trying to get at ascent/descent metrics

diff --git a/contrib/pangotest/pangotest.c b/contrib/pangotest/pangotest.c
index b021410051c801dce5b394e39e07d94fb72eb4a7..0445ad881cdaf89fd12511c2b7c28a72711e9699 100644 (file)
--- a/contrib/pangotest/pangotest.c
+++ b/contrib/pangotest/pangotest.c
@@ -9,8 +9,6 @@
 #define DEFAULT_FONT_SIZE 16.
 #define DEFAULT_TEXT "ABCgjpqyXYZ"
 #define FONT_DPI 96
-#define PANGO_SCALE 1024
-
 
 static void draw_text(cairo_t *cr, char *text, char *font_family, double font_size){
        static PangoFontMap *fontmap;
@@ -18,10 +16,12 @@ static void draw_text(cairo_t *cr, char *text, char *font_family, double font_si
        PangoLayout *layout;
        PangoFontDescription *desc;
        PangoRectangle logical_rect, ink_rect;
-       PangoLayoutIter* iter;
-       PangoFont* font;
-       cairo_font_options_t* options;
+       PangoLayoutIter *iter;
+       PangoFont *font;
+       PangoFontMetrics *fontmetrics;
+       cairo_font_options_t *options;
        const char *fontclass, *fontdesc;
+       int baseline, ascent, descent;
 
        if (!context) {
                fontmap = pango_cairo_font_map_new();
@@ -33,6 +33,7 @@ static void draw_text(cairo_t *cr, char *text, char *font_family, double font_si
                cairo_font_options_set_hint_metrics(options,CAIRO_HINT_METRICS_ON);
                cairo_font_options_set_subpixel_order(options,CAIRO_SUBPIXEL_ORDER_BGR);
                pango_cairo_context_set_font_options(context, options);
+//             pango_cairo_context_set_resolution(context, FONT_DPI);
                cairo_font_options_destroy(options);
                g_object_unref(fontmap);
        }
@@ -57,6 +58,7 @@ static void draw_text(cairo_t *cr, char *text, char *font_family, double font_si
        
        /* draw logical_rect - purple */
        pango_layout_get_extents (layout, &ink_rect, &logical_rect);
+
        cairo_set_source_rgb(cr,1.0,0.0,1.0);
        cairo_rectangle(cr,
                logical_rect.x/PANGO_SCALE, logical_rect.y/PANGO_SCALE,
@@ -73,10 +75,33 @@ static void draw_text(cairo_t *cr, char *text, char *font_family, double font_si
        /* draw baseline - red */
        cairo_set_source_rgb(cr,1.0,0.0,0.0);
        iter = pango_layout_get_iter(layout);
-       cairo_move_to(cr,logical_rect.y/PANGO_SCALE, pango_layout_iter_get_baseline (iter) / PANGO_SCALE);
+       baseline = pango_layout_iter_get_baseline (iter);
+
+       cairo_move_to(cr,logical_rect.y/PANGO_SCALE, baseline / PANGO_SCALE);
        cairo_rel_line_to(cr,logical_rect.width/PANGO_SCALE, 0);
        cairo_stroke(cr);
 
+       /* draw ascent - yellow */
+       cairo_set_source_rgb(cr,1.0,1.0,0.0);
+       fontmetrics = pango_context_get_metrics(context, NULL, NULL);
+
+       ascent = pango_font_metrics_get_ascent(fontmetrics);
+#if 0  /* I don't understand this value */
+       cairo_move_to(cr,logical_rect.y/PANGO_SCALE, (baseline - ascent) / PANGO_SCALE);
+       cairo_rel_line_to(cr,logical_rect.width/PANGO_SCALE, 0);
+       cairo_stroke(cr);
+#endif
+
+       /* draw descent - yellow */
+       descent = pango_font_metrics_get_descent(fontmetrics);
+#if 0  /* I don't understand this value */
+       cairo_move_to(cr,logical_rect.y/PANGO_SCALE, (baseline + descent) / PANGO_SCALE);
+       cairo_rel_line_to(cr,logical_rect.width/PANGO_SCALE, 0);
+       cairo_stroke(cr);
+#endif
+
+       pango_font_metrics_unref(fontmetrics);
+
        g_object_unref(layout);
 }