Yalantis/uCrop · error · CImgArgumentException

"[" cimg_appname "_math_parser] CImg<%s>: Function 'ellipse(

Error message

"[" cimg_appname "_math_parser] CImg<%s>: Function 'ellipse()': Invalid arguments '%s'. "

What it means

The math parser's ellipse() function expects either a fixed set of scalar arguments or a valid image index selector. This variant is thrown when no image selector (#ind) was given (ind==~0U) but the argument list does not match any supported ellipse() overload, so the collected extra arguments cannot be dispatched.

Source

Thrown at ucrop/src/main/jni/CImg.h:26709

                    if (i<i_end) {
                      cimg_forX(color,k) if (i<i_end) color[k] = (T)_mp_arg(i++);
                      else { color.resize(k,1,1,1,-1); break; }
                      color.resize(img._spectrum,1,1,1,0,2);
                    }
                  }
                }
              }
            }
          }
        }
        if (!is_invalid_arguments) {
          if (is_outlined) img.draw_ellipse(x0,y0,r1,r2,angle,color._data,opacity,pattern);
          else img.draw_ellipse(x0,y0,r1,r2,angle,color._data,opacity);
        } else {
          CImg<doubleT> args(i_end - 4);
          cimg_forX(args,k) args[k] = _mp_arg(4 + k);
          if (ind==~0U)
            throw CImgArgumentException("[" cimg_appname "_math_parser] CImg<%s>: Function 'ellipse()': "
                                        "Invalid arguments '%s'. ",
                                        mp.imgin.pixel_type(),args.value_string()._data);
          else
            throw CImgArgumentException("[" cimg_appname "_math_parser] CImg<%s>: Function 'ellipse()': "
                                        "Invalid arguments '#%u%s%s'. ",
                                        mp.imgin.pixel_type(),ind,args._width?",":"",args.value_string()._data);
        }
        return cimg::type<double>::nan();
      }

      static double mp_epoch(_cimg_math_parser& mp) {
        unsigned int
          year = (unsigned int)mp.opcode[2]==~0U?~0U:(unsigned int)std::max(_mp_arg(2),1900.),
          month = (unsigned int)mp.opcode[3]==~0U?~0U:(unsigned int)cimg::cut(_mp_arg(3),1.,12.),
          day = (unsigned int)mp.opcode[4]==~0U?~0U:(unsigned int)cimg::cut(_mp_arg(4),1.,31.),
          hour = (unsigned int)mp.opcode[5]==~0U?~0U:(unsigned int)cimg::cut(_mp_arg(5),0.,23.),
          minute = (unsigned int)mp.opcode[6]==~0U?~0U:(unsigned int)cimg::cut(_mp_arg(6),0.,59.),
          second = (unsigned int)mp.opcode[7]==~0U?~0U:(unsigned int)cimg::cut(_mp_arg(7),0.,60.);

View on GitHub (pinned to f788b534b4)

Solutions

  1. Check the ellipse() signature in your CImg version and supply the exact expected arguments (x,y,radius1,radius2,angle,color,...).
  2. Add the #image_index selector if you meant to draw on a specific image.
  3. Count the provided arguments — the message echoes them via value_string to spot extras/missing ones.
  4. Update the expression if it was written for a different CImg version with different arity.

Example fix

// before: missing second radius
 ellipse(x,y,r,angle)
// after
 ellipse(x,y,r1,r2,angle)
Defensive patterns

Strategy: validation

Validate before calling

// Validate ellipse() argument count against the expected signature before evaluation
const ELLIPSE_MIN_ARGS = 5; // x,y,r1,r2,angle
function checkEllipseArgs(args) { if (args.length < ELLIPSE_MIN_ARGS) throw new Error('ellipse() needs at least ' + ELLIPSE_MIN_ARGS + ' args, got ' + args.length); }

Type guard

function hasValidEllipseArity(args) { return [5,6,7,8].includes(args.length); }

Try / catch

try { evalMath(expr); } catch (e) { if (String(e).includes("Function 'ellipse()'") && String(e).includes('Invalid arguments')) { console.error('bad ellipse args:', e.message); fixExpr(); } else throw e; }

Prevention

When it happens

Trigger: Calling ellipse() in a math expression with an argument count or types that match no supported signature (e.g. wrong number of radii/angle/color arguments) without a #index prefix.

Common situations: Typos in argument count (missing radius or angle); passing color as multiple scalars beyond the supported arity; porting scripts between CImg versions where ellipse() gained/lost overloads.

Understand the failure class

Background: "missing required argument" and "the following required arguments were not provided": what required-argument errors mean and how to fix them — this error's family across 20 libraries.

Related errors

AI-assisted analysis of Yalantis/uCrop@f788b534b4 (2026-09-08). Data as JSON: /api/errors/a8429ec2bbdec4fe. Report an issue: GitHub.