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Ah the good old issue of coordinate system orientation.

• clockwise means moving from x axis towards the y axis if you consider a upstraight coordinate system, so Y running from bottom to top.
• however OpenCV uses the top left corner as origin and has a downwards pointing y axis.
• this means to achieve this you need to warp the movement over the x axis.
• and thus your rotation is actually clockwise in the OpenCV coordinate system.

I know it is sometimes a bit sketchy because coordinate systems are used in different constellations inside OpenCV, but now you know why you get this result.

Ah the good old issue of coordinate system orientation.

• clockwise means moving from x axis towards the y axis if you consider a upstraight coordinate system, so Y running from bottom to top.
• however OpenCV uses the top left corner as origin and has a downwards pointing y axis.
• this means to achieve this you need to warp the movement over the x axis.
• and thus your rotation is actually clockwise in the OpenCV coordinate system.

I know it is sometimes a bit sketchy because coordinate systems are used in different constellations inside OpenCV, but now you know why you get this result.