From 5bc9626dd60f9092337e94b497a0bbe0540b3be2 Mon Sep 17 00:00:00 2001
From: Shpoike <Shpoike@users.noreply.github.com>
Date: Sat, 25 May 2024 02:03:33 +0100
Subject: [PATCH] Handle dpi scaling / zooming in the browser port.

---
 engine/web/ftejslib.h  |  2 +-
 engine/web/ftejslib.js |  9 ++++++---
 engine/web/gl_vidweb.c | 11 +++++++++--
 3 files changed, 16 insertions(+), 6 deletions(-)

diff --git a/engine/web/ftejslib.h b/engine/web/ftejslib.h
index 3ea93069d..0f020037b 100644
--- a/engine/web/ftejslib.h
+++ b/engine/web/ftejslib.h
@@ -52,7 +52,7 @@ void emscriptenfte_settitle(const char *text);
 int emscriptenfte_setupcanvas(
 	int width,
 	int height,
-	void(*Resized)(int newwidth, int newheight),
+	void(*Resized)(int newwidth, int newheight, float scale),
 	void(*Mouse)(unsigned int devid,int abs,float x,float y,float z,float size),
 	void(*Button)(unsigned int devid, int down, int mbutton),
 	int(*Keyboard)(unsigned int devid, int down, int keycode, int unicode),
diff --git a/engine/web/ftejslib.js b/engine/web/ftejslib.js
index 09fd7d3f4..f00fe34d3 100644
--- a/engine/web/ftejslib.js
+++ b/engine/web/ftejslib.js
@@ -634,6 +634,9 @@ console.log("jaxis dev:" + idx + " axis:"+j+" val:"+gp.axes[j]+" mapping:"+gp.ma
 
 		window.onresize = function()
 		{
+			let scale = window.devicePixelRatio;	//urgh. haxx.
+			if (scale <= 0)
+				scale = 1;
 			//emscripten's browser library will revert sizes wrongly or something when we're fullscreen, so make sure that doesn't happen.
 //			if (Browser.isFullScreen)
 //			{
@@ -642,11 +645,11 @@ console.log("jaxis dev:" + idx + " axis:"+j+" val:"+gp.axes[j]+" mapping:"+gp.ma
 //			}
 //			else
 			{
-				var rect = Module['canvas'].getBoundingClientRect();
-				Browser.setCanvasSize(rect.width, rect.height, false);
+				let rect = Module['canvas'].getBoundingClientRect();
+				Browser.setCanvasSize(rect.width*scale, rect.height*scale, false);
 			}
 			if (FTEC.evcb.resize != 0)
-				{{{makeDynCall('vii','FTEC.evcb.resize')}}}(Module['canvas'].width, Module['canvas'].height);
+				{{{makeDynCall('viif','FTEC.evcb.resize')}}}(Module['canvas'].width, Module['canvas'].height, scale);
 		};
 		window.onresize();
 
diff --git a/engine/web/gl_vidweb.c b/engine/web/gl_vidweb.c
index 2063b1627..3df611100 100644
--- a/engine/web/gl_vidweb.c
+++ b/engine/web/gl_vidweb.c
@@ -334,13 +334,20 @@ static void IN_GamePadOrientationEvent(int joydevid, float px,float py,float pz,
 	IN_SetHandPosition(dev, org, ang, NULL, NULL);
 }
 
-static void VID_Resized(int width, int height)
+static void VID_Resized(int width, int height, float scale)
 {
 	extern cvar_t vid_conautoscale, vid_conwidth;
+	extern cvar_t vid_dpi_x, vid_dpi_y;
 	vid.pixelwidth = width;
 	vid.pixelheight = height;
 //Con_Printf("Resized: %i %i\n", vid.pixelwidth, vid.pixelheight);
 
+	//if you're zooming in, it should stay looking like its zoomed.
+	vid.dpi_x = 96*scale;
+	vid.dpi_y = 96*scale;
+	Cvar_ForceSetValue(&vid_dpi_x, vid.dpi_x);
+	Cvar_ForceSetValue(&vid_dpi_y, vid.dpi_y);
+
 	Cvar_ForceCallback(&vid_conautoscale);
 	Cvar_ForceCallback(&vid_conwidth);
 }
@@ -544,7 +551,7 @@ qboolean GLVID_Init (rendererstate_t *info, unsigned char *palette)
 
 	qglViewport (0, 0, vid.pixelwidth, vid.pixelheight);
 
-	VID_Resized(vid.pixelwidth, vid.pixelheight);
+	VID_Resized(vid.pixelwidth, vid.pixelheight, 1);
 
 	mouseactive = false;