GLAPI/glCopyTexImage2D

glCopyTexImage2D

Core in version		4.6
Core since version		1.0

glCopyTexImage2D: copy pixels into a 2D texture image

Function Definition

 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), 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 log₂(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.

Associated Gets

glGetTexImage

See Also

glCopyTexImage1D, glCopyTexSubImage1D, glCopyTexSubImage2D, glPixelStore, glTexImage1D, glTexImage2D, glTexSubImage1D, glTexSubImage2D, glTexParameter

Copyright

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/.