Add stereoscopic rendering through multiview

4 files changed, 103 insertions, 14 deletions

diff --git a/drivers/vulkan/rendering_device_vulkan.cpp b/drivers/vulkan/rendering_device_vulkan.cpp
index 4cb878eb4d..c69b516f37 100644
--- a/drivers/vulkan/rendering_device_vulkan.cpp
+++ b/drivers/vulkan/rendering_device_vulkan.cpp
@@ -3244,7 +3244,7 @@ bool RenderingDeviceVulkan::texture_is_format_supported_for_usage(DataFormat p_f
 /**** ATTACHMENT ****/
 /********************/
 
-VkRenderPass RenderingDeviceVulkan::_render_pass_create(const Vector<AttachmentFormat> &p_format, InitialAction p_initial_color_action, FinalAction p_final_color_action, InitialAction p_initial_depth_action, FinalAction p_final_depth_action, int *r_color_attachment_count) {
+VkRenderPass RenderingDeviceVulkan::_render_pass_create(const Vector<AttachmentFormat> &p_format, InitialAction p_initial_color_action, FinalAction p_final_color_action, InitialAction p_initial_depth_action, FinalAction p_final_depth_action, int *r_color_attachment_count, uint32_t p_view_count) {
 	Vector<VkAttachmentDescription> attachments;
 	Vector<VkAttachmentReference> color_references;
 	Vector<VkAttachmentReference> depth_stencil_references;
@@ -3469,6 +3469,31 @@ VkRenderPass RenderingDeviceVulkan::_render_pass_create(const Vector<AttachmentF
 	render_pass_create_info.dependencyCount = 0;
 	render_pass_create_info.pDependencies = nullptr;
 
+	const uint32_t view_mask = (1 << p_view_count) - 1;
+	const uint32_t correlation_mask = (1 << p_view_count) - 1;
+	VkRenderPassMultiviewCreateInfo render_pass_multiview_create_info;
+
+	if (p_view_count > 1) {
+		const VulkanContext::MultiviewCapabilities capabilities = context->get_multiview_capabilities();
+
+		// For now this only works with multiview!
+		ERR_FAIL_COND_V_MSG(!capabilities.is_supported, VK_NULL_HANDLE, "Multiview not supported");
+
+		// Make sure we limit this to the number of views we support.
+		ERR_FAIL_COND_V_MSG(p_view_count > capabilities.max_view_count, VK_NULL_HANDLE, "Hardware does not support requested number of views for Multiview render pass");
+
+		render_pass_multiview_create_info.sType = VK_STRUCTURE_TYPE_RENDER_PASS_MULTIVIEW_CREATE_INFO;
+		render_pass_multiview_create_info.pNext = nullptr;
+		render_pass_multiview_create_info.subpassCount = 1;
+		render_pass_multiview_create_info.pViewMasks = &view_mask;
+		render_pass_multiview_create_info.dependencyCount = 0;
+		render_pass_multiview_create_info.pViewOffsets = nullptr;
+		render_pass_multiview_create_info.correlationMaskCount = 1;
+		render_pass_multiview_create_info.pCorrelationMasks = &correlation_mask;
+
+		render_pass_create_info.pNext = &render_pass_multiview_create_info;
+	}
+
 	VkRenderPass render_pass;
 	VkResult res = vkCreateRenderPass(device, &render_pass_create_info, nullptr, &render_pass);
 	ERR_FAIL_COND_V_MSG(res, VK_NULL_HANDLE, "vkCreateRenderPass failed with error " + itos(res) + ".");
@@ -3479,11 +3504,12 @@ VkRenderPass RenderingDeviceVulkan::_render_pass_create(const Vector<AttachmentF
 	return render_pass;
 }
 
-RenderingDevice::FramebufferFormatID RenderingDeviceVulkan::framebuffer_format_create(const Vector<AttachmentFormat> &p_format) {
+RenderingDevice::FramebufferFormatID RenderingDeviceVulkan::framebuffer_format_create(const Vector<AttachmentFormat> &p_format, uint32_t p_view_count) {
 	_THREAD_SAFE_METHOD_
 
