graphics: Render fractions graphically

Render fractions using a grob Fixes: #47 Signed-off-by: Christophe de Dinechin <christophe@dinechin.org>
c3d · Feb 21, 2024 · ce709f4 · ce709f4
1 parent c8fceb9
commit ce709f4
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diff --git a/src/fraction.cc b/src/fraction.cc
@@ -28,7 +28,10 @@
 // ****************************************************************************
 
 #include "fraction.h"
+
 #include "algebraic.h"
+#include "grob.h"
+
 
 RECORDER(fraction, 16, "Fractions");
 
@@ -88,6 +91,43 @@ EVAL_BODY(fraction)
 }
 
 
+GRAPH_BODY(fraction)
+// ----------------------------------------------------------------------------
+//   Render a fraction in graphical mode
+// ----------------------------------------------------------------------------
+{
+    fraction_g obj = o;
+    // save<settings::font_id> save(g.font, settings::smaller_font(g.font));
+
+    // Render numerator and denominator
+    bignum_g num = obj->numerator();
+    bignum_g den = obj->denominator();
+    grob_g numg = num->graph(g);
+    grob_g deng = den->graph(g);
+
+    using pixsize = grob::pixsize;
+    pixsize nw = numg->width();
+    pixsize nh = numg->height();
+    pixsize dw = deng->width();
+    pixsize dh = deng->height();
+
+    pixsize gw = nw > dw ? nw : dw;
+    pixsize gh = nh + dh + 4;
+
+    grob_g result = grob::make(gw, gh);
+
+    surface ns = numg->pixels();
+    surface ds = deng->pixels();
+    surface rs = result->pixels();
+
+    rs.fill(0, 0, gw, gh, g.background);
+    rs.copy(ns, point((gw - nw)/2, 0));
+    rs.copy(ds, point((gw - dw)/2, nh + 4));
+    rs.fill(0, nh+1, gw, nh+2);
+    return result;
+}
+
+
 fraction_g fraction::make(integer_g n, integer_g d)
 // ----------------------------------------------------------------------------
 //   Create a reduced fraction from n and d

diff --git a/src/fraction.h b/src/fraction.h
@@ -102,6 +102,7 @@ struct fraction : algebraic
     HELP_DECL(fraction);
     EVAL_DECL(fraction);
     RENDER_DECL(fraction);
+    GRAPH_DECL(fraction);
     PREC_DECL(MULTIPLICATIVE);
 };
 

diff --git a/src/grob.h b/src/grob.h
@@ -258,6 +258,7 @@ struct grapher
           background(bg),
           flat(flat)
     {}
+    grapher(const grapher &other) = default;
 
     size    maxw;
     size    maxh;

diff --git a/src/settings.h b/src/settings.h
@@ -109,6 +109,30 @@ struct settings
         NUM_FONTS
     };
 
+
+    static font_id smaller_font(font_id f)
+    // ------------------------------------------------------------------------
+    //   Find the next smaller font
+    // ------------------------------------------------------------------------
+    {
+        switch (f)
+        {
+        default:
+        case HELP:
+        case STACK:     return HELP;
+        case EDITOR:    return STACK;
+        case LIB17:
+        case LIB18:     return LIB17;
+        case LIB20:     return LIB18;
+        case LIB22:     return LIB20;
+        case LIB25:     return LIB22;
+        case LIB28:     return LIB25;
+        case SKR18:
+        case SKR24:     return SKR18;
+        case FREE42:    return FREE42;
+        }
+    }
+
 #define ID(i)   static const object::id ID_##i = object::ID_##i;
 #include "ids.tbl"