeclarationUsage.Position, 0),

new VertexElement(0, 12, DeclarationType.Color, DeclarationMethod.Default, DeclarationUsage.Color, 0), VertexElement.VertexDeclarationEnd };

decl = new VertexDeclaration(device, velements)

VertexDeclaration in HLSL

This is same as ASM shader definition

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effect.SetValue(object_name_in_HLSL, object_in_application)

Send Value to ShaderWe need to send some values from application to GPU, besides the Vertices information. One data must be sent is the matrix that is the product of an object WorldMatrix, ViewMatrix and ProjectionMatrix. If we have more than one objects, then we need send more such matrix. If we want set light in Shader, then we need to send the light direction vector and the inverse matrix of object WorldMatrix. If we want to do animation, then some dynamic data are also to be sent. The basic usage is

For example:

effect.SetValue("WorldViewProj", MatrixWorldViewProj)

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Some control codeCullMode = None; // can be control in applicationCullMode = ccw;FillMode = WireFrame; // can be control in applicationFillMode = solid;Zenable = true;ZWriteEnable = true;ZFunc = less;StencilEnable = false;AlphaBlendEnable = false;AlphaTestEnable = false;ColorWriteEnable = red | green | blue;Srcblend = One;Destblend = One;

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Set Matrix Valueprivate void SetViewProjectPosition(){

Matrix matView = Matrix.LookAtLH( new Vector3( 0.0f, 2f, -5.0f ),

new Vector3( 0.0f, 0.0f, 0.0f ), new Vector3( 0.0f, 1.0f,

0.0f ) );Matrix matProj = Matrix.PerspectiveFovLH(

(float)Math.PI / 4.0f, (float)this.Width /(float)this.Height,

1.0f, 1000.0f );

float t = (float)Environment.TickCount/500f *Math.PI; Matrix matRot= Matrix.RotationY(t); Matrix worldViewProj = matRot * matView* matProj ;

effect.SetValue("WorldViewProj", worldViewProj);

}

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One Pass Renderprivate void Render(){ . . .. . . . .

device.BeginScene();device.RenderState.CullMode = Cull.None ;effect.Technique = "Transformation";device.VertexDeclaration = decl;device.SetStreamSource(0, VB,0);

effect.Begin(0);effect.BeginPass(0);device.DrawPrimitives(PrimitiveType.TriangleList, 0, 1);effect.EndPass(); effect.End();

device.EndScene();Device.Present();

}

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Multiple Passes Renderprivate void Render(){

. . . . . . . . . .

int numPasses = effect.Begin(0);for (int i = 0; i < numPasses; i++){

effect.BeginPass(i);device.DrawPrimitives( . . . . . . . . );effect.EndPass();

}effect.End();. . . . . . . . .

}

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Output

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HLSL with TextureIf we set texture data by code

device.SetTexture(0, texture0);

Then in HLSL we can use

sampler TextureSampler;

to get the image data. The pixel color will be

color = tex2D(TextureSampler, textureCoords);

However, we must use a pixel operation function to get the color. We won’t get Texture color in Vertex operation function

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Examplesampler TextureSampler; // input texture float4x4 WorldViewProj : WORLDVIEWPROJECTION;

void Rotation( in float4 inputPosition : POSITION,in float2 inputTexCoord : TEXCOORD0,out float4 outputPosition : POSITION,out float2 outputTexCoord : TEXCOORD0)

{ // Get position outputPosition = mul(inputPosition, WorldViewProj); outputTexCoord = inputTexCoord;}

This function only gets the position of the vertex. Also it output the texture coordinates outputTexCoord.

Any output could be used as the input of the next function.

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technique TransformTexture{ pass P0 {

VertexShader = compile vs_1_1 Rotation(); PixelShader = compile ps_1_1 TextureColor(); }}

void TextureColor( in float2 textureCoords : TEXCOORD0, out float4 diffuseColor : COLOR0)

{ // Get the texture color

diffuseColor = tex2D(TextureSampler, textureCoords);};

textureCoords is the out put of the last function

The pass will call two functions

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Output

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HLSL with Multiple TexturesIt is easy to send multiple textures to HLSL by SetValue(…)

After loading them, use code

Texture t1, t2, t3;

In HLSL, we set this way

effect.SetValue("Texture1", t1);effect.SetValue("Texture2", t2); effect.SetValue("Texture3", t3);

Texture Texture1;Texture Texture2;Texture Texture3; sampler samp1 = sampler_state { texture = <Texture1>; }sampler samp2 = sampler_state { texture = <Texture2>; } sampler samp3 = sampler_state { texture = <Texture3>; }

