From fcc065736e303088ef121c554318e0cc028a0666 Mon Sep 17 00:00:00 2001
From: Mikko Rasa <tdb@tdb.fi>
Date: Thu, 1 Sep 2022 22:31:17 +0300
Subject: [PATCH] Make it possible to query if a framebuffer can be presented

---
 source/backends/opengl/framebuffer_backend.h   | 2 ++
 source/backends/vulkan/commands_backend.cpp    | 8 +-------
 source/backends/vulkan/framebuffer_backend.cpp | 8 ++++++++
 source/backends/vulkan/framebuffer_backend.h   | 2 ++
 source/core/framebuffer.h                      | 2 ++
 5 files changed, 15 insertions(+), 7 deletions(-)

diff --git a/source/backends/opengl/framebuffer_backend.h b/source/backends/opengl/framebuffer_backend.h
index b2e93614..258db95f 100644
--- a/source/backends/opengl/framebuffer_backend.h
+++ b/source/backends/opengl/framebuffer_backend.h
@@ -27,6 +27,8 @@ protected:
 	void format_changed(const FrameFormat &);
 	static void require_layered();
 
+	bool is_presentable() const { return id==0; }
+
 	void resize_system(unsigned, unsigned);
 	void update(unsigned) const;
 	void update(unsigned, bool) const;
diff --git a/source/backends/vulkan/commands_backend.cpp b/source/backends/vulkan/commands_backend.cpp
index 9f53f1ce..5de0f090 100644
--- a/source/backends/vulkan/commands_backend.cpp
+++ b/source/backends/vulkan/commands_backend.cpp
@@ -10,7 +10,6 @@
 #include "rect.h"
 #include "renderpass.h"
 #include "semaphore.h"
-#include "swapchaintexture.h"
 #include "vulkan.h"
 
 using namespace std;
@@ -92,12 +91,7 @@ void VulkanCommands::begin_render_pass(bool clear, const ClearValue *clear_value
 	if(!primary_buffer)
 		begin_buffer(0);
 
-	fb_is_swapchain = false;
-	unsigned n_attachments = framebuffer->get_format().size();
-	for(unsigned i=0; (!fb_is_swapchain && i<n_attachments); ++i)
-		if(dynamic_cast<const SwapChainTexture *>(framebuffer->get_attachment(i)))
-			fb_is_swapchain = true;
-
+	fb_is_swapchain = framebuffer->is_presentable();
 	framebuffer->refresh();
 
 	RenderPass render_pass;
diff --git a/source/backends/vulkan/framebuffer_backend.cpp b/source/backends/vulkan/framebuffer_backend.cpp
index 9af8a2f7..4c68546f 100644
--- a/source/backends/vulkan/framebuffer_backend.cpp
+++ b/source/backends/vulkan/framebuffer_backend.cpp
@@ -3,6 +3,7 @@
 #include "framebuffer.h"
 #include "framebuffer_backend.h"
 #include "renderpass.h"
+#include "swapchaintexture.h"
 #include "vulkan.h"
 
 using namespace std;
@@ -53,6 +54,13 @@ bool VulkanFramebuffer::is_format_supported(const FrameFormat &fmt)
 	return true;
 }
 
+bool VulkanFramebuffer::is_presentable() const
+{
+	const Framebuffer &self = *static_cast<const Framebuffer *>(this);
+	return std::any_of(self.attachments.begin(), self.attachments.end(),
+		[](const Framebuffer::Attachment &a){ return dynamic_cast<const SwapChainTexture *>(a.tex); });
+}
+
 void VulkanFramebuffer::update(unsigned mask) const
 {
 	const Framebuffer &self = *static_cast<const Framebuffer *>(this);
diff --git a/source/backends/vulkan/framebuffer_backend.h b/source/backends/vulkan/framebuffer_backend.h
index 30ca1701..faca5658 100644
--- a/source/backends/vulkan/framebuffer_backend.h
+++ b/source/backends/vulkan/framebuffer_backend.h
@@ -31,6 +31,8 @@ protected:
 	void format_changed(const FrameFormat &) { }
 	static void require_layered() { }
 
+	bool is_presentable() const;
+
 	void update(unsigned) const;
 	void require_complete() const { }
 
diff --git a/source/core/framebuffer.h b/source/core/framebuffer.h
index b3359a34..4932f29a 100644
--- a/source/core/framebuffer.h
+++ b/source/core/framebuffer.h
@@ -120,6 +120,8 @@ public:
 	const Texture *get_resolve_attachment(unsigned) const;
 	bool has_resolve_attachments() const;
 
+	using FramebufferBackend::is_presentable;
+
 	/** Ensures that the framebuffer is complete, throwing an exception if it
 	isn't. */
 	void require_complete() const;
-- 
2.43.0