Type-in from the February 1987 issue of Amstrad Action.
John Keneally was the founder of Camel Micros (use 3rd link for info).
Program is Listed at end of video.
From Amstrad Action:
"We have had slow double-height, fast double-vheight. Basic double-height and machinecode double-height routines in past issues. A sensitive follow up would be a program for variable height or width. You have John Keneally of Exeter to thank for this.
The main routine is from line 6000 on. John has included a small demo which shows off the program's power. If you wish to use it in your own listings, the following variables must be set up:
a $: the string to display
x, y: graphic coordinates
mx, my: magnification factors - horizontal and vertical
dx, dy: change in horizontal and vertical position for each successive character.
Expressed as a proportion of thecharacter size. For normal horizontal writing make dx = 1 and dy = 0.
gink: pen color."
https://www.youtube.com/watch?v=dasRjKrHaPE (https://www.youtube.com/watch?v=dasRjKrHaPE)
Links:
https://cpcrulez.fr/applications_coding-variable_height.htm (https://cpcrulez.fr/applications_coding-variable_height.htm)
https://www.cpc-power.com/index.php?page=detail&num=13004 (https://www.cpc-power.com/index.php?page=detail&num=13004)
https://cpcrulez.fr/auteur-john_keneally.htm (https://cpcrulez.fr/auteur-john_keneally.htm)
https://www.cpc-power.com/index.php?page=staff&lenom=John%20KENEALLY (https://www.cpc-power.com/index.php?page=staff&lenom=John%20KENEALLY)
Not emulated - original hardware and software.
Please note that the aspect ratio for this YouTube video is 16:9 but the CPC monitor
has an aspect ratio of 4:3 so you may wish to adjust your viewing device accordingly.