glCopyTexImage2D
- specify a two-dimensional texture image with pixels from the color buffer
void glCopyTexImage2D(GLenum target, GLint level, GLenum internalformat, GLint x, GLint y, GLsizei width, GLsizei height, GLint border)
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 n
th mipmap reduction image.
internalformat
Specifies the color components of the texture. Must be one of the following symbolic constants: GL_ALPHA
, GL_LUMINANCE
, GL_LUMINANCE_ALPHA
, GL_RGB
, or GL_RGBA
.
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 2n + 2border for some integer n.
height
Specifies the height of the texture image. Must be 0 or 2m + 2border for some integer m.
border
Specifies the width of the border. Must be 0.
glCopyTexImage2D
defines a two-dimensional texture image with pixels from the color buffer.
The screen-aligned pixel rectangle with lower left corner at (x
, y
) and with a width of width + 2border and a height of height + 2border defines the texture array at the mipmap level specified by level
. internalformat
specifies the color components of the texture.
The red, green, blue, and alpha components of each pixel that is read are converted to an internal fixed-point or floating-point format with unspecified precision. The conversion maps the largest representable component value to 1.0, and component value 0 to 0.0. The values are then converted to the texture's internal format for storage in the texel array.
internalformat
must be chosen such that color buffer components can be dropped during conversion to the internal format, but new components cannot be added. For example, an RGB
color buffer can be used to create LUMINANCE
or RGB
textures, but not ALPHA
, LUMINANCE_ALPHA
or RGBA
textures.
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 color buffer are outside the window associated with the current rendering context, then the values obtained for those pixels are undefined.
An image with height or width of 0 indicates a null-texture.
GL_INVALID_ENUM
is generated if target
is not GL_TEXTURE_2D
.
GL_INVALID_OPERATION
is generated if internalformat
is not compatible with the color buffer format.
GL_INVALID_VALUE
is generated if level
is less than 0.
GL_INVALID_VALUE
may be generated if level
is greater than log2max, where 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 GL_MAX_TEXTURE_SIZE
, or if width
or height
cannot be represented as 2k + 2border for some integer k.
GL_INVALID_VALUE
is generated if border
is not 0.
GL_INVALID_ENUM
is generated if internalformat
is not an accepted constant.
glGet
with argument GL_MAX_TEXTURE_SIZE
Copyright © 2003-2004 Silicon Graphics, Inc.
This document is licensed under the SGI Free Software B License. For details, see http://oss.sgi.com/projects/FreeB/.
glCompressedTexImage2D
, glCopyTexSubImage2D
, glGet
, glTexEnv
, glTexImage2D
, glTexSubImage2D
, glTexParameter