How to rotate a vertex around a certain point?

by

The easiest approach is to compose three transformations:

  1. A translation that brings point 1 to the origin
  2. Rotation around the origin by the required angle
  3. A translation that brings point 1 back to its original position

When you work this all out, you end up with the following transformation (where x is the desired angle of rotation in radians):

newX = centerX + (point2x-centerX)*Math.cos(x) - (point2y-centerY)*Math.sin(x);

newY = centerY + (point2x-centerX)*Math.sin(x) + (point2y-centerY)*Math.cos(x);

Note that this makes the assumption that the angle x is negative for clockwise rotation (the so-called standard or right-hand orientation for the coordinate system). If that’s not the case, then you would need to reverse the sign on the terms involving sin(x).

More Related Contents:

  1. Calculating the angle between two lines without having to calculate the slope? (Java)
  2. How to generate Random point(x,y) in Java [closed]
  3. Fast algorithm to calculate n! / (q!)^r
  4. How to make fibonacci method? [closed]
  5. is there an algorithm to reverse a chosen part of a number? [closed]
  6. Decrement on While loops
  7. How to resolve a Java Rounding Double issue [duplicate]
  8. How to parse a mathematical expression given as a string and return a number? [duplicate]
  9. Convert latitude/longitude point to a pixels (x,y) on mercator projection
  10. Mod in Java produces negative numbers [duplicate]
  11. How does java do modulus calculations with negative numbers?
  12. Creating a triangle with for loops
  13. Java Round up Any Number
  14. Rounding BigDecimal to *always* have two decimal places
  15. midpoint between two latitude and longitude
  16. BigInteger.pow(BigInteger)?
  17. Create the square, rectangle, triangle of java in jframe [closed]
  18. Fast transcendent / trigonometric functions for Java
  19. Java check if two rectangles overlap at any point
  20. What’s the best practice to round a float to 2 decimals? [duplicate]
  21. Recursive Fibonacci memoization
  22. Logarithm for BigInteger
  23. pow (x,y) in Java
  24. Finding Signed Angle Between Vectors
  25. Java math function to convert positive int to negative and negative to positive?
  26. Easy way to keeping angles between -179 and 180 degrees
  27. How do I create an int array with randomly shuffled numbers in a given range [duplicate]
  28. Combinatoric ‘N choose R’ in java math?
  29. Find the max of 3 numbers in Java with different data types
  30. What is the algorithm for finding the center of a circle from three points?

Leave a Comment