UI: Refactor timecode functions into BLI_timecode

- deduplicate timecode_simple_string from image.c
- replace V2D_UNIT_SECONDSSEQ with V2D_UNIT_SECONDS
- avoid possible buffer overflow bugs (sprintf -> BLI_snprintf)
- remove option not to use timecode and split into 2 functions

Patch D227 by Andrew Buttery with own refactoring.

1 files changed, 218 insertions, 0 deletions

diff --git a/source/blender/blenlib/intern/timecode.c b/source/blender/blenlib/intern/timecode.c
new file mode 100644
index 00000000000..cd703741831
--- /dev/null
+++ b/source/blender/blenlib/intern/timecode.c
@@ -0,0 +1,218 @@
+/*
+ * ***** BEGIN GPL LICENSE BLOCK *****
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version. 
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ *
+ * The Original Code is Copyright (C) 2008 Blender Foundation.
+ * All rights reserved.
+ *
+ * 
+ * Contributor(s): Joshua Leung
+ *
+ * ***** END GPL LICENSE BLOCK *****
+ */
+
+/** \file blender/blendlib/intern/timecode.c
+ *  \ingroup blendlib
+ *
+ * Time-Code string formatting
+ */
+
+#include <stdio.h>
+
+
+#include "BLI_string.h"
+#include "BLI_math.h"
+
+#include "BLI_timecode.h"  /* own include */
+
+#include "BLI_strict_flags.h"
+
+#include "DNA_userdef_types.h"  /* for eTimecodeStyles only */
+
+
+/**
+ * Generate timecode/frame number string and store in \a str
+ *
+ * \param str  destination string
+ * \param maxncpy  maximum number of characters to copy ``sizeof(str)``
+ * \param power  special setting for #View2D grid drawing,
+ *        used to specify how detailed we need to be
+ * \param time_seconds  time total time in seconds
+ * \param fps  frames per second, typically from the #FPS macro
+ * \param timecode_style  enum from eTimecodeStyles
+ * \return length of \a str
+ */
+
+size_t BLI_timecode_string_from_time(
+        char *str, const size_t maxncpy, const int power, const float time_seconds,
+        const double fps, const short timecode_style)
+{
+	int hours = 0, minutes = 0, seconds = 0, frames = 0;
+	float time = time_seconds;
+	char neg[2] = {'\0'};
+	size_t rlen;
+
+	/* get cframes */
+	if (time < 0) {
+		/* correction for negative cfraues */
+		neg[0] = '-';
+		time = -time;
+	}
+
+	if (time >= 3600) {
+		/* hours */
+		/* XXX should we only display a single digit for hours since clips are
+		 *     VERY UNLIKELY to be more than 1-2 hours max? However, that would
+		 *     go against conventions...
+		 */
+		hours = (int)time / 3600;
+		time = (float)fmod(time, 3600);
+	}
+
+	if (time >= 60) {
+		/* minutes */
+		minutes = (int)time / 60;
+		time = (float)fmod(time, 60);
+	}
+
+	if (power <= 0) {
+		/* seconds + frames
+		 * Frames are derived from 'fraction' of second. We need to perform some additional rounding
+		 * to cope with 'half' frames, etc., which should be fine in most cases
+		 */
+		seconds = (int)time;
+		frames = iroundf((float)(((double)time - (double)seconds) * fps));
+	}
+	else {
+		/* seconds (with pixel offset rounding) */
+		seconds = iroundf(time);
+	}
+
+	switch (timecode_style) {
+		case USER_TIMECODE_MINIMAL:
+		{
+			/* - In general, minutes and seconds should be shown, as most clips will be
+			 *   within this length. Hours will only be included if relevant.
+			 * - Only show frames when zoomed in enough for them to be relevant
