fix [#27221] stamp text bug in lower lines

4 files changed, 16 insertions, 8 deletions

diff --git a/source/blender/blenfont/BLF_api.h b/source/blender/blenfont/BLF_api.h
index 93b9cbc0bdf..44d3cf2c61b 100644
--- a/source/blender/blenfont/BLF_api.h
+++ b/source/blender/blenfont/BLF_api.h
@@ -157,7 +157,7 @@ void BLF_shadow_offset(int fontid, int x, int y);
  *
  *	BLF_buffer(NULL, NULL, 0, 0, 0);
  */
-void BLF_buffer(int fontid, float *fbuf, unsigned char *cbuf, unsigned int w, unsigned int h, int nch);
+void BLF_buffer(int fontid, float *fbuf, unsigned char *cbuf, int w, int h, int nch);
 
 /*
  * Set the color to be used for text.
diff --git a/source/blender/blenfont/intern/blf.c b/source/blender/blenfont/intern/blf.c
index 930f55a48fa..5db71948024 100644
--- a/source/blender/blenfont/intern/blf.c
+++ b/source/blender/blenfont/intern/blf.c
@@ -657,7 +657,7 @@ void BLF_shadow_offset(int fontid, int x, int y)
 	}
 }
 
-void BLF_buffer(int fontid, float *fbuf, unsigned char *cbuf, unsigned int w, unsigned int h, int nch)
+void BLF_buffer(int fontid, float *fbuf, unsigned char *cbuf, int w, int h, int nch)
 {
 	FontBLF *font;
 
diff --git a/source/blender/blenfont/intern/blf_font.c b/source/blender/blenfont/intern/blf_font.c
index 80d0a48954a..708b3708ab7 100644
--- a/source/blender/blenfont/intern/blf_font.c
+++ b/source/blender/blenfont/intern/blf_font.c
@@ -218,7 +218,7 @@ void blf_font_buffer(FontBLF *font, const char *str)
 	FT_Vector delta;
 	FT_UInt glyph_index;
 	float a, *fbuf;
-	int pen_x, y, x, yb;
+	int pen_x, y, x;
 	int i, has_kerning, st, chx, chy;
 
 	if (!font->glyph_cache || (!font->b_fbuf && !font->b_cbuf))
@@ -276,13 +276,20 @@ void blf_font_buffer(FontBLF *font, const char *str)
 			/* dont draw beyond the buffer bounds */
 			int width_clip= g->width;
 			int height_clip= g->height;
+			int yb_start= g->pitch < 0 ? 0 : g->height-1;
 
 			if (width_clip + chx > font->bw)	width_clip  -= chx + width_clip - font->bw;
 			if (height_clip + pen_y > font->bh) height_clip -= pen_y + height_clip - font->bh;
-
-			yb= g->pitch < 0 ? 0 : g->height-1;
 			
+			/* drawing below the image? */
+			if(pen_y < 0) {
+				yb_start += (g->pitch < 0) ? -pen_y : pen_y;
+				height_clip += pen_y;
+				pen_y= 0;
+			}
+
 			if (font->b_fbuf) {
+				int yb= yb_start;
 				for (y=(chy >= 0 ? 0:-chy); y < height_clip; y++) {
 					for (x=(chx >= 0 ? 0:-chx); x < width_clip; x++) {
 						
@@ -311,6 +318,7 @@ void blf_font_buffer(FontBLF *font, const char *str)
 			}
 
 			if (font->b_cbuf) {
+				int yb= yb_start;
 				for (y= 0; y < height_clip; y++) {
 					for (x= 0; x < width_clip; x++) {
 						a= *(g->bitmap + x + (yb * g->pitch)) / 255.0f;
diff --git a/source/blender/blenfont/intern/blf_internal_types.h b/source/blender/blenfont/intern/blf_internal_types.h
index deb13006eaf..c4e192626e8 100644
--- a/source/blender/blenfont/intern/blf_internal_types.h
+++ b/source/blender/blenfont/intern/blf_internal_types.h
@@ -200,9 +200,9 @@ typedef struct FontBLF {
 	/* the same but unsigned char */
 	unsigned char *b_cbuf;
 
-	/* buffer size. */
-	unsigned int bw;
-	unsigned int bh;
+	/* buffer size, keep signed so comparisons with negative values work */
+	int bw;
+	int bh;
 
 	/* number of channels. */
 	int bch;