From de3d29e478ff57d6c2fd083a7838fe9b286503a6 Mon Sep 17 00:00:00 2001
From: Iliyas Jorio <iliyas@jor.io>
Date: Mon, 6 Feb 2023 19:21:46 +0100
Subject: [PATCH] HiDPI support

---
 src/SDLU.cpp | 29 +++++++++++++++++++++++++++++
 src/main.cpp | 18 ++++++++++--------
 2 files changed, 39 insertions(+), 8 deletions(-)

diff --git a/src/SDLU.cpp b/src/SDLU.cpp
index 51c69cb..e510375 100644
--- a/src/SDLU.cpp
+++ b/src/SDLU.cpp
@@ -423,6 +423,29 @@ MBoolean SDLU_CheckSDLTyping(SDL_Keycode* sdlKey)
 
 static MPoint SDLUi_TranslatePointFromWindowToFrontSurface(MPoint pt)
 {
+	// On macOS, the mouse position is relative to the window's "point size" on Retina screens.
+	int windowPointW = 1;
+	int windowPointH = 1;
+	int windowPixelW = 1;
+	int windowPixelH = 1;
+
+	SDL_GetWindowSize(g_window, &windowPointW, &windowPointH);
+#if SDL_VERSION_ATLEAST(2,26,0)
+	SDL_GetWindowSizeInPixels(g_window, &windowPixelW, &windowPixelH);
+#else
+	// Backwards compat with old versions of SDL
+	windowPixelW = windowPointW;
+	windowPixelH = windowPointH;
+#endif
+
+	if (windowPointW != windowPixelW || windowPointH != windowPixelH)
+	{
+		float dpiScaleX = (float) windowPixelW / (float) windowPointW;		// gGameWindowWidth is in actual pixels
+		float dpiScaleY = (float) windowPixelH / (float) windowPointH;		// gGameWindowHeight is in actual pixels
+		pt.h *= dpiScaleX;
+		pt.v *= dpiScaleY;
+	}
+
     SDL_Rect viewport;
     float scaleX, scaleY;
     SDL_RenderGetViewport(g_renderer, &viewport);
@@ -431,6 +454,12 @@ static MPoint SDLUi_TranslatePointFromWindowToFrontSurface(MPoint pt)
     pt.h = pt.h / scaleX - viewport.x;
     pt.v = pt.v / scaleY - viewport.y;
 
+    if (widescreen)
+    {
+        pt.h += g_widescreenCrop.x;
+        pt.v += g_widescreenCrop.y;
+    }
+
     return pt;
 }
 
diff --git a/src/main.cpp b/src/main.cpp
index 348e272..4833725 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -310,7 +310,7 @@ static char  candyCrisisResources[512];
 MBoolean fullscreen = false;
 MBoolean widescreen = false;
 MBoolean useNewTitle = widescreen;
-MBoolean crispUpscaling = true;
+MBoolean crispUpscaling = false;
 
 int main(int argc, char *argv[])
 {
@@ -564,14 +564,16 @@ void ReserveMonitor( void )
     int resW = 640;
     int resH = widescreen? 360: 480;
 
-	SDL_Rect displayBounds = { .x = 0, .y = 0, .w = 640, .h = 480 };
-	SDL_GetDisplayUsableBounds(0, &displayBounds);
-	int scaleX = (displayBounds.w * 95/100) / resW;	// allow covering at most 95% of the screen
-	int scaleY = (displayBounds.h * 95/100) / resH;
-	int scale = scaleX < scaleY ? scaleX : scaleY;
-	scale = scale < 1 ? 1 : scale;
+    SDL_Rect displayBounds = { .x = 0, .y = 0, .w = 640, .h = 480 };
+    SDL_GetDisplayUsableBounds(0, &displayBounds);
+    float scaleX = (displayBounds.w * 75/100) / (float)resW;	// allow covering at most 95% of the screen
+    float scaleY = (displayBounds.h * 75/100) / (float)resH;
+    float scale = scaleX < scaleY ? scaleX : scaleY;
+    if (crispUpscaling)
+        scale = (int) scale;
+    scale = scale < 1 ? 1 : scale;
 
-    SDL_CreateWindowAndRenderer(resW* scale, resH* scale, SDL_WINDOW_RESIZABLE, &g_window, &g_renderer);
+    SDL_CreateWindowAndRenderer(resW*scale, resH*scale, SDL_WINDOW_RESIZABLE | SDL_WINDOW_ALLOW_HIGHDPI, &g_window, &g_renderer);
 
     SDL_RenderSetLogicalSize(g_renderer, resW, resH);
     SDL_SetWindowTitle(g_window, "Candy Crisis");