GLTEXSTORAGE2D

Section: [FIXME: manual] (3G)
Updated: 01/26/2021
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NAME

glTexStorage2D, glTextureStorage2D - simultaneously specify storage for all levels of a two-dimensional or one-dimensional array texture  

C SPECIFICATION

void glTexStorage2D(GLenum target, GLsizei levels, GLenum internalformat, GLsizei width, GLsizei height);
void glTextureStorage2D(GLuint texture, GLsizei levels, GLenum internalformat, GLsizei width, GLsizei height);
 

PARAMETERS

target

Specifies the target to which the texture object is bound for glTexStorage2D. Must be one of GL_TEXTURE_2D, GL_TEXTURE_1D_ARRAY, GL_TEXTURE_RECTANGLE, GL_TEXTURE_CUBE_MAP, GL_PROXY_TEXTURE_2D, GL_PROXY_TEXTURE_1D_ARRAY, GL_PROXY_TEXTURE_RECTANGLE, or GL_PROXY_TEXTURE_CUBE_MAP.

texture

Specifies the texture object name for glTextureStorage2D. The effective target of texture must be one of the valid non-proxy target values above.

levels

Specify the number of texture levels.

internalformat

Specifies the sized internal format to be used to store texture image data.

width

Specifies the width of the texture, in texels.

height

Specifies the height of the texture, in texels.
 

DESCRIPTION

glTexStorage2D and glTextureStorage2D specify the storage requirements for all levels of a two-dimensional texture or one-dimensional texture array simultaneously. Once a texture is specified with this command, the format and dimensions of all levels become immutable unless it is a proxy texture. The contents of the image may still be modified, however, its storage requirements may not change. Such a texture is referred to as an immutable-format texture.

The behavior of glTexStorage2D depends on the target parameter. When target is GL_TEXTURE_2D, GL_PROXY_TEXTURE_2D, GL_TEXTURE_RECTANGLE, GL_PROXY_TEXTURE_RECTANGLE or GL_PROXY_TEXTURE_CUBE_MAP, calling glTexStorage2D is equivalent, assuming no errors are generated, to executing the following pseudo-code: 

    for (i = 0; i < levels; i++) {
        glTexImage2D(target, i, internalformat, width, height, 0, format, type, NULL);
        width = max(1, (width / 2));
        height = max(1, (height / 2));
    }

When target is GL_TEXTURE_CUBE_MAP, glTexStorage2D is equivalent to: 

    for (i = 0; i < levels; i++) {
        for (face in (+X, -X, +Y, -Y, +Z, -Z)) {
            glTexImage2D(face, i, internalformat, width, height, 0, format, type, NULL);
        }
        width = max(1, (width / 2));
        height = max(1, (height / 2));
    }

When target is GL_TEXTURE_1D_ARRAY or GL_PROXY_TEXTURE_1D_ARRAY, glTexStorage2D is equivalent to: 

    for (i = 0; i < levels; i++) {
        glTexImage2D(target, i, internalformat, width, height, 0, format, type, NULL);
        width = max(1, (width / 2));
    }

Calling glTextureStorage2D is equivalent to the above pseudo-code, where target is the effective target of texture and it is as if texture were bound to target for the purposes of glTexImage2D.

Since no texture data is actually provided, the values used in the pseudo-code for format and type are irrelevant and may be considered to be any values that are legal for the chosen internalformat enumerant. internalformat must be one of the sized internal formats given in Table 1 below, one of the sized depth-component formats GL_DEPTH_COMPONENT32F, GL_DEPTH_COMPONENT24, or GL_DEPTH_COMPONENT16, one of the combined depth-stencil formats, GL_DEPTH32F_STENCIL8, or GL_DEPTH24_STENCIL8, or the stencil-only format, GL_STENCIL_INDEX8. Upon success, the value of GL_TEXTURE_IMMUTABLE_FORMAT becomes GL_TRUE. The value of GL_TEXTURE_IMMUTABLE_FORMAT may be discovered by calling glGetTexParameter() with pname set to GL_TEXTURE_IMMUTABLE_FORMAT. No further changes to the dimensions or format of the texture object may be made. Using any command that might alter the dimensions or format of the texture object (such as glTexImage2D() or another call to glTexStorage2D) will result in the generation of a GL_INVALID_OPERATION error, even if it would not, in fact, alter the dimensions or format of the object.


