Zoom level now capped at 7, tiles outside the zoomed area shouldn't render anymore.

code/redalert/io/userinput.cpp

@@ -132,7 +132,7 @@ void UserInputClass::Process_Input(KeyNumType& key, int& flags)
 
 				if (state[SDL_SCANCODE_F6]) {
 					ZoomLevel++;
-					ZoomLevel = min(ZoomLevel, 6);
+					ZoomLevel = min(ZoomLevel, 7);
 					break;
 				}
 

code/redalert/startup.cpp

@@ -933,6 +933,10 @@ void Read_Setup_Options( RawFileClass *config_file )
 		ScreenWidth = ini.Get_Int("Options", "Width", 1280);
 		ScreenHeight = ini.Get_Int("Options", "Height", 720);
 		ZoomLevel = ini.Get_Int("Options", "ZoomLevel", 0);
+		if (ZoomLevel > 7)
+			ZoomLevel = 7;
+		if (ZoomLevel < 0)
+			ZoomLevel = 0;
 
 		/*
 		** See if an alternative socket number has been specified

code/redalert/tileset.cpp

@@ -274,6 +274,18 @@ void __cdecl Buffer_Draw_Stamp_Clip2(GraphicViewPortClass& viewport, const void
                     icon_index = 0;
                 }
 
+				int renderTargetScale = ZoomLevel;
+				if (Debug_Map) {
+					renderTargetScale = 0;
+				}
+
+				double scale = ((((float)ScreenWidth / (float)ScreenHeight) * (float)renderTargetScale) * 0.05) + 1;
+                float xstart_zoom = xstart * scale;
+                float ystart_zoom = ystart * scale;
+
+                if (xstart_zoom >= ScreenWidth || ystart_zoom >= ScreenHeight)
+                    return;
+
                //GL_SetClipRect(xstart, ystart, blit_width, blit_height);
                 GL_RenderImage(iconImage, xstart, ystart, blit_width, blit_height, 0, icon_index);
                //GL_ResetClipRect();