glCopyTexImage2D Subroutine

OpenGL 1.2 for AIX: Reference Manual

glCopyTexImage2D Subroutine

Purpose

Defines a two-dimensional (2D) texture image.

Library

OpenGL C bindings library: libGL.a

C Syntax

void glCopyTexImage2D(GLenum target,
     GLint  level,
     GLenum  internalFormat,
     GLint  xCoordinate,
     GLint  yCoordinate,
     GLsizei  width,
     GLsizei  height,
     GLint  border)

Description

The glCopyTexImage2D subroutine defines a two-dimensional 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 height 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 [0.0,1.0] 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.

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.
xCoordinate	Specifies the x window coordinate of the lower left corner of the row of pixels to be copied.
yCoordinate	Specifies the y window coordinate of the lower left corner of the row of pixels to be copied.
width	Specifies the width of the texture image. Must be 0 or 2*n + 2border for some integer n. The height of the texture image is 1.
height	Specifies the height of the texture image. Must be 0 or 2*m + 2border for some integer m.
border	Specifies the width of the border. Must be either 0 or 1.

Notes

The glCopyTexImage2D subroutine is available only if the GL version is 1.1 or greater.

1, 2, 3, or 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_INVALID_VALUE is generated if level is less than zero.

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 zero, greater than 2 + GL_MAX_TEXTURE_SIZE, or if width or height 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 one of the allowable values.

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

Associated Gets

glGetTexImage.

glIsEnabled with argument GL_TEXTURE_2D.

Related Information

The glCopyPixels subroutine, glCopyTexImage1D glPixelStore subroutine, glPixelTransfer subroutine, glTexEnv subroutine, glTexImage2D subroutine, glTexParameter subroutine.