Add some basic checks on printer resolution to try to debug issue #11

embroideryReader/frmMain.cs

@@ -527,9 +527,24 @@ namespace embroideryReader
         {
             if (design != null)
             {
-                float inchesPerMM = 0.03937007874015748031496062992126f;
-                e.Graphics.ScaleTransform((float)(e.PageSettings.PrinterResolution.X * inchesPerMM * 0.01f), (float)(e.PageSettings.PrinterResolution.Y * inchesPerMM * 0.01f));
-                using (Bitmap tempDrawArea = design.designToBitmap((float)settings.threadThickness, settings.filterStiches, settings.filterStitchesThreshold, e.PageSettings.PrinterResolution.X * inchesPerMM * 0.2f))
+                int xDpi = e.PageSettings.PrinterResolution.X;
+                int yDpi = e.PageSettings.PrinterResolution.Y;
+                // Basic checks on printer resolution
+                if(xDpi < 20 || xDpi > 10000)
+                {
+                    throw new ArgumentOutOfRangeException("Printer X DPI claims to be '" + xDpi + "', expected range 20 - 10000");
+                }
+                if (yDpi < 20 || yDpi > 10000)
+                {
+                    throw new ArgumentOutOfRangeException("Printer Y DPI claims to be '" + yDpi + "', expected range 20 - 10000");
+                }
+
+                const double inchesPerMM = 0.03937007874015748031496062992126f;
+                double graphicsXScaleFactor = xDpi * inchesPerMM * 0.01;
+                double graphicsYScaleFactor = yDpi * inchesPerMM * 0.01;
+                double designScaleFactor = xDpi * inchesPerMM * 0.2f;
+                e.Graphics.ScaleTransform((float)graphicsXScaleFactor, (float)graphicsYScaleFactor);
+                using (Bitmap tempDrawArea = design.designToBitmap((float)settings.threadThickness, settings.filterStiches, settings.filterStitchesThreshold, (float)designScaleFactor))
                 {
                     e.Graphics.DrawImage(tempDrawArea, 30, 30);
                 }