Load (DirectX HLSL Texture Object)

Reads texel data without any filtering or sampling.

ret Object.Load( typeX Location, [typeX SampleIndex, ] [typeX Offset ] );

typeX denotes that there are four possible types: int, int2, int3 or int4.

 

Parameters

Object

A texture-object type (except TextureCube or TextureCubeArray).

Location

[in] The texture coordinates; the last component specifies the mipmap level. This method uses a 0-based coordinate system and not a 0.0-1.0 UV system. The argument type is dependent on the texture-object type.

Object Type	Parameter Type
Buffer	int
Texture1D, Texture2DMS	int2
Texture1DArray, Texture2D, Texture2DMSArray	int3
Texture2DArray, Texture3D	int4

 

For example, to access a 2D texture, supply integer texel coordinates for the first two components and a mipmap level for the third component.

Note

When one or more of the coordinates in Location exceed the u, v, or w mipmap level dimensions of the texture, Load returns zero in all components. Direct3D guarantees to return zero for any resource that is accessed out of bounds.

 

SampleIndex

[in] A sampling index. Required for multi-sample textures. Not supported for other textures.

Texture Type	Parameter Type
Texture1D, Texture1DArray, Texture2D, Texture2DArray, Texture3D, Texture2DArray, TextureCube, TextureCubeArray	not supported
Texture2DMS, Texture2DMSArray¹	int

Offset

[in] An optional offset applied to the texture coordinates before sampling. The offset type is dependent on the texture-object type, and needs to be static.

Texture Type	Parameter Type
Texture1D, Texture1DArray	int
Texture2D, Texture2DArray, Texture2DMS, Texture2DMSArray	int2
Texture3D	int3

 

Note

SampleIndex must always be specified first with multi-sample textures.

 

Return Value

The return type matches the type in the Object declaration. For example, a Texture2D object that was declared as "Texture2d<uint4> myTexture;" has a return value of type uint4.

Minimum Shader Model

This function is supported in the following shader models.

vs_4_0	vs_4_1¹	ps_4_0	ps_4_1¹	gs_4_0	gs_4_1¹
x	x	x	x	x	x

 

• Shader Model 4.1 is available in Direct3D 10.1 or higher.

Example

This partial code example is from the Paint.fx file in the AdvancedParticles Sample.

// Object Declarations
Buffer<float4> g_ParticleBuffer;

// Shader body calling the intrinsic function
float4 PSPaint(PSQuadIn input) : SV_Target
{       
    ... 
    for( int i=g_ParticleStart; i<g_NumParticles; i+=g_ParticleStep )
    {
        ... 
        // load the particle
        float4 particlePos = g_ParticleBuffer.Load( i*4 );
        float4 particleColor = g_ParticleBuffer.Load( (i*4) + 2 );
        ...     
    }
    ...
}   

Related topics

Texture-Object