Fix delta scale, again...

src/hb-ot-layout-common-private.hh

@@ -566,6 +566,14 @@ struct ClassDef
 
 struct Device
 {
+  /* XXX speed up */
+
+  inline hb_position_t get_x_delta (hb_ot_layout_context_t *c) const
+  { return c->font->x_ppem ? get_delta (c->font->x_ppem) * (uint64_t) c->font->x_scale / c->font->x_ppem : 0; }
+
+  inline hb_position_t get_y_delta (hb_ot_layout_context_t *c) const
+  { return c->font->y_ppem ? get_delta (c->font->y_ppem) * (uint64_t) c->font->y_scale / c->font->y_ppem : 0; }
+
   inline int get_delta (unsigned int ppem_size) const
   {
     unsigned int f = deltaFormat;

src/hb-ot-layout-gdef-private.hh

@@ -144,8 +144,7 @@ struct CaretValueFormat3
   inline int get_caret_value (hb_ot_layout_context_t *c, hb_codepoint_t glyph_id HB_UNUSED) const
   {
     /* TODO vertical */
-    return c->scale_x (coordinate) +
-	   ((this+deviceTable).get_delta (c->font->x_ppem) * c->font->x_scale);
+    return c->scale_x (coordinate) + ((this+deviceTable).get_x_delta (c));
   }
 
   inline bool sanitize (hb_sanitize_context_t *c) {

src/hb-ot-layout-gpos-private.hh

@@ -112,16 +112,16 @@ struct ValueFormat : USHORT
 
     /* pixel -> fractional pixel */
     if (format & xPlaDevice) {
-      if (x_ppem) glyph_pos.x_offset  += (base + get_device (values++)).get_delta (x_ppem) * layout->font->x_scale; else values++;
+      if (x_ppem) glyph_pos.x_offset  += (base + get_device (values++)).get_x_delta (layout); else values++;
     }
     if (format & yPlaDevice) {
-      if (y_ppem) glyph_pos.y_offset  += (base + get_device (values++)).get_delta (y_ppem) * layout->font->y_scale; else values++;
+      if (y_ppem) glyph_pos.y_offset  += (base + get_device (values++)).get_y_delta (layout); else values++;
     }
     if (format & xAdvDevice) {
-      if (x_ppem) glyph_pos.x_advance += (base + get_device (values++)).get_delta (x_ppem) * layout->font->x_scale; else values++;
+      if (x_ppem) glyph_pos.x_advance += (base + get_device (values++)).get_x_delta (layout); else values++;
     }
     if (format & yAdvDevice) {
-      if (y_ppem) glyph_pos.y_advance += (base + get_device (values++)).get_delta (y_ppem) * layout->font->y_scale; else values++;
+      if (y_ppem) glyph_pos.y_advance += (base + get_device (values++)).get_y_delta (layout); else values++;
     }
   }
 
@@ -268,9 +268,9 @@ struct AnchorFormat3
 
       /* pixel -> fractional pixel */
       if (layout->font->x_ppem)
-	*x += (this+xDeviceTable).get_delta (layout->font->x_ppem) * layout->font->x_scale;
+	*x += (this+xDeviceTable).get_x_delta (layout);
       if (layout->font->y_ppem)
-	*y += (this+yDeviceTable).get_delta (layout->font->y_ppem) * layout->font->y_scale;
+	*y += (this+yDeviceTable).get_x_delta (layout);
   }
 
   inline bool sanitize (hb_sanitize_context_t *c) {

src/hb-ot-layout-private.hh

@@ -76,7 +76,7 @@ struct hb_ot_layout_context_t
   } info;
 
   /* Convert from font-space to user-space */
-  /* XXX div-by-zero */
+  /* XXX div-by-zero / speed up */
   inline hb_position_t scale_x (int16_t v) { return (int64_t) this->font->x_scale * v / this->face->head_table->unitsPerEm; }
   inline hb_position_t scale_y (int16_t v) { return (int64_t) this->font->y_scale * v / this->face->head_table->unitsPerEm; }
 };