1991-2006 Silicon Graphics, Inc. glTexSubImage2D 3G glTexSubImage2D specify a two-dimensional texture subimage void glTexSubImage2D GLenum target GLint level GLint xoffset GLint yoffset GLsizei width GLsizei height GLenum format GLenum type const GLvoid * data target Specifies the target texture of the active texture unit. 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. xoffset Specifies a texel offset in the x direction within the texture array. yoffset Specifies a texel offset in the y direction within the texture array. width Specifies the width of the texture subimage. height Specifies the height of the texture subimage. format Specifies the format of the pixel data. The following symbolic values are accepted: GL_ALPHA, GL_RGB, GL_RGBA, GL_LUMINANCE, and GL_LUMINANCE_ALPHA. type Specifies the data type of the pixel data. The following symbolic values are accepted: GL_UNSIGNED_BYTE, GL_UNSIGNED_SHORT_5_6_5, GL_UNSIGNED_SHORT_4_4_4_4, and GL_UNSIGNED_SHORT_5_5_5_1. data Specifies a pointer to the image data in memory. Texturing maps a portion of a specified texture image onto each graphical primitive for which texturing is active. Texturing is active when the current fragment shader or vertex shader makes use of built-in texture lookup functions. glTexSubImage2D redefines a contiguous subregion of an existing two-dimensional texture image. The texels referenced by data replace the portion of the existing texture array with x indices xoffset and xoffset + width - 1 , inclusive, and y indices yoffset and yoffset + height - 1 , inclusive. This region may not include any texels outside the range of the texture array as it was originally specified. It is not an error to specify a subtexture with zero width or height, but such a specification has no effect. Storage parameter GL_UNPACK_ALIGNMENT, set by glPixelStorei, affects the way that data is read out of client memory. See glPixelStorei for a description. glTexSubImage2D specifies a two-dimensional or cube-map subtexture for the current texture unit, specified with glActiveTexture. 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_ENUM is generated if format or type is not an accepted value. 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 xoffset < 0 , xoffset + width > w , yoffset < 0 , or yoffset + height > h , where w is the width and h is the height of the texture image being modified. GL_INVALID_VALUE is generated if width or height is less than 0. GL_INVALID_OPERATION is generated if the texture array has not been defined by a previous glTexImage2D or glCopyTexImage2D operation whose internalformat matches the format of glTexSubImage2D. GL_INVALID_OPERATION is generated if type is GL_UNSIGNED_SHORT_5_6_5 and format is not GL_RGB. GL_INVALID_OPERATION is generated if type is GL_UNSIGNED_SHORT_4_4_4_4 or GL_UNSIGNED_SHORT_5_5_5_1 and format is not GL_RGBA. glGet with argument GL_MAX_TEXTURE_SIZE or GL_MAX_CUBE_MAP_TEXTURE_SIZE glActiveTexture, glCompressedTexImage2D, glCompressedTexSubImage2D, glCopyTexImage2D, glCopyTexSubImage2D, glPixelStorei, glTexImage2D, glTexParameter 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/.