glTexStorage2D — simultaneously specify storage for all levels of a two-dimensional or one-dimensional array texture
void glTexStorage2D( | GLenum target, |
GLsizei levels, | |
GLenum internalformat, | |
GLsizei width, | |
GLsizei height) ; |
target
Specify the target of the operation. target
must be
one of GL_TEXTURE_2D
, GL_PROXY_TEXTURE_2D
,
GL_TEXTURE_1D_ARRAY
, GL_PROXY_TEXTURE_1D_ARRAY
,
GL_TEXTURE_RECTANGLE
, GL_PROXY_TEXTURE_RECTANGLE
,
or GL_PROXY_TEXTURE_CUBE_MAP
.
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.
glTexStorage2D
specifies 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
or GL_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)); }
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 |
GL_INVALID_ENUM
is generated if internalformat
is not a
valid sized internal format.
GL_INVALID_ENUM
is generated if target
is not
one of the accepted target enumerants.
GL_INVALID_VALUE
is generated if width
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
GL_INVALID_OPERATION
is generated if target
is not GL_TEXTURE_1D_ARRAY
or GL_PROXY_TEXTURE_1D_ARRAY
and levels
is greater than
Copyright © 2011 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. http://opencontent.org/openpub/.