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glextensions - GL_SGIS_texture_filter4.wiki

Contents

  • Dependencies
  • Overview
  • New Procedures and Functions
  • New Tokens
  • Errors
  • New Implementation Dependent State

Dependencies

None

Overview

This extension allows 1D and 2D textures to be filtered using an application-defined, four sample per dimension filter. (In addition to the NEAREST and LINEAR filters defined in the original GL Specification.) Such filtering results in higher image quality. It is defined only for non-mipmapped filters. The filter that is specified must be symmetric and separable (in the 2D case).

New Procedures and Functions

``` void TexFilterFuncSGIS(enum target, enum filter, sizei n, const float* weights);

void GetTexFilterFuncSGIS(enum target, enum filter, float* weights); ```

New Tokens

Accepted by the

<param>

parameter of TexParameteri and TexParameterf, and by the

<params>

parameter of TexParameteriv and TexParameterfv, when their

<pname>

parameter is TEXTURE_MIN_FILTER or TEXTURE_MAG_FILTER. Also accepted by the

<filter>

parameters of TexFilterFuncSGIS and GetTexFilterFuncSGIS:

|FILTER4_SGIS| |:------------|

Accepted by the

<pname>

parameter of GetTexParameteriv and GetTexParameterfv, when the

<target>

parameter is TEXTURE_1D or TEXTURE_2D:

|TEXTURE_FILTER4_SIZE_SGIS| |:---------------------------|

Errors

INVALID_ENUM is generated if TexFilterFuncSGIS or GetTexFilterFuncSGIS parameter

<target>

is not TEXTURE_1D or TEXTURE_2D.

INVALID_ENUM is generated if TexFilterFuncSGIS or GetTexFilterFuncSGIS parameter

<filter>

is not FILTER4_SGIS.

INVALID_VALUE is generated if TexFilterFuncSGIS parameter

<n>

does not equal 2m + 1 for some nonnegative integer value of m.

INVALID_ENUM is generated if GetTexParameteriv or GetTexParameterfv parameter

<pname>

is TEXTURE_FILTER4_SIZE_SGIS and parameter

<target>

is not TEXTURE_1D or TEXTURE_2D.

INVALID_OPERATION is generated if TexFilterFuncSGIS or GetTexFilterFuncSGIS is executed between execution of Begin and the corresponding execution of End.

New Implementation Dependent State

| Get Value | Get Command | Type | Minimum Value | |:--------------|:----------------|:---------|:------------------| |TEXTURE_FILTER4_SIZE_SGIS | GetTexParameterfv | R | 17 |