gecko-dev/gfx/cairo/win32-scaled-font-size.patch

Index: gfx/cairo/cairo/src/cairo-win32-font.c
===================================================================
RCS file: /cvsroot/mozilla/gfx/cairo/cairo/src/cairo-win32-font.c,v
retrieving revision 1.21
diff -u -p -1 -2 -r1.21 cairo-win32-font.c
--- gfx/cairo/cairo/src/cairo-win32-font.c	4 Apr 2007 01:09:15 -0000	1.21
+++ gfx/cairo/cairo/src/cairo-win32-font.c	14 Apr 2007 09:05:25 -0000
@@ -218,27 +218,33 @@ _get_system_quality (void)
 	    }
 
 	    if (smoothing_type == FE_FONTSMOOTHINGCLEARTYPE)
 		return CLEARTYPE_QUALITY;
 	}
 
 	return ANTIALIASED_QUALITY;
     } else {
 	return DEFAULT_QUALITY;
     }
 }
 
+/* If face_hfont is non-NULL then font_matrix must be a simple scale by some
+ * factor S, ctm must be the identity, logfont->lfHeight must be -S,
+ * logfont->lfWidth, logfont->lfEscapement, logfont->lfOrientation must
+ * all be 0, and face_hfont is the result of calling CreateFontIndirectW on
+ * logfont.
+ */
 static cairo_scaled_font_t *
 _win32_scaled_font_create (LOGFONTW                   *logfont,
-			   HFONT                      hfont,
+			   HFONT                      face_hfont,
 			   cairo_font_face_t	      *font_face,
 			   const cairo_matrix_t       *font_matrix,
 			   const cairo_matrix_t       *ctm,
 			   const cairo_font_options_t *options)
 {
     cairo_win32_scaled_font_t *f;
     cairo_matrix_t scale;
     cairo_status_t status;
 
     _cairo_win32_initialize ();
 
     f = malloc (sizeof(cairo_win32_scaled_font_t));
@@ -268,29 +274,38 @@ _win32_scaled_font_create (LOGFONTW     
 	case CAIRO_ANTIALIAS_SUBPIXEL:
 	    if (_have_cleartype_quality ())
 		f->quality = CLEARTYPE_QUALITY;
 	    else
 		f->quality = ANTIALIASED_QUALITY;
 	    break;
 	case CAIRO_ANTIALIAS_DEFAULT:
 	    ASSERT_NOT_REACHED;
 	}
     }
 
     f->em_square = 0;
-    f->scaled_hfont = hfont;
+    f->scaled_hfont = NULL;
     f->unscaled_hfont = NULL;
-
-    /* don't delete the hfont if it was passed in to us */
-    f->delete_scaled_hfont = !hfont;
+    if (f->quality == logfont->lfQuality ||
+        (logfont->lfQuality == DEFAULT_QUALITY &&
+         options->antialias == CAIRO_ANTIALIAS_DEFAULT)) {
+        /* If face_hfont is non-NULL, then we can use it to avoid creating our
+         * own --- because the constraints on face_hfont mentioned above
+         * guarantee it was created in exactly the same way that
+         * _win32_scaled_font_get_scaled_hfont would create it.
+         */
+        f->scaled_hfont = face_hfont;
+    }
+    /* don't delete the hfont if we're using the one passed in to us */
+    f->delete_scaled_hfont = !f->scaled_hfont;
 
     cairo_matrix_multiply (&scale, font_matrix, ctm);
     _compute_transform (f, &scale);
 
     _cairo_scaled_font_init (&f->base, font_face,
 			     font_matrix, ctm, options,
 			     &cairo_win32_scaled_font_backend);
 
     status = _cairo_win32_scaled_font_set_metrics (f);
     if (status) {
 	cairo_scaled_font_destroy (&f->base);
 	return NULL;
@@ -1479,133 +1494,177 @@ const cairo_scaled_font_backend_t cairo_
     _cairo_win32_scaled_font_glyph_init,
     _cairo_win32_scaled_font_text_to_glyphs,
     NULL,			/* ucs4_to_index */
     _cairo_win32_scaled_font_show_glyphs,
     _cairo_win32_scaled_font_load_truetype_table,
     _cairo_win32_scaled_font_map_glyphs_to_unicode,
 };
 
 /* cairo_win32_font_face_t */
 
 typedef struct _cairo_win32_font_face cairo_win32_font_face_t;
 
