Fix UI glitches drawing text at different sizes

Font height was ignoring DPI in some cases (camera-name & eyedropper).

source/blender/editors/include/UI_interface.h

@@ -981,8 +981,13 @@ void UI_fontstyle_draw_ex(
 void UI_fontstyle_draw(const struct uiFontStyle *fs, const struct rcti *rect, const char *str);
 void UI_fontstyle_draw_rotated(const struct uiFontStyle *fs, const struct rcti *rect, const char *str);
 void UI_fontstyle_draw_simple(const struct uiFontStyle *fs, float x, float y, const char *str);
+void UI_fontstyle_draw_simple_backdrop(
+        const uiFontStyle *fs, float x, float y, const char *str,
+        const unsigned char fg[4], const unsigned char bg[4]);
 
 int UI_fontstyle_string_width(const struct uiFontStyle *fs, const char *str);
+int UI_fontstyle_height_max(const struct uiFontStyle *fs);
+
 void UI_draw_icon_tri(float x, float y, char dir);
 
 uiStyle *UI_style_get(void);		/* use for fonts etc */

source/blender/editors/interface/interface_eyedropper.c

@@ -77,7 +77,9 @@ static void eyedropper_draw_cursor_text(const struct bContext *C, ARegion *ar, c
 	wmWindow *win = CTX_wm_window(C);
 	int x = win->eventstate->x;
 	int y = win->eventstate->y;
-	int width;
+	const unsigned char fg[4] = {255, 255, 255, 255};
+	const unsigned char bg[4] = {0, 0, 0, 50};
+
 
 	if ((name[0] == '\0') ||
 	    (BLI_rcti_isect_pt(&ar->winrct, x, y) == false))
@@ -85,19 +87,12 @@ static void eyedropper_draw_cursor_text(const struct bContext *C, ARegion *ar, c
 		return;
 	}
 
-	width = UI_fontstyle_string_width(fstyle, name);
 	x = x - ar->winrct.xmin;
 	y = y - ar->winrct.ymin;
 
-	y += 20;
+	y += U.widget_unit;
 
-	glColor4ub(0, 0, 0, 50);
-
-	UI_draw_roundbox_corner_set(UI_CNR_ALL | UI_RB_ALPHA);
-	UI_draw_roundbox(x, y, x + width + 8, y + 15, 4);
-
-	glColor4ub(255, 255, 255, 255);
-	UI_fontstyle_draw_simple(fstyle, x + 4, y + 4, name);
+	UI_fontstyle_draw_simple_backdrop(fstyle, x, y, name, fg, bg);
 }
 
 /** \} */

source/blender/editors/interface/interface_style.c

@@ -45,6 +45,7 @@
 
 #include "BKE_global.h"
 
+#include "BIF_gl.h"
 
 #include "BLF_api.h"
 #ifdef WITH_INTERNATIONAL
@@ -277,6 +278,47 @@ void UI_fontstyle_draw_simple(const uiFontStyle *fs, float x, float y, const cha
 		BLF_disable(fs->uifont_id, BLF_KERNING_DEFAULT);
 }
 
+/**
+ * Same as #UI_fontstyle_draw but draw a colored backdrop.
+ */
+void UI_fontstyle_draw_simple_backdrop(
+        const uiFontStyle *fs, float x, float y, const char *str,
+        const unsigned char fg[4], const unsigned char bg[4])
+{
+	if (fs->kerning == 1)
+		BLF_enable(fs->uifont_id, BLF_KERNING_DEFAULT);
+
+	UI_fontstyle_set(fs);
+
+	{
+		const float width = BLF_width(fs->uifont_id, str, BLF_DRAW_STR_DUMMY_MAX);
+		const float height = BLF_height_max(fs->uifont_id);
+		const float decent = BLF_descender(fs->uifont_id);
+		const float margin = height / 4.0f;
+
+		/* backdrop */
+		glColor4ubv(bg);
+
+		UI_draw_roundbox_corner_set(UI_CNR_ALL | UI_RB_ALPHA);
+		UI_draw_roundbox(
+		        x - margin,
+		        (y + decent) - margin,
+		        x + width + margin,
+		        (y + decent) + height + margin,
+		        margin);
+
+		glColor4ubv(fg);
+	}
+
+
+	BLF_position(fs->uifont_id, x, y, 0.0f);
+	BLF_draw(fs->uifont_id, str, BLF_DRAW_STR_DUMMY_MAX);
+
+	if (fs->kerning == 1)
+		BLF_disable(fs->uifont_id, BLF_KERNING_DEFAULT);
+}
+
+
 /* ************** helpers ************************ */
 /* XXX: read a style configure */
 uiStyle *UI_style_get(void)
@@ -329,6 +371,13 @@ int UI_fontstyle_string_width(const uiFontStyle *fs, const char *str)
 	return width;
 }
 
