glCopyTexImage2D(3G)
glCopyTexImage2D - copy pixels into a 2D texture image
As shipped in IRIX 6.5. First release of IRIX 6.5.
NAME 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. 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. 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 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. 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. 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 max, where 2 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 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 MACHINE DEPENDENCIES RealityEngine, RealityEngine2, and VTX systems do not support color matrix transformations on images as they are loaded to or read back from texture memory. RealityEngine, RealityEngine2, and VTX systems support glCopyTexImage2D and glCopyTexImage2DEXT with the following restrictions: 1. Only level 0 is supported; other levels result in a GL_INVALID_VALUE error. 2. glCopyTexImage2D and glCopyTexImage2DEXT cannot be used if a GLX video source is the current read drawable (see glXMakeCurrentReadSGI). Executing it will generate a GL_INVALID_OPERATION error. 3. GL_INTERLACE_SGIX is not supported (see glEnable). 4. Borders are not supported; hence the width of the border should be 0. On InfiniteReality systems, there is a performance benefit when the width of the image to be transferred to texture memory is a multiple of 8. Texture borders are not supported on InfiniteReality systems. Applications should use borderless textures and GL_CLAMP_TO_EDGE_SGIS wrap mode. The SGIX_interlace extension is supported only on InfiniteReality systems, on RealityEngine, RealityEngine2, and VTX systems, and on O2 systems. On High Impact and Maximum Impact systems the number of bits per component, represented internally, is the same for all components and will be 4, 8, or 12 bits per component. All specified internal formats will receive an equal or greater representation in this scheme, up to the 12-bit limit. High Impact and Maximum Impact on Indigo2 systems do not support texture internal formats of the type GL_INTENSITY or GL_ALPHA, although High Impact and Maximum Impact on Octane systems do support these types. High Impact and Maximum Impact on Indigo2 systems without the TRAM option card support 4 bits per component for GL_RGB and GL_RGBA, 4/8 bits per component for GL_LUMINANCE_ALPHA, and 4/8/12 bits per component for GL_LUMINANCE. SEE ALSO glCopyPixels, glCopyTexImage1D, glCopyTexSubImage1D, glCopyTexSubImage2D, glPixelStore, glPixelTransfer, glTexEnv, glTexGen, glTexImage1D, glTexImage2D, glTexSubImage1D, glTexSubImage2D, glTexParameter