1692395128739057844

archive/threads/NOTimothyLottes/2023-08-18-spc-last-crt-shader-was-broken-corrected-it-its/2023-08-18-Karyuutensei-how-many-passes-do-you-need-to-produce-this-result.md

@@ -0,0 +1,39 @@
+---
+title: "@NOTimothyLottes How many passes do you need to produce this result?"
+type: archive
+source: twitter
+source_url: "https://x.com/Karyuutensei/status/1692558954935550353"
+author: "Nick Tasios"
+handle: Karyuutensei
+post_id: "1692558954935550353"
+date: 2023-08-18
+archived: 2026-08-25
+draft: false
+tags:
+  - archive
+  - twitter
+  - NOTimothyLottes
+description: "@NOTimothyLottes How many passes do you need to produce this result?"
+in_reply_to: ""
+parent_post_id: "1692397318471926054"
+---
+
+## Source
+
+- URL: https://x.com/Karyuutensei/status/1692558954935550353
+- Author: Nick Tasios (@Karyuutensei)
+- Posted: 2023-08-18 15:27:55
+
+## Branch
+
+**1/**
+
+@NOTimothyLottes How many passes do you need to produce this result?
+
+**2/**
+
+@Karyuutensei 1 pass: 12 fetches/outpix, in 2 batches. I use 6 gather4's to grab a 4-wide(x)2-line region for the {R,G,B} channels. Then 6 more fetches to do energy conserving computation of output for each {nearest 2 lines}x{R,G,B} channel based {intensity, position vertically on scan}.
+
+## Related
+
+- Spine: [[archive/threads/NOTimothyLottes/2023-08-18-spc-last-crt-shader-was-broken-corrected-it-its]]

archive/threads/NOTimothyLottes/2023-08-18-spc-last-crt-shader-was-broken-corrected-it-its/index.md

@@ -7,8 +7,8 @@ author: "NOTimothyLottes"
 handle: NOTimothyLottes
 post_id: "1692395128739057844"
 date: 2023-08-18
-archived: 2026-08-23
-draft: true
+archived: 2026-08-25
+draft: false
 tags:
   - archive
   - twitter
@@ -30,10 +30,9 @@ in_reply_to: ""
 SPC: Last CRT shader was broken. Corrected it. It's energy conserving now, and correctly doing sub-pixel line width raster using the individual channels. Cell camera  shots below at different zooms.
 
 ![](https://pbs.twimg.com/media/F3yYY1iXYAAaAlE?format=jpg&name=orig)
-
 ![](https://pbs.twimg.com/media/F3yYZQwXcAABFvi?format=jpg&name=orig)
-
 ![](https://pbs.twimg.com/media/F3yYZo5WAAA0aRS?format=jpg&name=orig)
+
 **2/**
 
 Each scan line is simulated with only 3 pixels. But you get 9 sub-pixels to play with, so that is where the quality comes from. It reaches 7/8th of the display peak brightness, this compromise was so there is always some amount of perceptual scan effect.
@@ -42,6 +41,8 @@ Each scan line is simulated with only 3 pixels. But you get 9 sub-pixels to play
 
 The scan line thickness is adaptive proportional to linear brightness. When the scan thins out it is energy conserving and increases the thin pixel brightness to compensate. When it needs to go bright, it blooms the line. Lines have some overlap in bloom.
 
+Branches: [[archive/threads/NOTimothyLottes/2023-08-18-spc-last-crt-shader-was-broken-corrected-it-its/2023-08-18-Karyuutensei-how-many-passes-do-you-need-to-produce-this-result]]
+
 **4/**
 
 One human perceptual reason CRTs feel like they have more contrast than they do, is because an individual scan line is super bright when in focus. So the black surround feels darker to the mind.