Text Object: Vertical Alignment

A new option for Font/Text objects vertical alignment:

* Top Base-Line (current mode)
* Top
* Center
* Bottom

The Top is the equivalent as the Top-Baseline with an empty line at the begin of the
text. It's nice to have this option too though, since if we are driving
the alignment via Python we don't want to add extra lines to the text
only to accomodate to the desired vertical alignment.

The Center and Bottom are as intuitive as their name suggest.

When working with text boxes, the vertical alignment only work for
paragraphs that are not vertically full.

Many thanks to Campbell Barton (ideasman42 / @campbellbarton) for the
code review, code comments, and overall suggestions and changes :)

Reviewers: campbellbarton

Differential Revision: https://developer.blender.org/D2061

release/scripts/startup/bl_ui/properties_data_curve.py

@@ -370,8 +370,11 @@ class DATA_PT_paragraph(CurveButtonsPanelText, Panel):
 
         text = context.curve
 
-        layout.label(text="Align:")
-        layout.prop(text, "align", expand=True)
+        layout.label(text="Horizontal Alignment:")
+        layout.prop(text, "align_x", expand=True)
+
+        layout.label(text="Vertical Alignment:")
+        layout.prop(text, "align_y", expand=True)
 
         split = layout.split()
 

source/blender/blenkernel/intern/font.c

@@ -628,6 +628,8 @@ bool BKE_vfont_to_curve_ex(Main *bmain, Object *ob, int mode, ListBase *r_nubase
 	bool use_textbox;
 	VChar *che;
 	struct CharTrans *chartransdata = NULL, *ct;
+	/* Text at the beginning of the last used text-box (use for y-axis alignment). */
+	int i_textbox = 0;
 	struct TempLineInfo *lineinfo;
 	float *f, xof, yof, xtrax, linedist;
 	float twidth, maxlen = 0;
@@ -830,6 +832,7 @@ makebreak:
 			    (cu->totbox > (curbox + 1)) &&
 			    ((-(yof - tb_scale.y)) > (tb_scale.h - linedist) - yof_scale))
 			{
+				i_textbox = i + 1;
 				maxlen = 0;
 				curbox++;
 
@@ -983,6 +986,60 @@ makebreak:
 		}
 	}
 
+	/* top-baseline is default, in this case, do nothing */
+	if (cu->align_y != CU_ALIGN_Y_TOP_BASELINE) {
+		if (tb_scale.h != 0.0f) {
+			/* top and top-baseline are the same when text-boxes are used */
+			if (cu->align_y != CU_ALIGN_Y_TOP && i_textbox < slen) {
+				/* all previous textboxes are 'full', only align the last used text-box */
+				float yoff;
+				int lines;
+				struct CharTrans *ct_last, *ct_textbox;
+
+				ct_last = chartransdata + slen - 1;
+				ct_textbox = chartransdata + i_textbox;
+
+				lines = ct_last->linenr - ct_textbox->linenr + 1;
+				if (mem[slen - 1] == '\n') {
+					lines++;
+				}
+
+				if (cu->align_y == CU_ALIGN_Y_BOTTOM) {
+					yoff = (lines * linedist) - tb_scale.h;
+				}
+				else if (cu->align_y == CU_ALIGN_Y_CENTER) {
+					yoff = 0.5f * ((lines * linedist) - tb_scale.h);
+				}
+
+				ct = ct_textbox;
+				for (i = i_textbox - 1; i < slen; i++) {
+					ct->yof += yoff;
+					ct++;
+				}
+			}
+		}
+		else {
+			/* non text-box case handled separately */
+			ct = chartransdata;
+			float yoff;
+
+			if (cu->align_y == CU_ALIGN_Y_TOP) {
+				yoff = -linedist;
+			}
+			else if (cu->align_y == CU_ALIGN_Y_BOTTOM) {
+				yoff = (lnr - 1.0f) * linedist;
+			}
+			else if (cu->align_y == CU_ALIGN_Y_CENTER) {
+				yoff = (lnr - 2.0f) * linedist * 0.5f;
+			}
+
+			for (i = 0; i <= slen; i++) {
+				ct->yof += yoff;
+				ct++;
+			}
+		}
+	}
+
 	MEM_freeN(lineinfo);
 
 	/* TEXT ON CURVE */

source/blender/editors/object/object_edit.c

@@ -946,6 +946,7 @@ static void copy_attr(Main *bmain, Scene *scene, View3D *v3d, short event)
 						cu1 = base->object->data;
 
 						cu1->spacemode = cu->spacemode;
+						cu1->align_y = cu->align_y;
 						cu1->spacing = cu->spacing;
 						cu1->linedist = cu->linedist;
 						cu1->shear = cu->shear;

source/blender/makesdna/DNA_curve_types.h

@@ -230,7 +230,7 @@ typedef struct Curve {
 
 	/* font part */
 	short lines;
-	char spacemode, pad1;
+	char spacemode, align_y;
 	float spacing, linedist, shear, fsize, wordspace, ulpos, ulheight;
 	float xof, yof;
 	float linewidth;
@@ -329,6 +329,14 @@ enum {
 	CU_FLUSH              = 4,
 };
 
+/* Curve.align_y */
+enum {
+	CU_ALIGN_Y_TOP_BASELINE       = 0,
+	CU_ALIGN_Y_TOP                = 1,
+	CU_ALIGN_Y_CENTER             = 2,
+	CU_ALIGN_Y_BOTTOM             = 3,
+};
+
 /* Nurb.flag */
 enum {
 	CU_SMOOTH             = 1 << 0,

source/blender/makesrna/intern/rna_curve.c

@@ -962,11 +962,25 @@ static void rna_def_font(BlenderRNA *UNUSED(brna), StructRNA *srna)
 		{0, NULL, 0, NULL, NULL}
 	};
 
+	static EnumPropertyItem prop_align_y_items[] = {
+		{CU_ALIGN_Y_TOP_BASELINE, "TOP_BASELINE", 0, "Top Base-Line", "Align to top but use the base-line of the text"},
+		{CU_ALIGN_Y_TOP, "TOP", 0, "Top", "Align text to the top"},
+		{CU_ALIGN_Y_CENTER, "CENTER", 0, "Center", "Align text to the middle"},
+		{CU_ALIGN_Y_BOTTOM, "BOTTOM", 0, "Bottom", "Align text to the bottom"},
+		{0, NULL, 0, NULL, NULL}
+	};
+
 	/* Enums */
-	prop = RNA_def_property(srna, "align", PROP_ENUM, PROP_NONE);
+	prop = RNA_def_property(srna, "align_x", PROP_ENUM, PROP_NONE);
 	RNA_def_property_enum_sdna(prop, NULL, "spacemode");
 	RNA_def_property_enum_items(prop, prop_align_items);
-	RNA_def_property_ui_text(prop, "Text Align", "Text align from the object center");
+	RNA_def_property_ui_text(prop, "Text Horizontal Align", "Text horizontal align from the object center");
+	RNA_def_property_update(prop, 0, "rna_Curve_update_data");
+
+	prop = RNA_def_property(srna, "align_y", PROP_ENUM, PROP_NONE);
+	RNA_def_property_enum_sdna(prop, NULL, "align_y");
+	RNA_def_property_enum_items(prop, prop_align_y_items);
+	RNA_def_property_ui_text(prop, "Text Vertical Align", "Text vertical align from the object center");
 	RNA_def_property_update(prop, 0, "rna_Curve_update_data");
 
 	/* number values */