--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/libmlk-core/core/trace.h	Sat Nov 28 22:37:30 2020 +0100
@@ -0,0 +1,69 @@
+/*
+ * trace.h -- non-fatal message logs
+ *
+ * Copyright (c) 2020 David Demelier <markand@malikania.fr>
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#ifndef MOLKO_CORE_TRACE_H
+#define MOLKO_CORE_TRACE_H
+
+/**
+ * \file trace.h
+ * \brief Non-fatal message logs.
+ *
+ * The purpose of this module is to provide a feedback from the code when there
+ * are non-fatal programming error or unexpected results. In contrast to the
+ * \ref debug.h module this one is always activated no manner if the build
+ * is in Debug or Release.
+ *
+ * For example, having an animation with a delay of 0 is not a technical issue
+ * but is probably not what the use wants. Thus, a trace warning may be
+ * generated in that way.
+ */
+
+#include <stdarg.h>
+
+/**
+ * \brief Maximum length for a trace log.
+ */
+#define TRACE_LINE_MAX (1024)
+
+/**
+ * \brief Global trace handler.
+ *
+ * The default one use a simple printf on the standard output.
+ */
+extern void (*trace_handler)(const char *);
+
+/**
+ * Log some information.
+ *
+ * \pre fmt != NULL
+ * \param fmt the printf(3) format string
+ */
+void
+tracef(const char *fmt, ...);
+
+/**
+ * Similar to \ref tracef with a va_list arguments pointer.
+ *
+ * \pre fmt != NULL
+ * \param fmt the printf(3) format string
+ * \param ap the argument list
+ */
+void
+vtracef(const char *fmt, va_list ap);
+
+#endif /* !MOLKO_CORE_TRACE_H */