fglCopyTexImage2D(3G) OpenGL Reference fglCopyTexImage2D(3G)NAMEfglCopyTexImage2D - copy pixels into a 2D texture image
FORTRAN SPECIFICATION
SUBROUTINE fglCopyTexImage2D( INTEGER*4 target,
INTEGER*4 level,
INTEGER*4 internalformat,
INTEGER*4 x,
INTEGER*4 y,
INTEGER*4 width,
INTEGER*4 height,
INTEGER*4 border )
PARAMETERS
target Specifies the target texture. Must be GL_TEXTURE_2D.
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 internal format of the texture. Must be
one of the following symbolic constants: GL_ALPHA,
GL_ALPHA4, GL_ALPHA8, GL_ALPHA12, GL_ALPHA16,
GL_LUMINANCE, GL_LUMINANCE4, GL_LUMINANCE8,
GL_LUMINANCE12, GL_LUMINANCE16, GL_LUMINANCE_ALPHA,
GL_LUMINANCE4_ALPHA4, GL_LUMINANCE6_ALPHA2,
GL_LUMINANCE8_ALPHA8, GL_LUMINANCE12_ALPHA4,
GL_LUMINANCE12_ALPHA12, GL_LUMINANCE16_ALPHA16,
GL_INTENSITY, GL_INTENSITY4, GL_INTENSITY8,
GL_INTENSITY12, GL_INTENSITY16, GL_RGB, GL_R3_G3_B2,
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, or GL_RGBA16.
x, y Specify the window coordinates of the lower left corner
of the rectangular region of pixels to be copied.
width Specifies the width of the texture image. Must be 0 or
n
2 + 2*border for some integer n.
height Specifies the height of the texture image. Must be 0 or
m
2 + 2*border for some integer m.
border Specifies the width of the border. Must be either 0 or
1.
DESCRIPTIONfglCopyTexImage2D defines a two-dimensional texture image with pixels
from the current GL_READ_BUFFER.
Page 1
fglCopyTexImage2D(3G) OpenGL Reference fglCopyTexImage2D(3G)
The screen-aligned pixel rectangle with lower left corner at (x, y) and
with a width of width + 2 * border and a height of height + 2 * border
defines the texture array at the mipmap level specified by level.
internalformat specifies the internal format of the texture array.
The pixels in the rectangle are processed exactly as if fglCopyPixels had
been called, but the process stops just before final conversion. At this
point all pixel component values are clamped to the range [0,1] and then
converted to the texture's internal format for storage in the texel
array.
Pixel ordering is such that lower x and y screen coordinates correspond
to lower s and t texture coordinates.
If any of the pixels within the specified rectangle of the current
GL_READ_BUFFER are outside the window associated with the current
rendering context, then the values obtained for those pixels are
undefined.
NOTESfglCopyTexImage2D is available only if the GL version is 1.1 or greater.
Texturing has no effect in color index mode.
1, 2, 3, and 4 are not accepted values for internalformat.
An image with height or width of 0 indicates a NULL texture.
When the GL_ARB_imaging extension is supported, the RGBA components read
from the framebuffer may be processed by the imaging pipeline. See
fglTexImage1D for specific details.
ERRORS
GL_INVALID_ENUM is generated if target is not GL_TEXTURE_2D.
GL_INVALID_VALUE is generated if level is less than 0.
GL_INVALID_VALUE may be generated if level is greater than log max, where
2
max is the returned value of GL_MAX_TEXTURE_SIZE.
GL_INVALID_VALUE is generated if width or height is less than 0, greater
than 2 + GL_MAX_TEXTURE_SIZE, or if width or height cannot be represented
k
as 2 + 2 * border for some integer k.
GL_INVALID_VALUE is generated if border is not 0 or 1.
GL_INVALID_VALUE is generated if internalformat is not one of the
allowable values.
GL_INVALID_OPERATION is generated if fglCopyTexImage2D is executed
between the execution of fglBegin and the corresponding execution of
fglEnd.
Page 2
fglCopyTexImage2D(3G) OpenGL Reference fglCopyTexImage2D(3G)ASSOCIATED GETS
fglGetTexImage
fglIsEnabled with argument GL_TEXTURE_2D
MACHINE DEPENDENCIES
RealityEngine, RealityEngine2, and VTX systems do not support color
matrix transformations on images as they are loaded to or read back from
texture memory.
RealityEngine, RealityEngine2, and VTX systems support fglCopyTexImage2D
and fglCopyTexImage2DEXT with the following restrictions:
1. Only level 0 is supported; other levels result in a
GL_INVALID_VALUE error.
2. fglCopyTexImage2D and fglCopyTexImage2DEXT cannot be used if a
GLX video source is the current read drawable (see
fglXMakeCurrentReadSGI). Executing it will generate a
GL_INVALID_OPERATION error.
3. GL_INTERLACE_SGIX is not supported (see fglEnable).
4. Borders are not supported; hence the width of the border should
be 0.
On InfiniteReality systems, there is a performance benefit when the width
of the image to be transferred to texture memory is a multiple of 8.
Texture borders are not supported on InfiniteReality systems.
Applications should use borderless textures and GL_CLAMP_TO_EDGE_SGIS
wrap mode.
The SGIX_interlace extension is supported only on InfiniteReality
systems, on RealityEngine, RealityEngine2, and VTX systems, on Octane2
VPro systems, and on O2 systems.
The INGR_interlace_read extension is supported only on Octane2 VPro
systems, and on O2 systems.
On High Impact and Maximum Impact systems the number of bits per
component, represented internally, is the same for all components and
will be 4, 8, or 12 bits per component. All specified internal formats
will receive an equal or greater representation in this scheme, up to the
12-bit limit. High Impact and Maximum Impact on Indigo2 systems do not
support texture internal formats of the type GL_INTENSITY or GL_ALPHA,
although High Impact and Maximum Impact on Octane systems do support
these types.
High Impact and Maximum Impact on Indigo2 systems without the TRAM option
card support 4 bits per component for GL_RGB and GL_RGBA, 4/8 bits per
component for GL_LUMINANCE_ALPHA, and 4/8/12 bits per component for
Page 3
fglCopyTexImage2D(3G) OpenGL Reference fglCopyTexImage2D(3G)
GL_LUMINANCE.
SEE ALSO
fglCopyPixels, fglCopyTexImage1D, fglCopyTexSubImage1D,
fglCopyTexSubImage2D, fglPixelStore, fglPixelTransfer, fglTexEnv,
fglTexGen, fglTexImage1D, fglTexImage2D, fglTexSubImage1D,
fglTexSubImage2D, fglTexParameter
Page 4
