workaround freetype rounding behavior

4 files changed, 48 insertions, 13 deletions

diff --git a/base/matrix.c b/base/matrix.c
index 43c3f4e1..09a2de0f 100644
--- a/base/matrix.c
+++ b/base/matrix.c
@@ -76,6 +76,12 @@ fz_isrectilinear(fz_matrix m)
 			(fabs(m.a) < FLT_EPSILON && fabs(m.d) < FLT_EPSILON);
 }
 
+float
+fz_matrixexpansion(fz_matrix m)
+{
+	return sqrt(fabs(m.a * m.d - m.b * m.c));
+}
+
 fz_point
 fz_transformpoint(fz_matrix m, fz_point p)
 {
diff --git a/include/fitz/geometry.h b/include/fitz/geometry.h
index 8909b229..af734f72 100644
--- a/include/fitz/geometry.h
+++ b/include/fitz/geometry.h
@@ -45,6 +45,7 @@ fz_matrix fz_rotate(float theta);
 fz_matrix fz_translate(float tx, float ty);
 fz_matrix fz_invertmatrix(fz_matrix m);
 int fz_isrectilinear(fz_matrix m);
+float fz_matrixexpansion(fz_matrix m);
 
 fz_rect fz_intersectrects(fz_rect a, fz_rect b);
 fz_rect fz_mergerects(fz_rect a, fz_rect b);
diff --git a/mupdf/font.c b/mupdf/font.c
index 7c2346e3..b3fb6fc7 100644
--- a/mupdf/font.c
+++ b/mupdf/font.c
@@ -1,6 +1,8 @@
 #include <fitz.h>
 #include <mupdf.h>
 
+#define noHINT
+
 #include <ft2build.h>
 #include FT_FREETYPE_H
 #include <freetype/internal/ftobjs.h>
@@ -76,6 +78,7 @@ ftrender(fz_glyph *glyph, fz_font *fzfont, int cid, fz_matrix trm)
 	FT_Matrix m;
 	FT_Vector v;
 	FT_Error fterr;
+	float scale;
 	int gid;
 
 	if (font->cidtogid)
@@ -87,7 +90,6 @@ ftrender(fz_glyph *glyph, fz_font *fzfont, int cid, fz_matrix trm)
 	{
 		fz_hmtx subw;
 		int realw;
-		float scale;
 
 		FT_Set_Char_Size(face, 1000, 1000, 72, 72);
 
@@ -104,8 +106,6 @@ ftrender(fz_glyph *glyph, fz_font *fzfont, int cid, fz_matrix trm)
 			scale = 1.0;
 
 		trm = fz_concat(fz_scale(scale, 1.0), trm);
-
-		FT_Set_Char_Size(face, 64, 64, 72, 72);
 	}
 
 	glyph->w = 0;
@@ -114,20 +114,47 @@ ftrender(fz_glyph *glyph, fz_font *fzfont, int cid, fz_matrix trm)
 	glyph->top = 0;
 	glyph->bitmap = nil;
 
-	m.xx = trm.a * 65536;
-	m.yx = trm.b * 65536;
-	m.xy = trm.c * 65536;
-	m.yy = trm.d * 65536;
+	/* freetype mutilates complex glyphs if they are loaded
+	 * with FT_Set_Char_Size 1.0. it rounds the coordinates
+	 * before applying transformation. to get more precision in
+	 * freetype, we shift part of the scale in the matrix
+	 * into FT_Set_Char_Size instead
+	 */
+
+#ifdef HINT
+	scale = fz_matrixexpansion(trm);
+	m.xx = trm.a * 65536 / scale;
+	m.yx = trm.b * 65536 / scale;
+	m.xy = trm.c * 65536 / scale;
+	m.yy = trm.d * 65536 / scale;
+	v.x = 0;
+	v.y = 0;
+
+	FT_Set_Char_Size(face, 64 * scale, 64 * scale, 72, 72);
+	FT_Set_Transform(face, &m, &v);
+
+	fterr = FT_Load_Glyph(face, gid, FT_LOAD_NO_BITMAP);
+	if (fterr)
+		return fz_throw("freetype failed to load glyph: 0x%x", fterr);
+
+#else
+
+	m.xx = trm.a * 64;	/* should be 65536 */
+	m.yx = trm.b * 64;
+	m.xy = trm.c * 64;
+	m.yy = trm.d * 64;
 	v.x = trm.e * 64;
 	v.y = trm.f * 64;
 
-	FT_Set_Char_Size(face, 64, 64, 72, 72);
+	FT_Set_Char_Size(face, 65536, 65536, 72, 72); /* should be 64, 64 */
 	FT_Set_Transform(face, &m, &v);
 
 	fterr = FT_Load_Glyph(face, gid, FT_LOAD_NO_BITMAP | FT_LOAD_NO_HINTING);
 	if (fterr)
 		return fz_throw("freetype failed to load glyph: 0x%x", fterr);
 
+#endif
+
 	fterr = FT_Render_Glyph(face->glyph, ft_render_mode_normal);
 	if (fterr)
 		return fz_throw("freetype failed to render glyph: 0x%x", fterr);
@@ -489,8 +516,6 @@ printf("  builtin widths\n");
 	if (error)
 		goto cleanup;
 
-	FT_Set_Char_Size(face, 64, 64, 72, 72);
-
 printf("\n");
 
 	return nil;
@@ -772,8 +797,6 @@ printf("  cidtogidmap %d\n", len / 2);
 			goto cleanup;
 	}
 
-	FT_Set_Char_Size(face, 64, 64, 72, 72);
-
 printf("\n");
 
 	return nil;
diff --git a/mupdf/stream.c b/mupdf/stream.c
index 3ccb61b3..8d2cf5a1 100644
--- a/mupdf/stream.c
+++ b/mupdf/stream.c
@@ -299,9 +299,14 @@ makedecodefilter(fz_filter **filterp, pdf_xref *xref, fz_obj *stmobj, int oid, i
 			fz_dropobj(params);
 
 		fz_dropobj(filters);
+
+		*filterp = pipe;
+	}
+	else
+	{
+		*filterp = base;
 	}
 
-	*filterp = pipe;
 	return nil;
 
 cleanup2: