Add grid alignment form for checking the grid before painting

Form1.cs

@@ -10,6 +10,7 @@
 using System.Threading;
 using System.Threading.Tasks;
 using System.Windows.Forms;
+using static BrickadiaAutoPainter.Windows;
 
 namespace BrickadiaAutoPainter {
 	public partial class Form1 : Form {
@@ -132,5 +133,60 @@ private void paintButton_Click(object sender, EventArgs e) {
 		private void advancedSettingsButton_Click(object sender, EventArgs e) {
 			advancedSettingsForm.ShowDialog();
 		}
+
+		private void checkGridAlignment(object sender, EventArgs e) {
+			if (!topLeftPos.HasValue || !topRightPos.HasValue || !bottomLeftPos.HasValue || !bottomRightPos.HasValue) return;
+
+			int[] xs = new int[] { topLeftPos.Value.Item1, topRightPos.Value.Item1, bottomLeftPos.Value.Item1, bottomRightPos.Value.Item1 };
+			int[] ys = new int[] { topLeftPos.Value.Item2, topRightPos.Value.Item2, bottomLeftPos.Value.Item2, bottomRightPos.Value.Item2 };
+
+			int minX = Enumerable.Min(xs);
+			int minY = Enumerable.Min(ys);
+
+			int maxX = Enumerable.Max(xs);
+			int maxY = Enumerable.Max(ys);
+
+			int padding = 40; // padding to surround the cropped image with
+
+			Rectangle cropping = new Rectangle(minX - padding, minY - padding, maxX - minX + padding * 2, maxY - minY + padding * 2);
+
+			// take a screenshot AFTER minimizing the window
+			WindowState = FormWindowState.Minimized;
+			Thread.Sleep(500);
+			using Bitmap gameShot = ScreenCapture.CaptureWindow(Program.GetBrickadiaIntPtr());
+			WindowState = FormWindowState.Normal;
+
+			// add the grid
+			using Graphics graphics = Graphics.FromImage(gameShot);
+			SolidBrush gridMarkerBrush = new SolidBrush(Color.Gray);
+			SolidBrush cornerMarkerBrush = new SolidBrush(Color.Blue);
+
+			Action<Brush, int, int, int> drawPoint = (brush, x, y, r) => graphics.FillRectangle(brush, new Rectangle(x - r, y - r, r * 2, r * 2));
+
+			Perspective perspective = new Perspective(topLeftPos.Value, topRightPos.Value, bottomLeftPos.Value, bottomRightPos.Value);
+			int w = (int)numBricksX.Value;
+			int h = (int)numBricksY.Value;
+			for (int y = 0; y < w; y++) {
+				for (int x = 0; x < h; x++) {
+					double tx = x / (double)(w - 1);
+					double ty = y / (double)(h - 1);
+
+					(int, int) point = perspective.PointOn(tx, ty);
+					drawPoint(gridMarkerBrush, point.Item1, point.Item2, 2);
+				}
+			}
+
+			// and the corners
+			for (int i = 0; i < 4; i++)
+				drawPoint(cornerMarkerBrush, xs[i], ys[i], 5);
+
+			// finally crop the image
+			using Bitmap croppedGameShot = ScreenCapture.CropBitmap(gameShot, cropping);
+
+			// open the alignment form
+			GridAlignmentForm alignmentForm = new GridAlignmentForm();
+			alignmentForm.PictureBox.Image = croppedGameShot;
+			alignmentForm.ShowDialog();
+		}
 	}
 }

GridAlignmentForm.cs

@@ -0,0 +1,21 @@
+using System;
+using System.Collections.Generic;
+using System.ComponentModel;
+using System.Data;
+using System.Drawing;
+using System.Text;
+using System.Windows.Forms;
+
+namespace BrickadiaAutoPainter {
+	public partial class GridAlignmentForm : Form {
+		public PictureBox PictureBox => pictureBox;
+
+		public GridAlignmentForm() {
+			InitializeComponent();
+		}
+
+		private void okButton_Click(object sender, EventArgs e) {
+			Close();
+		}
+	}
+}