+int UI_fontstyle_height_max(const uiFontStyle *fs)
+{
+	UI_fontstyle_set(fs);
+	return BLF_height_max(fs->uifont_id);
+}
+
+
 /* ************** init exit ************************ */
 
 /* called on each startup.blend read */

source/blender/editors/space_view3d/view3d_draw.c

@@ -1281,8 +1281,9 @@ static void drawviewborder(Scene *scene, ARegion *ar, View3D *v3d)
 	/* camera name - draw in highlighted text color */
 	if (ca && (ca->flag & CAM_SHOWNAME)) {
 		UI_ThemeColor(TH_TEXT_HI);
-		BLF_draw_default(x1i, y1i - 15, 0.0f, v3d->camera->id.name + 2, sizeof(v3d->camera->id.name) - 2);
-		UI_ThemeColor(TH_WIRE);
+		BLF_draw_default(
+		        x1i, y1i - (0.7f * U.widget_unit), 0.0f,
+		        v3d->camera->id.name + 2, sizeof(v3d->camera->id.name) - 2);
 	}
 }
 

source/blender/windowmanager/intern/wm_dragdrop.c

@@ -268,16 +268,10 @@ void wm_drags_check_ops(bContext *C, wmEvent *event)
 static void wm_drop_operator_draw(const char *name, int x, int y)
 {
 	const uiFontStyle *fstyle = UI_FSTYLE_WIDGET;
-	int width = UI_fontstyle_string_width(fstyle, name);
-	int padding = 4 * UI_DPI_FAC;
-	
-	glColor4ub(0, 0, 0, 50);
-	
-	UI_draw_roundbox_corner_set(UI_CNR_ALL | UI_RB_ALPHA);
-	UI_draw_roundbox(x, y, x + width + 2 * padding, y + 4 * padding, padding);
-	
-	glColor4ub(255, 255, 255, 255);
-	UI_fontstyle_draw_simple(fstyle, x + padding, y + padding, name);
+	const unsigned char fg[4] = {255, 255, 255, 255};
+	const unsigned char bg[4] = {0, 0, 0, 50};
+
+	UI_fontstyle_draw_simple_backdrop(fstyle, x, y, name, fg, bg);
 }
 
 static const char *wm_drag_name(wmDrag *drag)
@@ -327,7 +321,7 @@ void wm_drags_draw(bContext *C, wmWindow *win, rcti *rect)
 	/* XXX todo, multiline drag draws... but maybe not, more types mixed wont work well */
 	glEnable(GL_BLEND);
 	for (drag = wm->drags.first; drag; drag = drag->next) {
-		int iconsize = 16 * UI_DPI_FAC; /* assumed to be 16 pixels */
+		int iconsize = UI_DPI_ICON_SIZE;
 		int padding = 4 * UI_DPI_FAC;
 		
 		/* image or icon */
@@ -384,10 +378,12 @@ void wm_drags_draw(bContext *C, wmWindow *win, rcti *rect)
 			else {
 				x = cursorx - 2 * padding;
 
-				if (cursory + iconsize + iconsize < winsize_y)
-					y = cursory + iconsize;
-				else
-					y = cursory - iconsize - 2 * UI_DPI_FAC;
+				if (cursory + iconsize + iconsize < winsize_y) {
+					y = (cursory + iconsize) + padding;
+				}
+				else {
+					y = (cursory - iconsize) - padding;
+				}
 			}
 			
 			if (rect) {