X-Git-Url: https://git.sesse.net/?p=movit;a=blobdiff_plain;f=util.h;h=082d1146a7f4c86c2d935ffeaa62307f6575b884;hp=414c20890027f8762e4a64a4fa2acd3d7428def1;hb=34f5f331bd3b643949ccbb0c3488af2823634d59;hpb=2463f8abd9662e08438e23e5c0d0f958ea4fe54e;ds=sidebyside

diff --git a/util.h b/util.h
index 414c208..082d114 100644
--- a/util.h
+++ b/util.h
@@ -36,7 +36,12 @@ std::string output_glsl_mat3(const std::string &name, const Eigen::Matrix3d &m);
 
 // Calculate where to sample, and with what weight, if one wants to use
 // the GPU's bilinear hardware to sample w1 * x[0] + w2 * x[1].
-void combine_two_samples(float w1, float w2, float *offset, float *total_weight);
+//
+// Note that since the GPU might have limited precision in its linear
+// interpolation, the effective weights might be different from the ones you
+// asked for. sum_sq_error, if not NULL, will contain the sum of the
+// (estimated) squared errors of the two weights.
+void combine_two_samples(float w1, float w2, float *offset, float *total_weight, float *sum_sq_error);
 
 #ifdef NDEBUG
 #define check_error()