Use correct font metrics from truetype files.

Kerning, etc. should now be correct, but we use a monospace font
so it doesn't matter.

diff --git a/src/document.cpp b/src/document.cpp
index e684f3e..6038b19 100644 (file)
--- a/src/document.cpp
+++ b/src/document.cpp
@@ -683,18 +683,28 @@ void Document::AddText(const string & text, Real scale, Real x, Real y)
        float font_scale = stbtt_ScaleForPixelHeight(&m_font, scale);
        Real x0(x);
        //Real y0(y);
+       int ascent = 0, descent = 0, line_gap = 0;
+       stbtt_GetFontVMetrics(&m_font, &ascent, &descent, &line_gap);
+       Real y_advance = Real(font_scale) * Real(ascent - descent + line_gap);
        for (unsigned i = 0; i < text.size(); ++i)
        {
                if (text[i] == '\n')
                {
-                       y += 0.5*scale;
+                       y += y_advance;
                        x = x0;
                }
                if (!isprint(text[i]))
                        continue;
                        
+               int advance_width = 0, left_side_bearing = 0, kerning = 0;
+               stbtt_GetCodepointHMetrics(&m_font, text[i], &advance_width, &left_side_bearing);
+               if (i > 1)
+               {
+                       kerning = stbtt_GetCodepointKernAdvance(&m_font, text[i-1], text[i]);
+               }
+               x += Real(font_scale) * Real(left_side_bearing + kerning);
                AddFontGlyphAtPoint(&m_font, text[i], font_scale, x, y);
-               x += 0.5*scale;
+               x += Real(font_scale) * Real(advance_width);
        }
 }