1 files changed, 102 insertions, 0 deletions
diff --git a/fscalc.cpp b/fscalc.cpp
new file mode 100644
index 0000000..6842a65
--- /dev/null
+++ b/fscalc.cpp
@@ -0,0 +1,102 @@
+#include <stdexcept>
+#include "fscalc.h"
+
+Font::Font(std::string s, int slant, int weight) {
+	FcPattern *tmp1, *tmp2, *final;
+	FcResult res;
+	FcChar8 *filename;
+	int fontindex;
+
+	if(!(fc = FcInitLoadConfigAndFonts()))
+		throw(std::runtime_error("failed to initialize fontconfig"));
+
+	if(FT_Init_FreeType(&library))
+		throw(std::runtime_error("failed to initialize freetype"));
+
+	aux = FcPatternCreate();
+
+	tmp1 = FcPatternBuild(NULL,
+		FC_FAMILY, FcTypeString, s.c_str(),
+		FC_SLANT, FcTypeInteger, slant,
+		FC_WEIGHT, FcTypeInteger, weight ? 300 : 100,
+		NULL);
+	if(!tmp1)
+		throw(std::runtime_error("failed to load font"));
+
+	tmp2 = FcFontRenderPrepare(fc, tmp1, aux);
+	FcPatternDestroy(tmp1);
+	final = FcFontMatch(fc, tmp2, &res);
+	FcPatternDestroy(tmp2);
+	if(!final)
+		throw(std::runtime_error("failed to load font"));
+
+	if(FcPatternGetString(final, FC_FILE, 0, &filename) != FcResultMatch || FcPatternGetInteger(final, FC_INDEX, 0, &fontindex) != FcResultMatch) {
+		FcPatternDestroy(final);
+		throw(std::runtime_error("failed to locate font"));
+	}
+
+	if(FT_New_Face(library, (char*)filename, fontindex, &face)) {
+		FcPatternDestroy(final);
+		throw(std::runtime_error("failed to create new face"));
+	}
+
+	FcPatternDestroy(final);
+	FcPatternDestroy(aux);
+// 	FcFini();
+}
+
+Font::~Font() {
+	FT_Done_Face(face);
+	FT_Done_FreeType(library);
+}
+
+void Font::set_font_size(int size) {
+	FT_Size_RequestRec req;
+	TT_OS2 *os2;
+	TT_HoriHeader *hori;
+	float scale = 1.0;
+
+	FT_Size_Metrics *m = &face->size->metrics;
+
+	os2 = (TT_OS2*)FT_Get_Sfnt_Table(face, ft_sfnt_os2);
+	hori = (TT_HoriHeader*)FT_Get_Sfnt_Table(face, ft_sfnt_hhea);
+	if(os2 && hori) {
+		int horisum = hori->Ascender - hori->Descender;
+		unsigned int winsum = os2->usWinAscent + os2->usWinDescent;
+		scale = (float)horisum / (float)winsum;
+	}
+
+	req.type = FT_SIZE_REQUEST_TYPE_REAL_DIM;
+	req.width = 0;
+	req.height = (FT_F26Dot6)(size * 64 * scale);
+	req.horiResolution = 0;
+	req.vertResolution = 0;
+	FT_Request_Size(face, &req);
+}
+
+double Font::get_kerning(FT_UInt left, FT_UInt right) {
+	if(FT_HAS_KERNING(face)) {
+		FT_Vector d;
+		FT_Get_Kerning(face, left, right, 0, &d);
+		return (double)d.x / 64.0;
+	} else return 0;
+}
+
+unsigned int Font::get_text_width(std::string s) {
+	FT_UInt prev = 0;
+	bool kerning = FT_HAS_KERNING(face);
+	double width = 0;
+	for(std::string::iterator c = s.begin(); c < s.end(); c++) {
+		int i = FT_Get_Char_Index(face, *c);
+		if(kerning && prev && i)
+			width += get_kerning(prev, i);
+		if(FT_Load_Char(face, *c, 0))
+			throw(std::runtime_error("failed to load char"));
+		width += (double)face->glyph->advance.x / 64.0;
+	}
+	return int(width);
+}
+
+unsigned int Font::get_line_height() {
+	return face->bbox.yMax - face->bbox.yMin;
+}