filter_kernels: add radius cutoff functionality

This allows filter functions to be prematurely cut off once their
contributions start becoming insignificant. This effectively prevents
wasted GPU time sampling from parts of the function that are essentially
reduced to zero by the window function, providing anywhere from a 10% to
20% speedup. (5700μs -> 4700μs for me)

1 files changed, 2 insertions, 0 deletions

diff --git a/video/out/filter_kernels.h b/video/out/filter_kernels.h
index 74cc3eb148..c9a89f6847 100644
--- a/video/out/filter_kernels.h
+++ b/video/out/filter_kernels.h
@@ -29,6 +29,7 @@ struct filter_kernel {
     struct filter_window f; // the kernel itself
     struct filter_window w; // window storage
     bool clamp; // clamp to the range [0-1]
+    double value_cutoff; // discard all contributions below this value (polar)
     // Constant values
     const char *window; // default window
     bool polar;         // whether or not the filter uses polar coordinates
@@ -38,6 +39,7 @@ struct filter_kernel {
                           // function radius to the possibly wider
                           // (in the case of downsampling) filter sample
                           // radius.
+    double radius_cutoff; // the true radius at which we can cut off the filter
 };
 
 extern const struct filter_window mp_filter_windows[];