Metadata: add hostname to the available metadata options

Having the hostname allows us to identify which machine rendered which
frame in our render farm.

This simply uses the host's name, and doesn't do any DNS lookup of any
IP address of the machine. As such, it's only usable for identification
purposes, and not for reachability over a network.

Reviewers: sergey, brecht

Reviewed By: sergey

Differential Revision: https://developer.blender.org/D4047

4 files changed, 79 insertions, 2 deletions

diff --git a/release/scripts/startup/bl_ui/properties_output.py b/release/scripts/startup/bl_ui/properties_output.py
index 06119140245..d7b482c4dc5 100644
--- a/release/scripts/startup/bl_ui/properties_output.py
+++ b/release/scripts/startup/bl_ui/properties_output.py
@@ -205,6 +205,8 @@ class RENDER_PT_stamp(RenderOutputButtonsPanel, Panel):
         col.prop(rd, "use_stamp_frame_range", text="Frame Range")
         col = flow.column()
         col.prop(rd, "use_stamp_memory", text="Memory")
+        col = flow.column()
+        col.prop(rd, "use_stamp_hostname", text="Hostname")
 
         col = flow.column()
         col.prop(rd, "use_stamp_camera", text="Camera")
diff --git a/source/blender/blenkernel/intern/image.c b/source/blender/blenkernel/intern/image.c
index 67dca475650..3ba5f333b8d 100644
--- a/source/blender/blenkernel/intern/image.c
+++ b/source/blender/blenkernel/intern/image.c
@@ -35,6 +35,16 @@
 #ifndef WIN32
 #  include <unistd.h>
 #else
+#  ifndef NOGDI
+#    define NOGDI
+#  endif
+#  ifndef NOMINMAX
+#    define NOMINMAX
+#  endif
+#  ifndef WIN32_LEAN_AND_MEAN
+#    define WIN32_LEAN_AND_MEAN
+#  endif
+#  include <Windows.h> /* for GetComputerName function */
 #  include <io.h>
 #endif
 
@@ -1545,6 +1555,7 @@ typedef struct StampData {
 	char strip[STAMP_NAME_SIZE];
 	char rendertime[STAMP_NAME_SIZE];
 	char memory[STAMP_NAME_SIZE];
+	char hostname[512];
 
 	/* Custom fields are used to put extra meta information header from render
 	 * engine to the result image.
@@ -1556,6 +1567,32 @@ typedef struct StampData {
 #undef STAMP_NAME_SIZE
 
 /**
+ * Obtain the hostname from the system.
+ *
+ * This simply determines the host's name, and doesn't do any DNS lookup of any
+ * IP address of the machine. As such, it's only usable for identification
+ * purposes, and not for reachability over a network.
+ *
+ * @param buffer Character buffer to write the hostname into.
+ * @param bufsize Size of the character buffer, including trailing '\0'.
+ */
+static void get_hostname(char *buffer, size_t bufsize)
+{
+#ifndef WIN32
+	if (gethostname(buffer, bufsize-1) < 0) {
+		strncpy(buffer, "-unknown-", bufsize);
+	}
+	/* When gethostname() truncates, it doesn't guarantee the trailing \0. */
+	buffer[bufsize - 1] = '\0';
+#else
+	DWORD bufsize_inout = bufsize;
+	if(!GetComputerName(buffer, &bufsize_inout)) {
+		strncpy(buffer, "-unknown-", bufsize);
+	}
+#endif
+}
+
+/**
  * \param do_prefix: Include a label like "File ", "Date ", etc. in the stamp data strings.
  * \param use_dynamic: Also include data that can change on a per-frame basis.
  */
@@ -1704,6 +1741,16 @@ static void stampdata(Scene *scene, Object *camera, StampData *stamp_data, int d
 	else {
 		stamp_data->frame_range[0] = '\0';
 	}
+
+	if (scene->r.stamp & R_STAMP_HOSTNAME) {
+		char hostname[500];    /* sizeof(stamp_data->hostname) minus some bytes for a label. */
+		get_hostname(hostname, sizeof(hostname));
+		SNPRINTF(stamp_data->hostname, do_prefix ? "Hostname %s" : "%s", hostname);
+	}
+	else {
+		stamp_data->hostname[0] = '\0';
+	}
+
 }
 
 /* Will always add prefix. */
@@ -1783,6 +1830,12 @@ static void stampdata_from_template(StampData *stamp_data,
 	else {
 		stamp_data->memory[0] = '\0';
 	}
+	if (scene->r.stamp & R_STAMP_HOSTNAME) {
+		SNPRINTF(stamp_data->hostname, "Hostname %s", stamp_data_template->hostname);
+	}
+	else {
+		stamp_data->hostname[0] = '\0';
+	}
 }
 
 void BKE_image_stamp_buf(
@@ -1910,7 +1963,22 @@ void BKE_image_stamp_buf(
 		y -= BUFF_MARGIN_Y * 2;
 	}
 
