ttf: improvement on not found glyphs (#8050)

vlib/x/ttf/render_bmp.v

@@ -515,6 +515,13 @@ fn (mut bmp BitMap) get_chars_bbox(in_string string) []int {
 		}
 		
 		c_index := bmp.tf.map_code(int(char))
+		// Glyph not found
+		if c_index == 0 {
+			w += int(space_cw * bmp.space_cw)
+			i += c_len
+			continue
+		}
+
 		ax , ay := bmp.tf.next_kern(c_index)
 		//dprintln("char_index: $c_index ax: $ax ay: $ay")
 
@@ -581,6 +588,12 @@ fn (mut bmp BitMap) get_bbox(in_string string) (int, int){
 		}
 		
 		c_index := bmp.tf.map_code(int(char))
+		// Glyph not found
+		if c_index == 0 {
+			w += int(space_cw * bmp.space_cw)
+			i += c_len
+			continue
+		}
 		ax , ay := bmp.tf.next_kern(c_index)
 		//dprintln("char_index: $c_index ax: $ax ay: $ay")
 
@@ -623,6 +636,25 @@ fn (mut bmp BitMap) get_bbox(in_string string) (int, int){
 * TTF draw glyph
 *
 ******************************************************************************/
+fn (mut bmp BitMap) draw_notdef_glyph(in_x int, in_w int) {
+	mut p := Point{in_x, 0, false}
+	x1 , y1 := bmp.trf_txt(p)
+	// init ch_matrix
+	bmp.ch_matrix[0] = bmp.tr_matrix[0] * bmp.scale * bmp.scale_x
+	bmp.ch_matrix[1] = bmp.tr_matrix[1] * bmp.scale * bmp.scale_x
+	bmp.ch_matrix[3] = bmp.tr_matrix[3] * -bmp.scale * bmp.scale_y
+	bmp.ch_matrix[4] = bmp.tr_matrix[4] * -bmp.scale * bmp.scale_y
+	bmp.ch_matrix[6] = int(x1)
+	bmp.ch_matrix[7] = int(y1)
+	x,y := bmp.trf_ch(p)
+	
+	y_h := fabs(bmp.tf.y_max-bmp.tf.y_min)* bmp.scale * 0.5
+
+	bmp.box(int(x), int(y), int(x - in_w), int(y - y_h), bmp.color)
+	bmp.line(int(x), int(y), int(x - in_w ), int(y - y_h), bmp.color)
+	bmp.line(int(x - in_w ), int(y), int(x), int(y - y_h), bmp.color)
+}
+
 pub
 fn (mut bmp BitMap) draw_text(in_string string) (int, int){
 	mut w := 0
@@ -653,6 +685,14 @@ fn (mut bmp BitMap) draw_text(in_string string) (int, int){
 		}
 		
 		c_index := bmp.tf.map_code(int(char))
+		// Glyph not found
+		if c_index == 0 {
+			bmp.draw_notdef_glyph(w, int(space_cw * bmp.space_cw))
+			w += int(space_cw * bmp.space_cw)
+			i += c_len
+			continue
+		}
+
 		ax , ay := bmp.tf.next_kern(c_index)
 		//dprintln("char_index: $c_index ax: $ax ay: $ay")
 
@@ -684,7 +724,6 @@ fn (mut bmp BitMap) draw_text(in_string string) (int, int){
 			width = int((cw+ax) * bmp.scale)
 		}
 		w += width + div_space_cw
-
 		i+= c_len
 	}
 

vlib/x/ttf/ttf.v

@@ -488,7 +488,6 @@ fn (mut tf TTF_File) read_compound_glyph(mut in_glyph Glyph){
 					y: int(y)
 					on_curve: p.on_curve
 				}
-		
 			}
 		}
 		tf.pos = old_pos