+/* If hfont is non-NULL then logfont->lfHeight must be -S for some S,
+ * logfont->lfWidth, logfont->lfEscapement, logfont->lfOrientation must
+ * all be 0, and hfont is the result of calling CreateFontIndirectW on
+ * logfont.
+ */
 struct _cairo_win32_font_face {
     cairo_font_face_t base;
     LOGFONTW logfont;
     HFONT hfont;
 };
 
 /* implement the platform-specific interface */
 
 static void
 _cairo_win32_font_face_destroy (void *abstract_face)
 {
 }
 
+static cairo_bool_t
+_is_scale (const cairo_matrix_t *matrix, double scale)
+{
+    return matrix->xx == scale && matrix->yy == scale &&
+           matrix->xy == 0. && matrix->yx == 0. &&
+           matrix->x0 == 0. && matrix->y0 == 0.;
+}
+
 static cairo_status_t
 _cairo_win32_font_face_scaled_font_create (void			*abstract_face,
 					   const cairo_matrix_t	*font_matrix,
 					   const cairo_matrix_t	*ctm,
 					   const cairo_font_options_t *options,
 					   cairo_scaled_font_t **font)
 {
+    HFONT hfont = NULL;
+
     cairo_win32_font_face_t *font_face = abstract_face;
 
     _cairo_win32_initialize ();
 
+    if (font_face->hfont) {
+        /* Check whether it's OK to go ahead and use the font-face's HFONT. */
+        if (_is_scale (ctm, 1.) &&
+            _is_scale (font_matrix, -font_face->logfont.lfHeight)) {
+            hfont = font_face->hfont;
+        }
+    }
+
     *font = _win32_scaled_font_create (&font_face->logfont,
-				       font_face->hfont,
+				       hfont,
 				       &font_face->base,
 				       font_matrix, ctm, options);
     if (*font)
 	return CAIRO_STATUS_SUCCESS;
     else
 	return CAIRO_STATUS_NO_MEMORY;
 }
 
 static const cairo_font_face_backend_t _cairo_win32_font_face_backend = {
     CAIRO_FONT_TYPE_WIN32,
     _cairo_win32_font_face_destroy,
     _cairo_win32_font_face_scaled_font_create
 };
 
 /**
- * cairo_win32_font_face_create_for_logfontw:
+ * cairo_win32_font_face_create_for_logfontw_hfont:
  * @logfont: A #LOGFONTW structure specifying the font to use.
- *   The lfHeight, lfWidth, lfOrientation and lfEscapement
- *   fields of this structure are ignored.
+ *   If hfont is null then the lfHeight, lfWidth, lfOrientation and lfEscapement
+ *   fields of this structure are ignored. Otherwise lfWidth, lfOrientation and
+ *   lfEscapement must be zero.
+ * @font: An #HFONT that can be used when the font matrix is a scale by
+ *   -lfHeight and the CTM is identity.
  *
  * Creates a new font for the Win32 font backend based on a
  * #LOGFONT. This font can then be used with
  * cairo_set_font_face() or cairo_scaled_font_create().
  * The #cairo_scaled_font_t
  * returned from cairo_scaled_font_create() is also for the Win32 backend
  * and can be used with functions such as cairo_win32_scaled_font_select_font().
  *
  * Return value: a newly created #cairo_font_face_t. Free with
  *  cairo_font_face_destroy() when you are done using it.
  **/
 cairo_font_face_t *
-cairo_win32_font_face_create_for_logfontw (LOGFONTW *logfont)
+cairo_win32_font_face_create_for_logfontw_hfont (LOGFONTW *logfont, HFONT font)
 {
     cairo_win32_font_face_t *font_face;
 
     _cairo_win32_initialize ();
 
     font_face = malloc (sizeof (cairo_win32_font_face_t));
     if (!font_face) {
-	_cairo_error (CAIRO_STATUS_NO_MEMORY);
-	return (cairo_font_face_t *)&_cairo_font_face_nil;
+        _cairo_error (CAIRO_STATUS_NO_MEMORY);
+        return (cairo_font_face_t *)&_cairo_font_face_nil;
     }
 
     font_face->logfont = *logfont;
-    font_face->hfont = NULL;
+    font_face->hfont = font;
 
