MapRender: PNG Output on maps with transparent objects (addendum)

[PirateIzzy]

This is an addendum to #240 since it seems to be happening again with Tallahart maps as of KMST 1.2.178. It seems that the render doesn't properly render the clouds or the blue pillars, with some of them even having strange vertical lines.

Map ID 410013600

• render (you can see the clouds look off)
  

• in-game
  

Map ID 410013601

• render (I drew red arrows to point to the vertical lines, but the clouds are also off)
  

• in-game
  
  

Map ID 410013602

• render (I drew red arrows here as well, but the clouds are off + the blue pillars don't have transparency)
  

• in-game
  

[Kagamia]

Seems these cases are all spine 4.x skeletons. The new spine renderer should have some bugs on additive blending.

[HikariCalyx]

As of KMST 1.2.1179, following maps are also affected:
993260000 993260300 993261300 993261701

[Kagamia]

Not sure if it is better than before.
410013602

[nanochromatic]

Thanks for taking a look, that looks better.

Two other things I notice in-game vs MapRender:

• Object outlines in-game are a bit smoother whereas object outlines in MapRender are more prominent:
  In-game
  
  MapRender
  

• MapRender produces vertical line artifacts (see red arrow in the screenshot)
  

[Kagamia]

@nanochromatic For the vertical lines, I think it may be due to 'half-pixel problem' and it is a little hard to investigate so far.

Per the color difference between wcR2 and in-game rendering, I found that the official spine-runtime 4.1 does not support BlendMode nor per texture properties (PMA, TextureFilters, etc.) so I need to fix it by myself.

[Kagamia]

Push a new commit: Kagamia/spine-runtimes@e565df6

Here's the final version.

[nanochromatic]

@Kagamia This looks awesome, great work! I think the vertical line issue has also been resolved as I no longer see any when rendering maps that previously were impacted (for example, 410013602 no longer has the lines).

I'll let @PirateIzzy chime in as well, but this looks to be fully resolved on my end.

[Kagamia]

@nanochromatic So the vertical line is likely due to pre-multiplied-alpha textures, the semi-transparent pixels are shown as dark black color.

I’m glad to see it was fixed. We can close this issue aflter double check.