attempt to do nicer DPI scaling

atsb · Jun 9, 2023 · 4a0aa6b · 4a0aa6b
1 parent 14cbf4d
commit 4a0aa6b
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Showing 3 changed files with 29 additions and 5 deletions.
diff --git a/src/engine/gl_main.c b/src/engine/gl_main.c
@@ -585,7 +585,17 @@ void GL_Init(void) {
     glEnable(GL_LINE_SMOOTH);
     glEnable(GL_POLYGON_SMOOTH);
 
-    dglViewport(0, 0, video_width, video_height);
+    float scalingForDPI = GetDPIDisplayScale();
+
+    glViewport(0, 0, video_width * scalingForDPI, video_height * scalingForDPI);
+
+    glMatrixMode(GL_PROJECTION);
+    glLoadIdentity();
+    glOrtho(0, video_width * scalingForDPI, video_height * scalingForDPI, 0, -1, 1);
+
+    glMatrixMode(GL_MODELVIEW);
+    glLoadIdentity();
+
     dglClearDepth(1.0f);
     dglDisable(GL_TEXTURE_2D);
     dglEnable(GL_CULL_FACE);

diff --git a/src/engine/i_video.c b/src/engine/i_video.c
@@ -70,6 +70,15 @@ boolean window_focused;
 int mouse_x = 0;
 int mouse_y = 0;
 
+/* Get the Current DPI Scaling */
+
+float GetDPIDisplayScale(void)
+{
+	float diag, hori, vert;
+	SDL_GetDisplayDPI(0, &diag, &hori, &vert);
+	return hori / 96.0f;
+}
+
 //
 // I_InitScreen
 //
@@ -150,12 +159,16 @@ void I_InitScreen(void) {
 		flags |= SDL_WINDOW_BORDERLESS;
 	}
 
+	/* DPI Scale */
+	float scalingForDPI = GetDPIDisplayScale();
+	I_Printf("DPI Factor: %f\n", scalingForDPI);
+
 	sprintf(title, "Doom64EX+ - Version Date: %s", version_date);
 	window = SDL_CreateWindow(title,
-		SDL_WINDOWPOS_CENTERED,
-		SDL_WINDOWPOS_CENTERED,
-		video_width,
-		video_height,
+		SDL_WINDOWPOS_UNDEFINED,
+		SDL_WINDOWPOS_UNDEFINED,
+		video_width * scalingForDPI,
+		video_height * scalingForDPI,
 		flags);
 
 	if (window == NULL) {

diff --git a/src/engine/i_video.h b/src/engine/i_video.h
@@ -37,6 +37,7 @@
 
 extern SDL_Surface* screen;
 extern SDL_Window* window;
+float GetDPIDisplayScale(void);
 void I_InitVideo(void);
 void I_InitScreen(void);
 void I_ShutdownVideo(void);