diff options
| -rw-r--r-- | CHANGELOG.adoc | 4 | ||||
| -rw-r--r-- | hittekaart/src/renderer/heatmap.rs | 11 |
2 files changed, 11 insertions, 4 deletions
diff --git a/CHANGELOG.adoc b/CHANGELOG.adoc index eeb2bc0..32bc6a5 100644 --- a/CHANGELOG.adoc +++ b/CHANGELOG.adoc @@ -8,6 +8,10 @@ Added: - The `storage::OsmAnd` and `storage::MbTiles` formats +Changed: + +- The gradient color scaling. + Removed: - The `storage::Sqlite` struct (`storage::OsmAnd` can be used instead) diff --git a/hittekaart/src/renderer/heatmap.rs b/hittekaart/src/renderer/heatmap.rs index c678a7a..5090935 100644 --- a/hittekaart/src/renderer/heatmap.rs +++ b/hittekaart/src/renderer/heatmap.rs @@ -137,7 +137,10 @@ fn colorize_tile(tile: &ImageBuffer<Luma<u8>, Vec<u8>>, lut: &[Rgba<u8>]) -> Rgb } fn prepare_lut(max: u8) -> Vec<Rgba<u8>> { - let gradient = colorgrad::preset::yl_or_rd(); + let gradient = colorgrad::GradientBuilder::new() + .css("rgba(0, 0, 0, 1) 0%, rgba(164, 0, 0, 1) 25%, rgba(224, 5, 0, 1) 50%, rgba(255, 187, 15, 1) 75%, rgba(255, 255, 255, 1) 100%") + .build::<colorgrad::LinearGradient>() + .unwrap(); iter::once([0, 0, 0, 0].into()) .chain((1..=max).map(|count| { let alpha = count as f32 / max as f32; @@ -145,10 +148,10 @@ fn prepare_lut(max: u8) -> Vec<Rgba<u8>> { // repetitions is worth as much as a jump from 9 to 10. By transforming alpha via the // cubic function given below, we give more weight to the "early" repetitions by having // a steeper slope, and less weight to later repetitions. - // There is no science behind the power 3, others work as well (if you adjust the + // There is no science behind the power 7, others work as well (if you adjust the // sign). It seemed like a decent trade-off though. - let alpha = (alpha - 1.0).powi(3) + 1.0; - let color = gradient.at(1.0 - alpha); + let alpha = (alpha - 1.0).powi(7) + 1.0; + let color = gradient.at(alpha); color.to_rgba8().into() })) .collect() |