use more properties according to XLFD

5 files changed, 176 insertions, 71 deletions

diff --git a/fonttosfnt.h b/fonttosfnt.h
index 202ab5a..a05e036 100644
--- a/fonttosfnt.h
+++ b/fonttosfnt.h
@@ -86,6 +86,22 @@ typedef struct _FontNameEntry {
     char *value;
 } FontNameEntryRec, *FontNameEntryPtr;
 
+typedef struct _Metrics {
+    int height;
+    int maxX;
+    int minX;
+    int maxY;
+    int minY;
+    int xHeight;
+    int capHeight;
+    int maxAwidth;
+    int awidth;
+    int ascent;
+    int descent;
+    int underlinePosition;
+    int underlineThickness;
+} MetricsRec, *MetricsPtr;
+
 typedef struct _Font {
     int numNames;
     struct _FontNameEntry *names;
@@ -93,8 +109,8 @@ typedef struct _Font {
     int weight;                 /* as in the OS/2 table */
     int width;                  /* as in the OS/2 table */
     int italicAngle;            /* degrees c-clockwise from the vertical */
-    int underlinePosition;
-    int underlineThickness;
+    MetricsRec pxMetrics;
+    MetricsRec metrics;
     unsigned foundry;
     struct _Strike *strikes;
 } FontRec, *FontPtr;
@@ -153,7 +169,7 @@ int findCode(CmapPtr, int);
 BitmapPtr strikeBitmapIndex(StrikePtr, CmapPtr, int);
 void strikeMetrics(StrikePtr, int*, int*, int*, int*, int*);
 int glyphMetrics(FontPtr, int, int*, int*, int*, int*, int*);
-void fontMetrics(FontPtr, int*, int*, int*, int*, int*);
+void fontMetrics(FontPtr, MetricsPtr);
 int maxIndex(CmapPtr);
 
 int readFile(char *filename, FontPtr);
@@ -173,6 +189,7 @@ int macTime(int *, unsigned *);
 unsigned faceFoundry(FT_Face);
 char *faceEncoding(FT_Face);
 int faceFlags(FT_Face);
+int faceIntProp(FT_Face, const char *);
 int faceWeight(FT_Face);
 int faceWidth(FT_Face);
 int faceItalicAngle(FT_Face);
diff --git a/read.c b/read.c
index a22ce41..db79a59 100644
--- a/read.c
+++ b/read.c
@@ -258,30 +258,6 @@ readFile(char *filename, FontPtr font)
         i++;
 #endif
         font->numNames = i;
-
-        font->flags = faceFlags(face) | (symbol ? FACE_SYMBOL : 0);
-        font->weight = faceWeight(face);
-        font->width = faceWidth(face);
-        font->foundry = faceFoundry(face);
-        font->italicAngle = faceItalicAngle(face);
-
-        rc = FT_Get_BDF_Property(face, "UNDERLINE_POSITION", &prop);
-        if(rc == 0 && prop.type == BDF_PROPERTY_TYPE_INTEGER)
-            font->underlinePosition = 
-                (double)prop.u.integer / face->available_sizes[0].height *
-                TWO_SIXTEENTH;
-        else
-            font->underlinePosition =
-                - 1.5 / face->available_sizes[0].height * TWO_SIXTEENTH;
-
-        rc = FT_Get_BDF_Property(face, "UNDERLINE_THICKNESS", &prop);
-        if(rc == 0 && prop.type == BDF_PROPERTY_TYPE_INTEGER)
-            font->underlineThickness = 
-                (double)prop.u.integer / face->available_sizes[0].height *
-                TWO_SIXTEENTH;
-        else
-            font->underlineThickness =
-                1.0 / face->available_sizes[0].height * TWO_SIXTEENTH;
     }
 
     if(face->num_fixed_sizes == 0) {
@@ -304,6 +280,19 @@ readFile(char *filename, FontPtr font)
         return -1;
     }
 
