Add spectral colormap (#11298)

Author: oxkitsune

Cargo.lock

@@ -3068,7 +3068,7 @@ checksum = "d6add3b8cff394282be81f3fc1a0605db594ed69890078ca6e2cab1c408bcf04"
 [[package]]
 name = "ecolor"
 version = "0.32.3"
-source = "git+https://github.com/emilk/egui.git?branch=main#c97c065a575ec6e657bb42872890a00d0fb391c1"
+source = "git+https://github.com/emilk/egui.git?branch=main#48d903d8797d0869b5d2b43a22346dede7d471d2"
 dependencies = [
  "bytemuck",
  "color-hex",
@@ -3085,7 +3085,7 @@ checksum = "18aade80d5e09429040243ce1143ddc08a92d7a22820ac512610410a4dd5214f"
 [[package]]
 name = "eframe"
 version = "0.32.3"
-source = "git+https://github.com/emilk/egui.git?branch=main#c97c065a575ec6e657bb42872890a00d0fb391c1"
+source = "git+https://github.com/emilk/egui.git?branch=main#48d903d8797d0869b5d2b43a22346dede7d471d2"
 dependencies = [
  "ahash",
  "bytemuck",
@@ -3123,7 +3123,7 @@ dependencies = [
 [[package]]
 name = "egui"
 version = "0.32.3"
-source = "git+https://github.com/emilk/egui.git?branch=main#c97c065a575ec6e657bb42872890a00d0fb391c1"
+source = "git+https://github.com/emilk/egui.git?branch=main#48d903d8797d0869b5d2b43a22346dede7d471d2"
 dependencies = [
  "accesskit",
  "ahash",
@@ -3143,7 +3143,7 @@ dependencies = [
 [[package]]
 name = "egui-wgpu"
 version = "0.32.3"
-source = "git+https://github.com/emilk/egui.git?branch=main#c97c065a575ec6e657bb42872890a00d0fb391c1"
+source = "git+https://github.com/emilk/egui.git?branch=main#48d903d8797d0869b5d2b43a22346dede7d471d2"
 dependencies = [
  "ahash",
  "bytemuck",
@@ -3162,7 +3162,7 @@ dependencies = [
 [[package]]
 name = "egui-winit"
 version = "0.32.3"
-source = "git+https://github.com/emilk/egui.git?branch=main#c97c065a575ec6e657bb42872890a00d0fb391c1"
+source = "git+https://github.com/emilk/egui.git?branch=main#48d903d8797d0869b5d2b43a22346dede7d471d2"
 dependencies = [
  "accesskit_winit",
  "arboard",
@@ -3225,7 +3225,7 @@ dependencies = [
 [[package]]
 name = "egui_extras"
 version = "0.32.3"
-source = "git+https://github.com/emilk/egui.git?branch=main#c97c065a575ec6e657bb42872890a00d0fb391c1"
+source = "git+https://github.com/emilk/egui.git?branch=main#48d903d8797d0869b5d2b43a22346dede7d471d2"
 dependencies = [
  "ahash",
  "egui",
@@ -3242,7 +3242,7 @@ dependencies = [
 [[package]]
 name = "egui_glow"
 version = "0.32.3"
-source = "git+https://github.com/emilk/egui.git?branch=main#c97c065a575ec6e657bb42872890a00d0fb391c1"
+source = "git+https://github.com/emilk/egui.git?branch=main#48d903d8797d0869b5d2b43a22346dede7d471d2"
 dependencies = [
  "bytemuck",
  "egui",
@@ -3258,7 +3258,7 @@ dependencies = [
 [[package]]
 name = "egui_kittest"
 version = "0.32.3"
-source = "git+https://github.com/emilk/egui.git?branch=main#c97c065a575ec6e657bb42872890a00d0fb391c1"
+source = "git+https://github.com/emilk/egui.git?branch=main#48d903d8797d0869b5d2b43a22346dede7d471d2"
 dependencies = [
  "dify",
  "eframe",
@@ -3332,7 +3332,7 @@ checksum = "48c757948c5ede0e46177b7add2e67155f70e33c07fea8284df6576da70b3719"
 [[package]]
 name = "emath"
 version = "0.32.3"
-source = "git+https://github.com/emilk/egui.git?branch=main#c97c065a575ec6e657bb42872890a00d0fb391c1"
+source = "git+https://github.com/emilk/egui.git?branch=main#48d903d8797d0869b5d2b43a22346dede7d471d2"
 dependencies = [
  "bytemuck",
  "serde",
@@ -3449,7 +3449,7 @@ dependencies = [
 [[package]]
 name = "epaint"
 version = "0.32.3"
-source = "git+https://github.com/emilk/egui.git?branch=main#c97c065a575ec6e657bb42872890a00d0fb391c1"
+source = "git+https://github.com/emilk/egui.git?branch=main#48d903d8797d0869b5d2b43a22346dede7d471d2"
 dependencies = [
  "ab_glyph",
  "ahash",
@@ -3468,7 +3468,7 @@ dependencies = [
 [[package]]
 name = "epaint_default_fonts"
 version = "0.32.3"
-source = "git+https://github.com/emilk/egui.git?branch=main#c97c065a575ec6e657bb42872890a00d0fb391c1"
+source = "git+https://github.com/emilk/egui.git?branch=main#48d903d8797d0869b5d2b43a22346dede7d471d2"
 
