From afe9f6a3ae0c8280303f0cd7bec740b3f86e0f59 Mon Sep 17 00:00:00 2001 From: Ben Harris Date: Sun, 22 Mar 2020 00:26:27 +0000 Subject: [PATCH] NOTES on good bitmap sizes. Conclusion: 20, 60, and 100 are good. --- NOTES | 29 +++++++++++++++++++++++++++++ 1 file changed, 29 insertions(+) diff --git a/NOTES b/NOTES index fce711c..fbfa9a1 100644 --- a/NOTES +++ b/NOTES @@ -498,3 +498,32 @@ http://www.twardoch.com/download/polishhowto/ ẞ: https://typography.guru/journal/capital-sharp-s-designs/ https://typography.guru/journal/how-to-draw-a-capital-sharp-s-r18/ + +Good bitmap sizes for Bedstead fulfill two characteristics: + +1: An integer number of output pixels per Bedstead pixel (so +horizontal and vertical lines work). + +2: Edges of diagonals don't pass through pixel centres (so no doubt +whether any pixel is in or out). + +The first requires that the height be 10n for integer n. + +The second requires that the height _not_ be 40n for integer n. + +So good sizes are 10, 20, 30, 50, 60, 70, 90, 100, etc. + +The best sizes would be those where the area of a (long) diagonal line +is correct. The outline version has an area of 1 - (0.25^2) + (0.75^2) = +1.5/pixel. Others: + +size | area/diagonal pixel +-----|-------------------- +10 | 1 +20 | 1+1/2 = 1.5 +30 | 1+6/9 = 1.67 +50 | 1+10/25 = 1.4 +60 | 1+18/36 = 1.5 +70 | 1+28/49 = 1.57 +90 | 1+36/81 = 1.44 +100 | 1+50/100 = 1.5 -- 2.30.2