Given an angle and length, how do I calculate the coordinates

user_198246 0
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Assuming the upper left corner is (0,0) and I'm given an angle of 30 degrees, a starting point of (0,300), a line length of 600, how do I calculate the ending point of the line so that the line is representative of the angle given.

The C pseudo-code is

main() {
  int x,y;

  getEndPoint(30, 600, 0, 300, &x, &y);
  printf("end x=%d, end y=%d", x, y);
}

// input angle can be from 0 - 90 degrees

void getEndPoint(int angle, int len, int start_x, int start_y, int *end_x, int *end_y) 
{

    calculate the endpoint here for angle and length

    *end_x = calculated_end_x;
    *end_y = calculated_end_y;
}
trigonometry math c c++
5 Answers

People are forgetting the complex library in C++, which does polar to rectangular conversions for us.

complex<double> getEndPoint(complex<double> const &startPoint, double magnitude, double radians)
{
    return startPoint + polar<double>(magnitude, radians);
}

int main()
{
    complex<double> startingPoint(0.0, 300.0);
    auto newPoint = getEndPoint(startingPoint, 600, 0.523598776);

    cout << newPoint << endl;
}

I'd also be careful with your chosen terminology. When I see get in a name, I think of it as retrieving an answer stored somewhere. In this example, we're computing something, and that could be false assurance given to a user of your code.

user_9049630
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