Make combine_two_pixels() handle the fact that the GPU has limited subpixel interpola...

[movit] / util.h

diff --git a/util.h b/util.h
index da2bf50b1283a1060020c47f33b2e20c50bd65fc..082d1146a7f4c86c2d935ffeaa62307f6575b884 100644 (file)
--- a/util.h
+++ b/util.h
@@ -7,6 +7,7 @@
 #include <stdlib.h>
 
 #include <string>
+#include <Eigen/Core>
 
 #include "opengl.h"
 
@@ -15,8 +16,9 @@
 // Converts a HSV color to RGB. Assumes h in [0, 2pi> or [-pi, pi>
 void hsv2rgb(float h, float s, float v, float *r, float *g, float *b);
 
-// Column major (same as OpenGL).
-typedef double Matrix3x3[9];
+// Converts a HSV color to RGB, but keeps luminance constant
+// (ie. color luminance is as if S=0).
+void hsv2rgb_normalized(float h, float s, float v, float *r, float *g, float *b);
 
 // Read a file from disk and return its contents.
 // Dies if the file does not exist.
@@ -26,17 +28,20 @@ std::string read_file(const std::string &filename);
 // and return the object number.
 GLuint compile_shader(const std::string &shader_src, GLenum type);
 
-// Compute a * b.
-void multiply_3x3_matrices(const Matrix3x3 a, const Matrix3x3 b, Matrix3x3 result);
-
-// Compute M * [x0 x1 x2]'.
-void multiply_3x3_matrix_float3(const Matrix3x3 M, float x0, float x1, float x2, float *y0, float *y1, float *y2);
-
-// Compute m^-1. Result is undefined if the matrix is singular or near-singular.
-void invert_3x3_matrix(const Matrix3x3 m, Matrix3x3 result);
-
 // Print a 3x3 matrix to standard output. Useful for debugging.
-void print_3x3_matrix(const Matrix3x3 m);
+void print_3x3_matrix(const Eigen::Matrix3d &m);
+
+// Output a GLSL 3x3 matrix declaration.
+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].
+//
+// 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()