 	FramebufferFormatKey key;
 	key.attachments = p_format;
+	key.view_count = p_view_count;
 
 	const Map<FramebufferFormatKey, FramebufferFormatID>::Element *E = framebuffer_format_cache.find(key);
 	if (E) {
@@ -3492,7 +3518,7 @@ RenderingDevice::FramebufferFormatID RenderingDeviceVulkan::framebuffer_format_c
 	}
 
 	int color_references;
-	VkRenderPass render_pass = _render_pass_create(p_format, INITIAL_ACTION_CLEAR, FINAL_ACTION_READ, INITIAL_ACTION_CLEAR, FINAL_ACTION_READ, &color_references); //actions don't matter for this use case
+	VkRenderPass render_pass = _render_pass_create(p_format, INITIAL_ACTION_CLEAR, FINAL_ACTION_READ, INITIAL_ACTION_CLEAR, FINAL_ACTION_READ, &color_references, p_view_count); //actions don't matter for this use case
 
 	if (render_pass == VK_NULL_HANDLE) { //was likely invalid
 		return INVALID_ID;
@@ -3505,6 +3531,7 @@ RenderingDevice::FramebufferFormatID RenderingDeviceVulkan::framebuffer_format_c
 	fb_format.color_attachments = color_references;
 	fb_format.render_pass = render_pass;
 	fb_format.samples = p_format[0].samples;
+	fb_format.view_count = p_view_count;
 	framebuffer_formats[id] = fb_format;
 	return id;
 }
@@ -3580,11 +3607,12 @@ RID RenderingDeviceVulkan::framebuffer_create_empty(const Size2i &p_size, Textur
 	framebuffer.format_id = framebuffer_format_create_empty(p_samples);
 	ERR_FAIL_COND_V(p_format_check != INVALID_FORMAT_ID && framebuffer.format_id != p_format_check, RID());
 	framebuffer.size = p_size;
+	framebuffer.view_count = 1;
 
 	return framebuffer_owner.make_rid(framebuffer);
 }
 
-RID RenderingDeviceVulkan::framebuffer_create(const Vector<RID> &p_texture_attachments, FramebufferFormatID p_format_check) {
+RID RenderingDeviceVulkan::framebuffer_create(const Vector<RID> &p_texture_attachments, FramebufferFormatID p_format_check, uint32_t p_view_count) {
 	_THREAD_SAFE_METHOD_
 
 	Vector<AttachmentFormat> attachments;
@@ -3594,6 +3622,8 @@ RID RenderingDeviceVulkan::framebuffer_create(const Vector<RID> &p_texture_attac
 		Texture *texture = texture_owner.getornull(p_texture_attachments[i]);
 		ERR_FAIL_COND_V_MSG(!texture, RID(), "Texture index supplied for framebuffer (" + itos(i) + ") is not a valid texture.");
 
+		ERR_FAIL_COND_V_MSG(texture->layers != p_view_count, RID(), "Layers of our texture doesn't match view count for this framebuffer");
+
 		if (i == 0) {
 			size.width = texture->width;
 			size.height = texture->height;
@@ -3609,7 +3639,7 @@ RID RenderingDeviceVulkan::framebuffer_create(const Vector<RID> &p_texture_attac
 		attachments.push_back(af);
 	}
 
-	FramebufferFormatID format_id = framebuffer_format_create(attachments);
+	FramebufferFormatID format_id = framebuffer_format_create(attachments, p_view_count);
 	if (format_id == INVALID_ID) {
 		return RID();
 	}
@@ -3621,6 +3651,7 @@ RID RenderingDeviceVulkan::framebuffer_create(const Vector<RID> &p_texture_attac
 	framebuffer.format_id = format_id;
 	framebuffer.texture_ids = p_texture_attachments;
 	framebuffer.size = size;
+	framebuffer.view_count = p_view_count;
 
