add background grid to canvas

Author: unitycoder

PixelArtTool/MainWindow.xaml

@@ -79,9 +79,14 @@
 		<Border BorderBrush="Black" BorderThickness="1" HorizontalAlignment="Left" Height="128" Margin="10,50,0,0" VerticalAlignment="Top" Width="64">
 			<Image x:Name="imgPalette" HorizontalAlignment="Left" Height="128" Margin="0,0,0,-30" VerticalAlignment="Top" Width="64" Stretch="Fill"/>
 		</Border>
-		<Border BorderBrush="Black" BorderThickness="1" HorizontalAlignment="Left" Height="256" Margin="89,50,0,0" VerticalAlignment="Top" Width="256">
-			<Image x:Name="imgCanvas" HorizontalAlignment="Left" Height="256" Margin="-1" VerticalAlignment="Top" Width="256" Stretch="Fill"/>
-		</Border>
+		<Grid>
+			<Border BorderBrush="Black" BorderThickness="1" HorizontalAlignment="Left" Height="256" Margin="89,50,0,0" VerticalAlignment="Top" Width="256">
+				<Image x:Name="imgGrid" HorizontalAlignment="Left" Height="256" Margin="-1" VerticalAlignment="Top" Width="256" Stretch="Fill"/>
+			</Border>
+			<Border BorderBrush="Black" BorderThickness="1" HorizontalAlignment="Left" Height="256" Margin="89,50,0,0" VerticalAlignment="Top" Width="256">
+				<Image x:Name="imgCanvas" HorizontalAlignment="Left" Height="256" Margin="-1" VerticalAlignment="Top" Width="256" Stretch="Fill"/>
+			</Border>
+		</Grid>
 		<Rectangle x:Name="rectCurrentColor" Fill="#FFF4F4F5" HorizontalAlignment="Left" Height="24" Margin="10,181,0,0" Stroke="Black" VerticalAlignment="Top" Width="24"/>
 	</Grid>
 </Window>

PixelArtTool/MainWindow.xaml.cs

@@ -23,10 +23,12 @@ public enum DrawMode : byte
     public partial class MainWindow : Window
     {
         WriteableBitmap canvasBitmap;
+        WriteableBitmap gridBitmap;
         WriteableBitmap paletteBitmap;
         Window w;
 
         Image drawingImage;
+        Image gridImage;
         Image paletteImage;
 
         // bitmap settings
@@ -40,6 +42,8 @@ public partial class MainWindow : Window
         int dpiX = 96;
         int dpiY = 96;
 
+        byte gridAlpha = 16;
+
         // colors
         PixelColor currentColor;
         PixelColor[] palette;
@@ -66,6 +70,18 @@ public MainWindow()
 
         void Start()
         {
+
+            // setup background grid
+            gridImage = imgGrid;
+            RenderOptions.SetBitmapScalingMode(gridImage, BitmapScalingMode.NearestNeighbor);
+            RenderOptions.SetEdgeMode(gridImage, EdgeMode.Aliased);
+            w = (MainWindow)Application.Current.MainWindow;
+            //var gridScaleX = (int)gridImage.Width / canvasResolutionX;
+            gridBitmap = new WriteableBitmap(canvasResolutionX, canvasResolutionY, dpiX, dpiY, PixelFormats.Bgra32, null);
+            gridImage.Source = gridBitmap;
+            DrawBackgroundGrid();
+
+
             // build drawing area
             drawingImage = imgCanvas;
             RenderOptions.SetBitmapScalingMode(drawingImage, BitmapScalingMode.NearestNeighbor);
@@ -615,7 +631,6 @@ private void CallUndo()
             if (currentUndoIndex > 0)
             {
                 canvasBitmap = undoBufferBitmap[--currentUndoIndex];
-                Console.WriteLine("restore undo " + currentUndoIndex);
                 imgCanvas.Source = canvasBitmap;
             }
         }
@@ -629,5 +644,23 @@ public void CanExecute_Undo(object sender, CanExecuteRoutedEventArgs e)
         {
             e.CanExecute = true;
         }
+
+        void DrawBackgroundGrid()
+        {
+            for (int x = 0; x < 16; x++)
+            {
+                for (int y = 0; y < 16; y++)
+                {
+                    PixelColor c = new PixelColor();
+                    c.Alpha = gridAlpha;
+                    byte v = (byte)(((x % 2) == (y % 2)) ? 255 : 0);
+                    c.Red = v;
+                    c.Green = v;
+                    c.Blue = v;
+                    SetPixel(gridBitmap, x, y, (int)c.ColorBGRA);
+                }
+            }
+        }
+
     } // class
 } // namespace