(Google translated)
GERNOT, I apologize if the problem is already known and being resolved.
Recently doing some testing on Android that creating a screen mode PORTRAIT and setting ORIENTATION = 1 to obtain a screen LANDSCAPE, GetPixel returned incorrect values and this error occurs on Windows creating the same mode screen.
After several tests I was able to understand that the read error occurs when you create a different screen mode from original, for example on a LANDSCAPE screen (then Width>Height and ORIENTATION = 1 or = 3) to obtain a PORTRAIT screen and viceversa if on a PORTRAIT screen (ie Height>Width and always ORIENTATION = 1 or = 3) to obtain a LANDSCAPE screen.
Also on these modes of Orientation I found a mathematical relationship that shows that the command GetPixel in reality can not find the correct value of the memory by the mouse coordinates but in other parts of the screen.
I conclude, therefore, that the problem is probably just mathematics where it reads the graphics memory to take the value of GetPixel in function of incorrect screen coordinates.
GERNOT, I apologize if the problem is already known and being resolved.
Recently doing some testing on Android that creating a screen mode PORTRAIT and setting ORIENTATION = 1 to obtain a screen LANDSCAPE, GetPixel returned incorrect values and this error occurs on Windows creating the same mode screen.
After several tests I was able to understand that the read error occurs when you create a different screen mode from original, for example on a LANDSCAPE screen (then Width>Height and ORIENTATION = 1 or = 3) to obtain a PORTRAIT screen and viceversa if on a PORTRAIT screen (ie Height>Width and always ORIENTATION = 1 or = 3) to obtain a LANDSCAPE screen.
Also on these modes of Orientation I found a mathematical relationship that shows that the command GetPixel in reality can not find the correct value of the memory by the mouse coordinates but in other parts of the screen.
I conclude, therefore, that the problem is probably just mathematics where it reads the graphics memory to take the value of GetPixel in function of incorrect screen coordinates.