 [[package]]
 name = "equivalent"

crates/store/re_types/definitions/rerun/components/colormap.fbs

@@ -52,4 +52,11 @@ enum Colormap: ubyte {
     /// It is especially suited for visualizing signed values.
     /// It interpolates from cyan to blue to dark gray to brass to yellow.
     CyanToYellow,
+
+    /// The Spectral colormap from Matplotlib.
+    ///
+    /// This is a diverging colormap, often used to visualize data with a meaningful center point,
+    /// where deviations from that center are important to highlight.
+    /// It interpolates from red to orange to yellow to green to blue to violet.
+    Spectral,
 }

crates/store/re_types/src/components/colormap.rs

@@ -14,7 +14,8 @@ impl Colormap {
             | Self::Plasma
             | Self::Turbo
             | Self::Viridis
-            | Self::CyanToYellow => {}
+            | Self::CyanToYellow
+            | Self::Spectral => {}
         }
 
         match value {
@@ -25,6 +26,7 @@ impl Colormap {
             v if v == Self::Turbo as u8 => Some(Self::Turbo),
             v if v == Self::Viridis as u8 => Some(Self::Viridis),
             v if v == Self::CyanToYellow as u8 => Some(Self::CyanToYellow),
+            v if v == Self::Spectral as u8 => Some(Self::Spectral),
             _ => None,
         }
     }

crates/store/re_types/src/components/colormap_ext.rs

@@ -9,6 +9,7 @@ const COLORMAP_PLASMA:         u32 = 4u;
 const COLORMAP_TURBO:          u32 = 5u;
 const COLORMAP_VIRIDIS:        u32 = 6u;
 const COLORMAP_CYAN_TO_YELLOW: u32 = 7u;
+const COLORMAP_SPECTRAL:       u32 = 8u;
 
 /// Returns a gamma-space sRGB in 0-1 range.
 ///
@@ -31,6 +32,8 @@ fn colormap_srgb(which: u32, t_unsaturated: f32) -> vec3f {
         return colormap_viridis_srgb(t);
     } else if which == COLORMAP_CYAN_TO_YELLOW {
         return colormap_cyan_to_yellow_srgb(t);
+    } else if which == COLORMAP_SPECTRAL {
+        return colormap_spectral_srgb(t);
     } else {
         return ERROR_RGBA.rgb;
     }
@@ -162,3 +165,17 @@ fn colormap_cyan_to_yellow_srgb(t: f32) -> vec3f {
     let u = t * 2. - 1.;
     return saturate(vec3f(1. + 3. * u, (1. + 3. * u * u) , 1. - 3. * u) / 4.);
 }
+
+/// Returns a gamma-space sRGB in 0-1 range.
+/// The input (`t`) must be in the 0-1 range.
+/// This is a polynomial approximation from Spectral color map.
+fn colormap_spectral_srgb(t: f32) -> vec3f {
+    let c0 = vec3f(0.584384543712538, 0.006424432561482, 0.231061410304836);
+    let c1 = vec3f(3.768572852617221, 2.487082885717158, 2.821174312084977);
+    let c2 = vec3f(-16.262574054760623, -6.243215992229093, -37.292187460541960);
+    let c3 = vec3f(39.821464952234010, 39.932449794574126, 186.340471613899751);
+    let c4 = vec3f(-46.140976850412727, -99.423798167148249, -388.532539629914481);
+    let c5 = vec3f(12.716626092708825, 96.954180217298671, 360.627239851094203);
+    let c6 = vec3f(5.942343111972585, -33.440386037285862, -123.635206049211334);
+    return c0 + t * (c1 + t * (c2 + t * (c3 + t * (c4 + t * (c5 + t * c6)))));
+}

crates/viewer/re_renderer/shader/colormap.wgsl

@@ -19,17 +19,19 @@ pub enum Colormap {
     Turbo = 5,
     Viridis = 6,
     CyanToYellow = 7,
+    Spectral = 8,
 }
 
 impl Colormap {
-    pub const ALL: [Self; 7] = [
+    pub const ALL: [Self; 8] = [
         Self::Grayscale,
         Self::Inferno,
         Self::Magma,
         Self::Plasma,
         Self::Turbo,
         Self::Viridis,
         Self::CyanToYellow,
+        Self::Spectral,
     ];
 }
 
