BLF: Add Support for Variable Fonts

Add support for Variable/Multiple Master font features. These are fonts
that contain a range of design variations along multiple axes. This
contains no client-facing options.

See D12977 for details and examples

Differential Revision: https://developer.blender.org/D12977

Reviewed by Brecht Van Lommel

1 files changed, 17 insertions, 0 deletions

diff --git a/source/blender/blenfont/intern/blf_internal_types.h b/source/blender/blenfont/intern/blf_internal_types.h
index 998093dae70..238301b9c4d 100644
--- a/source/blender/blenfont/intern/blf_internal_types.h
+++ b/source/blender/blenfont/intern/blf_internal_types.h
@@ -10,6 +10,10 @@
 #include "GPU_texture.h"
 #include "GPU_vertex_buffer.h"
 
+#include FT_MULTIPLE_MASTERS_H /* Variable font support. */
+
+#define BLF_VARIATIONS_MAX 16 /* Maximum variation axes per font. */
+
 /* -------------------------------------------------------------------- */
 /** \name Sub-Pixel Offset & Utilities
  *
@@ -125,6 +129,10 @@ typedef struct GlyphCacheBLF {
 
   /* and DPI. */
   unsigned int dpi;
+  float char_weight;
+  float char_slant;
+  float char_width;
+  float char_spacing;
 
   bool bold;
   bool italic;
@@ -275,6 +283,15 @@ typedef struct FontBLF {
   /* font size. */
   float size;
 
+  /* Axes data for Adobe MM, TrueType GX, or OpenType variation fonts.  */
+  FT_MM_Var *variations;
+
+  /* Character variation; 0=default, -1=min, +1=max. */
+  float char_weight;
+  float char_slant;
+  float char_width;
+  float char_spacing;
+
   /* max texture size. */
   int tex_size_max;