TextureNode: Add `isPlainGather()`. (#34119)

src/nodes/accessors/TextureNode.js

@@ -823,6 +823,18 @@ class TextureNode extends UniformNode {
 
 	}
 
+	/**
+	 * Returns `true` if the texture is sampled with a plain gather (`textureGather`),
+	 * meaning a gather without a compare value.
+	 *
+	 * @return {boolean} Whether a plain gather is used or not.
+	 */
+	isPlainGather() {
+
+		return this.gatherNode !== null && this.compareNode === null;
+
+	}
+
 	/**
 	 * Samples the texture by defining a depth node.
 	 *

src/renderers/webgl-fallback/nodes/GLSLNodeBuilder.js

@@ -883,7 +883,7 @@ ${ flowData.code }
 
 					snippet = `${typePrefix}sampler3D ${ uniform.name };`;
 
-				} else if ( texture.compareFunction && textureNode.compareNode !== null ) {
+				} else if ( texture.compareFunction && textureNode.isPlainGather() === false ) {
 
 					if ( texture.isArrayTexture === true ) {
 

src/renderers/webgpu/nodes/WGSLNodeBuilder.js

@@ -2142,7 +2142,7 @@ ${ flowData.code }
 
 				if ( needsSampler ) {
 
-					if ( this.isSampleCompare( texture ) && textureNode.compareNode !== null ) {
+					if ( this.isSampleCompare( texture ) && textureNode.isPlainGather() === false ) {
 
 						bindingSnippets.push( `@binding( ${ uniformIndexes.binding ++ } ) @group( ${ uniformIndexes.group } ) var ${ uniform.name }_sampler : sampler_comparison;` );
 

src/renderers/webgpu/utils/WebGPUBindingUtils.js

@@ -584,7 +584,7 @@ class WebGPUBindingUtils {
 
 				if ( binding.texture.isDepthTexture ) {
 
-					if ( binding.texture.compareFunction !== null && binding.textureNode.compareNode !== null && backend.hasCompatibility( Compatibility.TEXTURE_COMPARE ) ) {
+					if ( binding.texture.compareFunction !== null && binding.textureNode.isPlainGather() === false && backend.hasCompatibility( Compatibility.TEXTURE_COMPARE ) ) {
 
 						sampler.type = GPUSamplerBindingType.Comparison;
 

src/renderers/webgpu/utils/WebGPUTextureUtils.js

@@ -157,10 +157,12 @@ class WebGPUTextureUtils {
 		const texture = binding.texture;
 		const textureNode = binding.textureNode;
 
+		const isComparison = texture.isDepthTexture === true && texture.compareFunction !== null && textureNode.isPlainGather() === false && backend.hasCompatibility( Compatibility.TEXTURE_COMPARE );
+
 		const samplerKey = texture.minFilter + '-' + texture.magFilter + '-' +
 			texture.wrapS + '-' + texture.wrapT + '-' + ( texture.wrapR || '0' ) + '-' +
 			texture.anisotropy + '-' + ( texture.isDepthTexture === true ? 1 : 0 ) + '-' +
-			( texture.compareFunction !== null && textureNode.compareNode !== null ? texture.compareFunction : 0 );
+			( isComparison ? texture.compareFunction : 0 );
 
 		let samplerData = this._samplerCache.get( samplerKey );
 
@@ -174,7 +176,7 @@ class WebGPUTextureUtils {
 			_samplerDescriptor.mipmapFilter = this._convertMipmapFilterMode( texture.minFilter );
 
 			// Depth textures without compare function must use non-filtering (nearest) sampling
-			if ( texture.isDepthTexture && ( texture.compareFunction === null || textureNode.compareNode === null ) ) {
+			if ( texture.isDepthTexture && isComparison === false ) {
 
 				_samplerDescriptor.magFilter = GPUFilterMode.Nearest;
 				_samplerDescriptor.minFilter = GPUFilterMode.Nearest;
@@ -190,7 +192,7 @@ class WebGPUTextureUtils {
 
 			}
 
-			if ( texture.isDepthTexture && texture.compareFunction !== null && textureNode.compareNode !== null && backend.hasCompatibility( Compatibility.TEXTURE_COMPARE ) ) {
+			if ( isComparison ) {
 
 				_samplerDescriptor.compare = _compareToWebGPU[ texture.compareFunction ];