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From ecbbd7f0e5d4be987d417716d6b7baec8579cd34 Mon Sep 17 00:00:00 2001
From: Jonathan Kew <jkew@mozilla.com>
Date: Wed, 22 Apr 2026 13:00:22 -0700
Subject: [PATCH 08/29] Look up FreeType variation APIs at runtime
---
src/cairo-ft-font.c | 117 +++++++++++++++++++++++++++++++++++---------
1 file changed, 94 insertions(+), 23 deletions(-)
diff --git a/src/cairo-ft-font.c b/src/cairo-ft-font.c
index b86fe4fb8..2b104c97a 100644
--- a/src/cairo-ft-font.c
+++ b/src/cairo-ft-font.c
@@ -74,6 +74,7 @@
#elif !defined(access)
#define access(p, m) 0
#endif
+#include <dlfcn.h>
/* FreeType version older than 2.11 does not have the FT_RENDER_MODE_SDF enum value in FT_Render_Mode */
#if FREETYPE_MAJOR > 2 || (FREETYPE_MAJOR == 2 && FREETYPE_MINOR >= 11)
@@ -132,6 +133,16 @@ extern void mozilla_UnlockFTLibrary(FT_Library aLibrary);
? mozilla_UnlockSharedFTFace((unscaled)->face_context) \
: (void)CAIRO_MUTEX_UNLOCK((unscaled)->mutex))
+/**
+ * Function types for FreeType symbols we'll look up at runtime, rather than
+ * relying on build-time checks for availability.
+ */
+typedef FT_Error (*GetVarFunc) (FT_Face, FT_MM_Var**);
+typedef FT_Error (*DoneVarFunc) (FT_Library, FT_MM_Var*);
+typedef FT_Error (*GetVarDesignCoordsFunc) (FT_Face, FT_UInt, FT_Fixed*);
+typedef FT_Error (*SetVarDesignCoordsFunc) (FT_Face, FT_UInt, FT_Fixed*);
+typedef FT_Error (*GetVarBlendCoordsFunc) (FT_Face, FT_UInt, FT_Fixed*);
+
/**
* SECTION:cairo-ft
* @Title: FreeType Fonts
@@ -493,11 +504,30 @@ _cairo_ft_unscaled_font_init (cairo_ft_unscaled_font_t *unscaled,
unscaled->have_color = FT_HAS_COLOR (face) != 0;
unscaled->have_color_set = TRUE;
- if (FT_Get_MM_Var (face, &ft_mm_var) == 0) {
- unscaled->variations = _cairo_calloc_ab (ft_mm_var->num_axis, sizeof (FT_Fixed));
- if (unscaled->variations)
- FT_Get_Var_Design_Coordinates (face, ft_mm_var->num_axis, unscaled->variations);
- FT_Done_MM_Var (face->glyph->library, ft_mm_var);
+
+ static GetVarFunc getVar;
+ static DoneVarFunc doneVar;
+ static GetVarDesignCoordsFunc getVarDesignCoords;
+
+ static int firstTime = 1;
+ if (firstTime) {
+ getVar = (GetVarFunc) dlsym (RTLD_DEFAULT, "FT_Get_MM_Var");
+ doneVar = (DoneVarFunc) dlsym (RTLD_DEFAULT, "FT_Done_MM_Var");
+ getVarDesignCoords = (GetVarDesignCoordsFunc) dlsym (RTLD_DEFAULT, "FT_Get_Var_Design_Coordinates");
+ firstTime = 0;
+ }
+
+ if (getVar && getVarDesignCoords) {
+ if (0 == (*getVar) (face, &ft_mm_var))
+ {
+ unscaled->variations = _cairo_calloc_ab (ft_mm_var->num_axis, sizeof (FT_Fixed));
+ if (unscaled->variations)
+ (*getVarDesignCoords) (face, ft_mm_var->num_axis, unscaled->variations);
+ if (doneVar)
+ (*doneVar) (face->glyph->library, ft_mm_var);
+ else
+ free (ft_mm_var);
+ }
}
} else {
char *filename_copy;
@@ -2335,7 +2365,24 @@ cairo_ft_apply_variations (FT_Face face,
FT_Error ret;
unsigned int instance_id = scaled_font->unscaled->id >> 16;
- ret = FT_Get_MM_Var (face, &ft_mm_var);
+ static GetVarFunc getVar;
+ static DoneVarFunc doneVar;
+ static GetVarDesignCoordsFunc getVarDesignCoords;
+ static SetVarDesignCoordsFunc setVarDesignCoords;
