NAME¶

glTexImage1D - specify a one-dimensional texture image

C SPECIFICATION¶

PARAMETERS¶

target level internalFormat width border format type data

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 GL_RG GL_RGB GL_BGR GL_RGBA GL_BGRA GL_DEPTH_COMPONENT 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 Format	RGBA, Depth and Stencil Values	Internal Components
GL_DEPTH_COMPONENT	Depth	D
GL_DEPTH_STENCIL	Depth, Stencil	D, S
GL_RED	Red	R
GL_RG	Red, Green	R, G
GL_RGB	Red, Green, Blue	R, G, B
GL_RGBA	Red, Green, Blue, Alpha	R, 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 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

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 Format	Base Internal Format	Type
GL_COMPRESSED_RED	GL_RED	Generic
GL_COMPRESSED_RG	GL_RG	Generic
GL_COMPRESSED_RGB	GL_RGB	Generic
GL_COMPRESSED_RGBA	GL_RGBA	Generic
GL_COMPRESSED_SRGB	GL_RGB	Generic
GL_COMPRESSED_SRGB_ALPHA	GL_RGBA	Generic
GL_COMPRESSED_RED_RGTC1	GL_RED	Specific
GL_COMPRESSED_SIGNED_RED_RGTC1	GL_RED	Specific
GL_COMPRESSED_RG_RGTC2	GL_RG	Specific
GL_COMPRESSED_SIGNED_RG_RGTC2	GL_RG	Specific
GL_COMPRESSED_RGBA_BPTC_UNORM	GL_RGBA	Specific
GL_COMPRESSED_SRGB_ALPHA_BPTC_UNORM	GL_RGBA	Specific
GL_COMPRESSED_RGB_BPTC_SIGNED_FLOAT	GL_RGB	Specific
GL_COMPRESSED_RGB_BPTC_UNSIGNED_FLOAT	GL_RGB	Specific

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().

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 non-power-of-two textures are not supported and the width cannot be represented as 2 n + 2 ⁡ border 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¶

glGetTexImage() glGet() with argument GL_PIXEL_UNPACK_BUFFER_BINDING

SEE ALSO¶

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

COPYRIGHT¶

Copyright © 1991-2006 Silicon Graphics, Inc. Copyright © 2011 Khronos Group. This document is licensed under the SGI Free Software B License. For details, see http://oss.sgi.com/projects/FreeB/.