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D1002 by @plasmasolutions, with own refactoring.

Note, needed to do a bad-level call here (IMB -> BLF)
Also can't use the BLF API directly because its not thread-safe.
So keep the function isolated (blf_thumbs.c).

4 files changed, 94 insertions, 7 deletions

diff --git a/source/blender/imbuf/CMakeLists.txt b/source/blender/imbuf/CMakeLists.txt
index eadedbd5e00..bdd8230a6ff 100644
--- a/source/blender/imbuf/CMakeLists.txt
+++ b/source/blender/imbuf/CMakeLists.txt
@@ -66,6 +66,7 @@ set(SRC
 	intern/targa.c
 	intern/thumbs.c
 	intern/thumbs_blend.c
+	intern/thumbs_font.c
 	intern/util.c
 	intern/writeimage.c
 
diff --git a/source/blender/imbuf/IMB_thumbs.h b/source/blender/imbuf/IMB_thumbs.h
index bea531c1442..404052f2e8e 100644
--- a/source/blender/imbuf/IMB_thumbs.h
+++ b/source/blender/imbuf/IMB_thumbs.h
@@ -54,7 +54,8 @@ typedef enum ThumbSize {
 typedef enum ThumbSource {
 	THB_SOURCE_IMAGE,
 	THB_SOURCE_MOVIE,
-	THB_SOURCE_BLEND
+	THB_SOURCE_BLEND,
+	THB_SOURCE_FONT,
 } ThumbSource;
 
 /* don't generate thumbs for images bigger then this (100mb) */
@@ -79,6 +80,11 @@ void IMB_thumb_makedirs(void);
 ImBuf *IMB_thumb_load_blend(const char *path);
 void   IMB_thumb_overlay_blend(unsigned int *thumb, int width, int height, float aspect);
 
+/* special function for previewing fonts */
+ImBuf *IMB_thumb_load_font(
+        const char *filename,
+        unsigned int x, unsigned int y);
+
 #ifdef __cplusplus
 }
 #endif /* __cplusplus */
diff --git a/source/blender/imbuf/intern/thumbs.c b/source/blender/imbuf/intern/thumbs.c
index e88cbef206a..78f47b7bc34 100644
--- a/source/blender/imbuf/intern/thumbs.c
+++ b/source/blender/imbuf/intern/thumbs.c
@@ -330,15 +330,22 @@ ImBuf *IMB_thumb_create(const char *path, ThumbSize size, ThumbSource source, Im
 			if (!img) return NULL;
 		}
 		else {
-			if (THB_SOURCE_IMAGE == source || THB_SOURCE_BLEND == source) {
+			if (ELEM(source, THB_SOURCE_IMAGE, THB_SOURCE_BLEND, THB_SOURCE_FONT)) {
 				
 				/* only load if we didnt give an image */
 				if (img == NULL) {
-					if (THB_SOURCE_BLEND == source) {
-						img = IMB_thumb_load_blend(path);
-					}
-					else {
-						img = IMB_loadiffname(path, IB_rect | IB_metadata | IB_thumbnail, NULL);
+					switch (source) {
+						case THB_SOURCE_IMAGE:
+							img = IMB_loadiffname(path, IB_rect | IB_metadata, NULL);
+							break;
+						case THB_SOURCE_BLEND:
+							img = IMB_thumb_load_blend(path);
+							break;
+						case THB_SOURCE_FONT:
+							img = IMB_thumb_load_font(path, tsize, tsize);
+							break;
+						default:
+							BLI_assert(0); /* This should never happen */
 					}
 				}
 
diff --git a/source/blender/imbuf/intern/thumbs_font.c b/source/blender/imbuf/intern/thumbs_font.c
new file mode 100644
index 00000000000..c8982318d80
--- /dev/null
+++ b/source/blender/imbuf/intern/thumbs_font.c
@@ -0,0 +1,73 @@
+/*
+ * ***** 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.
+ *
+ * Contributor(s): Thomas Beck.
+ *
+ * ***** END GPL LICENSE BLOCK *****
+ */
+
+/** \file blender/imbuf/intern/thumbs_font.c
+ *  \ingroup imbuf
+ */
+
+#include "BLI_utildefines.h"
+
+#include "IMB_imbuf_types.h"
+#include "IMB_imbuf.h"
+
+#include "IMB_thumbs.h"
+
+
+/* XXX, bad level call */
+#include "../../blenfont/BLF_api.h"
+
+
+struct ImBuf *IMB_thumb_load_font(const char *filename, unsigned int x, unsigned int y)
+{
+	const int font_size = y / 4;
+	const char *thumb_str[] = {
+	    "AaBbCc",
+
+	    "The quick",
+	    "brown fox",
+	    "jumps over",
+	    "the lazy dog",
+	};
+
+	struct ImBuf *ibuf;
+	float font_color[4];
+
+	/* create a white image (theme color is used for drawing) */
+	font_color[0] = font_color[1] = font_color[2] = 1.0f;
+
+	/* fill with zero alpha */
+	font_color[3] = 0.0f;
+
+	ibuf = IMB_allocImBuf(x, y, 32, IB_rect | IB_metadata);
+	IMB_rectfill(ibuf, font_color);
+
+	/* draw with full alpha */
+	font_color[3] = 1.0f;
+
+	BLF_thumb_preview(
+	        filename, thumb_str, ARRAY_SIZE(thumb_str),
+	        font_color, font_size,
+	        (unsigned char *)ibuf->rect, ibuf->x, ibuf->y, ibuf->channels);
+
+	return ibuf;
+}
+