glGetInternalformat — retrieve information about implementation-dependent support for internal formats
void glGetInternalformativ(
|
GLenum target, |
| GLenum internalformat, | |
| GLenum pname, | |
| GLsizei bufSize, | |
GLint *params); |
void glGetInternalformati64v(
|
GLenum target, |
| GLenum internalformat, | |
| GLenum pname, | |
| GLsizei bufSize, | |
GLint64 *params); |
target
Indicates the usage of the internal format. target must be GL_TEXTURE_1D, GL_TEXTURE_1D_ARRAY,
GL_TEXTURE_2D, GL_TEXTURE_2D_ARRAY, GL_TEXTURE_3D,
GL_TEXTURE_CUBE_MAP, GL_TEXTURE_CUBE_MAP_ARRAY, GL_TEXTURE_RECTANGLE,
GL_TEXTURE_BUFFER,
GL_RENDERBUFFER, GL_TEXTURE_2D_MULTISAMPLE or GL_TEXTURE_2D_MULTISAMPLE_ARRAY.
internalformat
Specifies the internal format about which to retrieve information.
pname
Specifies the type of information to query.
bufSize
Specifies the maximum number of integers of the specified width that may be written to params by the function.
params
Specifies the address of a variable into which to write the retrieved information.
glGetInternalformativ and glGetInternalformati64v retrieve information about implementation-dependent support for
internal formats. target indicates the target with which the internal format will
be used and must be one of GL_RENDERBUFFER, GL_TEXTURE_2D_MULTISAMPLE,
or GL_TEXTURE_2D_MULTISAMPLE_ARRAY, corresponding to usage as a renderbuffer, two-dimensional
multisample texture or two-dimensional multisample array texture, respectively.
internalformat specifies the internal format about which to retrieve information and
must be a color-renderable, depth-renderable or stencil-renderable format.
The information retrieved will be written to memory addressed by the pointer specified in params. No
more than bufSize integers will be written to this memory.
If pname is GL_NUM_SAMPLE_COUNTS, the number of sample counts that would be
returned by querying GL_SAMPLES will be returned in params.
If pname is GL_SAMPLES, the sample counts supported for internalformat
and target are written into params in descending numeric order. Only positive values are returned.
Querying GL_SAMPLES with bufSize of one will return just the maximum supported number of
samples for this format. The maximum value in GL_SAMPLES is guaranteed to be at least the lowest of the following:
The value of
GL_MAX_INTEGER_SAMPLES if
internalformat is a signed or
unsigned integer format.
The value of
GL_MAX_DEPTH_TEXTURE_SAMPLES if
internalformat is a depth- or
stencil-renderable format and
target is
GL_TEXTURE_2D_MULTISAMPLE,
GL_TEXTURE_2D_MULTISAMPLE_ARRAY.
The value of
GL_MAX_COLOR_TEXTURE_SAMPLES if
internalformat is a
color-renderable format and
target is
GL_TEXTURE_2D_MULTISAMPLE or
GL_TEXTURE_2D_MULTISAMPLE_ARRAY.
The value of GL_MAX_SAMPLES.
If pname is GL_INTERNALFORMAT_SUPPORTED, params is set to GL_TRUE if internalformat
is a supported internal format for target and to GL_FALSE otherwise.
If pname is GL_INTERNALFORMAT_PREFERRED, params is set to GL_TRUE if internalformat
is an format for target that is preferred by the implementation and to GL_FALSE otherwise.
If pname is GL_INTERNALFORMAT_RED_SIZE, GL_INTERNALFORMAT_GREEN_SIZE,
GL_INTERNALFORMAT_BLUE_SIZE, GL_INTERNALFORMAT_ALPHA_SIZE, GL_INTERNALFORMAT_DEPTH_SIZE,
GL_INTERNALFORMAT_STENCIL_SIZE, or GL_INTERNALFORMAT_SHARED_SIZE then
params is set to the actual resolutions that would be used for storing image array components
for the resource for the red, green, blue, alpha, depth, stencil and shared channels respectively. If internalformat
is a compressed internal format, then params is set to the component resolution of an uncompressed internal format that produces
an image of roughly the same quality as the compressed algorithm. If the internal format is unsupported, or if a particular component is
not present in the format, 0 is written to params.
