From 2e7639d903a69bb30f51f2cbfa1739332d5e77f0 Mon Sep 17 00:00:00 2001
From: akallabeth <akallabeth@posteo.net>
Date: Sun, 25 Jan 2026 12:14:36 +0100
Subject: [PATCH] [client,sdl] add coordinat conversion functions

* pixel to screen mapper
* screen to pixel mapper
* local scaling add/remove for smart-sizing
---
 client/SDL/SDL3/sdl_context.cpp | 49 +++++++++++++++++++++++++++++++++
 client/SDL/SDL3/sdl_context.hpp |  7 +++++
 2 files changed, 56 insertions(+)

diff --git a/client/SDL/SDL3/sdl_context.cpp b/client/SDL/SDL3/sdl_context.cpp
index e3c0e6878..0942de432 100644
--- a/client/SDL/SDL3/sdl_context.cpp
+++ b/client/SDL/SDL3/sdl_context.cpp
@@ -927,6 +927,17 @@ bool SdlContext::handleEvent(const SDL_DisplayEvent* ev)
 	return true;
 }
 
+bool SdlContext::eventToPixelCoordinates(SDL_WindowID id, SDL_Event& ev)
+{
+	auto w = getWindowForId(id);
+	if (!w)
+		return false;
+	auto renderer = SDL_GetRenderer(w->window());
+	if (!renderer)
+		return false;
+	return SDL_ConvertEventToRenderCoordinates(renderer, &ev);
+}
+
 SDL_FPoint SdlContext::applyLocalScaling(const SDL_FPoint& val) const
 {
 	if (!freerdp_settings_get_bool(context()->settings, FreeRDP_SmartSizing))
@@ -946,6 +957,44 @@ void SdlContext::removeLocalScaling(float& x, float& y)
 	y /= _localScale.y;
 }
 
+SDL_FPoint SdlContext::screenToPixel(SDL_WindowID id, const SDL_FPoint& pos)
+{
+	auto w = getWindowForId(id);
+	if (!w)
+		return {};
+	auto renderer = SDL_GetRenderer(w->window());
+	if (!renderer)
+		return {};
+
+	SDL_FPoint rpos{};
+	if (!SDL_RenderCoordinatesFromWindow(renderer, pos.x, pos.y, &rpos.x, &rpos.y))
+		return {};
+	removeLocalScaling(rpos.x, rpos.y);
+	return rpos;
+}
+
+SDL_FPoint SdlContext::pixelToScreen(SDL_WindowID id, const SDL_FPoint& pos)
+{
+	auto w = getWindowForId(id);
+	if (!w)
+		return {};
+	auto renderer = SDL_GetRenderer(w->window());
+	if (!renderer)
+		return {};
+
+	SDL_FPoint rpos{};
+	if (!SDL_RenderCoordinatesToWindow(renderer, pos.x, pos.y, &rpos.x, &rpos.y))
+		return {};
+	return applyLocalScaling(rpos);
+}
+
+SDL_FRect SdlContext::pixelToScreen(SDL_WindowID id, const SDL_FRect& pos)
+{
+	const auto fpos = pixelToScreen(id, SDL_FPoint{ pos.x, pos.y });
+	const auto size = pixelToScreen(id, SDL_FPoint{ pos.w, pos.h });
+	return { fpos.x, fpos.y, size.x, size.y };
+}
+
 bool SdlContext::drawToWindows(const std::vector<SDL_Rect>& rects)
 {
 	for (auto& window : _windows)
diff --git a/client/SDL/SDL3/sdl_context.hpp b/client/SDL/SDL3/sdl_context.hpp
index 9b945f107..4b98a8807 100644
--- a/client/SDL/SDL3/sdl_context.hpp
+++ b/client/SDL/SDL3/sdl_context.hpp
@@ -120,6 +120,11 @@ class SdlContext
 
 	[[nodiscard]] wLog* getWLog();
 
+	[[nodiscard]] SDL_FPoint screenToPixel(SDL_WindowID id, const SDL_FPoint& pos);
+
+	[[nodiscard]] SDL_FPoint pixelToScreen(SDL_WindowID id, const SDL_FPoint& pos);
+	[[nodiscard]] SDL_FRect pixelToScreen(SDL_WindowID id, const SDL_FRect& pos);
+
 	[[nodiscard]] bool handleEvent(const SDL_WindowEvent* ev);
 	[[nodiscard]] bool handleEvent(const SDL_DisplayEvent* ev);
 
@@ -134,6 +139,8 @@ class SdlContext
 	[[nodiscard]] static BOOL endPaint(rdpContext* context);
 	[[nodiscard]] static DWORD WINAPI rdpThreadRun(SdlContext* sdl);
 
+	[[nodiscard]] bool eventToPixelCoordinates(SDL_WindowID id, SDL_Event& ev);
+
 	[[nodiscard]] SDL_FPoint applyLocalScaling(const SDL_FPoint& val) const;
 	void removeLocalScaling(float& x, float& y);