glInvalidateTexSubImage

glInvalidateTexSubImage: man4/glInvalidateTexSubImage.xml

glInvalidateTexSubImage invalidates all or part of a texture image. texture and level indicated which texture image is being invalidated. After this command, data in that subregion have undefined values. xoffset, yoffset, zoffset, width, height, and depth are interpreted as they are in glTexSubImage3D. For texture targets that don't have certain dimensions, this command treats those dimensions as having a size of 1. For example, to invalidate a portion of a two- dimensional texture, the application would use zoffset equal to zero and depth equal to one. Cube map textures are treated as an array of six slices in the z-dimension, where a value of zoffset is interpreted as specifying face GL_TEXTURE_CUBE_MAP_POSITIVE_X + zoffset. level must be greater than or equal to zero and be less than the base 2 logarithm of the maximum texture width, height, or depth. xoffset, yoffset and zoffset must be greater than or equal to zero and be less than the width, height or depth of the image, respectively. Furthermore, xoffset + width, yoffset + height, and zoffset + depth must be less than or equal to the width, height or depth of the image, respectively. For textures of targets GL_TEXTURE_RECTANGLE, GL_TEXTURE_BUFFER, GL_TEXTURE_2D_MULTISAMPLE, or GL_TEXTURE_2D_MULTISAMPLE_ARRAY, level must be zero.