[Teton] Factor drawing glyphs to screen into a separate class.

sys/teton/framebuffer/console.h

@@ -0,0 +1,23 @@
+#pragma once
+
+#include <glacier/string/string_view.h>
+
+#include "framebuffer/framebuffer.h"
+#include "framebuffer/psf.h"
+
+class Console {
+ public:
+  explicit Console(Framebuffer& fb, Psf& psf) : framebuf_(fb), psf_(psf) {}
+
+  void WriteChar(char c);
+  void WriteString(glcr::StringView str);
+
+  uint32_t rows() { return framebuf_.height() / (psf_.height() + 1); }
+  uint32_t cols() { return framebuf_.width() / (psf_.width() + 1); }
+
+ private:
+  // TODO: Don't store a reference here.
+  Framebuffer& framebuf_;
+  Psf& psf_;
+  uint64_t cursor_pos_ = 0;
+};