 	RID id = framebuffer_owner.make_rid(framebuffer);
 
@@ -5904,12 +5935,13 @@ Error RenderingDeviceVulkan::_draw_list_setup_framebuffer(Framebuffer *p_framebu
 	vk.final_color_action = p_final_color_action;
 	vk.initial_depth_action = p_initial_depth_action;
 	vk.final_depth_action = p_final_depth_action;
+	vk.view_count = p_framebuffer->view_count;
 
 	if (!p_framebuffer->framebuffers.has(vk)) {
 		//need to create this version
 		Framebuffer::Version version;
 
-		version.render_pass = _render_pass_create(framebuffer_formats[p_framebuffer->format_id].E->key().attachments, p_initial_color_action, p_final_color_action, p_initial_depth_action, p_final_depth_action);
+		version.render_pass = _render_pass_create(framebuffer_formats[p_framebuffer->format_id].E->key().attachments, p_initial_color_action, p_final_color_action, p_initial_depth_action, p_final_depth_action, nullptr, p_framebuffer->view_count);
 
 		VkFramebufferCreateInfo framebuffer_create_info;
 		framebuffer_create_info.sType = VK_STRUCTURE_TYPE_FRAMEBUFFER_CREATE_INFO;
diff --git a/drivers/vulkan/rendering_device_vulkan.h b/drivers/vulkan/rendering_device_vulkan.h
index a2527d5c33..f4fe9cf956 100644
--- a/drivers/vulkan/rendering_device_vulkan.h
+++ b/drivers/vulkan/rendering_device_vulkan.h
@@ -234,7 +234,12 @@ class RenderingDeviceVulkan : public RenderingDevice {
 
 	struct FramebufferFormatKey {
 		Vector<AttachmentFormat> attachments;
+		uint32_t view_count = 1;
 		bool operator<(const FramebufferFormatKey &p_key) const {
+			if (view_count != p_key.view_count) {
+				return view_count < p_key.view_count;
+			}
+
 			int as = attachments.size();
 			int bs = p_key.attachments.size();
 			if (as != bs) {
@@ -261,7 +266,7 @@ class RenderingDeviceVulkan : public RenderingDevice {
 		}
 	};
 
-	VkRenderPass _render_pass_create(const Vector<AttachmentFormat> &p_format, InitialAction p_initial_action, FinalAction p_final_action, InitialAction p_initial_depth_action, FinalAction p_final_depthcolor_action, int *r_color_attachment_count = nullptr);
+	VkRenderPass _render_pass_create(const Vector<AttachmentFormat> &p_format, InitialAction p_initial_action, FinalAction p_final_action, InitialAction p_initial_depth_action, FinalAction p_final_depthcolor_action, int *r_color_attachment_count = nullptr, uint32_t p_view_count = 1);
 
 	// This is a cache and it's never freed, it ensures
 	// IDs for a given format are always unique.
@@ -271,6 +276,7 @@ class RenderingDeviceVulkan : public RenderingDevice {
 		VkRenderPass render_pass = VK_NULL_HANDLE; //here for constructing shaders, never used, see section (7.2. Render Pass Compatibility from Vulkan spec)
 		int color_attachments = 0; //used for pipeline validation
 		TextureSamples samples;
+		uint32_t view_count = 1; // number of views
 	};
 
 	Map<FramebufferFormatID, FramebufferFormat> framebuffer_formats;
@@ -282,11 +288,16 @@ class RenderingDeviceVulkan : public RenderingDevice {
 			FinalAction final_color_action;
 			InitialAction initial_depth_action;
 			FinalAction final_depth_action;
+			uint32_t view_count;
 			bool operator<(const VersionKey &p_key) const {
 				if (initial_color_action == p_key.initial_color_action) {
 					if (final_color_action == p_key.final_color_action) {
 						if (initial_depth_action == p_key.initial_depth_action) {
-							return final_depth_action < p_key.final_depth_action;
+							if (final_depth_action == p_key.final_depth_action) {
+								return view_count < p_key.view_count;
+							} else {
+								return final_depth_action < p_key.final_depth_action;
+							}
 						} else {
 							return initial_depth_action < p_key.initial_depth_action;
 						}
@@ -309,6 +320,7 @@ class RenderingDeviceVulkan : public RenderingDevice {
 
