From a76c14b243ae848d1487b333752c2e73aea2de32 Mon Sep 17 00:00:00 2001
From: Ellpeck <me@ellpeck.de>
Date: Mon, 19 Jul 2021 23:10:27 +0200
Subject: [PATCH] Adjusted GenericStashFont line height calculations to result
 in the same values as GenericSpriteFont

---
 CHANGELOG.md                              |  4 ++++
 MLEM.Extended/Font/GenericStashFont.cs    | 17 +++++++++++---
 Sandbox/Content/Fonts/TestFont.spritefont |  2 +-
 Sandbox/GameImpl.cs                       | 28 ++++++++++++++++++++---
 4 files changed, 44 insertions(+), 7 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index b27cc4e..7297e1b 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -30,6 +30,10 @@ Improvements
 Fixes
 - Fixed a crash if a paragraph has a link formatting code, but no font
 
+### MLEM.Extended
+Improvements
+- Adjusted GenericStashFont line height calculations to result in the same values as GenericSpriteFont
+
 ### MLEM.Data
 Additions
 - Added the ability to specify a coordinate offset in data texture atlases
diff --git a/MLEM.Extended/Font/GenericStashFont.cs b/MLEM.Extended/Font/GenericStashFont.cs
index f4c3bc0..1b497ee 100644
--- a/MLEM.Extended/Font/GenericStashFont.cs
+++ b/MLEM.Extended/Font/GenericStashFont.cs
@@ -29,9 +29,7 @@ namespace MLEM.Extended.Font {
         /// <param name="italic">An italic version of the font</param>
         public GenericStashFont(SpriteFontBase font, SpriteFontBase bold = null, SpriteFontBase italic = null) {
             this.Font = font;
-            // SpriteFontBase provides no line height, so we measure the height of a new line for most fonts
-            // This doesn't work with static sprite fonts, but their size is always the one we calculate here
-            this.LineHeight = font is StaticSpriteFont s ? s.FontSize + s.LineSpacing : font.MeasureString("\n").Y;
+            this.LineHeight = CalculateLineHeight(font);
             this.Bold = bold != null ? new GenericStashFont(bold) : this;
             this.Italic = italic != null ? new GenericStashFont(italic) : this;
         }
@@ -51,5 +49,18 @@ namespace MLEM.Extended.Font {
             return this.Font.MeasureString(c.ToCachedString());
         }
 
+        private static float CalculateLineHeight(SpriteFontBase font) {
+            if (font is StaticSpriteFont s) {
+                // this is the same calculation used internally by StaticSpriteFont
+                return s.FontSize + s.LineSpacing;
+            } else {
+                // Y (min y) just stores the glyph's Y offset, whereas Y2 (max y) stores the glyph's height
+                // since we technically want line spacing rather than line height, we calculate it like this
+                var bounds = new Bounds();
+                font.TextBounds(" ", Vector2.Zero, ref bounds);
+                return bounds.Y2 + (bounds.Y2 - bounds.Y);
+            }
+        }
+
     }
 }
\ No newline at end of file
diff --git a/Sandbox/Content/Fonts/TestFont.spritefont b/Sandbox/Content/Fonts/TestFont.spritefont
index 54ab9ac..b44bd5d 100644
--- a/Sandbox/Content/Fonts/TestFont.spritefont
+++ b/Sandbox/Content/Fonts/TestFont.spritefont
@@ -11,7 +11,7 @@ with.
     <!--
     Modify this string to change the font that will be imported.
     -->
-    <FontName>Arial</FontName>
+    <FontName>Cadman_Roman.otf</FontName>
 
     <!--
     Size is a float value, measured in points. Modify this value to change
diff --git a/Sandbox/GameImpl.cs b/Sandbox/GameImpl.cs
index 9ce8fc1..5cd4587 100644
--- a/Sandbox/GameImpl.cs
+++ b/Sandbox/GameImpl.cs
@@ -8,9 +8,11 @@ using Microsoft.Xna.Framework.Input;
 using MLEM.Cameras;
 using MLEM.Data;
 using MLEM.Data.Content;
+using MLEM.Extended.Extensions;
 using MLEM.Extended.Font;
 using MLEM.Extended.Tiled;
 using MLEM.Extensions;
+using MLEM.Font;
 using MLEM.Formatting;
 using MLEM.Formatting.Codes;
 using MLEM.Input;
@@ -20,6 +22,7 @@ using MLEM.Textures;
 using MLEM.Ui;
 using MLEM.Ui.Elements;
 using MLEM.Ui.Style;
+using MonoGame.Extended;
 using MonoGame.Extended.Tiled;
 using Group = MLEM.Ui.Elements.Group;
 
