v1.0.0-rc.40

common/ColorScale.cpp

@@ -1,6 +1,7 @@
 // SPDX-FileCopyrightText: 2025 Filip Leonarski, Paul Scherrer Institute <filip.leonarski@psi.ch>
 // SPDX-License-Identifier: GPL-3.0-only
 
+#include <cmath>
 #include "ColorScale.h"
 #include "JFJochException.h"
 
@@ -13,8 +14,6 @@ void ColorScale::Select(ColorScaleEnum val) {
 }
 
 rgb ColorScale::Apply(float input, const std::vector<rgb> &map) {
-    input = std::clamp(input, 0.0f, 1.0f);
-
     size_t num_colors = map.size();
     if (num_colors < 2) {
         throw std::invalid_argument("Colormap must have at least two colors.");
@@ -35,7 +34,7 @@ rgb ColorScale::Apply(float input, const std::vector<rgb> &map) {
     };
 }
 
-rgb ColorScale::Apply(ColorScaleSpecial input) {
+rgb ColorScale::Apply(ColorScaleSpecial input) const {
     switch (input) {
         case ColorScaleSpecial::Gap:
             return gap;
@@ -44,18 +43,67 @@ rgb ColorScale::Apply(ColorScaleSpecial input) {
             return bad;
     }
 }
-rgb ColorScale::Apply(float input) const {
+
+rgb ColorScale::Apply(float input, float min, float max) const {
+    // Assume min and max is finite
+
+    if (!std::isfinite(input))
+        return gap;
+
+    float f;
+    if (input <= min)
+        f = 0.0f;
+    else if (input >= max)
+        f = 1.0f;
+    else
+        f = (input - min) / (max - min);
+
     switch (current) {
         case ColorScaleEnum::Viridis:
-            return Apply(input, viridis_colormap);
+            return Apply(f, viridis_colormap);
         case ColorScaleEnum::Heat:
-            return Apply(input, heat_colormap);
+            return Apply(f, heat_colormap);
         case ColorScaleEnum::Indigo:
-            return Apply(input, white_to_indigo_colormap);
+            return Apply(f, white_to_indigo_colormap);
         case ColorScaleEnum::BW:
-            return Apply(input, white_to_black_colormap);
+            return Apply(f, white_to_black_colormap);
         default:
             throw JFJochException(JFJochExceptionCategory::InputParameterInvalid,
                                   "Color scale unknown");
     }
 }
+
+ColorScale &ColorScale::Gap(rgb input) {
+    gap = input;
+    return *this;
+}
+
+ColorScale &ColorScale::BadPixel(rgb input) {
+    bad = input;
+    return *this;
+}
+
+rgb rainbowColor(float t) {
+    // Ensure t is in [0,1]
+    t = std::max(0.0f, std::min(1.0f, t));
+
+    // Convert to hue (0 to 6)
+    float hue = t * 6.0f;
+
+    int phase = static_cast<int>(hue);
+    float fract = hue - phase;
+
+    uint8_t p = static_cast<uint8_t>(255 * (1.0f - fract));
+    uint8_t q = static_cast<uint8_t>(255 * fract);
+    uint8_t full = 255;
+
+    switch (phase) {
+        case 0: return {full, q, 0};     // Red to Yellow
+        case 1: return {p, full, 0};     // Yellow to Green
+        case 2: return {0, full, q};     // Green to Cyan
+        case 3: return {0, p, full};     // Cyan to Blue
+        case 4: return {q, 0, full};     // Blue to Magenta
+        case 5: return {full, 0, p};     // Magenta to Red
+        default: return {full, 0, 0};    // Fallback (red)
+    }
+}