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Texture Texture1;Texture Texture2; Texture Texture3;

sampler samp1 = sampler_state { texture = <Texture1>; minfilter = LINEAR; mipfilter = LINEAR; magfilter = LINEAR;};sampler samp2 = sampler_state { texture = <Texture2>; minfilter = LINEAR; mipfilter = LINEAR; magfilter = LINEAR;}; sampler samp3 = sampler_state { texture = <Texture3>; minfilter = LINEAR; mipfilter = LINEAR; magfilter = LINEAR;};

float4x4 WorldViewProj : WORLDVIEWPROJECTION;

float4 Alpha;

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void Rotation( in float4 inputPosition : POSITION,in float2 inputTexCoord : TEXCOORD0,out float4 outputPosition : POSITION,out float2 outputTexCoord : TEXCOORD0 )

{ outputPosition = mul(inputPosition, WorldViewProj); outputTexCoord = inputTexCoord;}

void TextureColor1( in float2 textureCoords : TEXCOORD0, out float4 diffuseColor : COLOR0)

{ diffuseColor = tex2D(samp1, textureCoords); };

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void TextureColor2( in float2 textureCoords : TEXCOORD0,out float4 diffuseColor : COLOR0)




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{ vector color1 = tex2D(samp1, textureCoords); vector color2 = tex2D(samp2, textureCoords); diffuseColor = color1*color2 ; // must ps_2_0 version};void TextureColor5( in float2 textureCoords : TEXCOORD0,

out float4 diffuseColor : COLOR0){ vector color1 = tex2D(samp1, textureCoords); diffuseColor = 1-color1; };

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void TextureColor6( in float2 textureCoords : TEXCOORD0,out float4 diffuseColor : COLOR0){

vector color1 = tex2D(samp1, textureCoords); vector color2 = tex2D(samp2, textureCoords); diffuseColor = 0.9-(1-color1)*color2 ; };

void TextureColor7( in float2 textureCoords : TEXCOORD0,out float4 diffuseColor : COLOR0){

float4 a = float4(0.33f, 0.33f, 0.33f, 0.0f); vector color1 = tex2D(samp1, textureCoords); diffuseColor.xyz = dot(a, color1); diffuseColor.w=1.0;

};

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void TextureColor8( in float2 textureCoords : TEXCOORD0,out float4 diffuseColor : COLOR0) {

diffuseColor.x = textureCoords.x; diffuseColor.y = textureCoords.y; diffuseColor.z =0; diffuseColor.w = 1.0;

};void TextureColor9( in float2 textureCoords : TEXCOORD0,

out float4 diffuseColor : COLOR0) { vector color1 = tex2D(samp1, textureCoords); vector color2 = tex2D(samp2, textureCoords); diffuseColor = color1*Alpha + color2*(1-Alpha) ;};

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technique TransformTexture1{ pass P0 { VertexShader = compile vs_1_1 Rotation(); PixelShader = compile ps_1_1 TextureColor1(); }}

technique TransformTexture2{ pass P0 { VertexShader = compile vs_1_1 Rotation(); PixelShader = compile ps_1_1 TextureColor2(); }}technique TransformTexture3{ pass P0 { VertexShader = compile vs_1_1 Rotation(); PixelShader = compile ps_1_1 TextureColor3(); }}

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technique TransformTexture4{ pass P0 { VertexShader = compile vs_1_1 Rotation(); PixelShader = compile ps_2_0 TextureColor4(); }}technique TransformTexture5{ pass P0 { VertexShader = compile vs_1_1 Rotation(); PixelShader = compile ps_1_1 TextureColor5(); }}technique TransformTexture6{ pass P0 { VertexShader = compile vs_1_1 Rotation(); PixelShader = compile ps_2_0 TextureColor6(); }}

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technique TransformTexture7{ pass P0 { VertexShader = compile vs_1_1 Rotation(); PixelShader = compile ps_1_1 TextureColor7(); }}technique TransformTexture8{ pass P0 { VertexShader = compile vs_1_1 Rotation(); PixelShader = compile ps_1_1 TextureColor8(); }}technique TransformTexture9{ pass P0 { VertexShader = compile vs_1_1 Rotation(); PixelShader = compile ps_2_0 TextureColor9(); }}

