Bezier Curves: glMap1 and glEvalCoord1

void glMap1{fd}(GLenum target, TYPEu1, TYPEu2, GLint stride, GLint order, const TYPE*points);

The target parameter specifies what the control points represent (see Table),
and therefore how many values need to be supplied in points.
The second two parameters, u1 and u2, indicate the range for the variable u.
The variable stride is the number of single- or double-precision values (as appropriate) in each block of storage. Thus, it's an offset value between the beginning of one control point and the beginning of the next.
The order is the degree plus one, and it should agree with the number of control points.
The points parameter points to the first coordinate of the first control point. Using the example data structure for glMap1*(), use the following types for points:

GLfloat ctlpoints[dimPoints][nbPoints] in C
float ctlpoints[ nbPoints * dimPoint] in Java

The problem is that Java does not handle multidimensional arrays like C, where a multidimensional array, it is stored in memory as if it were 1D. Whereas to keep the control points in one memory block in Java they must be declared in a 1D array.

public void glMap1f(int target,
                    float u1,
                    float u2,
                    int stride,
                    int order,
                    float[] points,
                    int points_offset)

OR:

public void glMap1f(int target,
                    float u1,
                    float u2,
                    int stride,
                    int order,
                    FloatBuffer points)

The points can represent vertices, RGBA color data, normal vectors, or texture coordinates. Forexample, with GL_MAP1_COLOR_4, the evaluator generates color data along a curve in four-dimensional (RGBA) color space.

Parameter	Meaning
GL_MAP1_VERTEX_3	x, y, z vertex coordinates
GL_MAP1_VERTEX_4	x, y, z, w vertex coordinates
GL_MAP1_INDEX	color index
GL_MAP1_COLOR_4	R, G, B, A
GL_MAP1_NORMAL	normal coordinates
GL_MAP1_TEXTURE_COORD_1	s texture coordinates
GL_MAP1_TEXTURE_COORD_2	s, t texture coordinates
GL_MAP1_TEXTURE_COORD_3	s, t, r texture coordinates
GL_MAP1_TEXTURE_COORD_4	s, t, r, q texture coordinates

Also use the parameter values listed in the Table to enable each defined evaluator before you invoke it.
Pass the appropriate value to glEnable() or glDisable() to enable or disable the evaluator.

More than one evaluator can be evaluated at a time. If you have both a GL_MAP1_VERTEX_3 and a GL_MAP1_COLOR_4 evaluator defined and enabled, for example, then calls to glEvalCoord1() generate both a position and a color. Evaluators can be used to generate any combination of vertex, normal, color, and texture-coordinate data.

void glEvalCoord1{fd}{v}(TYPE u);

u is the value (or a pointer to the value, in the vector version of the command) that is the domain coordinate.