add min window size & use some constants for computing draw positions

Program.cs

@@ -275,7 +275,12 @@ public class Game : GameWindow {
     frameCount++;
     GL.Clear(ClearBufferMask.ColorBufferBit);
 
-    SetVertices(0, 0, windowWidth - 152, windowHeight);
+    int thumbnailWidth = 150;
+    int thumbnailHeight = 100;
+    int borderWidth = 2;
+    int photoWidth = windowWidth - thumbnailWidth - borderWidth;
+
+    SetVertices(0, 0, photoWidth, windowHeight);
     GL.BindBuffer(BufferTarget.ArrayBuffer, VertexBufferObject);
     GL.BufferData(BufferTarget.ArrayBuffer, vertices.Length * sizeof(float), vertices, BufferUsageHint.DynamicDraw);
     GL.ActiveTexture(TextureUnit.Texture0);
@@ -284,7 +289,7 @@ public class Game : GameWindow {
     GL.DrawElements(PrimitiveType.Triangles, indices.Length, DrawElementsType.UnsignedInt, 0);
 
     for (int i = 0; i < textures.Count; i++) {
-      SetVertices(windowWidth - 150, i * 100, windowWidth, i * 100 + 98);
+      SetVertices(windowWidth - thumbnailWidth, i * thumbnailHeight, windowWidth, i * thumbnailHeight + thumbnailHeight - borderWidth);
       GL.BindBuffer(BufferTarget.ArrayBuffer, VertexBufferObject);
       GL.BufferData(BufferTarget.ArrayBuffer, vertices.Length * sizeof(float), vertices, BufferUsageHint.DynamicDraw);
       GL.ActiveTexture(TextureUnit.Texture0);
@@ -360,6 +365,7 @@ static class Program {
     nwSettings.CurrentMonitor = bestMonitor.Handle;
     nwSettings.Location = new Vector2i(bestMonitor.WorkArea.Min.X + 1, bestMonitor.WorkArea.Min.Y + 31);
     nwSettings.Size = new Vector2i(bestMonitor.WorkArea.Size.X - 2, bestMonitor.WorkArea.Size.Y - 32);
+    nwSettings.MinimumSize = new Vector2i(640, 480);
     nwSettings.Title = "Totte";
     // FIXME: nwSettings.Icon = ...