If pname is GL_INTERNALFORMAT_RED_TYPE, GL_INTERNALFORMAT_GREEN_TYPE,
GL_INTERNALFORMAT_BLUE_TYPE, GL_INTERNALFORMAT_ALPHA_TYPE, GL_INTERNALFORMAT_DEPTH_TYPE,
or GL_INTERNALFORMAT_STENCIL_TYPE then params is set to a token identifying the data type used
to store the respective component. If the internalformat represents a compressed internal format then
the types returned specify how components are interpreted after decompression.
If pname is GL_MAX_WIDTH, GL_MAX_HEIGHT, GL_MAX_DEPTH,
or GL_MAX_LAYERS then pname is filled with the maximum width, height, depth or layer count
for textures with internal format internalformat, respectively. If pname is GL_MAX_COMBINED_DIMENSIONS
then pname is filled with the maximum combined dimensions of a texture of the specified internal format.
If pname is GL_COLOR_COMPONENTS then params is set to the value GL_TRUE
if the internal format contains any color component (i.e., red, green, blue or alpha) and to GL_FALSE otherwise. If
pname is GL_DEPTH_COMPONENTS or GL_STENCIL_COMPONENTS then params
is set to GL_TRUE if the internal format contains a depth or stencil component, respectively, and to GL_FALSE
otherwise.
If pname is GL_COLOR_RENDERABLE, GL_DEPTH_RENDERABLE or GL_STENCIL_RENDERABLE
then params is set to GL_TRUE if the specified internal format is color, depth or stencil renderable, respectively,
and to GL_FALSE otherwise.
If pname is GL_FRAMEBUFFER_RENDERABLE or GL_FRAMEBUFFER_RENDERABLE_LAYERED
then params is set to one of GL_FULL_SUPPORT,
GL_CAVEAT_SUPPORT or GL_NONE to indicate that framebuffer attachments (layered attachments in the
case of GL_FRAMEBUFFER_RENDERABLE_LAYERED) with that internal format are either
renderable with no restrictions, renderable with some restrictions or not renderable at all.
If pname is GL_FRAMEBUFFER_BLEND, params is set to GL_TRUE
to indicate that the internal format is supported for blending operations when attached to a framebuffer, and to GL_FALSE otherwise.
If pname is GL_READ_PIXELS then params is set to GL_FULL_SUPPORT,
GL_CAVEAT_SUPPORT or GL_NONE to that either full support, limited support or no support at all is supplied
for reading pixels from framebuffer attachments in the specified internal format.
If pname is GL_READ_PIXELS_FORMAT or GL_READ_PIXELS_TYPE then params
is filled with the format or type, respectively, most recommended to obtain the highest image quality and performance. For
GL_READ_PIXELS_FORMAT, the value returned in params is a token that is accepted for
the format argument to glReadPixels. For
GL_READ_PIXELS_TYPE, the value returned in params is a token that is accepted for
the type argument to glReadPixels.
If pname is GL_TEXTURE_IMAGE_FORMAT or GL_TEXTURE_IMAGE_TYPE then
params is filled with the implementation-recommended format or type to be used in calls to
glTexImage2D and other similar functions. For GL_TEXTURE_IMAGE_FORMAT,
params is filled with a token suitable for use as the format argument to
glTexImage2D. For GL_TEXTURE_IMAGE_TYPE,
params is filled with a token suitable for use as the type argument to
glTexImage2D.
If pname is GL_GET_TEXTURE_IMAGE_FORMAT or GL_GET_TEXTURE_IMAGE_TYPE then
params is filled with the implementation-recommended format or type to be used in calls to
glGetTexImage and other similar functions. For GL_GET_TEXTURE_IMAGE_FORMAT,
params is filled with a token suitable for use as the format argument to
glGetTexImage. For GL_GET_TEXTURE_IMAGE_TYPE,
params is filled with a token suitable for use as the type argument to
glGetTexImage.
If pname is GL_MIPMAP then pname is set to GL_TRUE
to indicate that the specified internal format supports mipmaps and to GL_FALSE otherwise.
If pname is GL_GENERATE_MIPMAP or GL_AUTO_GENERATE_MIPMAP then params
is indicates the level of support for manual or automatic mipmap generation for the specified internal format, respectively. Returned values
may be one of GL_FULL_SUPPORT, GL_CAVEAT_SUPPORT and GL_NONE to indicate
either full support, limited support or no support at all.
