add some basic zoom keybinds

Program.cs

@@ -232,7 +232,7 @@ public class UiGeometry {
   public UiGeometry(Vector2i windowSize) {
     WindowSize = windowSize;
 
-    int numThumbnails = 10;
+    int numThumbnails = 20;
     int thumbnailHeight = WindowSize.Y / numThumbnails;
     int thumbnailWidth = (int) 1.0 * thumbnailHeight * activeCamera.Resolution.X / activeCamera.Resolution.Y;
     for (int i = 0; i < numThumbnails; i++) {
@@ -277,6 +277,7 @@ public class Game : GameWindow {
   int photoIndex = 0;
   Shader shader = new();
   Matrix4 projection;
+  float zoomLevel = 0f;
 
   protected override void OnUpdateFrame(FrameEventArgs e) {
     base.OnUpdateFrame(e);
@@ -310,6 +311,30 @@ public class Game : GameWindow {
       upTimer = Int64.MaxValue;
     }
 
+    if (input.IsKeyDown(Keys.D0)) {
+      zoomLevel = 0f;
+    }
+
+    if (input.IsKeyDown(Keys.D1)) {
+      zoomLevel = 1f;
+    }
+
+    if (input.IsKeyDown(Keys.D2)) {
+      zoomLevel = 2f;
+    }
+
+    if (input.IsKeyDown(Keys.D3)) {
+      zoomLevel = 4f;
+    }
+
+    if (input.IsKeyDown(Keys.D4)) {
+      zoomLevel = 8f;
+    }
+
+    if (input.IsKeyDown(Keys.D5)) {
+      zoomLevel = 16f;
+    }
+
     // FIXME: make a proper Model class for tracking the state of the controls?
     if (input.IsKeyPressed(Keys.Down) || now > downTimer) {
       if (photoIndex < photos.Count - 1) {
@@ -361,7 +386,8 @@ public class Game : GameWindow {
     // Load textures from JPEGs.
     // string[] files = Directory.GetFiles(@"c:\users\colin\desktop\photos-test\");
     string[] files = Directory.GetFiles(@"c:\users\colin\pictures\photos\2023\07\14\");
-    //string[] files = Directory.GetFiles(@"C:\Users\colin\Pictures\photos\2018\06\23");
+    // string[] files = Directory.GetFiles(@"C:\Users\colin\Pictures\photos\2018\06\23");
+    // string[] files = Directory.GetFiles(@"C:\Users\colin\Desktop\Germany all\104D7000");
 
     for (int i = 0; i < files.Count(); i++) {
       string file = files[i];
@@ -391,6 +417,9 @@ public class Game : GameWindow {
     float scaleX = 1f * geometry.PhotoBox.Size.X / active.Size.X;
     float scaleY = 1f * geometry.PhotoBox.Size.Y / active.Size.Y;
     float scale = Math.Min(scaleX, scaleY);
+    if (zoomLevel > 0f) {
+      scale = zoomLevel;
+    }
 
     Vector2i renderSize = (Vector2i) (((Vector2) active.Size) * scale);
     Vector2i center = (Vector2i) geometry.PhotoBox.Center;