HP Workstation zx2000 OpenGL 1.1 Reference for HP-UX 11.x - Page 280

M glMap2 Equation 11-8 Equation 11-9 00 ≡ 1and  n  0 ≡ 1 glMap2 is used to define the basis and to specify what kind of values are produced. Once defined, a map can be enabled and disabled by calling glEnable and glDisable with the map name, one of the nine predefined values for target, described below. WhenglEvalCoord2 presents values u and v, the bivariate Bernstein polynomials are evaluated using û and v, where uˆ = u--u--2---------u--u--1-1-- vˆ = v--v--2---------v-v--1--1- target is a symbolic constant that indicates what kind of control points are provided in points, and what output is generated when the map is evaluated. It can assume one of nine predefined values: GL_MAP2_VERTEX_3 Each control point is three floating-point values representing x, y, and z. Internal glVertex3 commands are generated when the map is evaluated. GL_MAP2_VERTEX_4 Each control point is four floating-point values representing x, y, z, and w. Internal glVertex4 commands are generated when the map is evaluated. GL_MAP2_INDEX Each control point is a single floating-point value representing a color index. Internal glIndex commands are generated when the map is evaluated but the current index is not updated with the value of these glIndex commands. GL_MAP2_COLOR_4 Each control point is four floating-point values representing red, green, blue, and alpha. Internal glColor4 commands are generated when the map is evaluated but the current color is not updated with the value of these glColor4 commands. GL_MAP2_NORMAL Each control point is three floating-point values representing the x, y, and z components of a normal vector. Internal glNormal commands are generated when the map is evaluated but the current normal is not updated with the value of these glNormal commands. GL_MAP2_TEXTURE_COORD_1 Each control point is a single floating-point value representing the s texture coordinate. Internal glTexCoord1 commands are generated when the map is evaluated but the current texture coordinates are not updated with the value of these glTexCoord commands. GL_MAP2_TEXTURE_COORD_2 280 Chapter 11