Gl.TexImage1D (gb.opengl)

Specify a one-dimensional texture image.

Parameters

target

Specifies the target texture. Must be Gl.TEXTURE_1D or Gl.PROXY_TEXTURE_1D.

level

Specifies the level-of-detail number. Level 0 is the base image level. Level n is the nth mipmap reduction image.

internalFormat

Specifies the number of color components in the texture. Must be one of the following symbolic constants: Gl.COMPRESSED_RED, Gl.COMPRESSED_RG, Gl.COMPRESSED_RGB, Gl.COMPRESSED_RGBA, Gl.COMPRESSED_SRGB, Gl.COMPRESSED_SRGB_ALPHA, Gl.DEPTH_COMPONENT, Gl.DEPTH_COMPONENT16, Gl.DEPTH_COMPONENT24, Gl.DEPTH_COMPONENT32, Gl.R3_G3_B2, Gl.RED, Gl.RG, Gl.RGB, Gl.RGB4, Gl.RGB5, Gl.RGB8, Gl.RGB10, Gl.RGB12, Gl.RGB16, Gl.RGBA, Gl.RGBA2, Gl.RGBA4, Gl.RGB5_A1, Gl.RGBA8, Gl.RGB10_A2, Gl.RGBA12, Gl.RGBA16, Gl.SRGB, Gl.SRGB8, Gl.SRGB_ALPHA, or Gl.SRGB8_ALPHA8.

width

Specifies the width of the texture image. All implementations support texture images that are at least 1024 texels wide. The height of the 1D texture image is 1.

border

This value must be 0.

format

Specifies the format of the pixel data. The following symbolic values are accepted: Gl.RED, Gl.RG, Gl.RGB, Gl.BGR, Gl.RGBA, and Gl.BGRA.

type

Specifies the data type of the pixel data. The following symbolic values are accepted: Gl.UNSIGNED_BYTE, Gl.BYTE, Gl.UNSIGNED_SHORT, Gl.SHORT, Gl.UNSIGNED_INT, Gl.INT, Gl.FLOAT, Gl.UNSIGNED_BYTE_3_3_2, Gl.UNSIGNED_BYTE_2_3_3_REV, Gl.UNSIGNED_SHORT_5_6_5, Gl.UNSIGNED_SHORT_5_6_5_REV, Gl.UNSIGNED_SHORT_4_4_4_4, Gl.UNSIGNED_SHORT_4_4_4_4_REV, Gl.UNSIGNED_SHORT_5_5_5_1, Gl.UNSIGNED_SHORT_1_5_5_5_REV, Gl.UNSIGNED_INT_8_8_8_8, Gl.UNSIGNED_INT_8_8_8_8_REV, Gl.UNSIGNED_INT_10_10_10_2, and Gl.UNSIGNED_INT_2_10_10_10_REV.

data

Specifies a pointer to the image data in memory.

Description

Texturing maps a portion of a specified texture image onto each graphical primitive for which texturing is enabled. To enable and disable one-dimensional texturing, call Gl.Enable and Gl.Disable with argument Gl.TEXTURE_1D.

Texture images are defined with Gl.TexImage1D. The arguments describe the parameters of the texture image, such as width, width of the border, level-of-detail number (see Gl.TexParameter), and the internal resolution and format used to store the image. The last three arguments describe how the image is represented in memory.

If target is Gl.PROXY_TEXTURE_1D, no data is read from data, but all of the texture image state is recalculated, checked for consistency, and checked against the implementation's capabilities. If the implementation cannot handle a texture of the requested texture size, it sets all of the image state to 0, but does not generate an error (see Gl.GetError). To query for an entire mipmap array, use an image array level greater than or equal to 1.

If target is Gl.TEXTURE_1D, 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. Each data byte is treated as eight 1-bit elements, with bit ordering determined by Gl.UNPACK_LSB_FIRST (see Gl.PixelStore).

If a non-zero named buffer object is bound to the Gl.PIXEL_UNPACK_BUFFER target (see Gl.BindBuffer) 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 left end of the texture array. Subsequent elements progress left-to-right through the remaining texels in the texture array. The final element corresponds to the right end of the texture array.

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

Gl.RED

Each element is a single red component. The GL converts it to floating point and assembles it into an RGBA element by attaching 0 for green and blue, and 1 for alpha. Each component is then multiplied by the signed scale factor Gl.c_SCALE, added to the signed bias Gl.c_BIAS, and clamped to the range /edit/0,1.

Gl.RG

Each element is a single red/green double The GL converts it to floating point and assembles it into an RGBA element by attaching 0 for blue, and 1 for alpha. Each component is then multiplied by the signed scale factor Gl.c_SCALE, added to the signed bias Gl.c_BIAS, and clamped to the range /edit/0,1.

