Don't dither alpha.

[movit] / util.h

diff --git a/util.h b/util.h
index b53bac76ce742367c618e47d1a4578d926bb8cd8..79b5987ae05a329691ba73f546390c7a0f364c11 100644 (file)
--- a/util.h
+++ b/util.h
@@ -1,15 +1,13 @@
-#ifndef _UTIL_H
-#define _UTIL_H 1
+#ifndef _MOVIT_UTIL_H
+#define _MOVIT_UTIL_H 1
 
 // Various utilities.
 
+#include <GL/glew.h>
 #include <stdio.h>
 #include <stdlib.h>
-
-#include <string>
 #include <Eigen/Core>
-
-#include "opengl.h"
+#include <string>
 
 #define BUFFER_OFFSET(i) ((char *)NULL + (i))
 
@@ -34,10 +32,26 @@ 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 %s:%d\n", err, __FILE__, __LINE__); exit(1); } }
 #endif
 
-#endif // !defined(_UTIL_H)
+// CHECK() is like assert(), but retains any side effects no matter the compilation mode.
+#ifdef NDEBUG
+#define CHECK(x) (void)(x)
+#else
+#define CHECK(x) do { bool ok = x; if (!ok) { fprintf(stderr, "%s:%d: %s: Assertion `%s' failed.\n", __FILE__, __LINE__, __PRETTY_FUNCTION__, #x); abort(); } } while (false)
+#endif
+
+#endif // !defined(_MOVIT_UTIL_H)