Parameters

Description

Texturing allows elements of an image array to be read by shaders.

To define texture images, call glTexImage3D. The arguments describe the parameters of the texture image, such as height, width, depth, width of the border, level-of-detail number (see glTexParameter), and number of color components provided. The last three arguments describe how the image is represented in memory.

If target is GL_TEXTURE_3D, data is read from data as a sequence of signed or unsigned bytes, shorts, or longs, or single-precision floating-point values, depending on type. These values are grouped into sets of one, two, three, or four values, depending on format, to form elements.

If a non-zero named buffer object is bound to the GL_PIXEL_UNPACK_BUFFER target (see glBindBuffer) while a texture image is specified, data is treated as a byte offset into the buffer object's data store.

The first element corresponds to the lower left corner of the texture image. Subsequent elements progress left-to-right through the remaining texels in the lowest row of the texture image, and then in successively higher rows of the texture image. The final element corresponds to the upper right corner of the texture image.

format determines the composition of each element in data. It can assume one of these symbolic values:

If an application wants to store the texture at a certain resolution or in a certain format, it can request the resolution and format with internalFormat. The GL will choose an internal representation with least the internal component sizes, and exactly the component types shown for that format, although it may not match exactly.

internalFormat may be one of the unsized (base) internal formats shown, together with valid format and type combinations, in Table 1, below

internalFormat may also be one of the sized internal formats shown, together with valid format and type combinations, in Table 2, below

If the internalFormat parameter is GL_SRGB, GL_SRGB8, or GL_SRGB8_ALPHA8, the texture is treated as if the red, green, blue, or luminance components are encoded in the sRGB color space. Any alpha component is left unchanged. The conversion from the sRGB encoded component ${\mathit{c}}_{\mathit{s}}$ to a linear component ${\mathit{c}}_{\mathit{l}}$ is:

${\mathit{c}}_{\mathit{l}}=\{\begin{array}{ll}\frac{{\mathit{c}}_{\mathit{s}}}{12.92}\hfill & if{\mathit{c}}_{\mathit{s}}\le 0.04045\hfill \\ {\left(\frac{c_s+0.055}{1.055}\right)}^{2.4}\hfill & if{\mathit{c}}_{\mathit{s}}>0.04045\hfill \end{array}$

Assume ${\mathit{c}}_{\mathit{s}}$ is the sRGB component in the range [0,1].

A one-component texture image uses only the red component of the RGBA color extracted from data. A two-component image uses the R and A values. A three-component image uses the R, G, and B values. A four-component image uses all of the RGBA components.

Notes

The glPixelStorei mode affects texture images.

data may be a null pointer. In this case texture memory is allocated to accommodate a texture of width width, height height, and depth depth. You can then download subtextures to initialize this texture memory. The image is undefined if the user tries to apply an uninitialized portion of the texture image to a primitive.

glTexImage3D specifies the two-dimensional array or three-dimensional texture for the texture object bound to the current texture unit, specified with glActiveTexture.

Errors

GL_INVALID_ENUM is generated if target is not GL_TEXTURE_3D or GL_TEXTURE_2D_ARRAY.

GL_INVALID_ENUM is generated if format is not an accepted format constant. Format constants other than GL_STENCIL_INDEX and GL_DEPTH_COMPONENT are accepted.

GL_INVALID_ENUM is generated if type is not a type constant.

GL_INVALID_VALUE is generated if level is less than 0.

GL_INVALID_VALUE may be generated if level is greater than ${\mathit{log}}_2\left(\mathit{max}\right)$, where max is the returned value of GL_MAX_3D_TEXTURE_SIZE.

GL_INVALID_VALUE is generated if internalFormat is not one of the accepted resolution and format symbolic constants.

GL_INVALID_VALUE is generated if width, height, or depth is less than 0 or greater than GL_MAX_3D_TEXTURE_SIZE.

GL_INVALID_VALUE is generated if border is not 0 or 1.

GL_INVALID_OPERATION is generated if the combination of internalFormat, format and type is not one of those in the tables above.

GL_INVALID_OPERATION is generated if target is GL_TEXTURE_3D and format is GL_DEPTH_COMPONENT, or GL_DEPTH_STENCIL.

GL_INVALID_OPERATION is generated if a non-zero buffer object name is bound to the GL_PIXEL_UNPACK_BUFFER target and the buffer object's data store is currently mapped.

GL_INVALID_OPERATION is generated if a non-zero buffer object name is bound to the GL_PIXEL_UNPACK_BUFFER target and the data would be unpacked from the buffer object such that the memory reads required would exceed the data store size.

GL_INVALID_OPERATION is generated if a non-zero buffer object name is bound to the GL_PIXEL_UNPACK_BUFFER target and data is not evenly divisible into the number of bytes needed to store in memory a datum indicated by type.

Associated Gets

glGet with argument GL_PIXEL_UNPACK_BUFFER_BINDING

API Version Support

See Also

glActiveTexture, glCompressedTexImage2D, glCompressedTexImage3D, glCompressedTexSubImage2D, glCompressedTexSubImage3D, glCopyTexImage2D, glCopyTexSubImage2D, glCopyTexSubImage3D, glPixelStorei, glTexImage2D, glTexSubImage2D, glTexSubImage3D, glTexParameter

Copyright

Copyright © 1991-2006 Silicon Graphics, Inc. Copyright © 2010-2014 Khronos Group. This document is licensed under the SGI Free Software B License. For details, see https://web.archive.org/web/20171022161616/http://oss.sgi.com/projects/FreeB/.