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 3957b863c1ec8a635ab720f88a263320d0c54919..082d1146a7f4c86c2d935ffeaa62307f6575b884 100644 (file)
--- a/util.h
+++ b/util.h
@@ -1,20 +1,52 @@
 #ifndef _UTIL_H
 #define _UTIL_H 1
 
+// Various utilities.
+
 #include <stdio.h>
 #include <stdlib.h>
 
 #include <string>
+#include <Eigen/Core>
+
+#include "opengl.h"
 
-// assumes h in [0, 2pi> or [-pi, pi>
+#define BUFFER_OFFSET(i) ((char *)NULL + (i))
+
+// 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);
 
+// 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.
 std::string read_file(const std::string &filename);
 
+// Compile the given GLSL shader (typically a vertex or fragment shader)
+// and return the object number.
+GLuint compile_shader(const std::string &shader_src, GLenum type);
+
+// Print a 3x3 matrix to standard output. Useful for debugging.
+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()
 #else
-#define check_error() { int err = glGetError(); if (err != GL_NO_ERROR) { printf("GL error 0x%x at line %d\n", err, __LINE__); exit(1); } }
+#define check_error() { int err = glGetError(); if (err != GL_NO_ERROR) { printf("GL error 0x%x at %s:%d\n", err, __FILE__, __LINE__); exit(1); } }
 #endif
 
 #endif // !defined(_UTIL_H)