vo_gpu: split --linear-scaling into two separate options

Since linear downscaling makes sense to handle independently from
linear/sigmoid upscaling, we split this option up. Now,
linear-downscaling is its own option that only controls linearization
when downscaling and nothing more. Likewise, linear-upscaling /
sigmoid-upscaling are two mutually exclusive options (the latter
overriding the former) that apply only to upscaling and no longer
implicitly enable linear light downscaling as well.

The old behavior was very confusing, as evidenced by issues such
as #6213. The current behavior should make much more sense, and only
minimally breaks backwards compatibility (since using linear-scaling
directly was very uncommon - most users got this for free as part of
gpu-hq and relied only on that).

Closes #6213.

1 files changed, 2 insertions, 1 deletions

diff --git a/video/out/gpu/video.h b/video/out/gpu/video.h
index 2184599582..ca8b6f65d4 100644
--- a/video/out/gpu/video.h
+++ b/video/out/gpu/video.h
@@ -112,8 +112,9 @@ struct gl_video_opts {
     float tone_mapping_param;
     float tone_mapping_desat;
     int gamut_warning;
-    int linear_scaling;
     int correct_downscaling;
+    int linear_downscaling;
+    int linear_upscaling;
     int sigmoid_upscaling;
     float sigmoid_center;
     float sigmoid_slope;