+    font->flags = faceFlags(face) | (symbol ? FACE_SYMBOL : 0);
+    font->weight = faceWeight(face);
+    font->width = faceWidth(face);
+    font->foundry = faceFoundry(face);
+    font->italicAngle = faceItalicAngle(face);
+    font->pxMetrics.height = face->available_sizes[0].height;
+    font->pxMetrics.xHeight = faceIntProp(face, "X_HEIGHT");
+    font->pxMetrics.capHeight = faceIntProp(face, "CAP_HEIGHT");
+    font->pxMetrics.ascent = faceIntProp(face, "FONT_ASCENT");
+    font->pxMetrics.descent = faceIntProp(face, "FONT_DESCENT");
+    font->pxMetrics.underlinePosition = faceIntProp(face, "UNDERLINE_POSITION");
+    font->pxMetrics.underlineThickness = faceIntProp(face, "UNDERLINE_THICKNESS");
+
     for(int i = 0; i < face->num_fixed_sizes; i++) {
         if(verbose_flag)
             fprintf(stderr, "size %d: %dx%d\n",
diff --git a/struct.c b/struct.c
index bcb07ba..1c14931 100644
--- a/struct.c
+++ b/struct.c
@@ -42,8 +42,32 @@ makeFont(void)
     font->weight = 500;
     font->width = 5;
     font->italicAngle = 0;
-    font->underlinePosition = - TWO_SIXTEENTH;
-    font->underlineThickness = TWO_SIXTEENTH;
+    font->pxMetrics.height = UNDEF;
+    font->pxMetrics.maxX = UNDEF;
+    font->pxMetrics.minX = UNDEF;
+    font->pxMetrics.maxY = UNDEF;
+    font->pxMetrics.minY = UNDEF;
+    font->pxMetrics.xHeight = UNDEF;
+    font->pxMetrics.capHeight = UNDEF;
+    font->pxMetrics.maxAwidth = UNDEF;
+    font->pxMetrics.awidth = UNDEF;
+    font->pxMetrics.ascent = UNDEF;
+    font->pxMetrics.descent = UNDEF;
+    font->pxMetrics.underlinePosition = UNDEF;
+    font->pxMetrics.underlineThickness = UNDEF;
+    font->metrics.height = UNDEF;
+    font->metrics.maxX = UNDEF;
+    font->metrics.minX = UNDEF;
+    font->metrics.maxY = UNDEF;
+    font->metrics.minY = UNDEF;
+    font->metrics.xHeight = UNDEF;
+    font->metrics.capHeight = UNDEF;
+    font->metrics.maxAwidth = UNDEF;
+    font->metrics.awidth = UNDEF;
+    font->metrics.ascent = UNDEF;
+    font->metrics.descent = UNDEF;
+    font->metrics.underlinePosition = UNDEF;
+    font->metrics.underlineThickness = UNDEF;
     font->foundry = makeName("UNKN");
     font->strikes = NULL;
     return font;
@@ -480,31 +504,90 @@ glyphMetrics(FontPtr font, int code,
 }
 
 void
-fontMetrics(FontPtr font,
-            int *max_awidth_return,
-            int *min_x_return, int *min_y_return,
-            int *max_x_return, int *max_y_return)
+fontMetrics(FontPtr font, MetricsPtr metrics)
 {
     int i, rc;
-    int max_awidth = 0;
-    int min_x = 10000 * 65536, min_y = 10000 * 65536;
-    int max_x = -10000 * 65536, max_y = -10000 * 65536;
+    double sumAwidth = 0;
+    unsigned count = 0;
+
+    metrics->height = UNDEF /* TODO */;
+    metrics->maxAwidth = 0;
+    metrics->maxX = -10000 * TWO_SIXTEENTH;
+    metrics->maxY = -10000 * TWO_SIXTEENTH;
+    metrics->minX = 10000 * TWO_SIXTEENTH;
+    metrics->minY = 10000 * TWO_SIXTEENTH;
+    metrics->ascent = UNDEF;
+    metrics->descent = UNDEF;
+    metrics->underlinePosition = UNDEF;
+    metrics->underlineThickness = UNDEF;
+
     for(i = 0; i < FONT_CODES; i++) {
         int awidth, x0, y0, x1, y1;
         rc = glyphMetrics(font, i, &awidth, &x0, &y0, &x1, &y1);
         if(rc < 0)
             continue;
-        if(awidth > max_awidth)
-            max_awidth = awidth;
-        if(x0 < min_x) min_x = x0;
-        if(y0 < min_y) min_y = y0;
-        if(x1 > max_x) max_x = x1;
-        if(y1 > max_y) max_y = y1;
+
+        if(awidth > metrics->maxAwidth) metrics->maxAwidth = awidth;
+        if(x0 < metrics->minX) metrics->minX = x0;
+        if(y0 < metrics->minY) metrics->minY = y0;
+        if(x1 > metrics->maxX) metrics->maxX = x1;
+        if(y1 > metrics->maxY) metrics->maxY = y1;
+
+	if(awidth > 0) {
+	    sumAwidth += awidth;
+	    count++;
+	}
     }
-    if(max_awidth_return) *max_awidth_return = max_awidth;
-    if(min_x_return) *min_x_return = min_x;
-    if(min_y_return) *min_y_return = min_y;
-    if(max_x_return) *max_x_return = max_x;
-    if(max_y_return) *max_y_return = max_y;
-}
 
