pass font to canvas.print(...)

src/gfx/canvas.cpp

@@ -3,3 +3,18 @@
 //
 
 #include "gfx/canvas.h"
+
+canvas::canvas(int w, int h) : width_(w), height_(h) {
+}
+
+void canvas::draw(int x, int y) {
+    hal_draw(x, y);
+}
+
+void canvas::print(int x, int y, const char *str, font& f) {
+    f.print(x, y, str, *this);
+}
+
+void canvas::print(int x, int y, char *str, font& f) {
+    f.print(x, y, str, *this);
+}