@@ -43,6 +45,7 @@ impl std::fmt::Display for Colormap {
             Self::Turbo => write!(f, "Turbo"),
             Self::Viridis => write!(f, "Viridis"),
             Self::CyanToYellow => write!(f, "CyanToYellow"),
+            Self::Spectral => write!(f, "Spectral"),
         }
     }
 }
@@ -56,6 +59,7 @@ pub fn colormap_srgb(which: Colormap, t: f32) -> [u8; 4] {
         Colormap::Magma => colormap_magma_srgb(t),
         Colormap::Inferno => colormap_inferno_srgb(t),
         Colormap::CyanToYellow => colormap_cyan_to_yellow_srgb(t),
+        Colormap::Spectral => colormap_spectral_srgb(t),
     }
 }
 
@@ -211,3 +215,25 @@ pub fn colormap_cyan_to_yellow_srgb(t: f32) -> [u8; 4] {
         255,
     ]
 }
+
+/// Returns sRGB polynomial approximation from Spectral color map, assuming `t` is normalized.
+pub fn colormap_spectral_srgb(t: f32) -> [u8; 4] {
+    const C0: Vec3A = Vec3A::new(0.584384543712538, 0.006424432561482, 0.231061410304836);
+    const C1: Vec3A = Vec3A::new(3.768572852617221, 2.487082885717158, 2.821174312084977);
+    const C2: Vec3A = Vec3A::new(-16.262574054760623, -6.243215992229093, -37.292187460541960);
+    const C3: Vec3A = Vec3A::new(39.821464952234010, 39.932449794574126, 186.340471613899751);
+    const C4: Vec3A = Vec3A::new(
+        -46.140976850412727,
+        -99.423798167148249,
+        -388.532539629914481,
+    );
+    const C5: Vec3A = Vec3A::new(12.716626092708825, 96.954180217298671, 360.627239851094203);
+    const C6: Vec3A = Vec3A::new(5.942343111972585, -33.440386037285862, -123.635206049211334);
+
+    debug_assert!((0.0..=1.0).contains(&t));
+
+    let c = C0 + t * (C1 + t * (C2 + t * (C3 + t * (C4 + t * (C5 + t * C6)))));
+
+    let c = c * 255.0;
+    [c.x as u8, c.y as u8, c.z as u8, 255]
+}

crates/viewer/re_renderer/src/colormap.rs

@@ -2,9 +2,13 @@
 
 use std::time::Duration;
 
-use egui_kittest::kittest::Queryable as _;
+use egui::accesskit::Role;
+use egui_kittest::{SnapshotOptions, kittest::Queryable as _};
 
+use re_test_context::TestContext;
+use re_types::components::Colormap;
 use re_viewer::viewer_test_utils;
+use re_viewer_context::{MaybeMutRef, ViewerContext};
 
 /// Navigates from welcome to settings screen and snapshots it.
 #[tokio::test]
@@ -36,3 +40,44 @@ async fn settings_screen() {
     );
     harness.snapshot("settings_screen");
 }
+
+/// Tests the colormap selector UI with snapshot testing.
+/// This is defined here instead of in `re_viewer/tests` because it depends on `re_test_context`,
+/// which depends on `re_viewer_context`.
+#[test]
+fn colormap_selector_ui() {
+    let mut test_context = TestContext::new();
+    test_context.component_ui_registry = re_component_ui::create_component_ui_registry();
+    re_data_ui::register_component_uis(&mut test_context.component_ui_registry);
+
+    let mut harness = test_context.setup_kittest_for_rendering().build_ui(|ui| {
+        re_ui::apply_style_and_install_loaders(ui.ctx());
+
+        test_context.run(&ui.ctx().clone(), |ctx: &ViewerContext<'_>| {
+            ui.horizontal(|ui| {
+                ui.label("Colormap:");
+
+                let mut test_colormap = Colormap::Spectral;
+                let mut colormap_ref = MaybeMutRef::MutRef(&mut test_colormap);
+
+                re_viewer_context::gpu_bridge::colormap_edit_or_view_ui(ctx, ui, &mut colormap_ref);
+            });
+        });
+    });
+
+    harness.run();
+    harness.fit_contents();
+    harness.snapshot("colormap_selector_closed");
+
+    // give the combo box some room to open
+    harness.set_size(egui::Vec2::new(200.0, 250.0));
+    harness.get_by_role(Role::ComboBox).click(); // open combo box
+    harness.run();
+
+    harness.fit_contents();
+    harness.run();
+    harness.snapshot_options(
+        "colormap_selector_open",
+        &SnapshotOptions::new().threshold(2.0),
+    );
+}

crates/viewer/re_viewer/tests/app_kittest.rs

@@ -157,5 +157,6 @@ pub fn colormap_to_re_renderer(colormap: re_types::components::Colormap) -> re_r
         re_types::components::Colormap::Turbo => re_renderer::Colormap::Turbo,
         re_types::components::Colormap::Viridis => re_renderer::Colormap::Viridis,
         re_types::components::Colormap::CyanToYellow => re_renderer::Colormap::CyanToYellow,
+        re_types::components::Colormap::Spectral => re_renderer::Colormap::Spectral,
     }
 }