-	/* Top left corner, below File, Date, Memory, Rendertime */
+	/* Top left corner, below File, Date, Rendertime, Memory */
+	if (TEXT_SIZE_CHECK(stamp_data.hostname, w, h)) {
+		y -= h;
+
+		/* and space for background. */
+		buf_rectfill_area(rect, rectf, width, height, scene->r.bg_stamp, display,
+		                  0, y - BUFF_MARGIN_Y, w + BUFF_MARGIN_X, y + h + BUFF_MARGIN_Y);
+
+		BLF_position(mono, x, y + y_ofs, 0.0);
+		BLF_draw_buffer(mono, stamp_data.hostname, BLF_DRAW_STR_DUMMY_MAX);
+
+		/* the extra pixel for background. */
+		y -= BUFF_MARGIN_Y * 2;
+	}
+
+	/* Top left corner, below File, Date, Memory, Rendertime, Hostname */
 	BLF_enable(mono, BLF_WORD_WRAP);
 	if (TEXT_SIZE_CHECK_WORD_WRAP(stamp_data.note, w, h)) {
 		y -= h;
@@ -2091,6 +2159,7 @@ void BKE_stamp_info_callback(void *data, struct StampData *stamp_data, StampCall
 	CALL(strip, "Strip");
 	CALL(rendertime, "RenderTime");
 	CALL(memory, "Memory");
+	CALL(hostname, "Hostname");
 
 	LISTBASE_FOREACH(StampDataCustomField *, custom_field, &stamp_data->custom_fields) {
 		if (noskip || custom_field->value[0]) {
diff --git a/source/blender/makesdna/DNA_scene_types.h b/source/blender/makesdna/DNA_scene_types.h
index b191c4c5a7c..c1853ce1745 100644
--- a/source/blender/makesdna/DNA_scene_types.h
+++ b/source/blender/makesdna/DNA_scene_types.h
@@ -1724,10 +1724,11 @@ enum {
 #define R_STAMP_MEMORY		0x2000
 #define R_STAMP_HIDE_LABELS	0x4000
 #define R_STAMP_FRAME_RANGE	0x8000
+#define R_STAMP_HOSTNAME	0x10000
 #define R_STAMP_ALL (R_STAMP_TIME|R_STAMP_FRAME|R_STAMP_DATE|R_STAMP_CAMERA|R_STAMP_SCENE| \
                      R_STAMP_NOTE|R_STAMP_MARKER|R_STAMP_FILENAME|R_STAMP_SEQSTRIP|        \
                      R_STAMP_RENDERTIME|R_STAMP_CAMERALENS|R_STAMP_MEMORY|                 \
-                     R_STAMP_HIDE_LABELS|R_STAMP_FRAME_RANGE)
+                     R_STAMP_HIDE_LABELS|R_STAMP_FRAME_RANGE|R_STAMP_HOSTNAME)
 
 /* RenderData.alphamode */
 #define R_ADDSKY		0
diff --git a/source/blender/makesrna/intern/rna_scene.c b/source/blender/makesrna/intern/rna_scene.c
index fe4d69b910f..4372f167c28 100644
--- a/source/blender/makesrna/intern/rna_scene.c
+++ b/source/blender/makesrna/intern/rna_scene.c
@@ -5189,6 +5189,11 @@ static void rna_def_scene_render_data(BlenderRNA *brna)
 	RNA_def_property_ui_text(prop, "Stamp Peak Memory", "Include the peak memory usage in image metadata");
 	RNA_def_property_update(prop, NC_SCENE | ND_RENDER_OPTIONS, NULL);
 
+	prop = RNA_def_property(srna, "use_stamp_hostname", PROP_BOOLEAN, PROP_NONE);
+	RNA_def_property_boolean_sdna(prop, NULL, "stamp", R_STAMP_HOSTNAME);
+	RNA_def_property_ui_text(prop, "Stamp Hostname", "Include the hostnamename of the machine running Blender");
+	RNA_def_property_update(prop, NC_SCENE | ND_RENDER_OPTIONS, NULL);
+
 	prop = RNA_def_property(srna, "stamp_font_size", PROP_INT, PROP_NONE);
 	RNA_def_property_int_sdna(prop, NULL, "stamp_font_id");
 	RNA_def_property_range(prop, 8, 64);