GridAlignmentForm.resx

@@ -0,0 +1,63 @@
+<root>
+  <xsd:schema id="root" xmlns="" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:msdata="urn:schemas-microsoft-com:xml-msdata">
+    <xsd:import namespace="http://www.w3.org/XML/1998/namespace" />
+    <xsd:element name="root" msdata:IsDataSet="true">
+      <xsd:complexType>
+        <xsd:choice maxOccurs="unbounded">
+          <xsd:element name="metadata">
+            <xsd:complexType>
+              <xsd:sequence>
+                <xsd:element name="value" type="xsd:string" minOccurs="0" />
+              </xsd:sequence>
+              <xsd:attribute name="name" use="required" type="xsd:string" />
+              <xsd:attribute name="type" type="xsd:string" />
+              <xsd:attribute name="mimetype" type="xsd:string" />
+              <xsd:attribute ref="xml:space" />
+            </xsd:complexType>
+          </xsd:element>
+          <xsd:element name="assembly">
+            <xsd:complexType>
+              <xsd:attribute name="alias" type="xsd:string" />
+              <xsd:attribute name="name" type="xsd:string" />
+            </xsd:complexType>
+          </xsd:element>
+          <xsd:element name="data">
+            <xsd:complexType>
+              <xsd:sequence>
+                <xsd:element name="value" type="xsd:string" minOccurs="0" msdata:Ordinal="1" />
+                <xsd:element name="comment" type="xsd:string" minOccurs="0" msdata:Ordinal="2" />
+              </xsd:sequence>
+              <xsd:attribute name="name" type="xsd:string" use="required" msdata:Ordinal="1" />
+              <xsd:attribute name="type" type="xsd:string" msdata:Ordinal="3" />
+              <xsd:attribute name="mimetype" type="xsd:string" msdata:Ordinal="4" />
+              <xsd:attribute ref="xml:space" />
+            </xsd:complexType>
+          </xsd:element>
+          <xsd:element name="resheader">
+            <xsd:complexType>
+              <xsd:sequence>
+                <xsd:element name="value" type="xsd:string" minOccurs="0" msdata:Ordinal="1" />
+              </xsd:sequence>
+              <xsd:attribute name="name" type="xsd:string" use="required" />
+            </xsd:complexType>
+          </xsd:element>
+        </xsd:choice>
+      </xsd:complexType>
+    </xsd:element>
+  </xsd:schema>
+  <resheader name="resmimetype">
+    <value>text/microsoft-resx</value>
+  </resheader>
+  <resheader name="version">
+    <value>2.0</value>
+  </resheader>
+  <resheader name="reader">
+    <value>System.Resources.ResXResourceReader, System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>
+  </resheader>
+  <resheader name="writer">
+    <value>System.Resources.ResXResourceWriter, System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>
+  </resheader>
+  <data name="label1.Text" xml:space="preserve">
+    <value>Ensure that the superimposed points match neatly with each brick. Blue dots are the corners you provided, and gray dots are assumed pixel locations. If the grid is not accurate, close this window, reset dimensions, and/or recapture corners.</value>
+  </data>
+</root>

Robot.cs

@@ -26,6 +26,10 @@ class Robot : IDisposable {
 		private int paletteX = 0;
 		private int paletteY = 0;
 
+		public Perspective CreatePerspective() {
+			return new Perspective(TopLeft.Value, TopRight.Value, BottomLeft.Value, BottomRight.Value);
+		}
+
 		public void ChangePaletteColor((int, int) previous, (int, int) next) {
 			(int px, int py) = previous;
 			(int nx, int ny) = next;
@@ -83,14 +87,9 @@ public Bitmap GeneratePreview() {
 		}
 
 		public void Paint() {
-			(int, int) topLeft = TopLeft.Value;
-			(int, int) topRight = TopRight.Value;
-			(int, int) bottomLeft = BottomLeft.Value;
-			(int, int) bottomRight = BottomRight.Value;
-
 			Dictionary<(int, int), List<(int, int)>> palettePixelPair = new Dictionary<(int, int), List<(int, int)>>();
 
-			Perspective perspective = new Perspective(topLeft, topRight, bottomLeft, bottomRight);
+			Perspective perspective = CreatePerspective();
 			using Bitmap bitmap = new Bitmap(Image, new Size(Width, Height));
 			for (int iy = 0; iy < bitmap.Height; iy++) {
 				for (int ix = 0; ix < bitmap.Width; ix++) {

ScreenCapture.cs

@@ -0,0 +1,25 @@
+using System;
+using System.Collections.Generic;
+using System.Drawing;
+using System.Drawing.Imaging;
+using System.Text;
+
+namespace BrickadiaAutoPainter {
+	class ScreenCapture {
+		public static Bitmap CaptureWindow(IntPtr window) {
+			Windows.RECT rect = new Windows.RECT();
+			Windows.GetWindowRect(window, ref rect);
+			Rectangle rectangle = new Rectangle(rect.left, rect.top, rect.right - rect.left, rect.bottom - rect.top);
+
+			Bitmap bitmap = new Bitmap(rectangle.Width, rectangle.Height);
+			using Graphics graphics = Graphics.FromImage(bitmap);
+			graphics.CopyFromScreen(new Point(rectangle.Left, rectangle.Top), Point.Empty, rectangle.Size);
+
+			return bitmap;
+		}
+
+		public static Bitmap CropBitmap(Bitmap bitmap, Rectangle cropping) {
+			return bitmap.Clone(cropping, PixelFormat.Format32bppArgb);
+		}
+	}
+}