Function l_selection_gradient

src/nhlsel.c:861–915

Gradients are versatile enough, with so many independently optional * arguments, that it doesn't seem helpful to provide a non-table form with * non-obvious argument order. */ selection.gradient({ type = "radial", x = 3, y = 5, x2 = 10, y2 = 12, * mindist = 4, maxdist = 10, limited = false }); */

/* selection.gradient({ type = "radial", x = 3, y = 5, x2 = 10, y2 = 12,
 *                      mindist = 4, maxdist = 10, limited = false });    */
staticfn int
l_selection_gradient(lua_State *L)
{
    int argc = lua_gettop(L);
    struct selectionvar *sel = (struct selectionvar *) 0;
    /* if x2 and y2 aren't set, the gradient has a single center point of x,y;
     * if they are set, the gradient is centered on a (x,y) to (x2,y2) line */
    coordxy x = 0, y = 0, x2 = -1, y2 = -1;
    /* points are always added within mindist of the center; the chance for a
     * point between mindist and maxdist to be added to the selection starts
     * at 100% at mindist and decreases linearly to 0% at maxdist */
    coordxy mindist = 0, maxdist = 0;
    long type = 0;
    static const char *const gradtypes[] = {
        "radial", "square", NULL
    };
    static const int gradtypes2i[] = {
        SEL_GRADIENT_RADIAL, SEL_GRADIENT_SQUARE, -1
    };

    if (argc == 1 && lua_type(L, 1) == LUA_TTABLE) {
        lcheck_param_table(L);
        type = gradtypes2i[get_table_option(L, "type", "radial", gradtypes)];
        x = (coordxy) get_table_int(L, "x");
        y = (coordxy) get_table_int(L, "y");
        x2 = (coordxy) get_table_int_opt(L, "x2", -1);
        y2 = (coordxy) get_table_int_opt(L, "y2", -1);
        cvt_to_abscoord(&x, &y);
        cvt_to_abscoord(&x2, &y2);
        /* maxdist is required because there's no obvious default value for
         * it, whereas mindist has an obvious default of 0 */
        maxdist = get_table_int(L, "maxdist");
        mindist = get_table_int_opt(L, "mindist", 0);

        lua_pop(L, 1);
        (void) l_selection_new(L);
        sel = l_selection_check(L, 1);
    } else {
        nhl_error(L, "selection.gradient requires table argument");
        /* NOTREACHED */
    }

    /* someone might conceivably want to draw a gradient somewhere off-map. So
     * the only coordinate that's "illegal" for that is (-1,-1).
     * If a level designer really needs to draw a gradient line using that
     * coordinate, they can do so by setting regular x and y to -1. */
    if (x2 == -1 && y2 == -1) {
        x2 = x;
        y2 = y;
    }

    selection_do_gradient(sel, x, y, x2, y2, type, mindist, maxdist);
    lua_settop(L, 1);
    return 1;
}

DISABLE_WARNING_UNREACHABLE_CODE