glTexImage1D.3G man page

glTexImage1D — specify a one-dimensional texture image

C Specification

void glTexImage1D(GLenum target, GLint level, GLint internalFormat, GLsizei width, GLint border, GLenum format, GLenum type, const GLvoid * data);

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 base internal formats given in Table 1, one of the sized internal formats given in Table 2, or one of the compressed internal formats given in Table 3, below.

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, GL_BGRA, GL_RED_INTEGER, GL_RG_INTEGER, GL_RGB_INTEGER, GL_BGR_INTEGER, GL_RGBA_INTEGER, GL_BGRA_INTEGER, GL_STENCIL_INDEX, GL_DEPTH_COMPONENT, GL_DEPTH_STENCIL.

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 glEnable() and

glDisable with argument GL_TEXTURE_1D.

Texture images are defined with glTexImage1D. The arguments describe the parameters of the texture image, such as width, width of the border, level-of-detail number (see glTexParameter()), 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 glGetError()). 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 glPixelStore()).

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 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 clamped to the range [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 clamped to the range [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 clamped to the range [0,1].

GL_RGBA, GL_BGRA

Each element contains all four components. Each component clamped to the range [0,1].

GL_DEPTH_COMPONENT

Each element is a single depth value. The GL converts it to floating point and clamps to the range [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.)

internalFormat may be one of the base internal formats shown in Table 1, below

Table 1. Base Internal Formats

Base Internal FormatRGBA, Depth and Stencil ValuesInternal Components
GL_DEPTH_COMPONENTDepthD
GL_DEPTH_STENCILDepth, StencilD, S
GL_REDRedR
GL_RGRed, GreenR, G
GL_RGBRed, Green, BlueR, G, B
GL_RGBARed, Green, Blue, AlphaR, G, B, A

internalFormat may also be one of the sized internal formats shown in Table 2, below

Table 2. Sized Internal Formats

Sized Internal FormatBase Internal FormatRed BitsGreen BitsBlue BitsAlpha BitsShared Bits
GL_R8GL_RED8
GL_R8_SNORMGL_REDs8
GL_R16GL_RED16
GL_R16_SNORMGL_REDs16
GL_RG8GL_RG88
GL_RG8_SNORMGL_RGs8s8
GL_RG16GL_RG1616
GL_RG16_SNORMGL_RGs16s16
GL_R3_G3_B2GL_RGB332
GL_RGB4GL_RGB444
GL_RGB5GL_RGB555
GL_RGB8GL_RGB888
GL_RGB8_SNORMGL_RGBs8s8s8
GL_RGB10GL_RGB101010
GL_RGB12GL_RGB121212
GL_RGB16_SNORMGL_RGB161616
GL_RGBA2GL_RGB2222
GL_RGBA4GL_RGB4444
GL_RGB5_A1GL_RGBA5551
GL_RGBA8GL_RGBA8888
GL_RGBA8_SNORMGL_RGBAs8s8s8s8
GL_RGB10_A2GL_RGBA1010102
GL_RGB10_A2UIGL_RGBAui10ui10ui10ui2
GL_RGBA12GL_RGBA12121212
GL_RGBA16GL_RGBA16161616
GL_SRGB8GL_RGB888
GL_SRGB8_ALPHA8GL_RGBA8888
GL_R16FGL_REDf16
GL_RG16FGL_RGf16f16
GL_RGB16FGL_RGBf16f16f16
GL_RGBA16FGL_RGBAf16f16f16f16
GL_R32FGL_REDf32
GL_RG32FGL_RGf32f32
GL_RGB32FGL_RGBf32f32f32
GL_RGBA32FGL_RGBAf32f32f32f32
GL_R11F_G11F_B10FGL_RGBf11f11f10
GL_RGB9_E5GL_RGB999 5
GL_R8IGL_REDi8
GL_R8UIGL_REDui8
GL_R16IGL_REDi16
GL_R16UIGL_REDui16
GL_R32IGL_REDi32
GL_R32UIGL_REDui32
GL_RG8IGL_RGi8i8
GL_RG8UIGL_RGui8ui8
GL_RG16IGL_RGi16i16
GL_RG16UIGL_RGui16ui16
GL_RG32IGL_RGi32i32
GL_RG32UIGL_RGui32ui32
GL_RGB8IGL_RGBi8i8i8
GL_RGB8UIGL_RGBui8ui8ui8
GL_RGB16IGL_RGBi16i16i16
GL_RGB16UIGL_RGBui16ui16ui16
GL_RGB32IGL_RGBi32i32i32
GL_RGB32UIGL_RGBui32ui32ui32
GL_RGBA8IGL_RGBAi8i8i8i8
GL_RGBA8UIGL_RGBAui8ui8ui8ui8
GL_RGBA16IGL_RGBAi16i16i16i16
GL_RGBA16UIGL_RGBAui16ui16ui16ui16
GL_RGBA32IGL_RGBAi32i32i32i32
GL_RGBA32UIGL_RGBAui32ui32ui32ui32

Finally, internalFormat may also be one of the generic or compressed compressed texture formats shown in Table 3 below

Table 3. Compressed Internal Formats

Compressed Internal FormatBase Internal FormatType
GL_COMPRESSED_REDGL_REDGeneric
GL_COMPRESSED_RGGL_RGGeneric
GL_COMPRESSED_RGBGL_RGBGeneric
GL_COMPRESSED_RGBAGL_RGBAGeneric
GL_COMPRESSED_SRGBGL_RGBGeneric
GL_COMPRESSED_SRGB_ALPHAGL_RGBAGeneric
GL_COMPRESSED_RED_RGTC1GL_REDSpecific
GL_COMPRESSED_SIGNED_RED_RGTC1GL_REDSpecific
GL_COMPRESSED_RG_RGTC2GL_RGSpecific
GL_COMPRESSED_SIGNED_RG_RGTC2GL_RGSpecific
GL_COMPRESSED_RGBA_BPTC_UNORMGL_RGBASpecific
GL_COMPRESSED_SRGB_ALPHA_BPTC_UNORMGL_RGBASpecific
GL_COMPRESSED_RGB_BPTC_SIGNED_FLOATGL_RGBSpecific
GL_COMPRESSED_RGB_BPTC_UNSIGNED_FLOATGL_RGBSpecific

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 c s to a linear component c l is:

c l = { c s 12.92 if c s ≤ 0.04045 ( c s + 0.055 1.055 ) 2.4 if c s > 0.04045

Assume c s is the sRGB component in the range [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 glGetTexLevelParameter(). 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 glTexParameter() for details on texture comparison.

Notes

glPixelStore() 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.

glTexImage1D specifies the one-dimensional texture for the current texture unit, specified with glActiveTexture().

GL_STENCIL_INDEX may be used for format only if the GL version is 4.4 or higher.

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 log 2 ⁡ max, 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 border is not 0.

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

glGetTexImage()

glGet() with argument GL_PIXEL_UNPACK_BUFFER_BINDING

Version Support

OpenGL Version
Function / Feature Name2.02.13.03.13.23.34.04.14.24.34.44.5
glTexImage1D

See Also

glActiveTexture(), glCompressedTexImage1D(), glCompressedTexSubImage1D(), glCopyTexImage1D(), glCopyTexSubImage1D(), glGetCompressedTexImage(), glPixelStore(), glTexImage2D(), glTexImage3D(), glTexSubImage1D(), glTexSubImage2D(), glTexSubImage3D(), glTexParameter()

Info

12/28/2016 [FIXME: source] [FIXME: manual]