GLSLNodeBuilder: Fix array texture layer support for filtered sampling (#33008)

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

@@ -545,10 +545,13 @@ ${ flowData.code }
 	 * @param {string} textureProperty - The name of the texture uniform in the shader.
 	 * @param {string} uvSnippet - A GLSL snippet that represents texture coordinates used for sampling.
 	 * @param {string} levelSnippet - A GLSL snippet that represents the mip level, with level 0 containing a full size version of the texture.
+	 * @param {?string} depthSnippet - A GLSL snippet that represents 0-based texture array index to sample.
 	 * @param {?string} offsetSnippet - A GLSL snippet that represents the offset that will be applied to the unnormalized texture coordinate before sampling the texture.
 	 * @return {string} The GLSL snippet.
 	 */
-	generateTextureLevel( texture, textureProperty, uvSnippet, levelSnippet, offsetSnippet ) {
+	generateTextureLevel( texture, textureProperty, uvSnippet, levelSnippet, depthSnippet, offsetSnippet ) {
+
+		if ( depthSnippet ) uvSnippet = `vec3( ${ uvSnippet }, ${ depthSnippet } )`;
 
 		if ( offsetSnippet ) {
 
@@ -567,10 +570,13 @@ ${ flowData.code }
 	 * @param {string} textureProperty - The name of the texture uniform in the shader.
 	 * @param {string} uvSnippet - A GLSL snippet that represents texture coordinates used for sampling.
 	 * @param {string} biasSnippet - A GLSL snippet that represents the bias to apply to the mip level before sampling.
+	 * @param {?string} depthSnippet - A GLSL snippet that represents 0-based texture array index to sample.
 	 * @param {?string} offsetSnippet - A GLSL snippet that represents the offset that will be applied to the unnormalized texture coordinate before sampling the texture.
 	 * @return {string} The GLSL snippet.
 	 */
-	generateTextureBias( texture, textureProperty, uvSnippet, biasSnippet, offsetSnippet ) {
+	generateTextureBias( texture, textureProperty, uvSnippet, biasSnippet, depthSnippet, offsetSnippet ) {
+
+		if ( depthSnippet ) uvSnippet = `vec3( ${ uvSnippet }, ${ depthSnippet } )`;
 
 		if ( offsetSnippet ) {
 
@@ -589,10 +595,13 @@ ${ flowData.code }
 	 * @param {string} textureProperty - The name of the texture uniform in the shader.
 	 * @param {string} uvSnippet - A GLSL snippet that represents texture coordinates used for sampling.
 	 * @param {Array<string>} gradSnippet - An array holding both gradient GLSL snippets.
+	 * @param {?string} depthSnippet - A GLSL snippet that represents 0-based texture array index to sample.
 	 * @param {?string} offsetSnippet - A GLSL snippet that represents the offset that will be applied to the unnormalized texture coordinate before sampling the texture.
 	 * @return {string} The GLSL snippet.
 	 */
-	generateTextureGrad( texture, textureProperty, uvSnippet, gradSnippet, offsetSnippet ) {
+	generateTextureGrad( texture, textureProperty, uvSnippet, gradSnippet, depthSnippet, offsetSnippet ) {
+
+		if ( depthSnippet ) uvSnippet = `vec3( ${ uvSnippet }, ${ depthSnippet } )`;
 
 		if ( offsetSnippet ) {