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protected override void OnKeyDown(KeyEventArgs e){

if(e.KeyCode ==Keys.Up) flag--;if(e.KeyCode ==Keys.Down) flag++;if(flag==6) flag=1;if(flag==0) flag =5;if (flag==1)effect.Technique = "TransformTexture1";if(flag==2)effect.Technique = "TransformTexture2";if(flag==3)effect.Technique = "TransformTexture3";if(flag==4)effect.Technique = "TransformTexture4";if(flag==5)effect.Technique = "TransformTexture5";if(flag==6)effect.Technique = "TransformTexture6";if(flag==7)effect.Technique = "TransformTexture7";if(flag==8)effect.Technique = "TransformTexture8";if(flag==9)effect.Technique = "TransformTexture9";

}

Control code in application

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HLSL with Lights

Color = lightColor*saturate(dot(lightDirection, objectNormal))

All lights are applied to the last position of the 3D object. However, in HLSL the object is in its original position. Therefore we can either multiply the inverse of the world matrix of the object to the lights direction or multiply world matrix to the normal direction of the 3D object in HLSL.

The formula of the color is:

Two directions lightDirection and objectNormal must be normalized and in the same world coordinate system

LastColor = Color *(1-ambient) +ambient)

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HLSL AnimationHLSL animation is exactly same as ASM shader animation.

Mesh0 Mesh1 left eyebrow down

Mesh2 right eyebrow down

Mesh3 smile

The animation formula is

mesh0+ *(mesh1-mesh0)+ *(mesh2-mesh0)+ *(mesh3-mesh0)

Here , and are floating numbers between 0 and 1

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VertexElement[] TweenElements = new VertexElement[]{

new VertexElement(0, 0, DeclarationType.Float3, DeclarationMethod.Default, DeclarationUsage.Position, 0),

new VertexElement(0, 12, DeclarationType.Float3, DeclarationMethod.Default, DeclarationUsage.Normal, 0),

new VertexElement(0, 24, DeclarationType.Float2, DeclarationMethod.Default, DeclarationUsage.TextureCoordinate, 0),



new VertexElement(1, 24, DeclarationType.Float2, DeclarationMethod.Default, DeclarationUsage.TextureCoordinate, 1)

Declare Vertex Element for HLSL

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VertexElement.VertexDeclarationEnd

};

VertexDeclaration declaration ;

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public struct Vertex // preparing for shader

{

public Vector3 p;

public Vector3 n;

public float tu, tv;

public static readonly VertexFormats Format =

VertexFormats.Position | VertexFormats.Normal |

VertexFormats.Texture1;

}

Define Vertex Format

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private VertexBuffer CreateVertexBufferWithFormat(Mesh mesh)

{

int total = mesh.NumberVertices ; Vertex[] src = (Vertex[])mesh.LockVertexBuffer(typeof(Vertex),

LockFlags.None, total);

VertexBuffer VB = new VertexBuffer(typeof(Vertex), total , device, Usage.WriteOnly, 0, Pool.Managed);

Vertex[] dst = (Vertex[])VB.Lock(0, typeof(Vertex), 0, total);

for(int k=0; k<total; k++) { dst[k] = src[k]; }

VB.Unlock();

mesh.UnlockVertexBuffer();

return VB;

}

Create VertexBuffer that has vertex Format

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private void SetMesh() {

ExtendedMaterial[] emtrl;Mesh0 = Mesh.FromFile("base.x", MeshFlags.Managed,

device, out emtrl );materials = new Material[ emtrl.Length ];

textures = new Texture[ emtrl.Length ];for(int i = 0; i < emtrl.Length; i++){if (emtrl[i].TextureFilename != null){ textures[i] = TextureLoader.FromFile( device,

emtrl[i].TextureFilename);}

mesh1 = Mesh.FromFile( "smile.x", MeshFlags.Managed, device);

mesh2 = Mesh.FromFile( "l-ebrow-down.x", MeshFlags.Managed, device);

mesh3 = Mesh.FromFile( "l-ebrow-down.x", MeshFlags.Managed, device);

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VB0 = CreateVertexBufferWithFormat(mesh0);




GraphicsStream stream = VB0.Lock(0, mesh0.NumberVertices, LockFlags.None) ;

radius =Geometry.ComputeBoundingSphere( stream, mesh0.NumberVertices,Vertex.Format,

out vCenter);

Matrix S = Matrix.Scaling(4/radius, 4/radius, 4/radius);

Matrx T = Matrix.Translation (-vCenter);

worldMatrix = T*S;

effect = Effect.FromFile(device, "HardwareHLSL.fx", null, null, ShaderFlags.NotCloneable, null );

