Support scale in ttf composite glyphs

jkseppan · jkseppan · commit 5b2f6fb317b4 · 2020-07-27T13:01:06.000+03:00
Fixes #17197
diff --git a/extern/ttconv/pprdrv_tt.cpp b/extern/ttconv/pprdrv_tt.cpp
@@ -107,6 +107,31 @@ Fixed getFixed(BYTE *s)
     return val;
 } /* end of getFixed() */
 
+/*
+** Get a 16 bit fixed point (2.14) number.
+*/
+F2DOT14 getF2DOT14(BYTE *s)
+{
+    F2DOT14 val={0, 0};
+
+    int sign = s[0] & 0x80;
+    int bit = (s[0] & 0x40) >> 6;
+    if (sign) {
+      val.whole = bit-2;
+    } else {
+      val.whole = bit;
+    }
+    val.fraction = ((s[0] & 0x3f) << 8) + s[1];
+
+    return val;
+}
+
+float F2DOT14value(F2DOT14 f)
+{
+    return f.whole + (float)f.fraction/16384;
+}
+
+
 /*-----------------------------------------------------------------------
 ** Load a TrueType font table into memory and return a pointer to it.
 ** The font's "file" and "offset_table" fields must be set before this
diff --git a/extern/ttconv/pprdrv_tt2.cpp b/extern/ttconv/pprdrv_tt2.cpp
@@ -417,6 +417,7 @@ void GlyphToType3::do_composite(TTStreamWriter& stream, struct TTFONT *font, BYT
     USHORT glyphIndex;
     int arg1;
     int arg2;
+    F2DOT14 mat00 = {1, 0}, mat01 = {0, 0}, mat10 = {0, 0}, mat11 = {1, 0};
 
     /* Once around this loop for each component. */
     do
@@ -444,14 +445,21 @@ void GlyphToType3::do_composite(TTStreamWriter& stream, struct TTFONT *font, BYT
 
         if (flags & WE_HAVE_A_SCALE)
         {
+            mat00 = mat11 = getF2DOT14(glyph);
             glyph += 2;
         }
         else if (flags & WE_HAVE_AN_X_AND_Y_SCALE)
         {
+            mat00 = getF2DOT14(glyph);
+            mat11 = getF2DOT14(glyph+2);
             glyph += 4;
         }
         else if (flags & WE_HAVE_A_TWO_BY_TWO)
         {
+            mat00 = getF2DOT14(glyph);
+            mat01 = getF2DOT14(glyph+2);
+            mat10 = getF2DOT14(glyph+4);
+            mat11 = getF2DOT14(glyph+6);
             glyph += 8;
         }
         else
@@ -472,7 +480,10 @@ void GlyphToType3::do_composite(TTStreamWriter& stream, struct TTFONT *font, BYT
                    subglyph here.  However, that doesn't seem to work with
                    xpdf or gs (only acrobat), so instead, this just includes
                    the subglyph here inline. */
-                stream.printf("q 1 0 0 1 %d %d cm\n", topost(arg1), topost(arg2));
+                stream.printf("q %.6f %.6f %.6f %.6f %d %d cm\n",
+                              F2DOT14value(mat00), F2DOT14value(mat01),
+                              F2DOT14value(mat10), F2DOT14value(mat11),
+                              topost(arg1), topost(arg2));
             }
             else
             {
diff --git a/extern/ttconv/truetype.h b/extern/ttconv/truetype.h
@@ -41,6 +41,13 @@ typedef struct
     unsigned short int fraction;
     } Fixed;
 
+/* A 2.14 fixed point number */
+typedef struct
+    {
+    SHORT whole;
+    USHORT fraction;
+    } F2DOT14;
+
 /* This structure tells what we have found out about */
 /* the current font. */
 struct TTFONT
@@ -86,6 +93,8 @@ struct TTFONT
 ULONG getULONG(BYTE *p);
 USHORT getUSHORT(BYTE *p);
 Fixed getFixed(BYTE *p);
+F2DOT14 getF2DOT14(BYTE *p);
+float F2DOT14value(F2DOT14 f);
 
 /*
 ** Get an funits word.

Original file line number	Diff line number	Diff line change
`@@ -417,6 +417,7 @@ void GlyphToType3::do_composite(TTStreamWriter& stream, struct TTFONT *font, BYT`
`417`	`417`	`USHORT glyphIndex;`
`418`	`418`	`int arg1;`
`419`	`419`	`int arg2;`
	`420`	`+ F2DOT14 mat00 = {1, 0}, mat01 = {0, 0}, mat10 = {0, 0}, mat11 = {1, 0};`
`420`	`421`
`421`	`422`	`/* Once around this loop for each component. */`
`422`	`423`	`do`
`@@ -444,14 +445,21 @@ void GlyphToType3::do_composite(TTStreamWriter& stream, struct TTFONT *font, BYT`
`444`	`445`
`445`	`446`	`if (flags & WE_HAVE_A_SCALE)`
`446`	`447`	`{`
	`448`	`+ mat00 = mat11 = getF2DOT14(glyph);`
`447`	`449`	`glyph += 2;`
`448`	`450`	`}`
`449`	`451`	`else if (flags & WE_HAVE_AN_X_AND_Y_SCALE)`
`450`	`452`	`{`
	`453`	`+ mat00 = getF2DOT14(glyph);`
	`454`	`+ mat11 = getF2DOT14(glyph+2);`
`451`	`455`	`glyph += 4;`
`452`	`456`	`}`
`453`	`457`	`else if (flags & WE_HAVE_A_TWO_BY_TWO)`
`454`	`458`	`{`
	`459`	`+ mat00 = getF2DOT14(glyph);`
	`460`	`+ mat01 = getF2DOT14(glyph+2);`
	`461`	`+ mat10 = getF2DOT14(glyph+4);`
	`462`	`+ mat11 = getF2DOT14(glyph+6);`
`455`	`463`	`glyph += 8;`
`456`	`464`	`}`
`457`	`465`	`else`
`@@ -472,7 +480,10 @@ void GlyphToType3::do_composite(TTStreamWriter& stream, struct TTFONT *font, BYT`
`472`	`480`	`subglyph here. However, that doesn't seem to work with`
`473`	`481`	`xpdf or gs (only acrobat), so instead, this just includes`
`474`	`482`	`the subglyph here inline. */`
`475`		`- stream.printf("q 1 0 0 1 %d %d cm\n", topost(arg1), topost(arg2));`
	`483`	`+ stream.printf("q %.6f %.6f %.6f %.6f %d %d cm\n",`
	`484`	`+ F2DOT14value(mat00), F2DOT14value(mat01),`
	`485`	`+ F2DOT14value(mat10), F2DOT14value(mat11),`
	`486`	`+ topost(arg1), topost(arg2));`
`476`	`487`	`}`
`477`	`488`	`else`
`478`	`489`	`{`