If pname is GL_COLOR_ENCODING then the color encoding for the resource is returned in
params. Possible values for color buffers are GL_LINEAR or GL_SRGB,
for linear or sRGB-encoded color components, respectively. For non-color
formats (such as depth or stencil), or for unsupported resources,
the value GL_NONE is returned.
If pname is GL_SRGB_READ, or GL_SRGB_WRITE then params
indicates the level of support for reading and writing to sRGB encoded images, respectively. For GL_SRGB_READ,
support for converting from sRGB colorspace on read operations is returned in params and for GL_SRGB_WRITE,
support for converting to sRGB colorspace on write operations to the resource is returned in params. params may be
set to GL_FULL_SUPPORT, GL_CAVEAT_SUPPORT, or GL_NONE to indicate
full support, limited support or no support at all, respecitively.
If pname is GL_FILTER the params is set to either GL_TRUE
or GL_FALSE to indicate support or lack thereof for filter modes other than GL_NEAREST or GL_NEAREST_MIPMAP
for the specified internal format.
If pname is GL_VERTEX_TEXTURE, GL_TESS_CONTROL_TEXTURE, GL_TESS_EVALUATION_TEXTURE,
GL_GEOMETRY_TEXTURE, GL_FRAGMENT_TEXTURE, or GL_COMPUTE_TEXTURE, then the value
written to params indicates support for use of the resource as a source of texturing in the vertex, tessellation control,
tessellation evaluation, geometry, fragment and compute shader stages, respectively. params may be set to
GL_FULL_SUPPORT, GL_CAVEAT_SUPPORT or GL_NONE to indicate full support,
limited support or no support at all, respectively.
If pname is GL_TEXTURE_SHADOW, GL_TEXTURE_GATHER or GL_TEXTURE_GATHER_SHADOW then the value written to
params indicates the level of support for using the resource with a shadow sampler, in gather operations or as a shadow sampler in gather operations, respectively. Returned values
may be GL_FULL_SUPPORT, GL_CAVEAT_SUPPORT or GL_NONE to indicate full support,
limited support or no support at all, respectively.
If pname is GL_SHADER_IMAGE_LOAD, GL_SHADER_IMAGE_STORE or GL_SHADER_IMAGE_ATOMIC
then the value returned in params indicates the level of support for image loads, stores and atomics for resources of the specified internal
format. Returned values
may be GL_FULL_SUPPORT, GL_CAVEAT_SUPPORT or GL_NONE to indicate full support,
limited support or no support at all, respectively.
If pname is GL_IMAGE_TEXEL_SIZE then the size of a texel when the resource when used as
an image texture is returned in params. If the resource is not supported for image
textures zero is returned.
If pname is GL_IMAGE_COMPATIBILITY_CLASS then the compatibility class of the resource when
used as an image texture is returned in params. The possible values
returned are GL_IMAGE_CLASS_4_X_32, GL_IMAGE_CLASS_2_X_32, GL_IMAGE_CLASS_1_X_32,
GL_IMAGE_CLASS_4_X_16, GL_IMAGE_CLASS_2_X_16, GL_IMAGE_CLASS_1_X_16,
GL_IMAGE_CLASS_4_X_8, GL_IMAGE_CLASS_2_X_8, GL_IMAGE_CLASS_1_X_8,
GL_IMAGE_CLASS_11_11_10, and GL_IMAGE_CLASS_10_10_10_2, which correspond to
the 4x32, 2x32, 1x32, 4x16, 2x16, 1x16, 4x8, 2x8, 1x8, the class
(a) 11/11/10 packed floating-point format, and the class (b)
10/10/10/2 packed formats, respectively.
If the resource is not supported for image textures, GL_NONE is returned.
If pname is GL_IMAGE_PIXEL_FORMAT or GL_IMAGE_PIXEL_TYPE then
the pixel format or type of the resource when used as an image texture is returned in params, respectively.
In either case, the resource is not supported for image textures GL_NONE is returned.
If pname is GL_IMAGE_FORMAT_COMPATIBILITY_TYPE, the matching criteria use for the
resource when used as an image textures is returned in params. Possible values returned in params are
GL_IMAGE_FORMAT_COMPATIBILITY_BY_SIZE or GL_IMAGE_FORMAT_COMPATIBILITY_BY_CLASS.
If the resource is not supported for image textures, GL_NONE is returned.