+    if (count) metrics->awidth = sumAwidth / count;
+
+    if(font->pxMetrics.ascent == UNDEF)
+	metrics->ascent = metrics->maxY;
+    else
+	metrics->ascent =
+	    font->pxMetrics.ascent
+	    * TWO_SIXTEENTH / font->pxMetrics.height;
+
+    if(font->pxMetrics.descent == UNDEF)
+	metrics->descent = metrics->minY;
+    else
+	metrics->descent =
+	    font->pxMetrics.descent
+	    * TWO_SIXTEENTH / font->pxMetrics.height;
+
+    if(font->pxMetrics.capHeight == UNDEF)
+	/* TODO get ascent of letter 'X' - how to do lookups of ascii codes ? */
+	metrics->capHeight = metrics->ascent;
+    else
+	metrics->capHeight =
+	    font->pxMetrics.capHeight
+	    * TWO_SIXTEENTH / font->pxMetrics.height;
+
+    if(font->pxMetrics.xHeight == UNDEF)
+	/* TODO get ascent of letter 'x' - how to do lookups of ascii codes ? */
+	metrics->xHeight = metrics->ascent * 2 / 3;
+    else
+	metrics->xHeight =
+	    font->pxMetrics.xHeight
+	    * TWO_SIXTEENTH / font->pxMetrics.height;
+
+    if(font->pxMetrics.underlinePosition == UNDEF)
+	metrics->underlinePosition = - metrics->descent * 2;
+    else
+	metrics->underlinePosition =
+	    font->pxMetrics.underlinePosition
+	    * TWO_SIXTEENTH / font->pxMetrics.height;
+
+    if(font->pxMetrics.underlineThickness == UNDEF)
+	/* TODO: this could be refined according to
+	 * X Logical Font Description Conventions (xlfd.txt)
+	 * by also considering the font weight. */
+	/* make sure thickness is at least one pixel. */
+	metrics->underlineThickness =
+	    TWO_SIXTEENTH
+	    / (font->pxMetrics.height < 9 ? font->pxMetrics.height : 9);
+    else
+	metrics->underlineThickness =
+	    font->pxMetrics.underlineThickness
+	    * TWO_SIXTEENTH / font->pxMetrics.height;
+}
diff --git a/util.c b/util.c
index fc6eb38..ba9d096 100644
--- a/util.c
+++ b/util.c
@@ -391,6 +391,19 @@ faceFlags(FT_Face face)
     return flags;
 }
 
+int
+faceIntProp(FT_Face face, const char *name)
+{
+    int rc;
+    BDF_PropertyRec prop;
+
+    rc = FT_Get_BDF_Property(face, name, &prop);
+    if(rc == 0 && prop.type == BDF_PROPERTY_TYPE_INTEGER)
+	return prop.u.integer;
+    else
+	return UNDEF;
+}
+
 char *
 faceEncoding(FT_Face face)
 {
diff --git a/write.c b/write.c
index 6ad09a6..5ee0f79 100644
--- a/write.c
+++ b/write.c
@@ -61,7 +61,6 @@ static int writemaxp(FILE*, FontPtr);
 static int writename(FILE*, FontPtr);
 static int writepost(FILE*, FontPtr);
 
