From: Mikko Rasa <tdb@tdb.fi>
Date: Thu, 3 May 2018 17:19:10 +0000 (+0300)
Subject: Allocate slightly larger image when creating packed texture
X-Git-Url: http://git.tdb.fi/?p=ttf2png.git;a=commitdiff_plain;h=2894ee8a8f6d5852f3cbda1e5b6f64e03d2356e9

Allocate slightly larger image when creating packed texture

When rendering a very small number of glyphs the packing imperfections
become more pronounced, overflowing the allocated area more easily.
---

diff --git a/ttf2png.c b/ttf2png.c
index a634b2b..13e5a80 100644
--- a/ttf2png.c
+++ b/ttf2png.c
@@ -919,18 +919,18 @@ int render_packed(Font *font, unsigned margin, unsigned padding, bool npot)
 		area = a;
 	}
 
-	/* Find an image size that's no higher than wide, allowing for some
-	imperfections in the packing. */
+	/* Find an image size that's approximately square. */
 	for(font->image.w=1;; font->image.w<<=1)
 	{
 		if(font->image.w<=margin*2)
 			continue;
-		font->image.h = (area*5/4)/(font->image.w-margin*2)+margin*2;
+		font->image.h = area/(font->image.w-margin*2)+margin*2;
 		if(font->image.h<=font->image.w)
 			break;
 	}
-	if(!npot)
-		font->image.h = round_to_pot(font->image.h);
+
+	/* Add some extra space to accommodate packing imperfections. */
+	font->image.h = font->image.h*3/2;
 
 	/* Allocate arrays for storing the image and keeping track of used pixels and
 	glyphs.  Since glyphs are rectangular and the image is filled starting from