+
+ static int firstTime = 1;
+ if (firstTime) {
+ getVar = (GetVarFunc) dlsym (RTLD_DEFAULT, "FT_Get_MM_Var");
+ doneVar = (DoneVarFunc) dlsym (RTLD_DEFAULT, "FT_Done_MM_Var");
+ getVarDesignCoords = (GetVarDesignCoordsFunc) dlsym (RTLD_DEFAULT, "FT_Get_Var_Design_Coordinates");
+ setVarDesignCoords = (SetVarDesignCoordsFunc) dlsym (RTLD_DEFAULT, "FT_Set_Var_Design_Coordinates");
+ firstTime = 0;
+ }
+
+ if (!getVar || !setVarDesignCoords)
+ return;
+
+ ret = (*getVar) (face, &ft_mm_var);
if (ret == 0) {
FT_Fixed *current_coords;
FT_Fixed *coords;
@@ -2400,21 +2447,28 @@ skip:
}
current_coords = malloc (sizeof (FT_Fixed) * ft_mm_var->num_axis);
- ret = FT_Get_Var_Design_Coordinates (face, ft_mm_var->num_axis, current_coords);
- if (ret == 0) {
- for (i = 0; i < ft_mm_var->num_axis; i++) {
- if (coords[i] != current_coords[i])
- break;
+
+ if (getVarDesignCoords) {
+ ret = (*getVarDesignCoords) (face, ft_mm_var->num_axis, current_coords);
+ if (ret == 0) {
+ for (i = 0; i < ft_mm_var->num_axis; i++) {
+ if (coords[i] != current_coords[i])
+ break;
+ }
+ if (i == ft_mm_var->num_axis)
+ goto done;
}
- if (i == ft_mm_var->num_axis)
- goto done;
}
- FT_Set_Var_Design_Coordinates (face, ft_mm_var->num_axis, coords);
+ (*setVarDesignCoords) (face, ft_mm_var->num_axis, coords);
done:
free (coords);
free (current_coords);
- FT_Done_MM_Var (face->glyph->library, ft_mm_var);
+
+ if (doneVar)
+ (*doneVar) (face->glyph->library, ft_mm_var);
+ else
+ free (ft_mm_var);
}
}
@@ -3636,6 +3690,18 @@ _cairo_ft_is_synthetic (void *abstract_font,
FT_Face face;
FT_Error error;
+ static GetVarFunc getVar;
+ static DoneVarFunc doneVar;
+ static GetVarBlendCoordsFunc getVarBlendCoords;
+
+ static int firstTime = 1;
+ if (firstTime) {
+ getVar = (GetVarFunc) dlsym (RTLD_DEFAULT, "FT_Get_MM_Var");
+ doneVar = (DoneVarFunc) dlsym (RTLD_DEFAULT, "FT_Done_MM_Var");
+ getVarBlendCoords = (GetVarBlendCoordsFunc) dlsym (RTLD_DEFAULT, "FT_Get_Var_Blend_Coordinates");
+ firstTime = 0;
+ }
+
if (scaled_font->ft_options.synth_flags != 0) {
*is_synthetic = TRUE;
return status;
@@ -3656,7 +3722,7 @@ _cairo_ft_is_synthetic (void *abstract_font,
* are the same as the font tables */
*is_synthetic = TRUE;
- error = FT_Get_MM_Var (face, &mm_var);
+ error = getVar ? (*getVar) (face, &mm_var) : -1;
if (error) {
status = _cairo_error (_cairo_ft_to_cairo_error (error));
goto cleanup;
@@ -3673,18 +3739,23 @@ _cairo_ft_is_synthetic (void *abstract_font,
* coordinates. In this case the current outlines match the
* font tables.
*/
- FT_Get_Var_Blend_Coordinates (face, num_axis, coords);
- *is_synthetic = FALSE;
- for (i = 0; i < num_axis; i++) {
- if (coords[i]) {
- *is_synthetic = TRUE;
- break;
+ if (getVarBlendCoords) {
+ (*getVarBlendCoords) (face, num_axis, coords);
+ *is_synthetic = FALSE;
+ for (i = 0; i < num_axis; i++) {
+ if (coords[i]) {
+ *is_synthetic = TRUE;
+ break;
+ }
}
}
cleanup:
free (coords);
- FT_Done_MM_Var (face->glyph->library, mm_var);
+ if (doneVar)
+ (*doneVar) (face->glyph->library, mm_var);
+ else
+ free (mm_var);
}
_cairo_ft_unscaled_font_unlock_face (unscaled);
--
2.53.0