-int max_awidth, min_x, min_y, max_x, max_y;
 static CmapPtr current_cmap = NULL;
 static int numglyphs, nummetrics;
 static int write_error_occurred, read_error_occurred;
@@ -219,7 +218,7 @@ writeFile(char *filename, FontPtr font)
     int offset[15], length[15];
     StrikePtr strike;
 
-    fontMetrics(font, &max_awidth, &min_x, &min_y, &max_x, &max_y);
+    fontMetrics(font, &font->metrics);
 
     out = fopen(filename, "wb+");
     if(out == NULL)
@@ -451,10 +450,12 @@ writehead(FILE* out, FontPtr font)
     writeLONG(out, time_hi);    /* modified */
     writeULONG(out, time_lo);
 
-    writeUSHORT(out, FONT_UNITS_FLOOR(min_x));
-    writeUSHORT(out, FONT_UNITS_FLOOR(min_y));
-    writeUSHORT(out, FONT_UNITS_CEIL(max_x));
-    writeUSHORT(out, FONT_UNITS_CEIL(max_y));
+    /* bounding box for all glyphs */
+    writeUSHORT(out, FONT_UNITS_FLOOR(font->metrics.minX));
+    writeUSHORT(out, FONT_UNITS_FLOOR(font->metrics.minY));
+    writeUSHORT(out, FONT_UNITS_CEIL(font->metrics.maxX));
+    writeUSHORT(out, FONT_UNITS_CEIL(font->metrics.maxY));
+
     writeUSHORT(out, font->flags); /* macStyle */
     writeUSHORT(out, 1);        /* lowestRecPPEM */
     writeSHORT(out, 0);         /* fontDirectionHint */
@@ -849,13 +850,15 @@ writehhea(FILE* out, FontPtr font)
     degreesToFraction(font->italicAngle, &num, &den);
 
     writeULONG(out, 0x00010000); /* version */
-    writeSHORT(out, FONT_UNITS_CEIL(max_y)); /* ascender */
-    writeSHORT(out, FONT_UNITS_FLOOR(min_y)); /* descender */
+    writeSHORT(out, FONT_UNITS_CEIL(font->metrics.ascent)); /* ascender */
+    writeSHORT(out, 0-FONT_UNITS_CEIL(font->metrics.descent)); /* descender */
     writeSHORT(out, 0);		/* lineGap */
-    writeUSHORT(out, FONT_UNITS(max_awidth)); /* advanceWidthMax */
-    writeSHORT(out, FONT_UNITS_FLOOR(min_x)); /* minLeftSideBearing */
-    writeSHORT(out, FONT_UNITS_FLOOR(min_x)); /* minRightSideBearing */
-    writeSHORT(out, FONT_UNITS_CEIL(max_x)); /* xMaxExtent */
+    writeUSHORT(out, FONT_UNITS(font->metrics.maxAwidth)); /* advanceWidthMax */
+    /* TODO: the next three are not calculated according to spec, are they ?
+     * https://docs.microsoft.com/en-us/typography/opentype/spec/hhea */
+    writeSHORT(out, FONT_UNITS_FLOOR(font->metrics.minX)); /* minLeftSideBearing */
+    writeSHORT(out, FONT_UNITS_FLOOR(font->metrics.minX)); /* minRightSideBearing */
+    writeSHORT(out, FONT_UNITS_CEIL(font->metrics.maxX)); /* xMaxExtent */
     writeSHORT(out, den);       /* caretSlopeRise */
     writeSHORT(out, num);       /* caretSlopeRun */
     writeSHORT(out, 0);         /* reserved */
@@ -974,8 +977,8 @@ writepost(FILE* out, FontPtr font)
     