     _cairo_font_face_init (&font_face->base, &_cairo_win32_font_face_backend);
 
     return &font_face->base;
 }
 
 /**
+ * cairo_win32_font_face_create_for_logfontw:
+ * @logfont: A #LOGFONTW structure specifying the font to use.
+ *   The lfHeight, lfWidth, lfOrientation and lfEscapement
+ *   fields of this structure are ignored.
+ *
+ * Creates a new font for the Win32 font backend based on a
+ * #LOGFONT. This font can then be used with
+ * cairo_set_font_face() or cairo_scaled_font_create().
+ * The #cairo_scaled_font_t
+ * returned from cairo_scaled_font_create() is also for the Win32 backend
+ * and can be used with functions such as cairo_win32_scaled_font_select_font().
+ *
+ * Return value: a newly created #cairo_font_face_t. Free with
+ *  cairo_font_face_destroy() when you are done using it.
+ **/
+cairo_font_face_t *
+cairo_win32_font_face_create_for_logfontw (LOGFONTW *logfont)
+{
+    return cairo_win32_font_face_create_for_logfontw_hfont (logfont, NULL);
+}
+
+/**
  * cairo_win32_font_face_create_for_hfont:
  * @font: An #HFONT structure specifying the font to use.
  *
  * Creates a new font for the Win32 font backend based on a
  * #HFONT. This font can then be used with
  * cairo_set_font_face() or cairo_scaled_font_create().
  * The #cairo_scaled_font_t
  * returned from cairo_scaled_font_create() is also for the Win32 backend
  * and can be used with functions such as cairo_win32_scaled_font_select_font().
  *
  * Return value: a newly created #cairo_font_face_t. Free with
  *  cairo_font_face_destroy() when you are done using it.
  **/
 cairo_font_face_t *
 cairo_win32_font_face_create_for_hfont (HFONT font)
 {
-    cairo_win32_font_face_t *font_face;
-
-    _cairo_win32_initialize ();
+    LOGFONTW logfont;
+    GetObject (font, sizeof(logfont), &logfont);
 
-    font_face = malloc (sizeof (cairo_win32_font_face_t));
-    if (!font_face) {
-	_cairo_error (CAIRO_STATUS_NO_MEMORY);
-	return (cairo_font_face_t *)&_cairo_font_face_nil;
+    if (logfont.lfEscapement != 0 || logfont.lfOrientation != 0 ||
+        logfont.lfWidth != 0) {
+        /* We can't use this font because that optimization requires that
+         * lfEscapement, lfOrientation and lfWidth be zero. */
+        font = NULL;
     }
 
-    font_face->hfont = font;
-
-    _cairo_font_face_init (&font_face->base, &_cairo_win32_font_face_backend);
-
-    return &font_face->base;
+    return cairo_win32_font_face_create_for_logfontw_hfont (&logfont, font);
 }
 
 /**
  * cairo_win32_scaled_font_select_font:
  * @scaled_font: A #cairo_scaled_font_t from the Win32 font backend. Such an
  *   object can be created with cairo_win32_scaled_font_create_for_logfontw().
  * @hdc: a device context
  *
  * Selects the font into the given device context and changes the
  * map mode and world transformation of the device context to match
  * that of the font. This function is intended for use when using
  * layout APIs such as Uniscribe to do text layout with the
Index: gfx/cairo/cairo/src/cairo-win32.h
===================================================================
RCS file: /cvsroot/mozilla/gfx/cairo/cairo/src/cairo-win32.h,v
retrieving revision 1.14
diff -u -p -1 -2 -r1.14 cairo-win32.h
--- gfx/cairo/cairo/src/cairo-win32.h	24 Jan 2007 23:53:03 -0000	1.14
+++ gfx/cairo/cairo/src/cairo-win32.h	14 Apr 2007 09:05:25 -0000
@@ -61,24 +61,27 @@ cairo_win32_surface_create_with_dib (cai
 cairo_public HDC
 cairo_win32_surface_get_dc (cairo_surface_t *surface);
 
 cairo_public cairo_surface_t *
 cairo_win32_surface_get_image (cairo_surface_t *surface);
 
 cairo_public cairo_font_face_t *
 cairo_win32_font_face_create_for_logfontw (LOGFONTW *logfont);
 
 cairo_public cairo_font_face_t *
 cairo_win32_font_face_create_for_hfont (HFONT font);
 
+cairo_public cairo_font_face_t *
+cairo_win32_font_face_create_for_logfontw_hfont (LOGFONTW *logfont, HFONT font);
+
 cairo_public cairo_status_t
 cairo_win32_scaled_font_select_font (cairo_scaled_font_t *scaled_font,
 				     HDC                  hdc);
 
 cairo_public void
 cairo_win32_scaled_font_done_font (cairo_scaled_font_t *scaled_font);
 
 cairo_public double
 cairo_win32_scaled_font_get_metrics_factor (cairo_scaled_font_t *scaled_font);
 
 cairo_public void
 cairo_win32_scaled_font_get_logical_to_device (cairo_scaled_font_t *scaled_font,