XRManager: Fix foveation. (#30417)

src/renderers/common/Textures.js

@@ -127,18 +127,9 @@ class Textures extends DataMap {
 
 		const options = { sampleCount };
 
-		// when using the WebXR Layers API, the render target uses external textures which
-		// require no manual updates
+		// XR render targets require no texture updates
 
-		if ( renderTarget.isXRRenderTarget === true && renderTarget.hasExternalTextures === true ) {
-
-			if ( depthTexture && renderTarget.autoAllocateDepthBuffer === true ) {
-
-				this.updateTexture( depthTexture, options );
-
-			}
-
-		} else {
+		if ( renderTarget.isXRRenderTarget !== true ) {
 
 			for ( let i = 0; i < textures.length; i ++ ) {
 

src/renderers/common/XRRenderTarget.js

@@ -46,7 +46,7 @@ class XRRenderTarget extends RenderTarget {
 		 * Allocating a depth buffer is the default behavior of XR render
 		 * targets. However, when using the WebXR Layers API, this flag
 		 * must be set to `false` when the `ignoreDepthValues` property of
-		 * the projection layers evaluates to `true`.
+		 * the projection layers evaluates to `false`.
 		 *
 		 * Reference: {@link https://www.w3.org/TR/webxrlayers-1/#dom-xrprojectionlayer-ignoredepthvalues}.
 		 *

src/renderers/webgl-fallback/WebGLBackend.js

@@ -1963,14 +1963,24 @@ class WebGLBackend extends Backend {
 
 				}
 
-				if ( descriptor.depthTexture !== null ) {
+				if ( renderTarget.isXRRenderTarget && renderTarget.autoAllocateDepthBuffer === true ) {
 
-					const textureData = this.get( descriptor.depthTexture );
-					const depthStyle = stencilBuffer ? gl.DEPTH_STENCIL_ATTACHMENT : gl.DEPTH_ATTACHMENT;
-					textureData.renderTarget = descriptor.renderTarget;
-					textureData.cacheKey = cacheKey; // required for copyTextureToTexture()
+					const renderbuffer = gl.createRenderbuffer();
+					this.textureUtils.setupRenderBufferStorage( renderbuffer, descriptor, 0 );
+					renderTargetContextData.xrDepthRenderbuffer = renderbuffer;
+
+				} else {
 
-					gl.framebufferTexture2D( gl.FRAMEBUFFER, depthStyle, gl.TEXTURE_2D, textureData.textureGPU, 0 );
+					if ( descriptor.depthTexture !== null ) {
+
+						const textureData = this.get( descriptor.depthTexture );
+						const depthStyle = stencilBuffer ? gl.DEPTH_STENCIL_ATTACHMENT : gl.DEPTH_ATTACHMENT;
+						textureData.renderTarget = descriptor.renderTarget;
+						textureData.cacheKey = cacheKey; // required for copyTextureToTexture()
+
+						gl.framebufferTexture2D( gl.FRAMEBUFFER, depthStyle, gl.TEXTURE_2D, textureData.textureGPU, 0 );
+
+					}
 
 				}
 
@@ -1989,11 +1999,17 @@ class WebGLBackend extends Backend {
 
 					// rebind depth
 
-					if ( descriptor.depthTexture !== null ) {
+					const depthStyle = stencilBuffer ? gl.DEPTH_STENCIL_ATTACHMENT : gl.DEPTH_ATTACHMENT;
 
-						const textureData = this.get( descriptor.depthTexture );
-						const depthStyle = stencilBuffer ? gl.DEPTH_STENCIL_ATTACHMENT : gl.DEPTH_ATTACHMENT;
+					if ( renderTarget.autoAllocateDepthBuffer === true ) {
+
+						const renderbuffer = renderTargetContextData.xrDepthRenderbuffer;
+						gl.bindRenderbuffer( gl.RENDERBUFFER, renderbuffer );
+						gl.framebufferRenderbuffer( gl.FRAMEBUFFER, depthStyle, gl.RENDERBUFFER, renderbuffer );
 
+					} else {
+
+						const textureData = this.get( descriptor.depthTexture );
 						gl.framebufferTexture2D( gl.FRAMEBUFFER, depthStyle, gl.TEXTURE_2D, textureData.textureGPU, 0 );
 
 					}
@@ -2046,7 +2062,7 @@ class WebGLBackend extends Backend {
 					if ( depthRenderbuffer === undefined ) {
 
 						depthRenderbuffer = gl.createRenderbuffer();
-						this.textureUtils.setupRenderBufferStorage( depthRenderbuffer, descriptor );
+						this.textureUtils.setupRenderBufferStorage( depthRenderbuffer, descriptor, samples );
 
 						renderTargetContextData.depthRenderbuffer = depthRenderbuffer;
 

src/renderers/webgl-fallback/utils/WebGLTextureUtils.js

@@ -917,13 +917,14 @@ class WebGLTextureUtils {
 	 *
 	 * @param {WebGLRenderbuffer} renderbuffer - The render buffer.
 	 * @param {RenderContext} renderContext - The render context.
+	 * @param {Number} samples - The MSAA sample count.
 	 */
-	setupRenderBufferStorage( renderbuffer, renderContext ) {
+	setupRenderBufferStorage( renderbuffer, renderContext, samples ) {
 
 		const { gl } = this;
 		const renderTarget = renderContext.renderTarget;
 
-		const { samples, depthTexture, depthBuffer, stencilBuffer, width, height } = renderTarget;
+		const { depthTexture, depthBuffer, stencilBuffer, width, height } = renderTarget;
 
 		gl.bindRenderbuffer( gl.RENDERBUFFER, renderbuffer );