Table 1. Sized Internal Formats

Sized Internal Format Base Internal Format Red Bits Green Bits Blue Bits Alpha Bits Shared Bits
GL_R8 GL_RED 8        
GL_R8_SNORM GL_RED s8        
GL_R16 GL_RED 16        
GL_R16_SNORM GL_RED s16        
GL_RG8 GL_RG 8 8      
GL_RG8_SNORM GL_RG s8 s8      
GL_RG16 GL_RG 16 16      
GL_RG16_SNORM GL_RG s16 s16      
GL_R3_G3_B2 GL_RGB 3 3 2    
GL_RGB4 GL_RGB 4 4 4    
GL_RGB5 GL_RGB 5 5 5    
GL_RGB8 GL_RGB 8 8 8    
GL_RGB8_SNORM GL_RGB s8 s8 s8    
GL_RGB10 GL_RGB 10 10 10    
GL_RGB12 GL_RGB 12 12 12    
GL_RGB16_SNORM GL_RGB 16 16 16    
GL_RGBA2 GL_RGB 2 2 2 2  
GL_RGBA4 GL_RGB 4 4 4 4  
GL_RGB5_A1 GL_RGBA 5 5 5 1  
GL_RGBA8 GL_RGBA 8 8 8 8  
GL_RGBA8_SNORM GL_RGBA s8 s8 s8 s8  
GL_RGB10_A2 GL_RGBA 10 10 10 2  
GL_RGB10_A2UI GL_RGBA ui10 ui10 ui10 ui2  
GL_RGBA12 GL_RGBA 12 12 12 12  
GL_RGBA16 GL_RGBA 16 16 16 16  
GL_SRGB8 GL_RGB 8 8 8    
GL_SRGB8_ALPHA8 GL_RGBA 8 8 8 8  
GL_R16F GL_RED f16        
GL_RG16F GL_RG f16 f16      
GL_RGB16F GL_RGB f16 f16 f16    
GL_RGBA16F GL_RGBA f16 f16 f16 f16  
GL_R32F GL_RED f32        
GL_RG32F GL_RG f32 f32      
GL_RGB32F GL_RGB f32 f32 f32    
GL_RGBA32F GL_RGBA f32 f32 f32 f32  
GL_R11F_G11F_B10F GL_RGB f11 f11 f10    
GL_RGB9_E5 GL_RGB 9 9 9   5
GL_R8I GL_RED i8        
GL_R8UI GL_RED ui8        
GL_R16I GL_RED i16        
GL_R16UI GL_RED ui16        
GL_R32I GL_RED i32        
GL_R32UI GL_RED ui32        
GL_RG8I GL_RG i8 i8      
GL_RG8UI GL_RG ui8 ui8      
GL_RG16I GL_RG i16 i16      
GL_RG16UI GL_RG ui16 ui16      
GL_RG32I GL_RG i32 i32      
GL_RG32UI GL_RG ui32 ui32      
GL_RGB8I GL_RGB i8 i8 i8    
GL_RGB8UI GL_RGB ui8 ui8 ui8    
GL_RGB16I GL_RGB i16 i16 i16    
GL_RGB16UI GL_RGB ui16 ui16 ui16    
GL_RGB32I GL_RGB i32 i32 i32    
GL_RGB32UI GL_RGB ui32 ui32 ui32    
GL_RGBA8I GL_RGBA i8 i8 i8 i8  
GL_RGBA8UI GL_RGBA ui8 ui8 ui8 ui8  
GL_RGBA16I GL_RGBA i16 i16 i16 i16  
GL_RGBA16UI GL_RGBA ui16 ui16 ui16 ui16  
GL_RGBA32I GL_RGBA i32 i32 i32 i32  
GL_RGBA32UI GL_RGBA ui32 ui32 ui32 ui32  

 

NOTES

GL_STENCIL_INDEX8 is accepted for internalformat only if the GL version is 4.4 or higher.  

ERRORS

GL_INVALID_OPERATION is generated by glTexStorage2D if zero is bound to target.

GL_INVALID_OPERATION is generated by glTextureStorage2D if texture is not the name of an existing texture object.

GL_INVALID_ENUM is generated if internalformat is not a valid sized internal format.

GL_INVALID_ENUM is generated if target or the effective target of texture is not one of the accepted targets described above.

GL_INVALID_VALUE is generated if width, height or levels are less than 1.

GL_INVALID_OPERATION is generated if target is GL_TEXTURE_1D_ARRAY or GL_PROXY_TEXTURE_1D_ARRAY and levels is greater than log 2 width + 1.

GL_INVALID_OPERATION is generated if target is not GL_TEXTURE_1D_ARRAY or GL_PROXY_TEXTURE_1D_ARRAY and levels is greater than log 2 max width ,   height + 1.  

VERSION SUPPORT

 OpenGL Version
Function / Feature Name 2.0 2.1 3.0 3.1 3.2 3.3 4.0 4.1 4.2 4.3 4.4 4.5
glTexStorage2D - - - - - - - - ✔ ✔ ✔ ✔
glTextureStorage2D - - - - - - - - - - - ✔

 

SEE ALSO

glTexImage2D(), glTexStorage1D(), glTexStorage3D().  

COPYRIGHT

Copyright © 2011-2014 Khronos Group. This material may be distributed subject to the terms and conditions set forth in the Open Publication License, v 1.0, 8 June 1999. m[blue]http://opencontent.org/openpub/m[].  

COPYRIGHT


Copyright © 2011-2014 Khronos Group

 

Index

NAME
C SPECIFICATION
PARAMETERS
DESCRIPTION
NOTES
ERRORS
VERSION SUPPORT
SEE ALSO
COPYRIGHT
COPYRIGHT