Remove C++11 dependency from ResampleEffect.

[movit] / colorspace_conversion_effect.cpp

diff --git a/colorspace_conversion_effect.cpp b/colorspace_conversion_effect.cpp
index 3f075d2b721141ef6c13428c24b93c854d4879f3..2b8a0ca329fd34b3d535fca0cbdfb56584b8ff1d 100644 (file)
--- a/colorspace_conversion_effect.cpp
+++ b/colorspace_conversion_effect.cpp
@@ -1,24 +1,29 @@
 #include <assert.h>
-
+#include <Eigen/Core>
 #include <Eigen/LU>
 
 #include "colorspace_conversion_effect.h"
+#include "d65.h"
 #include "util.h"
 
 using namespace Eigen;
+using namespace std;
+
+namespace movit {
 
 // Color coordinates from Rec. 709; sRGB uses the same primaries.
-double rec709_x_R = 0.640,  rec709_x_G = 0.300,  rec709_x_B = 0.150;
-double rec709_y_R = 0.330,  rec709_y_G = 0.600,  rec709_y_B = 0.060;
+static const double rec709_x_R = 0.640, rec709_x_G = 0.300, rec709_x_B = 0.150;
+static const double rec709_y_R = 0.330, rec709_y_G = 0.600, rec709_y_B = 0.060;
 
 // Color coordinates from Rec. 601. (Separate for 525- and 625-line systems.)
-double rec601_525_x_R = 0.630, rec601_525_x_G = 0.310, rec601_525_x_B = 0.155;
-double rec601_525_y_R = 0.340, rec601_525_y_G = 0.595, rec601_525_y_B = 0.070;
-double rec601_625_x_R = 0.640, rec601_625_x_G = 0.290, rec601_625_x_B = 0.150;
-double rec601_625_y_R = 0.330, rec601_625_y_G = 0.600, rec601_625_y_B = 0.060;
+static const double rec601_525_x_R = 0.630, rec601_525_x_G = 0.310, rec601_525_x_B = 0.155;
+static const double rec601_525_y_R = 0.340, rec601_525_y_G = 0.595, rec601_525_y_B = 0.070;
+static const double rec601_625_x_R = 0.640, rec601_625_x_G = 0.290, rec601_625_x_B = 0.150;
+static const double rec601_625_y_R = 0.330, rec601_625_y_G = 0.600, rec601_625_y_B = 0.060;
 
-// The D65 white point. Given in both Rec. 601 and 709.
-double d65_x = 0.3127, d65_y = 0.3290;
+// Color coordinates from Rec. 2020.
+static const double rec2020_x_R = 0.708, rec2020_x_G = 0.170, rec2020_x_B = 0.131;
+static const double rec2020_y_R = 0.292, rec2020_y_G = 0.797, rec2020_y_B = 0.046;
 
 ColorspaceConversionEffect::ColorspaceConversionEffect()
        : source_space(COLORSPACE_sRGB),
@@ -28,7 +33,7 @@ ColorspaceConversionEffect::ColorspaceConversionEffect()
        register_int("destination_space", (int *)&destination_space);
 }
 
-Matrix3d get_xyz_matrix(Colorspace space)
+Matrix3d ColorspaceConversionEffect::get_xyz_matrix(Colorspace space)
 {
        if (space == COLORSPACE_XYZ) {
                return Matrix3d::Identity();
@@ -50,6 +55,10 @@ Matrix3d get_xyz_matrix(Colorspace space)
                x_R = rec601_625_x_R; x_G = rec601_625_x_G; x_B = rec601_625_x_B;
                y_R = rec601_625_y_R; y_G = rec601_625_y_G; y_B = rec601_625_y_B;
                break;
+       case COLORSPACE_REC_2020:
+               x_R = rec2020_x_R; x_G = rec2020_x_G; x_B = rec2020_x_B;
+               y_R = rec2020_y_R; y_G = rec2020_y_G; y_B = rec2020_y_B;
+               break;
        default:
                assert(false);
        }
@@ -59,14 +68,6 @@ Matrix3d get_xyz_matrix(Colorspace space)
        double z_G = 1.0 - x_G - y_G;
        double z_B = 1.0 - x_B - y_B;
 
-       // Find the XYZ coordinates of D65 (white point for both Rec. 601 and 709),
-       // normalized so that Y=1.
-       Vector3d d65_XYZ(
-               d65_x / d65_y,
-               1.0,
-               (1.0 - d65_x - d65_y) / d65_y
-       );
-
        // We have, for each primary (example is with red):
        //
        //   X_R / (X_R + Y_R + Z_R) = x_R
@@ -75,8 +76,8 @@ Matrix3d get_xyz_matrix(Colorspace space)
        //
        // Some algebraic fiddling yields (unsurprisingly):
        //
-       //   X_R = (x_R / y_R) Y_R
-       //   Z_R = (z_R / y_R) Y_R
+       //   X_R = (x_R / y_R) Y_R   (so define k1 = x_R / y_R)
+       //   Z_R = (z_R / y_R) Y_R   (so define k4 = z_R / y_R)
        //
        // We also know that since RGB=(1,1,1) should give us the
        // D65 illuminant, we must have
@@ -85,8 +86,8 @@ Matrix3d get_xyz_matrix(Colorspace space)
        //   Y_R + Y_G + Y_B = D65_Y
        //   Z_R + Z_G + Z_B = D65_Z
        //
-       // But since we already know how to express Y and Z by
-       // some constant multiple of X, this reduces to
+       // But since we already know how to express X and Z by
+       // some constant multiple of Y, this reduces to
        //
        //   k1 Y_R + k2 Y_G + k3 Y_B = D65_X
        //      Y_R +    Y_G +    Y_B = D65_Y
@@ -107,6 +108,7 @@ Matrix3d get_xyz_matrix(Colorspace space)
        temp(2,1) = z_G / y_G;
        temp(2,2) = z_B / y_B;
 
+       Vector3d d65_XYZ(d65_X, d65_Y, d65_Z);
        Vector3d Y_RGB = temp.inverse() * d65_XYZ;
 
        // Now convert xyY -> XYZ.
@@ -127,7 +129,7 @@ Matrix3d get_xyz_matrix(Colorspace space)
        return m;
 }
 
-std::string ColorspaceConversionEffect::output_fragment_shader()
+string ColorspaceConversionEffect::output_fragment_shader()
 {
        // Create a matrix to convert from source space -> XYZ,
        // another matrix to convert from XYZ -> destination space,
@@ -142,3 +144,5 @@ std::string ColorspaceConversionEffect::output_fragment_shader()
        return output_glsl_mat3("PREFIX(conversion_matrix)", m) +
                read_file("colorspace_conversion_effect.frag");
 }
+
+}  // namespace movit