Fix Color::get_{r,g,b,a}8

[dalexeev]

Closes #47022.

[aaronfranke]

This is good, but while we're changing these lines, this can be better. Color always uses 32-bit floats, so these should have f as a suffix (or we could also do 255 without the .0 for the same behavior, but 255.0f makes our intentions clear):

	_FORCE_INLINE_ void set_r8(int32_t r8) { r = (CLAMP(r8, 0, 255) / 255.0); }
	_FORCE_INLINE_ int32_t get_r8() const { return int32_t(CLAMP(Math::round(r * 255.0f), 0.0f, 255.0f)); }
	_FORCE_INLINE_ void set_g8(int32_t g8) { g = (CLAMP(g8, 0, 255) / 255.0); }
	_FORCE_INLINE_ int32_t get_g8() const { return int32_t(CLAMP(Math::round(g * 255.0f), 0.0f, 255.0f)); }
	_FORCE_INLINE_ void set_b8(int32_t b8) { b = (CLAMP(b8, 0, 255) / 255.0); }
	_FORCE_INLINE_ int32_t get_b8() const { return int32_t(CLAMP(Math::round(b * 255.0f), 0.0f, 255.0f)); }
	_FORCE_INLINE_ void set_a8(int32_t a8) { a = (CLAMP(a8, 0, 255) / 255.0); }
	_FORCE_INLINE_ int32_t get_a8() const { return int32_t(CLAMP(Math::round(a * 255.0f), 0.0f, 255.0f)); }

[dalexeev]

Can we do this:

_FORCE_INLINE_ int32_t get_r8() const { return CLAMP(int32_t(Math::round(r * 255.0f)), 0, 255); }

?

[aaronfranke]

The core devs did the opposite in this commit, so I don't think we should undo it: 771b3c5#diff-338a6122d06ba451b648508685a84917a457cf904b0aa28e736c62fe4dd950b6R197

[akien-mga]

Thanks!

[akien-mga]

In #47022 you state that it affects 3.2.4-rc4 too, but the code seems different and does use round AFAICT:

godot/core/variant_op.cpp

Lines 1664 to 1671 in 137f71f

	} else if (p_index == CoreStringNames::singleton->r8) {
	return int(Math::round(v->r * 255.0));
	} else if (p_index == CoreStringNames::singleton->g8) {
	return int(Math::round(v->g * 255.0));
	} else if (p_index == CoreStringNames::singleton->b8) {
	return int(Math::round(v->b * 255.0));
	} else if (p_index == CoreStringNames::singleton->a8) {
	return int(Math::round(v->a * 255.0));

godot/core/variant_op.cpp

Lines 2507 to 2518 in 137f71f

	} else if (*str == "r8") {
	valid = true;
	return (int)Math::round(v->r * 255.0);
	} else if (*str == "g8") {
	valid = true;
	return (int)Math::round(v->g * 255.0);
	} else if (*str == "b8") {
	valid = true;
	return (int)Math::round(v->b * 255.0);
	} else if (*str == "a8") {
	valid = true;
	return (int)Math::round(v->a * 255.0);

If the issue is still reproducible in 3.x, it likely needs a different fix.

[dalexeev]

@akien-mga The problem is reproduced in 3.3. But it seems that the reason is really something else. I can't figure out what.