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glCopyTexImage2D — copy pixels into a 2D texture image

C Specification

void glCopyTexImage2D(GLenum  target,
 GLint  level,
 GLenum  internalformat,
 GLint  x,
 GLint  y,
 GLsizei  width,
 GLsizei  height,
 GLint  border);

Parameters

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, GL_TEXTURE_CUBE_MAP_NEGATIVE_Z, or GL_PROXY_TEXTURE_CUBE_MAP.

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_COMPRESSED_ALPHA, GL_COMPRESSED_LUMINANCE, GL_COMPRESSED_LUMINANCE_ALPHA, GL_COMPRESSED_INTENSITY, GL_COMPRESSED_RGB, GL_COMPRESSED_RGBA, GL_DEPTH_COMPONENT, GL_DEPTH_COMPONENT16, GL_DEPTH_COMPONENT24, GL_DEPTH_COMPONENT32, 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, GL_RGBA16, GL_SLUMINANCE, GL_SLUMINANCE8, GL_SLUMINANCE_ALPHA, GL_SLUMINANCE8_ALPHA8, 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. Must be 0 or 2 n + 2 ⁡ border for some integer n.

height

Specifies the height of the texture image. Must be 0 or 2 m + 2 ⁡ border for some integer m.

border

Specifies the width of the border. Must be either 0 or 1.

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 + 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 glCopyPixels 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

glCopyTexImage2D 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 ARB_imaging extension is supported, the RGBA components read from the framebuffer may be processed by the imaging pipeline. See glTexImage1D for specific details.

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, GL_TEXTURE_CUBE_MAP_NEGATIVE_Z, or GL_PROXY_TEXTURE_CUBE_MAP are available only if the GL version is 1.3 or greater.

GL_DEPTH_COMPONENT, GL_DEPTH_COMPONENT16, GL_DEPTH_COMPONENT24, and GL_DEPTH_COMPONENT32 are available only if the GL version is 1.4 or greater.

The GL_SRGB, GL_SRGB8, GL_SRGB_ALPHA, GL_SRGB8_ALPHA8, GL_SLUMINANCE, GL_SLUMINANCE8, GL_SLUMINANCE_ALPHA, and GL_SLUMINANCE8_ALPHA8 internal formats are only available if the GL version is 2.1 or greater. See glTexImage2D for specific details about sRGB conversion.

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 2 ⁢ 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 2 + GL_MAX_TEXTURE_SIZE.

GL_INVALID_VALUE is generated if non-power-of-two textures are not supported and the width or depth cannot be represented as 2 k + 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 an accepted format.

GL_INVALID_OPERATION is generated if glCopyTexImage2D is executed between the execution of glBegin and the corresponding execution of glEnd.

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

glIsEnabled with argument GL_TEXTURE_2D or GL_TEXTURE_CUBE_MAP

See Also

glCopyPixels, glCopyTexImage1D, glCopyTexSubImage1D, glCopyTexSubImage2D, glPixelStore, glPixelTransfer, glTexEnv, glTexGen, 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/.