Release 0.13.1

native/dark_color.h

@@ -0,0 +1,16 @@
+#ifndef HYPERDRM_DARK_COLOR_H
+#define HYPERDRM_DARK_COLOR_H
+/* Suppress near-black histogram residuals without changing channel ratios.
+ * Apply only to fresh histogram colors, before continuity and interpolation. */
+static inline void dark_color_filter(unsigned char color[3]) {
+    unsigned peak = color[0];
+    for (unsigned c = 1; c < 3; c++)
+        if (color[c] > peak)
+            peak = color[c];
+    if (peak >= 24)
+        return;
+    unsigned gain = peak > 12 ? peak - 12 : 0;
+    for (unsigned c = 0; c < 3; c++)
+        color[c] = (unsigned char)((color[c] * gain + 6) / 12);
+}
+#endif