If pname is GL_SIMULTANEOUS_TEXTURE_AND_DEPTH_TEST or GL_SIMULTANEOUS_TEXTURE_AND_STENCIL_TEST,
support for using the resource both as a source for texture sampling while it is bound as a buffer for depth or stencil test, respectively, is written to params.
Possible values returned are GL_FULL_SUPPORT, GL_CAVEAT_SUPPORT, or GL_NONE to indicate
full support, limited support or no support at all. If the resource or operation is not supported, GL_NONE is returned.
If pname is GL_SIMULTANEOUS_TEXTURE_AND_DEPTH_WRITE or GL_SIMULTANEOUS_TEXTURE_AND_STENCIL_WRITE,
support for using the resource both as a source for texture sampling while performing depth or stencil writes to the resources, respectively, is written to params.
Possible values returned are GL_FULL_SUPPORT, GL_CAVEAT_SUPPORT, or GL_NONE to indicate
full support, limited support or no support at all. If the resource or operation is not supported, GL_NONE is returned.
If pname is GL_TEXTURE_COMPRESSED then GL_TRUE is returned in params
if internalformat is a compressed internal format. GL_FALSE is returned in params
otherwise.
If pname is GL_TEXTURE_COMPRESSED_BLOCK_WIDTH, GL_TEXTURE_COMPRESSED_BLOCK_HEIGHT or
GL_TEXTURE_COMPRESSED_BLOCK_SIZE then the width, height or total size, respectively of a block (in basic machine units) is returned in
params. If the internal format is not compressed, or the resource is not supported, 0 is returned.
If pname is GL_CLEAR_BUFFER, the level of support for using the resource with glClearBufferData
and glClearBufferSubData is returned in params. Possible values returned are GL_FULL_SUPPORT,
GL_CAVEAT_SUPPORT, or GL_NONE to indicate
full support, limited support or no support at all, respectively. If the resource or operation is not supported, GL_NONE is returned.
If pname is GL_TEXTURE_VIEW, the level of support for using the resource with the glTextureView
command is returned in params. Possible values returned are GL_FULL_SUPPORT,
GL_CAVEAT_SUPPORT, or GL_NONE to indicate
full support, limited support or no support at all, respectively. If the resource or operation is not supported, GL_NONE is returned.
If pname is GL_VIEW_COMPATIBILITY_CLASS then the compatibility class of the resource when
used as a texture view is returned in params. The possible values
returned are GL_VIEW_CLASS_128_BITS, GL_VIEW_CLASS_96_BITS,
GL_VIEW_CLASS_64_BITS, GL_VIEW_CLASS_48_BITS, GL_VIEW_CLASS_32_BITS,
GL_VIEW_CLASS_24_BITS, GL_VIEW_CLASS_16_BITS, GL_VIEW_CLASS_8_BITS,
GL_VIEW_CLASS_S3TC_DXT1_RGB, GL_VIEW_CLASS_S3TC_DXT1_RGBA,
GL_VIEW_CLASS_S3TC_DXT3_RGBA, GL_VIEW_CLASS_S3TC_DXT5_RGBA,
GL_VIEW_CLASS_RGTC1_RED, GL_VIEW_CLASS_RGTC2_RG, GL_VIEW_CLASS_BPTC_UNORM, and
GL_VIEW_CLASS_BPTC_FLOAT.
If pname is GL_CLEAR_TEXTURE then the presence of support for using the
glClearTexImage and glClearTexSubImage
commands with the resource is written to params. Possible values written are GL_FULL_SUPPORT,
GL_CAVEAT_SUPPORT, or GL_NONE to indicate
full support, limited support or no support at all, respectively. If the resource or operation is not supported, GL_NONE is returned.
glGetInternalformativ is available only if the
GL version is 4.2 or higher.
