--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/libui/ui/debug.h	Thu Oct 15 10:32:18 2020 +0200
@@ -0,0 +1,131 @@
+/*
+ * debug.h -- debugging interfaces
+ *
+ * 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_DEBUG_H
+#define MOLKO_DEBUG_H
+
+/**
+ * \file debug.h
+ * \brief Debugging interfaces.
+ *
+ * This module provides functions to draw debugging information within the game
+ * window. It is mostly used for information only when state of the game is
+ * better inspected via direct window information rather than writing in the
+ * console.
+ *
+ * Predefined core states may print debugging information if
+ * debug_options.enabled variable is set to true. However, you need to specify
+ * the font to use in order to work.
+ *
+ * Each call to \ref debug_printf or \ref debug_vprintf automatically adjust
+ * next coordinate for rendering the text. As such, user may simply print
+ * several lines of text without having to deal with that manually.
+ *
+ * Example, activate global debugging.
+ *
+ * \code
+ * struct font *f = font_openf("foo.ttf", 10);
+ *
+ * if (!f)
+ * 	error_fatal();
+ *
+ * debug_options.default_font = f;
+ * debug_options.enabled = true;
+ * \endcode
+ *
+ * Example, print debugging information manually.
+ *
+ * \code
+ * struct debug_report report = {
+ * 	.color = 0x00ff00ff,
+ * 	.font = myfont          // Optional if debug_options.default_font is set.
+ * };
+ *
+ * debug_printf("current position: %d, %d\n", x, y);
+ * \endcode
+ */
+
+#include <stdbool.h>
+#include <stdarg.h>
+
+#include <core/font.h>
+
+/**
+ * Maximum content length per report.
+ */
+#define DEBUG_LINE_MAX 1024
+
+struct theme;
+
+/**
+ * \brief Debugging options.
+ *
+ * Fill this structure with appropriate values to change debugging behavior
+ * in core API.
+ */
+struct debug_options {
+	bool enable;                    /*!< (+) Enable core API debugging. */
+};
+
+/**
+ * \brief Debug context.
+ *
+ * Use this structure each time you need to print one or more messages.
+ */
+struct debug_report {
+	struct theme *theme;            /*!< (+&?) Theme to use. */
+	unsigned long color;            /*!< (+) Font foreground color to use. */
+	unsigned int count;             /*!< (-) Number of messages already printed. */
+};
+
+/**
+ * Global debugging options.
+ */
+extern struct debug_options debug_options;
+
+/**
+ * Convenient macro to initialize \ref debug_report with default values.
+ */
+#define DEBUG_INIT_DEFAULTS {                   \
+        .font = debug_options.default_font,     \
+        .color = debug_options.default_color,   \
+        .style = debug_options.default_style    \
+}
+
+/**
+ * Print debugging information into the screen.
+ *
+ * \pre report != NULL
+ * \pre fmt != NULL
+ * \param report the reporting context
+ * \param fmt the printf(3) format string
+ * \note The message length must not exceed DEBUG_LINE_MAX, otherwise its
+ *       result is truncated.
+ */
+void
+debug_printf(struct debug_report *report, const char *fmt, ...);
+
+/**
+ * Similar to \ref debug_printf but with a va_list object.
+ *
+ * \see \ref debug_printf
+ */
+void
+debug_vprintf(struct debug_report *report, const char *fmt, va_list ap);
+
+#endif /* !MOLKO_DEBUG_H */