Revert "DataUtils: Add `toRGB9E5()` and `fromRGB9E5()`. (#28012)" (#28025)

This reverts commit a03a74a1bec9bf6302f6b8b95c37a41ff6a6571e.

docs/api/en/extras/DataUtils.html

@@ -29,25 +29,6 @@
 			precision floating point value.
 		</p>
 
-
-		<h3>[method:Uint32Array toRGB9E5]( [param:Number r], [param:Number g], [param:Number b], [param:Uint32Array target] )</h3>
-		<p>
-			r -- A float representing the R channel.<br />
-			g -- A float representing the G channel.<br />
-			b -- A float representing the B channel.<br />
-			target -- An instance of `Uint32Array` with length `1`.<br /><br />
-
-			This method packs three floats into a single Uint32 value which is required for the `RGB9E5` texture format.
-		</p>
-
-		<h3>[method:Array fromRGB9E5]( [param:Uint32Array val], [param:Array target] )</h3>
-		<p>
-			val -- An instance of `Uint32Array` with length `1`.<br />
-			target -- An array holding the three unpacked floats.<br /><br />
-
-			This method unpacks three floats from a single Uint32 value holding a `RGB9E5` texel.
-		</p>
-
 		<h2>Source</h2>
 
 		<p>

src/extras/DataUtils.js

@@ -164,108 +164,13 @@ function fromHalfFloat( val ) {
 
 }
 
-// RGB9E5 packing/unpacking
-
-const RGB9E5_MANTISSA_BITS = 9;
-const RGB9E5_EXP_BIAS = 15;
-const RGB9E5_MAX_VALID_BIASED_EXP = 31;
-
-const MAX_RGB9E5_EXP = ( RGB9E5_MAX_VALID_BIASED_EXP - RGB9E5_EXP_BIAS );
-const RGB9E5_MANTISSA_VALUES = ( 1 << RGB9E5_MANTISSA_BITS );
-const MAX_RGB9E5_MANTISSA = ( RGB9E5_MANTISSA_VALUES - 1 );
-const MAX_RGB9E5 = ( ( MAX_RGB9E5_MANTISSA ) / RGB9E5_MANTISSA_VALUES * ( 1 << MAX_RGB9E5_EXP ) );
-
-function ClampRange_for_rgb9e5( x ) {
-
-	if ( x > 0.0 ) {
-
-		if ( x >= MAX_RGB9E5 ) {
-
-			return MAX_RGB9E5;
-
-		} else {
-
-			return x;
-
-		}
-
-	} else {
-
-		/* NaN gets here too since comparisons with NaN always fail! */
-		return 0.0;
-
-	}
-
-}
-
-function FloorLog2( x ) {
-
-	return Math.floor( Math.log2( x ) );
-
-}
-
-// reference https://registry.khronos.org/OpenGL/extensions/EXT/EXT_texture_shared_exponent.txt
-
-function toRGB9E5( r, g, b, target ) {
-
-	const rc = ClampRange_for_rgb9e5( r );
-	const gc = ClampRange_for_rgb9e5( g );
-	const bc = ClampRange_for_rgb9e5( b );
-
-	const maxrgb = Math.max( rc, gc, bc );
-	let exp_shared = Math.max( - RGB9E5_EXP_BIAS - 1, FloorLog2( maxrgb ) ) + 1 + RGB9E5_EXP_BIAS;
-
-	let denom = Math.pow( 2, exp_shared - RGB9E5_EXP_BIAS - RGB9E5_MANTISSA_BITS );
-	const maxm = Math.floor( maxrgb / denom + 0.5 );
-
-	if ( maxm == MAX_RGB9E5_MANTISSA + 1 ) {
-
-		denom *= 2;
-		exp_shared += 1;
-
-	}
-
-	const rm = Math.floor( rc / denom + 0.5 );
-	const gm = Math.floor( gc / denom + 0.5 );
-	const bm = Math.floor( bc / denom + 0.5 );
-
-	//
-
-	target[ 0 ] = ( rm << 0 ) | ( gm << 9 ) | ( bm << 18 ) | ( exp_shared << 27 );
-
-	return target;
-
-}
-
-function fromRGB9E5( val, target ) {
-
-	const r = ( val[ 0 ] >> 0 ) & 0x1FF;
-	const g = ( val[ 0 ] >> 9 ) & 0x1FF;
-	const b = ( val[ 0 ] >> 18 ) & 0x1FF;
-	const e = ( val[ 0 ] >> 27 ) & 0x01F;
-
-	const exponent = e - RGB9E5_EXP_BIAS - RGB9E5_MANTISSA_BITS;
-	const scale = Math.pow( 2, exponent );
-
-	target[ 0 ] = r * scale;
-	target[ 1 ] = g * scale;
-	target[ 2 ] = b * scale;
-
-	return target;
-
-}
-
 const DataUtils = {
 	toHalfFloat: toHalfFloat,
 	fromHalfFloat: fromHalfFloat,
-	toRGB9E5: toRGB9E5,
-	fromRGB9E5: fromRGB9E5
 };
 
 export {
 	toHalfFloat,
 	fromHalfFloat,
-	toRGB9E5,
-	fromRGB9E5,
 	DataUtils
 };