 		Map<VersionKey, Version> framebuffers;
 		Size2 size;
+		uint32_t view_count;
 	};
 
 	RID_Owner<Framebuffer, true> framebuffer_owner;
@@ -938,11 +950,11 @@ public:
 	/**** FRAMEBUFFER ****/
 	/*********************/
 
-	virtual FramebufferFormatID framebuffer_format_create(const Vector<AttachmentFormat> &p_format);
+	virtual FramebufferFormatID framebuffer_format_create(const Vector<AttachmentFormat> &p_format, uint32_t p_view_count = 1);
 	virtual FramebufferFormatID framebuffer_format_create_empty(TextureSamples p_samples = TEXTURE_SAMPLES_1);
 	virtual TextureSamples framebuffer_format_get_texture_samples(FramebufferFormatID p_format);
 
-	virtual RID framebuffer_create(const Vector<RID> &p_texture_attachments, FramebufferFormatID p_format_check = INVALID_ID);
+	virtual RID framebuffer_create(const Vector<RID> &p_texture_attachments, FramebufferFormatID p_format_check = INVALID_ID, uint32_t p_view_count = 1);
 	virtual RID framebuffer_create_empty(const Size2i &p_size, TextureSamples p_samples = TEXTURE_SAMPLES_1, FramebufferFormatID p_format_check = INVALID_ID);
 
 	virtual FramebufferFormatID framebuffer_get_format(RID p_framebuffer);
diff --git a/drivers/vulkan/vulkan_context.cpp b/drivers/vulkan/vulkan_context.cpp
index 23c0a64568..6ed43b5d31 100644
--- a/drivers/vulkan/vulkan_context.cpp
+++ b/drivers/vulkan/vulkan_context.cpp
@@ -337,6 +337,9 @@ Error VulkanContext::_initialize_extensions() {
 				extension_names[enabled_extension_count++] = VK_EXT_DEBUG_UTILS_EXTENSION_NAME;
 				enabled_debug_utils = true;
 			}
+			if (!strcmp(VK_KHR_GET_PHYSICAL_DEVICE_PROPERTIES_2_EXTENSION_NAME, instance_extensions[i].extensionName)) {
+				extension_names[enabled_extension_count++] = VK_KHR_GET_PHYSICAL_DEVICE_PROPERTIES_2_EXTENSION_NAME;
+			}
 			if (enabled_extension_count >= MAX_EXTENSIONS) {
 				free(instance_extensions);
 				ERR_FAIL_V_MSG(ERR_BUG, "Enabled extension count reaches MAX_EXTENSIONS, BUG");
@@ -504,6 +507,8 @@ Error VulkanContext::_check_capabilities() {
 
 	// assume not supported until proven otherwise
 	multiview_capabilities.is_supported = false;
+	multiview_capabilities.geometry_shader_is_supported = false;
+	multiview_capabilities.tessellation_shader_is_supported = false;
 	multiview_capabilities.max_view_count = 0;
 	multiview_capabilities.max_instance_count = 0;
 	subgroup_capabilities.size = 0;
@@ -529,7 +534,8 @@ Error VulkanContext::_check_capabilities() {
 
 		device_features_func(gpu, &device_features);
 		multiview_capabilities.is_supported = multiview_features.multiview;
-		// For now we ignore if multiview is available in geometry and tessellation as we do not currently support those
+		multiview_capabilities.geometry_shader_is_supported = multiview_features.multiviewGeometryShader;
+		multiview_capabilities.tessellation_shader_is_supported = multiview_features.multiviewTessellationShader;
 	}
 
 	// check extended properties
@@ -573,7 +579,7 @@ Error VulkanContext::_check_capabilities() {
 
