implement depth resolve for metal

Author: huisedenanhai

drivers/metal/metal_device_properties.h

@@ -97,6 +97,7 @@ struct API_AVAILABLE(macos(11.0), ios(14.0), tvos(14.0)) MetalFeatures {
 	bool supports_image_atomic_32_bit = false; /**< If true, 32-bit atomic operations on images are supported by the GPU. */
 	bool supports_image_atomic_64_bit = false; /**< If true, 64-bit atomic operations on images are supported by the GPU. */
 	bool supports_native_image_atomics = false; /**< If true, native image atomic operations are supported by the OS. */
+	bool supports_msaa_depth_resolve = false;
 };
 
 struct MetalLimits {

drivers/metal/metal_device_properties.mm

@@ -130,6 +130,11 @@
 		features.supports_native_image_atomics = false;
 	}
 
+	features.supports_msaa_depth_resolve = [p_device supportsFamily:MTLGPUFamilyApple3] || [p_device supportsFamily:MTLGPUFamilyMac2];
+	if (@available(macos 13.0, ios 16.0, *)) {
+		features.supports_msaa_depth_resolve = features.supports_msaa_depth_resolve || [p_device supportsFamily:MTLGPUFamilyMetal3];
+	}
+
 	if (@available(macOS 13.0, iOS 16.0, tvOS 16.0, *)) {
 		features.needs_arg_encoders = !([p_device supportsFamily:MTLGPUFamilyMetal3] && features.argument_buffers_tier == MTLArgumentBuffersTier2);
 	}

drivers/metal/metal_objects.h

@@ -239,6 +239,7 @@ struct MDSubpass {
 	LocalVector<RDD::AttachmentReference> color_references;
 	RDD::AttachmentReference depth_stencil_reference;
 	LocalVector<RDD::AttachmentReference> resolve_references;
+	RDD::AttachmentReference depth_stencil_resolve_reference;
 
 	MTLFmtCaps getRequiredFmtCapsForAttachmentAt(uint32_t p_index) const;
 };

drivers/metal/metal_objects.mm

@@ -49,6 +49,7 @@
 /**************************************************************************/
 
 #import "metal_objects.h"
+#include <cstdint>
 
 #import "metal_utils.h"
 #import "pixel_formats.h"
@@ -640,6 +641,12 @@
 		// see: https://github.com/KhronosGroup/MoltenVK/blob/d20d13fe2735adb845636a81522df1b9d89c0fba/MoltenVK/MoltenVK/GPUObjects/MVKRenderPass.mm#L407
 	}
 
+	uint32_t depth_resolve_index = subpass.depth_stencil_resolve_reference.attachment;
+	if (depth_resolve_index != RDD::AttachmentReference::UNUSED && fb_info.has_texture(depth_resolve_index)) {
+		id<MTLTexture> resolve_tex = fb_info.get_texture(depth_resolve_index);
+		CRASH_COND_MSG(!flags::all(pf.getCapabilities(resolve_tex.pixelFormat), kMTLFmtCapsResolve), "not implemented: unresolvable texture types");
+	}
+
 	render.end_encoding();
 }
 
@@ -751,9 +758,24 @@
 		MDAttachment const &attachment = pass.attachments[idx];
 		id<MTLTexture> tex = fb.get_texture(idx);
 		ERR_FAIL_NULL_MSG(tex, "Frame buffer depth / stencil texture is null.");
+
+		uint32_t depth_resolve_index = subpass.depth_stencil_resolve_reference.attachment;
+		bool has_resolve = depth_resolve_index != RDD::AttachmentReference::UNUSED;
+		bool can_resolve = true;
+		if (has_resolve) {
+			MTLRenderPassDepthAttachmentDescriptor *da = desc.depthAttachment;
+			id<MTLTexture> resolve_tex = fb.get_texture(depth_resolve_index);
+			can_resolve = flags::all(pf.getCapabilities(resolve_tex.pixelFormat), kMTLFmtCapsResolve);
+			if (can_resolve) {
+				da.resolveTexture = resolve_tex;
+			} else {
+				CRASH_NOW_MSG("unimplemented: using a texture format that is not supported for resolve");
+			}
+		}
+
 		if (attachment.type & MDAttachmentType::Depth) {
 			MTLRenderPassDepthAttachmentDescriptor *da = desc.depthAttachment;
-			if (attachment.configureDescriptor(da, pf, subpass, tex, render.is_rendering_entire_area, false, false, false)) {
+			if (attachment.configureDescriptor(da, pf, subpass, tex, render.is_rendering_entire_area, has_resolve, can_resolve, false)) {
 				da.clearDepth = render.clear_values[idx].depth;
 			}
 		}
@@ -1727,6 +1749,10 @@
 		flags::set(caps, kMTLFmtCapsDSAtt);
 	}
 
+	if (depth_stencil_resolve_reference.attachment == p_index) {
+		flags::set(caps, kMTLFmtCapsResolve);
+	}
+
 	return caps;
 }
 

drivers/metal/rendering_device_driver_metal.mm

@@ -49,6 +49,7 @@
 /**************************************************************************/
 
 #import "rendering_device_driver_metal.h"
+#include "servers/rendering/rendering_device_commons.h"
 
 #import "pixel_formats.h"
 #import "rendering_context_driver_metal.h"
@@ -1843,6 +1844,7 @@ bool isArrayTexture(MTLTextureType p_type) {
 		subpass.color_references = p_subpasses[i].color_references;
 		subpass.depth_stencil_reference = p_subpasses[i].depth_stencil_reference;
 		subpass.resolve_references = p_subpasses[i].resolve_references;
+		subpass.depth_stencil_resolve_reference = p_subpasses[i].depth_resolve_reference;
 	}
 
 	static const MTLLoadAction LOAD_ACTIONS[] = {
@@ -2772,6 +2774,8 @@ bool isArrayTexture(MTLTextureType p_type) {
 			return device_properties->features.supports_native_image_atomics;
 		case SUPPORTS_VULKAN_MEMORY_MODEL:
 			return true;
+		case SUPPORTS_FRAMEBUFFER_DEPTH_RESOLVE:
+			return device_properties->features.supports_msaa_depth_resolve;
 		default:
 			return false;
 	}

platform/visionos/app_visionos.swift

@@ -56,7 +56,7 @@ struct ContentStageConfiguration: CompositorLayerConfiguration {
 
 		GDTAppDelegateServiceVisionOS.layerRendererCapabilities = capabilities as __CP_OBJECT_cp_layer_renderer_capabilities
 
-		configuration.depthFormat = .depth32Float
+		configuration.depthFormat = .depth32Float_stencil8
 		configuration.colorFormat = .rgba16Float
 
 		let foveationEnabled = capabilities.supportsFoveation