     writeULONG(out, 0x00030000); /* FormatType */
     writeULONG(out, font->italicAngle); /* italicAngle */
-    writeSHORT(out, FONT_UNITS(font->underlinePosition));
-    writeSHORT(out, FONT_UNITS(font->underlineThickness));
+    writeSHORT(out, FONT_UNITS(font->metrics.underlinePosition));
+    writeSHORT(out, FONT_UNITS(font->metrics.underlineThickness));
     writeULONG(out, fixed_pitch); /* isFixedPitch */
     writeULONG(out, 0);         /* minMemType42 */
     writeULONG(out, 0);         /* maxMemType42 */
@@ -990,7 +993,7 @@ writeOS2(FILE* out, FontPtr font)
     int i;
 
     writeUSHORT(out, 0x0001);
-    writeSHORT(out, FONT_UNITS(max_awidth / 2)); /* xAvgCharWidth; */
+    writeSHORT(out, FONT_UNITS(font->metrics.awidth)); /* xAvgCharWidth; */
     writeUSHORT(out, font->weight);  /* usWeightClass; */
     writeUSHORT(out, font->width); /* usWidthClass; */
     writeSHORT(out, 0);         /* fsType; */
@@ -1002,7 +1005,7 @@ writeOS2(FILE* out, FontPtr font)
     writeSHORT(out, UNITS_PER_EM / 5); /* ySuperscriptYSize; */
     writeSHORT(out, 0);         /* ySuperscriptXOffset; */
     writeSHORT(out, UNITS_PER_EM / 5); /* ySuperscriptYOffset; */
-    writeSHORT(out, FONT_UNITS(font->underlineThickness)); 
+    writeSHORT(out, FONT_UNITS(font->metrics.underlineThickness));
     /* yStrikeoutSize; */
     writeSHORT(out, UNITS_PER_EM / 4); /* yStrikeoutPosition; */
     writeSHORT(out, 0);         /* sFamilyClass; */
@@ -1023,11 +1026,11 @@ writeOS2(FILE* out, FontPtr font)
     writeUSHORT(out, i);	/* fsSelection; */
     writeUSHORT(out, 0x20);     /* usFirstCharIndex; */
     writeUSHORT(out, 0xFFFD);   /* usLastCharIndex; */
-    writeUSHORT(out, FONT_UNITS_CEIL(max_y)); /* sTypoAscender; */
-    writeUSHORT(out, FONT_UNITS_FLOOR(min_y)); /* sTypoDescender; */
+    writeUSHORT(out, FONT_UNITS_CEIL(font->metrics.ascent)); /* sTypoAscender; */
+    writeUSHORT(out, FONT_UNITS_FLOOR(font->metrics.descent)); /* sTypoDescender; */
     writeUSHORT(out, 0);	/* sTypoLineGap; */
-    writeUSHORT(out, FONT_UNITS_CEIL(max_y)); /* usWinAscent; */
-    writeUSHORT(out, -FONT_UNITS_FLOOR(min_y)); /* usWinDescent; */
+    writeUSHORT(out, FONT_UNITS_CEIL(font->metrics.maxY)); /* usWinAscent; */
+    writeUSHORT(out, -FONT_UNITS_FLOOR(font->metrics.minY)); /* usWinDescent; */
     writeULONG(out, 3);         /* ulCodePageRange1; */
     writeULONG(out, 0);         /* ulCodePageRange2; */
     return 0;
@@ -1067,11 +1070,11 @@ writePCLT(FILE* out, FontPtr font)
 
     writeULONG(out, 0x00010000); /* version */
     writeULONG(out, 0);         /* FontNumber */
-    writeUSHORT(out, FONT_UNITS(max_awidth)); /* pitch */
-    writeUSHORT(out, FONT_UNITS(max_y));    /* xHeight */
+    writeUSHORT(out, FONT_UNITS(font->metrics.maxAwidth)); /* pitch */
+    writeUSHORT(out, FONT_UNITS(font->metrics.xHeight));    /* xHeight */
     writeUSHORT(out, style);    /* style */
     writeUSHORT(out, 6 << 12);  /* TypeFamily */
-    writeUSHORT(out, FONT_UNITS(max_y)); /* CapHeight */
+    writeUSHORT(out, FONT_UNITS(font->metrics.xHeight)); /* CapHeight */
     writeUSHORT(out, 0);        /* SymbolSet */
     writeCHARs(out, name, 16);  /* TypeFace */
     writeBYTEs(out, charComplement, 8); /* CharacterComplement */