X-Git-Url: https://git.sesse.net/?p=movit;a=blobdiff_plain;f=util.h;h=209a7dca42958a9313ed3f5d441267d9000e187a;hp=dcb84a0cbf7e259b8717c9861d2cc066d386a032;hb=3d1f6c11c53cd9d3d5c1fb60f4accf050b7f135e;hpb=a5f301c52c22bc29ade2a2b39f4ff3e4b10310a7

diff --git a/util.h b/util.h
index dcb84a0..209a7dc 100644
--- a/util.h
+++ b/util.h
@@ -1,25 +1,38 @@
 #ifndef _UTIL_H
 #define _UTIL_H 1
 
+// Various utilities.
+
 #include <stdio.h>
 #include <stdlib.h>
 
 #include <string>
 
-#include <GL/gl.h>
+#include "opengl.h"
 
 #define BUFFER_OFFSET(i) ((char *)NULL + (i))
 
-// assumes h in [0, 2pi> or [-pi, pi>
+// 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];
 
+// 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);
+
+// Compute a * b.
 void multiply_3x3_matrices(const Matrix3x3 a, const Matrix3x3 b, Matrix3x3 result);
+
+// 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);
 
 #ifdef NDEBUG