}

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private void SetViewAndProjection(){

viewMatrix = Matrix.LookAtLH( new Vector3(0, 0, -8),

new Vector3(0, 0, 0), new Vector3(0,1,0));

projectionMatrix = Matrix.PerspectiveFovLH(

(float)Math.PI / 4f,

(float)this.Width / (float)this.Height,

0.1f, 10000f );

worldMatrix = T*S*rotationMatrix;

Matrix mat = worldMatrix*viewMatrix * projectionMatrix;

effect.SetValue( "WorldViewProjection", mat); effect.SetValue( "World", rotationMatrix );

}

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protected override void OnMouseDown(MouseEventArgs e){

if(e.Button ==MouseButtons.Right ) return;down = true; lastX = e.X ; lastY = e.Y ;

}

protected override void OnMouseUp(MouseEventArgs e){ down = false; }

protected override void OnMouseMove(MouseEventArgs e){

if(!down) return; float dx = (float)(lastX - e.X) ;

float dy = (float)(lastY - e.Y) ;lastX = e.X ; lastY = e.Y ;

Matrix mat = Matrix.RotationYawPitchRoll(dx/80f, dy/80f, 0.0f);

rotationMatrix = mat*rotationMatrix;

}

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public void SetWeight()

{

float t1 = 1f;

float t2 = 1.25f;

float t3 = 1.5f;

float time = (float) Environment.TickCount /400;

Wight1 = (float)Math.Pow( Math.Sin( t1 * time), 2);



effect.SetValue( "Weight1", Wight1 );



}

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private void Render(){ device.Clear(ClearFlags.ZBuffer | ClearFlags.Target,

0x000000ff, 1.0f, 0);AttributeRange[] attributes = mesh0.GetAttributeTable(); device.BeginScene();SetWeight();SetViewAndProjection();

device.SetStreamSource(0, VB0,0 ); device.SetStreamSource(1, VB1,0 );device.SetStreamSource(2, VB2,0 );device.SetStreamSource(3, VB3, 0 );

device.VertexDeclaration = declaration;

effect.Technique = "Tween";

device.Indices = mesh0.IndexBuffer;int numPasses = effect.Begin( FX.None );

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for (int pass = 0; pass < numPasses; pass++){

effect.BeginPass(pass);for( int i = 0; i < attributes.Length; i++){

effect.SetValue("Tex0", textures[i]); effect.SetValue("UseTexture", textures[i] != null ); effect.SetValue("MaterialDiffuse",

ColorToVector4( materials[i].Diffuse )); effect.CommitChanges();

device.DrawIndexedPrimitives( PrimitiveType.TriangleList, 0, attributes[i].VertexStart,

attributes[i].VertexCount, attributes[i].FaceStart * 3, attributes[i].FaceCount ); } effect.EndPass();}effect.End();device.EndScene();device.Present();

}

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HLSL codefloat4x4 WorldViewProjection; // World * View * Projectionfloat4x4 World; // World matrixfloat3 LightDirection = { 0, 0.5f, -1 };float4 MaterialDiffuse;

float Weight1;float Weight2;float Weight3;

bool UseTexture = false;

texture Tex0;sampler Tex0Sampler = sampler_state{

Texture = <Tex0>; MinFilter = Linear; MagFilter = Linear; MipFilter = Linear;

};

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struct VS_INPUT{ float4 position0 : POSITION0; float3 normal0 : NORMAL0; float2 tex0 : TEXCOORD0;

float4 position1 : POSITION1; float3 normal1 : NORMAL1;



};

void ps( in float2 tex0 : TEXCOORD0 , in float3 normal : TEXCOORD1, out float4 color : COLOR0 )

{ if (UseTexture) { color = tex2D( Tex0Sampler, tex0 );} else { color = MaterialDiffuse; } color *= saturate(dot(LightDirection, normal)); };

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void vsTween( in VS_INPUT input,out float4 position : POSITION0,out float2 tex1 : TEXCOORD0, out float3 normal : TEXCOORD1)

{float4 pos = input.position0;pos += (input.position1 - input.position0) * Weight1;pos += (input.position2 - input.position0) * Weight2;pos += (input.position3 - input.position0) * Weight3;position = mul(pos, WorldViewProjection);

float3 nor = input.normal0;nor += (input.normal1 - input.normal0) * Weight1;nor += (input.normal2 - input.normal0) * Weight2;nor += (input.normal3 - input.normal0) * Weight3;

normal = mul( nor, World );

tex1 = input.tex0;

};

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technique Tween{ pass P0 { VertexShader = compile vs_2_0 vsTween(); PixelShader = compile ps_2_0 ps(); }}

1 high level shader language (hlsl) chapter 11. 2 what is hlsl? the previous vertex and pixel shader...

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