Question

So I have some openGL code (such code for example)

/*   FUNCTION:        YCamera :: CalculateWorldCoordinates
     ARGUMENTS:       x         mouse x coordinate
                      y         mouse y coordinate
                      vec       where to store coordinates
     RETURN:          n/a
     DESCRIPTION:     Convert mouse coordinates into world coordinates
*/
void YCamera :: CalculateWorldCoordinates(float x, float y, YVector3 *vec) { // START GLint viewport[4]; GLdouble mvmatrix[16], projmatrix[16];

 GLint real_y;
GLdouble mx, my, mz;

glGetIntegerv(GL_VIEWPORT, viewport);
glGetDoublev(GL_MODELVIEW_MATRIX, mvmatrix);
glGetDoublev(GL_PROJECTION_MATRIX, projmatrix);

real_y = viewport[3] - (GLint) y - 1;   // viewport[3] is height of window in pixels
gluUnProject((GLdouble) x, (GLdouble) real_y, 1.0, mvmatrix, projmatrix, viewport, &mx, &my, &mz);

/*      'mouse' is the point where mouse projection reaches FAR_PLANE.
        World coordinates is intersection of line(camera->mouse) with plane(z=0) (see LaMothe 306)

        Equation of line in 3D:
                (x-x0)/a = (y-y0)/b = (z-z0)/c          

        Intersection of line with plane:
                z = 0
                x-x0 = a(z-z0)/c  <=> x = x0+a(0-z0)/c  <=> x = x0 -a*z0/c
                y = y0 - b*z0/c

*/
double lx = fPosition.x - mx;
double ly = fPosition.y - my;
double lz = fPosition.z - mz;
double sum = lx*lx + ly*ly + lz*lz;
double normal = sqrt(sum);
double z0_c = fPosition.z / (lz/normal);

vec->x = (float) (fPosition.x - (lx/normal)*z0_c);
vec->y = (float) (fPosition.y - (ly/normal)*z0_c);
vec->z = 0.0f;
}

I want to run It but with out precompiling. Is there any way to do such thing

Was it helpful?

Solution

This is possible with LWJGL (OpenGL binding) and the REPL in Scala (runs on the JVM). I imagine that other languages like Clojure/Jython could also handle this request -- either through LWJGL or Jogl. There are also OpenGL bindings for a whole host of languages that don't require (explicit) compiling or come with their own REPL and/or 'integrated IDE'.

C normally always requires a compilation, but I did find this: http://neugierig.org/software/c-repl/ and I'm sure there are other projects similar in nature.

Happy coding.

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