This shader uses the equation described by R. Keys in the paper 'Cubic Convolution Interpolation for Digital Image Processing' which is, in this case, the same as a Catmull-Rom spline. This produces a sharper upscaled image than bilinear filtering.
The new shader is selected by setting gl_glsl_filter to 2. Consequently, gl_glsl_filter is now treated as an int rather than a boolean.
Also fixed a variable name problem in the code guarded by GLSL_SOURCE_ON_DISK.
1. Off-by-one pixel coordinates
2. Sampling of wrong pixels at some non-integer stretch factors
First was noticed while comparing screenshots of the software and opengl w/glsl renderers (opengl output was shifted up and to the right). Fixed by subtracting a 1/2 pixel from the texture coordinates when calculating the bottom left pixel to use for interpolation.
Second was apparent when running pac-man fullscreen on a 1920x1080 screen and allowing non-integer stretching. Manifested as irregular horizontal 'steps' in the output. Fixed by sampling from the center of all pixels which should avoid any funny business in regards to pixel coordinate rounding.
---------------------------
ibm5170_cdrom.xml:
The 11th Hour - Der Nachfolger von 7th Guest [archive.org]
Advanced Dungeons & Dragons 2nd Edition Masterpiece Collection [archive.org]
AH-64D Longbow [archive.org]
Atlantis - Das sagenhafte Abenteuer [archive.org]
---------------------------
ibm5170_cdrom:
3-D Ultra Pinball [archive.org]
5 Plus One - Super Tetris [archive.org]
688I Hunter-Killer [archive.org]
A-10 Cuba! [archive.org]
Ace Ventura [archive.org]
Aces of the Pacific [archive.org]
Aces over Europe [archive.org]
Activision's Atari 2600 Action Pack [archive.org]
Activision's Atari 2600 Action Pack 2 [archive.org]
Activision Game Vault Volume 3 [archive.org]
Advanced Destroyer Simulator [archive.org]
Afterlife [archive.org]
Air Warrior III [archive.org]
Air Warrior Plus [archive.org]
Alien Legacy [archive.org]
Alien Odyssey [archive.org]
Aliens - A Comic Book Adventure [archive.org]
Amazon - Guardians of Eden [archive.org]
Animal [archive.org]
Arcade's Greatest Hits - The Midway Collection 2 [archive.org]
Archibald Applebrook's Abenteuer [archive.org]
Archon Ultra [archive.org]
Are You Afraid of the Dark - The Tale of Orpheo's Curse [archive.org]
Armored Fist [archive.org]
Around the World in 80 Days [archive.org]
Ascendancy [archive.org]
Atari Arcade Hits [archive.org]
A.T.F. - Advanced Tactical Fighters [archive.org]
Awesome Adventures of Victor Vector & Yondo, The - The Cyberplasm Formula [archive.org]
Halloween Harry - Alien Carnage [Archive.org]
Updated year, publisher and developer for Orb of Halucidon from my original copy of the manual.
Updated publisher for Air Traffic Controller from my original copy of the manual.
- Doubled line size when in single-layer + high color mode. Software that uses this combination (secre2, debut2, ayayo123 "X68000 version") now looks mostly correct.
- Made the line wrapping code aware of VRAM page selection. Fixes a small number of cases where half of the screen would "shake" without this check.
* Basic anchor links for FAQ page
* Add verbose logging for CFG files
We already have verbose logging for INI files that get parsed, so having CFGs get similar treatment is useful.