@@ -74,9 +77,10 @@ namespace Sandbox {
             //var font = new GenericSpriteFont(LoadContent<SpriteFont>("Fonts/TestFont"));
             //var font = new GenericBitmapFont(LoadContent<BitmapFont>("Fonts/Regular"));
             var font = new GenericStashFont(system.GetFont(32));
+            var spriteFont = new GenericSpriteFont(LoadContent<SpriteFont>("Fonts/TestFont"));
             this.UiSystem.Style = new UntexturedStyle(this.SpriteBatch) {
                 Font = font,
-                TextScale = 0.1F,
+                TextScale = 0.5F,
                 PanelTexture = new NinePatch(new TextureRegion(tex, 0, 8, 24, 24), 8),
                 ButtonTexture = new NinePatch(new TextureRegion(tex, 24, 8, 16, 16), 4)
             };
@@ -84,6 +88,14 @@ namespace Sandbox {
             this.UiSystem.AutoScaleWithScreen = true;
             this.UiSystem.GlobalScale = 5;
 
+            /*this.OnDraw += (g, time) => {
+                const string strg = "This is a test string\nto test things\n\nMany things are being tested, like the ability\nfor this font to agree\n\nwith newlines";
+                this.SpriteBatch.Begin();
+                spriteFont.DrawString(this.SpriteBatch, strg, new Vector2(600, 100), Color.White, 0, Vector2.Zero, 1, SpriteEffects.None, 0);
+                font.DrawString(this.SpriteBatch, strg, new Vector2(600, 100), Color.White, 0, Vector2.Zero, 2, SpriteEffects.None, 0);
+                this.SpriteBatch.End();
+            };*/
+
             var panel = new Panel(Anchor.Center, new Vector2(0, 100), Vector2.Zero) {SetWidthBasedOnChildren = true};
             panel.AddChild(new Button(Anchor.AutoLeft, new Vector2(100, 10)));
             panel.AddChild(new Button(Anchor.AutoCenter, new Vector2(80, 10)));
@@ -129,7 +141,7 @@ namespace Sandbox {
             Console.WriteLine("The res is " + res);
 
             var gradient = this.SpriteBatch.GenerateGradientTexture(Color.Green, Color.Red, Color.Blue, Color.Yellow);
-            this.OnDraw += (game, time) => {
+            /*this.OnDraw += (game, time) => {
                 this.SpriteBatch.Begin();
                 this.SpriteBatch.Draw(this.SpriteBatch.GetBlankTexture(), new Rectangle(640 - 4, 360 - 4, 8, 8), Color.Green);
 
@@ -141,7 +153,7 @@ namespace Sandbox {
 
                 this.SpriteBatch.Draw(gradient, new Rectangle(300, 100, 200, 200), Color.White);
                 this.SpriteBatch.End();
-            };
+            };*/
 
             var sc = 4;
             var formatter = new TextFormatter();
@@ -218,6 +230,16 @@ namespace Sandbox {
                     CanBeMoused = false
                 });
             }
+            var par = loadPanel.AddChild(new Paragraph(Anchor.AutoLeft, 1, "This is another\ntest string\n\nwith many lines\nand many more!"));
+            par.OnUpdated = (e, time) => {
+                GenericFont newFont = Input.IsModifierKeyDown(ModifierKey.Shift) ? spriteFont : font;
+                if (newFont != par.RegularFont.Value) {
+                    par.TextScaleMultiplier = newFont == font ? 1 : 0.5F;
+                    par.RegularFont = newFont;
+                    par.ForceUpdateArea();
+                }
+            };
+            par.OnDrawn = (e, time, batch, a) => batch.DrawRectangle(e.DisplayArea.ToExtended(), Color.Red);
             this.UiSystem.Add("Load", loadGroup);
         }