Hi, Michael

On Thu, May 22, 2014 at 4:56 AM, Michael Mc Donnell <michael@mcdonnell.dk> wrote:

The easiest way to get your patches accepted, in my experience, is to write an automated test. That way it is easier for everyone to verify that your patch is doing the right thing. We will be able to run it on the Wine Testbot and see it working.

OK, I'll try to write a unit test. I found this tutorial - https://www.winehq.org/docs/winedev-guide/testing, is it the correct thing to read?

You might be able to get your patch in without the automated test, but I think you need to explain clearly what was wrong with the old code and what you are doing instead. A few more simplified examples that test other cases in your bug report might also help.

The trouble is I don't quite remember the exact steps I took 5 years ago to come up with the new formula. However, I do remember I came up to it by solving a system of linear equations. Since XFORM matrix is applied to each point, I took 3-4 measurements of how points are transformed by PlgBlt, and then used that to make equations of the type applyXFORM(xSrc) = xDest. By solving the equations for the XFORM matrix, I came up with the correct formula I need to get the XFORM matrix from the input variables. I used an online linear equation solver, so there's no human error.

I'll try to recreate the steps, maybe it'll be easier to just explain them. I'll look into making automated tests, too.