The tokens
GL_INTERNALFORMAT_SUPPORTED,
GL_INTERNALFORMAT_PREFERRED,
GL_INTERNALFORMAT_RED_SIZE,
GL_INTERNALFORMAT_GREEN_SIZE,
GL_INTERNALFORMAT_BLUE_SIZE,
GL_INTERNALFORMAT_ALPHA_SIZE,
GL_INTERNALFORMAT_DEPTH_SIZE,
GL_INTERNALFORMAT_STENCIL_SIZE,
GL_INTERNALFORMAT_SHARED_SIZE,
GL_INTERNALFORMAT_RED_TYPE,
GL_INTERNALFORMAT_GREEN_TYPE,
GL_INTERNALFORMAT_BLUE_TYPE,
GL_INTERNALFORMAT_ALPHA_TYPE,
GL_INTERNALFORMAT_DEPTH_TYPE,
GL_INTERNALFORMAT_STENCIL_TYPE,
GL_MAX_WIDTH,
GL_MAX_HEIGHT,
GL_MAX_DEPTH,
GL_MAX_LAYERS,
GL_MAX_COMBINED_DIMENSIONS,
GL_COLOR_COMPONENTS,
GL_DEPTH_COMPONENTS,
GL_STENCIL_COMPONENTS,
GL_COLOR_RENDERABLE,
GL_DEPTH_RENDERABLE,
GL_STENCIL_RENDERABLE,
GL_FRAMEBUFFER_RENDERABLE,
GL_FRAMEBUFFER_RENDERABLE_LAYERED,
GL_FRAMEBUFFER_BLEND,
GL_READ_PIXELS,
GL_READ_PIXELS_FORMAT,
GL_READ_PIXELS_TYPE,
GL_TEXTURE_IMAGE_FORMAT,
GL_TEXTURE_IMAGE_TYPE,
GL_GET_TEXTURE_IMAGE_FORMAT,
GL_GET_TEXTURE_IMAGE_TYPE,
GL_MIPMAP,
GL_GENERATE_MIPMAP,
GL_AUTO_GENERATE_MIPMAP,
GL_COLOR_ENCODING,
GL_SRGB_READ,
GL_SRGB_WRITE,
GL_SRGB_DECODE_ARB,
GL_FILTER,
GL_VERTEX_TEXTURE,
GL_TESS_CONTROL_TEXTURE,
GL_TESS_EVALUATION_TEXTURE,
GL_GEOMETRY_TEXTURE,
GL_FRAGMENT_TEXTURE,
GL_COMPUTE_TEXTURE,
GL_TEXTURE_SHADOW,
GL_TEXTURE_GATHER,
GL_TEXTURE_GATHER_SHADOW,
GL_SHADER_IMAGE_LOAD,
GL_SHADER_IMAGE_STORE,
GL_SHADER_IMAGE_ATOMIC,
GL_IMAGE_TEXEL_SIZE,
GL_IMAGE_COMPATIBILITY_CLASS,
GL_IMAGE_PIXEL_FORMAT,
GL_IMAGE_PIXEL_TYPE,
GL_IMAGE_FORMAT_COMPATIBILITY_TYPE,
GL_SIMULTANEOUS_TEXTURE_AND_DEPTH_TEST,
GL_SIMULTANEOUS_TEXTURE_AND_STENCIL_TEST,
GL_SIMULTANEOUS_TEXTURE_AND_DEPTH_WRITE,
GL_SIMULTANEOUS_TEXTURE_AND_STENCIL_WRITE,
GL_TEXTURE_COMPRESSED,
GL_TEXTURE_COMPRESSED_BLOCK_WIDTH,
GL_TEXTURE_COMPRESSED_BLOCK_HEIGHT,
GL_TEXTURE_COMPRESSED_BLOCK_SIZE,
GL_CLEAR_BUFFER,
GL_TEXTURE_VIEW, and
GL_VIEW_COMPATIBILITY_CLASS are supported only if the GL
version is 4.3 or higher.
The GL_CLEAR_TEXTURE token is accepted for pname only
if the GL version is 4.4 or higher.
GL_INVALID_VALUE is generated if bufSize is negative.
GL_INVALID_ENUM is generated if pname is not GL_SAMPLES or GL_NUM_SAMPLE_COUNTS.
GL_INVALID_ENUM is generated if internalformat is not color-, depth-, or stencil-renderable.
GL_INVALID_ENUM is generated if target is not one of GL_TEXTURE_2D_MULTISAMPLE,
GL_TEXTURE_2D_MULTISAMPLE_ARRAY or GL_RENDERBUFFER.
| 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 |
glGetInternalformati64v
|
- | - | - | - | - | - | - | - | - | ✔ | ✔ | ✔ |
glGetInternalformativ
|
- | - | - | - | - | - | - | - | ✔ | ✔ | ✔ | ✔ |
Copyright © 2011-2018 Khronos Group. This material may be distributed subject to the terms and conditions set forth in the Open Publication License, v 1.0, 8 June 1999. http://opencontent.org/openpub/.