Thanks to pixel repacking using cpu data cache, this has a low runtime
cost even for TGL_LINEAR.
Adds support for TGL_NEAREST.
Adds support for TGL_MIRRORED_REPEAT, TGL_CLAMP_TO_EDGE and TGL_REPEAT.
Also, add support for more texture clamping and resampling options.
Mipmaps are not supported, although their sampling modes will be
applied - but to the full-size texture instead of selected mipmap.
Note: Texture sampler is still chosen at texture creation time.
longcurrent_color is assigned per vertex, but it is not saved on each
vertex on creation (unlike their "color" attribute, used when lighting
is enabled).
As a consequence, and because rendering happens asynchronously (rather,
following the draw call queue managed by zdirtyrect.cpp when requested
to flip current buffer), longcurrent_color at clipping time can be
different to the one at vertex declaration time, causing color artifacts.
The effect is most noticeable in EMI set shi, in the grog dispenser +
shipyard manager closeup angle, when Guybrush exits the screen by
crossing its right border: dark triangles become visible on his face.
Instead, always use the color attribute, which is already properly
initialised on vertex creation.
Paweł Kołodziejski
Eugene Sandulenko
Orgad Shaneh
Vincent Pelletier
Stefano Musumeci