+			 *   (using separator of '+' for frames).
+			 *   When showing frames, use slightly different display to avoid confusion with mm:ss format
+			 */
+			if (power <= 0) {
+				/* include "frames" in display */
+				if (hours) {
+					rlen = BLI_snprintf(str, maxncpy, "%s%02d:%02d:%02d+%02d", neg, hours, minutes, seconds, frames);
+				}
+				else if (minutes) {
+					rlen = BLI_snprintf(str, maxncpy, "%s%02d:%02d+%02d", neg, minutes, seconds, frames);
+				}
+				else {
+					rlen = BLI_snprintf(str, maxncpy, "%s%d+%02d", neg, seconds, frames);
+				}
+			}
+			else {
+				/* don't include 'frames' in display */
+				if (hours) {
+					rlen = BLI_snprintf(str, maxncpy, "%s%02d:%02d:%02d", neg, hours, minutes, seconds);
+				}
+				else {
+					rlen = BLI_snprintf(str, maxncpy, "%s%02d:%02d", neg, minutes, seconds);
+				}
+			}
+			break;
+		}
+		case USER_TIMECODE_SMPTE_MSF:
+		{
+			/* reduced SMPTE format that always shows minutes, seconds, frames. Hours only shown as needed. */
+			if (hours) {
+				rlen = BLI_snprintf(str, maxncpy, "%s%02d:%02d:%02d:%02d", neg, hours, minutes, seconds, frames);
+			}
+			else {
+				rlen = BLI_snprintf(str, maxncpy, "%s%02d:%02d:%02d", neg, minutes, seconds, frames);
+			}
+			break;
+		}
+		case USER_TIMECODE_MILLISECONDS:
+		{
+			/* reduced SMPTE. Instead of frames, milliseconds are shown */
+
+			/* precision of decimal part */
+			const int ms_dp = (power <= 0) ? (1 - power) : 1;
+
+			/* to get 2 digit whole-number part for seconds display
+			 * (i.e. 3 is for 2 digits + radix, on top of full length) */
+			const int s_pad = ms_dp + 3;
+
+			if (hours) {
+				rlen = BLI_snprintf(str, maxncpy, "%s%02d:%02d:%0*.*f", neg, hours, minutes, s_pad, ms_dp, time);
+			}
+			else {
+				rlen = BLI_snprintf(str, maxncpy, "%s%02d:%0*.*f", neg, minutes, s_pad,  ms_dp, time);
+			}
+			break;
+		}
+		case USER_TIMECODE_SECONDS_ONLY:
+		{
+			/* only show the original seconds display */
+			/* round to whole numbers if power is >= 1 (i.e. scale is coarse) */
+			if (power <= 0) {
+				rlen = BLI_snprintf(str, maxncpy, "%.*f", 1 - power, time_seconds);
+			}
+			else {
+				rlen = BLI_snprintf(str, maxncpy, "%d", iroundf(time_seconds));
+			}
+			break;
+		}
+		case USER_TIMECODE_SMPTE_FULL:
+		default:
+		{
+			/* full SMPTE format */
+			rlen = BLI_snprintf(str, maxncpy, "%s%02d:%02d:%02d:%02d", neg, hours, minutes, seconds, frames);
+			break;
+		}
+	}
+
+	return rlen;
+}
+
+
+/**
+ * Generate time string and store in \a str
+ *
+ * \param str  destination string
+ * \param maxncpy  maximum number of characters to copy ``sizeof(str)``
+ * \param power  special setting for #View2D grid drawing,
+ *        used to specify how detailed we need to be
+ * \param time_seconds  time total time in seconds
+ * \param seconds  time in seconds.
+ * \return length of \a str
+ *
+ * \note in some cases this is used to print non-seconds values.
+ */
+size_t BLI_timecode_string_from_time_simple(
+        char *str, const size_t maxncpy, const int power, const float time_seconds)
+{
+	size_t rlen;
+
+	/* round to whole numbers if power is >= 1 (i.e. scale is coarse) */
+	if (power <= 0) {
+		rlen = BLI_snprintf(str, maxncpy, "%.*f", 1 - power, time_seconds);
+	}
+	else {
+		rlen = BLI_snprintf(str, maxncpy, "%d", iroundf(time_seconds));
+	}
+
+	return rlen;
+}