 #ifdef DEBUG_ENABLED
 			print_line("- Vulkan multiview supported:");
-			print_line("  max views: " + itos(multiview_capabilities.max_view_count));
+			print_line("  max view count: " + itos(multiview_capabilities.max_view_count));
 			print_line("  max instances: " + itos(multiview_capabilities.max_instance_count));
 		} else {
 			print_line("- Vulkan multiview not supported");
@@ -772,6 +778,10 @@ Error VulkanContext::_create_physical_device() {
 				swapchainExtFound = 1;
 				extension_names[enabled_extension_count++] = VK_KHR_SWAPCHAIN_EXTENSION_NAME;
 			}
+			if (!strcmp(VK_KHR_MULTIVIEW_EXTENSION_NAME, device_extensions[i].extensionName)) {
+				// if multiview is supported, enable it
+				extension_names[enabled_extension_count++] = VK_KHR_MULTIVIEW_EXTENSION_NAME;
+			}
 			if (enabled_extension_count >= MAX_EXTENSIONS) {
 				free(device_extensions);
 				ERR_FAIL_V_MSG(ERR_BUG, "Enabled extension count reaches MAX_EXTENSIONS, BUG");
@@ -964,6 +974,39 @@ Error VulkanContext::_create_device() {
 		queues[1].flags = 0;
 		sdevice.queueCreateInfoCount = 2;
 	}
+
+#ifdef VK_VERSION_1_2
+	VkPhysicalDeviceVulkan11Features vulkan11features;
+
+	vulkan11features.sType = VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_VULKAN_1_1_FEATURES;
+	vulkan11features.pNext = nullptr;
+	// !BAS! Need to figure out which ones of these we want enabled...
+	vulkan11features.storageBuffer16BitAccess = 0;
+	vulkan11features.uniformAndStorageBuffer16BitAccess = 0;
+	vulkan11features.storagePushConstant16 = 0;
+	vulkan11features.storageInputOutput16 = 0;
+	vulkan11features.multiview = multiview_capabilities.is_supported;
+	vulkan11features.multiviewGeometryShader = multiview_capabilities.geometry_shader_is_supported;
+	vulkan11features.multiviewTessellationShader = multiview_capabilities.tessellation_shader_is_supported;
+	vulkan11features.variablePointersStorageBuffer = 0;
+	vulkan11features.variablePointers = 0;
+	vulkan11features.protectedMemory = 0;
+	vulkan11features.samplerYcbcrConversion = 0;
+	vulkan11features.shaderDrawParameters = 0;
+
+	sdevice.pNext = &vulkan11features;
+#elif VK_VERSION_1_1
+	VkPhysicalDeviceMultiviewFeatures multiview_features;
+
+	multiview_features.sType = VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_MULTIVIEW_FEATURES;
+	multiview_features.pNext = nullptr;
+	multiview_features.multiview = multiview_capabilities.is_supported;
+	multiview_features.multiviewGeometryShader = multiview_capabilities.geometry_shader_is_supported;
+	multiview_features.multiviewTessellationShader = multiview_capabilities.tessellation_shader_is_supported;
+
+	sdevice.pNext = &multiview_features;
+#endif
+
 	err = vkCreateDevice(gpu, &sdevice, nullptr, &device);
 	ERR_FAIL_COND_V(err, ERR_CANT_CREATE);
 
diff --git a/drivers/vulkan/vulkan_context.h b/drivers/vulkan/vulkan_context.h
index 3d9b295c5a..738ead4f96 100644
--- a/drivers/vulkan/vulkan_context.h
+++ b/drivers/vulkan/vulkan_context.h
@@ -56,8 +56,10 @@ public:
 
 	struct MultiviewCapabilities {
 		bool is_supported;
-		int32_t max_view_count;
-		int32_t max_instance_count;
+		bool geometry_shader_is_supported;
+		bool tessellation_shader_is_supported;
+		uint32_t max_view_count;
+		uint32_t max_instance_count;
 	};
 
 private: