When rotating a sprite with the gfx_RotatedTransparentSprite, an asset undergoes a slight mutilation even when the passed value is 128 (180 degrees). It is reflected across the x-axis, but parts of it are offset relative to the unrotated original. The sprite is 16x16, which is much smaller than the stated 210 x 210 threshold for artifacts. Code and the asset in question are included:
gfx_TransparentSprite(arrowFilled, 111 + 98 + 15, 71); gfx_RotatedTransparentSprite(arrowFilled, 111 + 98 + 15, 169, 128);
Original asset:
Result of rotation:
The 'head' of the arrow is noticeably offset relative to the 'body', which is not present in the original.
I haven't tested it for other angle values and other sprites yet, but this issue would probably generalize to others, as I see nothing special in this asset. Since gfx_RotatedTransparentSprite uses (I believe) the same logic as the other rotated sprite drawing routines, it makes sense that it would also affect the others.
Of course, I expect significant distortions to occur when the rotation angle is not a multiple of 64 (90 degrees), as resolution is very low, but it seems to me that this shouldn't happen for angular multiples of 90, much less 180 degrees? I'm not familiar with the inner workings of graphx, but it's intuitive that this is one of the special situations where a rotation would not cause a distortion...
When rotating a sprite with the gfx_RotatedTransparentSprite, an asset undergoes a slight mutilation even when the passed value is 128 (180 degrees). It is reflected across the x-axis, but parts of it are offset relative to the unrotated original. The sprite is 16x16, which is much smaller than the stated 210 x 210 threshold for artifacts. Code and the asset in question are included:
gfx_TransparentSprite(arrowFilled, 111 + 98 + 15, 71); gfx_RotatedTransparentSprite(arrowFilled, 111 + 98 + 15, 169, 128);Original asset:
Result of rotation:
The 'head' of the arrow is noticeably offset relative to the 'body', which is not present in the original.
I haven't tested it for other angle values and other sprites yet, but this issue would probably generalize to others, as I see nothing special in this asset. Since gfx_RotatedTransparentSprite uses (I believe) the same logic as the other rotated sprite drawing routines, it makes sense that it would also affect the others.
Of course, I expect significant distortions to occur when the rotation angle is not a multiple of 64 (90 degrees), as resolution is very low, but it seems to me that this shouldn't happen for angular multiples of 90, much less 180 degrees? I'm not familiar with the inner workings of graphx, but it's intuitive that this is one of the special situations where a rotation would not cause a distortion...