--- OpenGLPluginX-orig.c	Sat May 22 17:17:20 2004
+++ OpenGLPluginX.c	Fri Jun 11 19:22:03 2004
@@ -176,5 +176,14 @@
 //  only clear when resizing, since raster content always fills the viewport
 //	glClear(GL_COLOR_BUFFER_BIT);
-	
+    float overlay_scale_x = 1;
+    float overlay_scale_y = 1;
+	if (ctx->prefs.overlay_scaling) // scale overlay-pixels to match game-pixel scaling
+	{
+        //printf("DEBUG: OpenGL overlay_scaling is indeed on\n");
+#define RGB_TRIPLET_PIXELS 4.0 // overlay image dimensions must be multiples of four
+		overlay_scale_x = (float)( (ctx->viewportWidth / RGB_TRIPLET_PIXELS) / (ctx->screenTexture.w ) );
+		overlay_scale_y = (float)( (ctx->viewportHeight / RGB_TRIPLET_PIXELS) / (ctx->screenTexture.h ) );
+	}
+    
 	DoBlit(inParams);
 	if (ctx->prefs.overlay)
@@ -185,11 +194,12 @@
 			glVertex2f(-1.0, -1.0);
 			glMultiTexCoord2fv(GL_TEXTURE0, &ctx->screenTexCoords[2]);
-			glMultiTexCoord2f(GL_TEXTURE1,ctx->overlayTexture.fullx,0);					
+			glMultiTexCoord2f(GL_TEXTURE1,(float)(ctx->overlayTexture.fullx/overlay_scale_x),0);					
 			glVertex2f(1.0, -1.0);
 			glMultiTexCoord2fv(GL_TEXTURE0, &ctx->screenTexCoords[4]);
-			glMultiTexCoord2f(GL_TEXTURE1,ctx->overlayTexture.fullx,ctx->overlayTexture.fully);					
+			glMultiTexCoord2f(GL_TEXTURE1,(float)(ctx->overlayTexture.fullx/overlay_scale_x),
+                              (float)(ctx->overlayTexture.fully/overlay_scale_y));					
 			glVertex2f(1.0, 1.0);
 			glMultiTexCoord2fv(GL_TEXTURE0, &ctx->screenTexCoords[6]);
-			glMultiTexCoord2f(GL_TEXTURE1,0,ctx->overlayTexture.fully);					
+			glMultiTexCoord2f(GL_TEXTURE1,0,(float)(ctx->overlayTexture.fully/overlay_scale_y));					
 			glVertex2f(-1.0, 1.0);
 		glEnd();
@@ -907,6 +917,7 @@
 				0, GL_RGBA, GL_UNSIGNED_BYTE, defaultOverlay);
 	}
-	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
-	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
+	// Is this necessary to fall back to GL_NEAREST?
+	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, ctx->prefs.overlay_scaling ? GL_LINEAR : GL_NEAREST );
+	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, ctx->prefs.overlay_scaling ? GL_LINEAR : GL_NEAREST );
     glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
     glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
@@ -988,4 +999,9 @@
 					err = noErr;
 					break;
+				case 'Oscl':
+					value = GetControl32BitValue (cmd.source.control);
+					SetPrefAsBoolean (value, CFSTR("openGL_Overlay_scaling"));
+					err = noErr;
+					break;
 			}
 			break;
@@ -1152,4 +1198,5 @@
 		ControlID  menuID = { kCreator, 4 };
 		ControlID  syncID = { kCreator, 5 };
+		ControlID  oscalingID = { kCreator, 6 };
 		Boolean		b;
 
@@ -1159,5 +1206,10 @@
 		if (control)
 			SetControlValue( control, b );
-
+        
+		GetPrefAsBoolean(&b, CFSTR("openGL_Overlay_scaling"),true);
+		GetControlByID( myDialog, &oscalingID, &control );
+		if (control)
+			SetControlValue( control, b );
+        
 		GetPrefAsBoolean(&b, CFSTR("openGL_bilinear"),false);
 		GetControlByID( myDialog, &smoothID, &control );
@@ -1197,4 +1249,5 @@
 	GetPrefAsBoolean(&c->prefs.bilinear,CFSTR("openGL_bilinear"),false);
 	GetPrefAsBoolean(&c->prefs.overlay,CFSTR("openGL_arcade"),false);
+	GetPrefAsBoolean(&c->prefs.overlay_scaling,CFSTR("openGL_Overlay_scaling"),false);
 	GetPrefAsStr255 ((StringPtr)&c->prefs.overlayFileName, CFSTR("openGL_Overlay"));
 }
--- OpenGLPluginX-orig.h	Fri Jun 11 19:41:11 2004
+++ OpenGLPluginX.h	Thu Jun  3 23:16:18 2004
@@ -32,4 +32,5 @@
 	Boolean  bilinear;
 	Boolean	 overlay;
+	Boolean	 overlay_scaling;
 	unsigned char   overlayFileName[256];
 } OpenGLPluginPreferences;