Edit

Share via

Effect Variable Syntax (Direct3D 10)

  • Article

An effect variable is declared with the following syntax.

Syntax

DataType VariableName [ : SemanticName ] < Annotations >;

Name Description
DataType Any basic or texture type.
VariableName An ASCII string that uniquely identifies the name of the effect variable.
SemanticName A ASCII string that denotes additional information about how a variable should be used. A semantic is an ASCII string that can be either a predefined system-value or a custom-user string.
Annotations One or more pieces of user-supplied information (metadata) that is ignored by the effect system. For syntax, see Annotation Syntax (Direct3D 10).

 

An effect variable that is declared outside of all functions, is considered global in scope; variables declared within a function are local to that function.

Example

The BasicHLSL10 sample uses global variables without semantics for material colors, light properties and transformation matrices.

This example illustrates global effect variables.

float4 g_MaterialAmbientColor;      // Material's ambient color
float4 g_MaterialDiffuseColor;      // Material's diffuse color
float3 g_LightDir[3];               // Light's direction in world space
float4x4 g_mWorld;                  // World matrix for object

This example illustrates effect variables that are local to a shader function.

VS_OUTPUT RenderSceneVS( ... )
{
    float3 vNormalWorldSpace;
    float4 vAnimatedPos;

    // shader body
}

This example illustrates function parameters that have semantics.

VS_OUTPUT RenderSceneVS( float4 vPos : SV_POSITION,
                         float3 vNormal : NORMAL,
                         float2 vTexCoord0 : TEXCOORD0,
                         uniform int nNumLights,
                         uniform bool bTexture,
                         uniform bool bAnimate )
{
  ...
}

This example illustrates declaring a texture variable.

Texture2D g_MeshTexture;            // Color texture for mesh

Sampling a texture is done with a texture sampler. To set up a sampler in an effect, see the sampler type.

Effect Format