remove c++ includes from tone_mapping.hpp

the tone_mapping.hpp header was including <opencv2/opencv.hpp>, which pulls in tons of c++ template types (cv::Scalar_, std::vector, std::shared_ptr, etc). bindgen was generating layout tests for these templates but couldn't determine their correct sizes, causing test failures.

Author: salarkhan

tone_mapping.cpp

@@ -1,4 +1,6 @@
 #include "tone_mapping.hpp"
+#include <opencv2/opencv.hpp>
+#include <lcms2.h>
 #include <cstring>
 #include <memory>
 #include <algorithm>
@@ -12,6 +14,18 @@ static inline float calculate_luminance(float r, float g, float b) {
     return 0.2126f * r + 0.7152f * g + 0.0722f * b;
 }
 
+/**
+ * Applies HDR to SDR tone mapping using Reinhard algorithm.
+ *
+ * This function detects PQ (Perceptual Quantizer) HDR profiles and applies
+ * luminance-based tone mapping to reduce brightness while preserving color
+ * relationships. Non-PQ images are returned unchanged (as a copy).
+ *
+ * @param src Source image (BGR or BGRA format, 8-bit)
+ * @param icc_data ICC profile data from the source image
+ * @param icc_len Length of ICC profile data in bytes
+ * @return Tone-mapped image (caller owns the pointer), or nullptr on error
+ */
 cv::Mat* apply_hdr_to_sdr_tone_mapping(
     const cv::Mat* src,
     const uint8_t* icc_data,

tone_mapping.hpp

@@ -24,27 +24,3 @@ opencv_mat apply_tone_mapping_ffi(
 #ifdef __cplusplus
 }
 #endif
-
-// C++ implementation details (not visible to C/FFI)
-#ifdef __cplusplus
-#include <opencv2/opencv.hpp>
-#include <lcms2.h>
-
-/**
- * Applies HDR to SDR tone mapping using Reinhard algorithm.
- *
- * This function detects PQ (Perceptual Quantizer) HDR profiles and applies
- * luminance-based tone mapping to reduce brightness while preserving color
- * relationships. Non-PQ images are returned unchanged (as a copy).
- *
- * @param src Source image (BGR or BGRA format, 8-bit)
- * @param icc_data ICC profile data from the source image
- * @param icc_len Length of ICC profile data in bytes
- * @return Tone-mapped image (caller owns the pointer), or nullptr on error
- */
-cv::Mat* apply_hdr_to_sdr_tone_mapping(
-    const cv::Mat* src,
-    const uint8_t* icc_data,
-    size_t icc_len
-);
-#endif