glTexImage2D — specify a two-dimensional texture image
void glTexImage2D( |
GLenum target, |
GLint level, | |
GLint internalFormat, | |
GLsizei width, | |
GLsizei height, | |
GLint border, | |
GLenum format, | |
GLenum type, | |
const GLvoid * data) ; |
target
Specifies the target texture. Must be GL_TEXTURE_2D
, GL_PROXY_TEXTURE_2D
, GL_TEXTURE_1D_ARRAY
, GL_PROXY_TEXTURE_1D_ARRAY
,GL_TEXTURE_RECTANGLE
, GL_PROXY_TEXTURE_RECTANGLE
, GL_TEXTURE_CUBE_MAP_POSITIVE_X
, GL_TEXTURE_CUBE_MAP_NEGATIVE_X
,GL_TEXTURE_CUBE_MAP_POSITIVE_Y
, GL_TEXTURE_CUBE_MAP_NEGATIVE_Y
, GL_TEXTURE_CUBE_MAP_POSITIVE_Z
, GL_TEXTURE_CUBE_MAP_NEGATIVE_Z
, orGL_PROXY_TEXTURE_CUBE_MAP
.
level
Specifies the level-of-detail number. Level 0 is the base image level. Level n is the nth mipmap reduction image. If target
is GL_TEXTURE_RECTANGLE
orGL_PROXY_TEXTURE_RECTANGLE
, level
must be 0.
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.
height
Specifies the height of the texture image, or the number of layers in a texture array, in the case of the GL_TEXTURE_1D_ARRAY
andGL_PROXY_TEXTURE_1D_ARRAY
targets. All implementations support 2D texture images that are at least 1024 texels high, and texture arrays that are at least 256 layers deep.
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
, andGL_UNSIGNED_INT_2_10_10_10_REV
.
data
Specifies a pointer to the image data in memory.
Texturing allows elements of an image array to be read by shaders.
To define texture images, call glTexImage2D
. The arguments describe the parameters of the texture image, such as height, width, 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_PROXY_TEXTURE_2D
, GL_PROXY_TEXTURE_1D_ARRAY
, GL_PROXY_TEXTURE_CUBE_MAP
, or GL_PROXY_TEXTURE_RECTANGLE
, no data is read fromdata
, 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_2D
, GL_TEXTURE_RECTANGLE
or one of the GL_TEXTURE_CUBE_MAP
targets, 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
(seeglPixelStore).
If target
is GL_TEXTURE_1D_ARRAY
, data is interpreted as an array of one-dimensional images.
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:
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 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 is 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].
GL_DEPTH_STENCIL
Each element is a pair of depth and stencil values. The depth component of the pair is interpreted as in GL_DEPTH_COMPONENT
. The stencil component is interpreted based on specified the depth + stencil internal format.
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
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
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
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
, orGL_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_ALPHA
, or 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 cs to a linear component cl is:
cl=⎧⎩⎨⎪⎪cs12.92(cs+0.0551.055)2.4ifcs≤0.04045ifcs>0.04045
Assume cs is the sRGB component in the range [0,1].
Use the GL_PROXY_TEXTURE_2D
, GL_PROXY_TEXTURE_1D_ARRAY
, GL_PROXY_TEXTURE_RECTANGLE
, or GL_PROXY_TEXTURE_CUBE_MAP
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 extracted from data
. A two-component image uses the R and G 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.
The glPixelStore mode affects texture images.
data
may be a null pointer. In this case, texture memory is allocated to accommodate a texture of width width
and height height
. 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.
glTexImage2D
specifies the two-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.
GL_INVALID_ENUM
is generated if target
is not GL_TEXTURE_2D
, GL_TEXTURE_1D_ARRAY
, GL_TEXTURE_RECTANGLE
, GL_PROXY_TEXTURE_2D
,GL_PROXY_TEXTURE_1D_ARRAY
, GL_PROXY_TEXTURE_RECTANGLE
, GL_PROXY_TEXTURE_CUBE_MAP
, GL_TEXTURE_CUBE_MAP_POSITIVE_X
,GL_TEXTURE_CUBE_MAP_NEGATIVE_X
, GL_TEXTURE_CUBE_MAP_POSITIVE_Y
, GL_TEXTURE_CUBE_MAP_NEGATIVE_Y
, GL_TEXTURE_CUBE_MAP_POSITIVE_Z
, orGL_TEXTURE_CUBE_MAP_NEGATIVE_Z
.
GL_INVALID_ENUM
is generated if target
is one of the six cube map 2D image targets and the width and height parameters are not equal.
GL_INVALID_ENUM
is generated if type
is not a type constant.
GL_INVALID_VALUE
is generated if width
is less than 0 or greater than GL_MAX_TEXTURE_SIZE
.
GL_INVALID_VALUE
is generated if target
is not GL_TEXTURE_1D_ARRAY
or GL_PROXY_TEXTURE_1D_ARRAY
and height
is less than 0 or greater thanGL_MAX_TEXTURE_SIZE
.
GL_INVALID_VALUE
is generated if target
is GL_TEXTURE_1D_ARRAY
or GL_PROXY_TEXTURE_1D_ARRAY
and height
is less than 0 or greater thanGL_MAX_ARRAY_TEXTURE_LAYERS
.
GL_INVALID_VALUE
is generated if level
is less than 0.
GL_INVALID_VALUE
may be generated if level
is greater than log2(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
or height
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
,GL_UNSIGNED_SHORT_5_6_5_REV
, or GL_UNSIGNED_INT_10F_11F_11F_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
,GL_UNSIGNED_INT_2_10_10_10_REV
, or GL_UNSIGNED_INT_5_9_9_9_REV
, and format
is neither GL_RGBA
nor GL_BGRA
.
GL_INVALID_OPERATION
is generated if target
is not GL_TEXTURE_2D
, GL_PROXY_TEXTURE_2D
, GL_TEXTURE_RECTANGLE
, or GL_PROXY_TEXTURE_RECTANGLE
, and internalFormat
is GL_DEPTH_COMPONENT
, GL_DEPTH_COMPONENT16
, GL_DEPTH_COMPONENT24
, or GL_DEPTH_COMPONENT32F
.
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_COMPONENT32F
.
GL_INVALID_OPERATION
is generated if internalFormat
is GL_DEPTH_COMPONENT
, GL_DEPTH_COMPONENT16
, GL_DEPTH_COMPONENT24
, orGL_DEPTH_COMPONENT32F
, 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
.
GL_INVALID_VALUE
is generated if target
is GL_TEXTURE_RECTANGLE
or GL_PROXY_TEXTURE_RECTANGLE
and level
is not 0.
glGetTexImage
glGet with argument GL_PIXEL_UNPACK_BUFFER_BINDING
OpenGL Version | ||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|
Function / Feature Name | 2.0 | 2.1 | 3.0 | 3.1 | 3.2 | 3.3 | 4.0 | 4.1 | 4.2 | 4.3 | 4.4 | 4.5 |
glTexImage2D |
✔ | ✔ | ✔ | ✔ | ✔ | ✔ | ✔ | ✔ | ✔ | ✔ | ✔ | ✔ |
Copyright © 1991-2006 Silicon Graphics, Inc. Copyright © 2011-2014 Khronos Group. This document is licensed under the SGI Free Software B License. For details, see http://oss.sgi.com/projects/FreeB/.