GlCopyTexImage2D

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_glCopyTexImage2D: copy pixels into a 2D texture image


Syntax

SUB _glCopyTexImage2D (BYVAL target AS _UNSIGNED LONG, BYVAL level AS LONG, BYVAL internalFormat AS _UNSIGNED LONG, BYVAL x AS LONG, BYVAL y AS LONG, BYVAL width AS LONG, BYVAL height AS LONG, BYVAL border AS LONG)
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, _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, or _GL_TEXTURE_CUBE_MAP_NEGATIVE_Z.
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_COMPRESSED_RED, _GL_COMPRESSED_RG, _GL_COMPRESSED_RGB, _GL_COMPRESSED_RGBA. _GL_COMPRESSED_SRGB, _GL_COMPRESSED_SRGB_ALPHA. _GL_DEPTH_COMPONENT, _GL_DEPTH_COMPONENT16, _GL_DEPTH_COMPONENT24, _GL_DEPTH_COMPONENT32, _GL_RED, _GL_RG, _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, _GL_RGBA16, _GL_SRGB, _GL_SRGB8, _GL_SRGB_ALPHA, or _GL_SRGB8_ALPHA8.
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.
height
Specifies the height of the texture image.
border
This value must be 0.


Description

_glCopyTexImage2D defines a two-dimensional texture image, or cube-map texture image with pixels from the current _GL_READ_BUFFER.

The screen-aligned pixel rectangle with lower left corner at (x, y) and with a width of width and a height of height 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 _glReadPixels 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.

When internalformat is one of the sRGB types, the GL does not automatically convert the source pixels to the sRGB color space. In this case, the _glPixelMap function can be used to accomplish the conversion.


Notes:

1, 2, 3, and 4 are not accepted values for internalformat.

An image with height or width of 0 indicates a NULL texture.


Errors

_GL_INVALID_ENUM is generated if target is not _GL_TEXTURE_2D, _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, or _GL_TEXTURE_CUBE_MAP_NEGATIVE_Z.

_GL_INVALID_VALUE is generated if level is less than 0.

_GL_INVALID_VALUE may be generated if level is greater than log<sub>2</sub>(max}, where max is the returned value of _GL_MAX_TEXTURE_SIZE.

_GL_INVALID_VALUE is generated if width is less than 0 or greater than _GL_MAX_TEXTURE_SIZE.

_GL_INVALID_VALUE is generated if border is not 0.

_GL_INVALID_VALUE is generated if internalformat is not an accepted format.

_GL_INVALID_OPERATION is generated if internalformat is _GL_DEPTH_COMPONENT, _GL_DEPTH_COMPONENT16, _GL_DEPTH_COMPONENT24, or _GL_DEPTH_COMPONENT32 and there is no depth buffer.


Use With:

_glGetTexImage


See also

_GL _glActiveTexture, _glBindTexture, _glBindFramebuffer, _glCopyTexImage1D, _glCopyImageSubData, _glCopyTexSubImage1D, _glCopyTexSubImage2D, _glReadBuffer


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



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