HP Workstation zx2000 OpenGL 1.1 Reference for HP-UX 11.x - Page 433

T glTexGen Finally, let m = 2 sqrt(fx2 + fy2 + (fz + 1)2). Then the values assigned to the s and t texture coordinates are s = fx/m + 1/2 t = fy/m + 1/2 To enable or disable a texture-coordinate generation function, call glEnable or glDisable with one of the symbolic texture-coordinate names (GL_TEXTURE_GEN_S, GL_TEXTURE_GEN_T, GL_TEXTURE_GEN_R, or GL_TEXTURE_GEN_Q) as the argument. When enabled, the specified texture coordinate is computed according to the generating function associated with that coordinate. When disabled, subsequent vertices take the specified texture coordinate from the current set of texture coordinates. Initially, all texture generation functions are set to GL_EYE_LINEAR and are disabled. Both s plane equations are (1, 0, 0, 0), both t plane equations are (0, 1, 0, 0), and all r and q plane equations are (0, 0, 0, 0). Errors • GL_INVALID_ENUM is generated when coord or pname is not an accepted defined value, or when pname is GL_TEXTURE_GEN_MODE and params is not an accepted defined value. • GL_INVALID_ENUM is generated when pname is GL_TEXTURE_GEN_MODE, params is GL_SPHERE_MAP, and coord is either GL_R or GL_Q. • GL_INVALID_OPERATION is generated if glTexGen is executed between the execution of glBegin and the corresponding execution of glEnd. Associated Gets glGetTexGen glIsEnabled with argument GL_TEXTURE_GEN_S glIsEnabled with argument GL_TEXTURE_GEN_T glIsEnabled with argument GL_TEXTURE_GEN_R glIsEnabled with argument GL_TEXTURE_GEN_Q See Also glCopyPixels, glCopyTexImage2D, glCopyTexSubImage1D, glCopyTexSubImage2D, glTexEnv, glTexImage1D, glTexImage2D, glTexParameter, glTexSubImage1D, glTexSubImage2D Chapter 18 433