Calculating points of rectangle after rotation (Trig) help!

Colby L · 2015-08-17T19:53:17

I'm missing an essential step and it's been a while since I've taken trig. Here is the code I'm using. It seems like maybe it's rotating around (0,0) instead of the players pos, which would explain the negative numbers and why the first point isn't always the same (or my math is simply off ). I've taken too much time on something that should be simple. Rescue me/point me in the right direction? I was using this article as a guide, but even in the figure I can see this formula is not rotating the rectangle how I was excpecting. -> https://msdn.microsoft.com/en-us/library/dd162943%28v=vs.85%29.aspx. public Polygon toRectangle(Image image) { //determine verticies of rectangle after rotation //original points float x1 = image.getX(); float y1 = image.getY(); System.out.println("First set is: " + x1 + ", " + y1); float x2 = image.getX() + image.getWidth(); float y2 = image.getY(); System.out.println("Second set is: " + x2 + ", " + y2); float x3 = image.getX() + image.getWidth(); float y3 = image.getY() + image.getHeight(); System.out.println("Third set is: " + x3 + ", " + y3); float x4 = image.getX(); float y4 = image.getY() + image.getHeight(); System.out.println("Fourth set is: " + x4 + ", " + y4); //x' = (x * cos A) - (y * sin A) //y' = (x * sin A) + (y * cos A) //Points after rotation float newX1 = (float)(x1 * Math.cos(image.getRotation())) - (float)(y1 * Math.sin(image.getRotation()))); float newY1 = (float)(x1 * Math.sin(image.getRotation())) + (float)(y1 * Math.cos(image.getRotation()))); float newX2 = (float)(x2 * Math.cos(image.getRotation())) - (float)(y2 * Math.sin(image.getRotation()))); float newY2 = (float)(x2 * Math.sin(image.getRotation())) + (float)(y2 * Math.cos(image.getRotation()))); float newX3 = (float)(x3 * Math.cos(image.getRotation())) - (float)(y3 * Math.sin(image.getRotation()))); float newY3 = (float)(x3 * Math.sin(image.getRotation())) + (float)(y3 * Math.cos(image.getRotation()))); float newX4 = (float)(x4 * Math.cos(image.getRotation())) - (float)(y4 * Math.sin(image.getRotation()))); float newY4 = (float)(x4 * Math.sin(image.getRotation())) + (float)(y4 * Math.cos(image.getRotation()))); System.out.println("First Point after rotation of " + image.getRotation() + ": " + newX1 +", " + newY1 ); System.out.println("Second Point: " + newX2 +", " + newY2 ); System.out.println("Third Point: " + newX3 +", " + newY3 ); System.out.println("Fourth Point: " + newX4 +", " + newY4 ); return new Polygon(new float[]{(float)newX1,(float)newY1,(float)newX2,(float)newY2,(float)newX3,(float)newY3,(float)newX4,(float)newY4}); And the output... Attacking Animation duration: 0.4 Animation ends at: 1437844348816 Curren time is: 1437844348416 First set is: 314.0, 208.0 Second set is: 349.0, 208.0 Third set is: 349.0, 283.0 Fourth set is: 314.0, 283.0 First Point after rotation of 90.0: -326.64642, 187.51566 Second Point: -342.32898, 218.80551 Third Point: -409.37872, 185.19998 Fourth Point: -393.69617, 153.91013 Attacking Animation duration: 0.4 Animation ends at: 1437844353899 Curren time is: 1437844353499 First set is: 314.0, 207.0 Second set is: 349.0, 207.0 Third set is: 349.0, 282.0 Fourth set is: 314.0, 282.0 First Point after rotation of -180.0: -353.75507, 127.68069 Second Point: -374.70117, 155.72104 Third Point: -434.7876, 110.83652 Fourth Point: -413.8415, 82.79617 Attacking Animation duration: 0.4 Animation ends at: 1437844357899 Curren time is: 1437844357499 First set is: 314.0, 207.0 Second set is: 349.0, 207.0 Third set is: 349.0, 282.0 Fourth set is: 314.0, 282.0 First Point after rotation of -90.0: 44.362198, -373.4662 Second Point: 28.679626, -404.75604 Third Point: 95.72937, -438.36157 Fourth Point: 111.41194, -407.07172 Attacking Animation duration: 0.4 Animation ends at: 1437844361816 Curren time is: 1437844361416 First set is: 314.0, 210.0 Second set is: 349.0, 210.0 Third set is: 349.0, 285.0 Fourth set is: 314.0, 285.0 First Point after rotation of 0.0: 314.0, 210.0 Second Point: 349.0, 210.0 Third Point: 349.0, 285.0 Fourth Point: 314.0, 285.0 Mob Hit! Should I be converting degrees to radians? I seriously didn't excpect this function to cause me any trouble Any help is appreciated!