I understand that multiplying by the identity matrix is like multiplying by 1. Why would you multiply a matrix that will only contain the same result?
Also, I'm experimenting with some OpenGL code and found some very interesting things. Like for example:
When you use
setIdentity(), the image rotates slower:
Matrix.setIdentityM(mProjectionMatrix, 0); Matrix.rotateM(mProjectionMatrix, 0, angleInDegrees, 0.0f, 0.0f, 1.0f);
But if you try to remove the
setIdentity(), the image will rotate so fast...
first it will rotate clockwise so fast, and then it will become slower until it stops and then it will begin to rotate counter clockwise, and then will stop again, then rotate clockwise.
I really don't understand how the identity matrix affects them despite multiplying by 1.
Can someone explain to me what's going on?
Here is the tutorial I am following.