Add lut_float to TransferFunction.

2 files changed, 25 insertions, 0 deletions

diff --git a/src/transfer_function.cc b/src/transfer_function.cc
index 0dfdb338..00cd2c9c 100644
--- a/src/transfer_function.cc
+++ b/src/transfer_function.cc
@@ -73,6 +73,29 @@ TransferFunction::lut_unlocked (int bit_depth, bool inverse) const
 }
 
 
+float const *
+TransferFunction::lut_float (int bit_depth, bool inverse) const
+{
+	boost::mutex::scoped_lock lm (_mutex);
+
+	map<pair<int, bool>, float*>::const_iterator i = _luts_float.find (make_pair(bit_depth, inverse));
+	if (i != _luts_float.end()) {
+		return i->second;
+	}
+
+	double const* lut_double = lut_unlocked (bit_depth, inverse);
+
+	int size = lrint(pow(2.0f, bit_depth));
+	float* lut_float = new float[size];
+	for (int i = 0; i < size; ++i) {
+		lut_float[i] = static_cast<float> (lut_double[i]);
+	}
+
+	_luts_float[make_pair(bit_depth, inverse)] = lut_float;
+	return lut_float;
+}
+
+
 int const *
 TransferFunction::lut_int (int bit_depth, bool inverse, int multiplier) const
 {
diff --git a/src/transfer_function.h b/src/transfer_function.h
index 9d35b281..e497ae8a 100644
--- a/src/transfer_function.h
+++ b/src/transfer_function.h
@@ -55,6 +55,7 @@ public:
 
 	/** @return A look-up table (of size 2^bit_depth) whose values range from 0 to 1 */
 	double const * lut (int bit_depth, bool inverse) const;
+	float const * lut_float (int bit_depth, bool inverse) const;
 	int const * lut_int (int bit_depth, bool inverse, int multiplier) const;
 
 	virtual bool about_equal (boost::shared_ptr<const TransferFunction> other, double epsilon) const = 0;
@@ -67,6 +68,7 @@ private:
 	double const * lut_unlocked (int bit_depth, bool inverse) const;
 
 	mutable std::map<std::pair<int, bool>, double*> _luts;
+	mutable std::map<std::pair<int, bool>, float*> _luts_float;
 
 	struct IntDescription {
 		IntDescription (int bit_depth_, bool inverse_, int multipler_)