From 5a94adcf2692b6d02d929d62823123d33c4f4bfd Mon Sep 17 00:00:00 2001
From: kd-11 <karokidii@gmail.com>
Date: Sun, 22 Mar 2026 15:54:29 +0300
Subject: [PATCH] overlays: Implement SDF config transforms

---
 rpcs3/Emu/RSX/Overlays/overlay_controls.cpp | 34 +++++++++++++++++++++
 rpcs3/Emu/RSX/Overlays/overlay_controls.h   |  5 +++
 rpcs3/Emu/RSX/VK/VKOverlays.cpp             |  1 +
 3 files changed, 40 insertions(+)

diff --git a/rpcs3/Emu/RSX/Overlays/overlay_controls.cpp b/rpcs3/Emu/RSX/Overlays/overlay_controls.cpp
index 0a1af3c6c5..67c9fdf36f 100644
--- a/rpcs3/Emu/RSX/Overlays/overlay_controls.cpp
+++ b/rpcs3/Emu/RSX/Overlays/overlay_controls.cpp
@@ -54,6 +54,40 @@ namespace rsx
 			return result;
 		}
 
+		void compiled_resource::sdf_config_t::transform(const areaf& target_viewport, const sizef& virtual_viewport)
+		{
+			const f32 scale_x = target_viewport.width() / virtual_viewport.width;
+			const f32 scale_y = target_viewport.height() / virtual_viewport.height;
+
+			// Ideally the average should match the x and y scaling but arithmetic drift shifts the values around a bit.
+			// Also we need a way to define perfect circles when the aspect ratio is not respected.
+			const f32 scale_av = (scale_x + scale_y) / 2;
+
+			hx *= scale_x;
+			hy *= scale_y;
+			br *= scale_av;
+			bw *= scale_av;
+
+			// Account for flipped viewport
+			if (target_viewport.x2 < target_viewport.x1)
+			{
+				cx = target_viewport.width() -  (cx * scale_x) + target_viewport.x2;
+			}
+			else
+			{
+				cx = cx * scale_x + target_viewport.x1;
+			}
+
+			if (target_viewport.y2 < target_viewport.y1)
+			{
+				cy = target_viewport.height() - (cy * scale_y) + target_viewport.y2;
+			}
+			else
+			{
+				cy = cy * scale_y + target_viewport.y1;
+			}
+		}
+
 		image_info::image_info(const std::string& filename, bool grayscaled)
 		{
 			fs::file f(filename, fs::read + fs::isfile);
diff --git a/rpcs3/Emu/RSX/Overlays/overlay_controls.h b/rpcs3/Emu/RSX/Overlays/overlay_controls.h
index 0932eaa9ed..7b88af2e12 100644
--- a/rpcs3/Emu/RSX/Overlays/overlay_controls.h
+++ b/rpcs3/Emu/RSX/Overlays/overlay_controls.h
@@ -115,6 +115,11 @@ namespace rsx
 				f32 bw; // Border width
 
 				color4f border_color;
+
+				// Transform a SDF definition from one reference frame to another
+				// Target viewport - your actual render area
+				// Virtual viewport - the internal design viewport
+				void transform(const areaf& target_viewport, const sizef& virtual_viewport);
 			};
 
 			struct command_config
diff --git a/rpcs3/Emu/RSX/VK/VKOverlays.cpp b/rpcs3/Emu/RSX/VK/VKOverlays.cpp
index c555e7a341..0436ab527d 100644
--- a/rpcs3/Emu/RSX/VK/VKOverlays.cpp
+++ b/rpcs3/Emu/RSX/VK/VKOverlays.cpp
@@ -660,6 +660,7 @@ namespace vk
 			m_disable_vertex_snap = command.config.disable_vertex_snap;
 
 			m_sdf_config = command.config.sdf_config;
+			m_sdf_config.transform(static_cast<areaf>(viewport), { m_scale_offset.x, m_scale_offset.y });
 
 			vk::image_view* src = nullptr;
 			switch (command.config.texture_ref)