Gl.RGB

Gl.BGR

Each element is an RGB triple. The GL converts it to floating point and assembles it into an RGBA element by attaching 1 for alpha. Each component is then multiplied by the signed scale factor Gl.c_SCALE, added to the signed bias Gl.c_BIAS, and clamped to the range /edit/0,1.

Gl.RGBA

Gl.BGRA

Each element contains all four components. Each component is multiplied by the signed scale factor Gl.c_SCALE, added to the signed bias Gl.c_BIAS, and clamped to the range /edit/0,1.

Gl.DEPTH_COMPONENT

Each element is a single depth value. The GL converts it to floating point, multiplies by the signed scale factor Gl.DEPTH_SCALE, adds the signed bias Gl.DEPTH_BIAS, and clamps to the range /edit/0,1.

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 that closely approximates that requested by internalFormat, but it may not match exactly. (The representations specified by Gl.RED, Gl.RG, Gl.RGB and Gl.RGBA must match exactly.)

If the internalFormat parameter is one of the generic compressed formats, Gl.COMPRESSED_RED, Gl.COMPRESSED_RG, Gl.COMPRESSED_RGB, or Gl.COMPRESSED_RGBA, the GL will replace the internal format with the symbolic constant for a specific internal format and compress the texture before storage. If no corresponding internal format is available, or the GL can not compress that image for any reason, the internal format is instead replaced with a corresponding base internal format.

If the internalFormat parameter is Gl.SRGB, Gl.SRGB8, Gl.SRGB_ALPHAor Gl.SRGB8_ALPHA8, the texture is treated as if the red, green, or blue 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:

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

Use the Gl.PROXY_TEXTURE_1D target to try out a resolution and format. The implementation will update and recompute its best match for the requested storage resolution and format. To then query this state, call Gl.GetTexLevelParameter. If the texture cannot be accommodated, texture state is set to 0.

A one-component texture image uses only the red component of the RGBA color 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.

Image-based shadowing can be enabled by comparing texture r coordinates to depth texture values to generate a boolean result. See Gl.TexParameter for details on texture comparison.

Notes

Gl.PixelStore modes affect texture images.

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

Gl.TexImage1D specifies the one-dimensional texture for the current texture unit, specified with Gl.ActiveTexture.

Errors

Gl.INVALID_ENUM is generated if target is not Gl.TEXTURE_1D or Gl.PROXY_TEXTURE_1D.

Gl.INVALID_ENUM is generated if format is not an accepted format constant. Format constants other than Gl.STENCIL_INDEX 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_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 is less than 0 or greater than Gl.MAX_TEXTURE_SIZE.

Gl.INVALID_VALUE is generated if non-power-of-two textures are not supported and the width cannot be represented as $2^{\mathit{n}}+2\left(\mathit{border}\right)$ for some integer value of n.

Gl.INVALID_VALUE is generated if border is not 0 or 1.

Gl.INVALID_OPERATION is generated if type is one of Gl.UNSIGNED_BYTE_3_3_2, Gl.UNSIGNED_BYTE_2_3_3_REV, Gl.UNSIGNED_SHORT_5_6_5, or Gl.UNSIGNED_SHORT_5_6_5_REV and format is not Gl.RGB.

Gl.INVALID_OPERATION is generated if type is one of Gl.UNSIGNED_SHORT_4_4_4_4, Gl.UNSIGNED_SHORT_4_4_4_4_REV, Gl.UNSIGNED_SHORT_5_5_5_1, Gl.UNSIGNED_SHORT_1_5_5_5_REV, Gl.UNSIGNED_INT_8_8_8_8, Gl.UNSIGNED_INT_8_8_8_8_REV, Gl.UNSIGNED_INT_10_10_10_2, or Gl.UNSIGNED_INT_2_10_10_10_REV and format is neither Gl.RGBA nor Gl.BGRA.

Gl.INVALID_OPERATION is generated if format is Gl.DEPTH_COMPONENT and internalFormat is not Gl.DEPTH_COMPONENT, Gl.DEPTH_COMPONENT16, Gl.DEPTH_COMPONENT24, or Gl.DEPTH_COMPONENT32.

Gl.INVALID_OPERATION is generated if internalFormat is Gl.DEPTH_COMPONENT, Gl.DEPTH_COMPONENT16, Gl.DEPTH_COMPONENT24, or Gl.DEPTH_COMPONENT32, and format is not Gl.DEPTH_COMPONENT.

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

Gl.GetTexImage

Gl.Get with argument Gl.PIXEL_UNPACK_BUFFER_BINDING

See also

See original documentation on OpenGL website