Support loading more DDS formats

[BlueCube3310]

Depends on #80900

Adds support for loading the following DDS formats:

• RGB10A2,
• BGRA4,
• BC6U / BPTC_UF,
• BC6S / BPTC_SF,
• BC7 / BPTC_RGBA,
• R16F,
• RG16F,
• RGBA16F,
• R32F,
• RG32F,
• RGBA32F
• RGB9E5

An MRP containing DDS files encoded in these formats: DDSFormatsExtended.zip
Godot 4.2-dev3 is unable to load any of them correctly.

[fire]

I support this, but I haven't had the chance to review and test what happens when I give it dds that are currently unsupported but will be supported.

[clayjohn]

Code looks good. Tested locally with the images provided, and those from #80900 and can confirm that it works well.

Since this includes all the changes in #80900, should we just go ahead and merge this and close #80900?

[akien-mga]

Since this includes all the changes in #80900, should we just go ahead and merge this and close #80900?

Either that, or if it makes sense to keep the commits separate (which it could, first refactor, then add features), then this PR should be rebases on top of 80900 and kept as two commits, instead of squashed.

[Zireael07]

Looks like something went wrong when rebasing

[clayjohn]

Now that #80900 has been merged, this just needs a rebase and we can merge it :)

[clayjohn]

Also, in case you are interested, I ran into another unsupported format in the wild
NormalsFittingTexture.zip

Renderdoc opens it as an A8_UNORM.

To be clear, I am not requesting you add support for another format to this PR.

[Calinou]

Renderdoc opens it as an A8_UNORM.

For context:

$ file NormalsFittingTexture.dds
NormalsFittingTexture.dds: Microsoft DirectDraw Surface (DDS): 1024 x 1024, 8-bit color, alpha only

[BlueCube3310]

Also, in case you are interested, I ran into another unsupported format in the wild NormalsFittingTexture.zip

Renderdoc opens it as an A8_UNORM.

I'll open another PR in the future with support for slightly less common formats such as this one. But on the topic of this format, what should Godot import it as? The engine doesn't support images with only the alpha channel, so should it be treated as l8 or l8a8 with fully black/white luminance channel?

[clayjohn]

Also, in case you are interested, I ran into another unsupported format in the wild NormalsFittingTexture.zip
Renderdoc opens it as an A8_UNORM.

I'll open another PR in the future with support for slightly less common formats such as this one. But on the topic of this format, what should Godot import it as? The engine doesn't support images with only the alpha channel, so should it be treated as l8 or l8a8 with fully black/white luminance channel?

I would think l8. As its half the size of l8a8

[YuriSizov]

Thanks!