x86_64: vga: improve text printing code

2 files changed, 50 insertions, 4 deletions

diff --git a/source/arch/x86_64/include/arch/boot/pointers.hpp b/source/arch/x86_64/include/arch/boot/pointers.hpp
index 052b115..dcd14fe 100644
--- a/source/arch/x86_64/include/arch/boot/pointers.hpp
+++ b/source/arch/x86_64/include/arch/boot/pointers.hpp
@@ -6,7 +6,6 @@
 namespace teachos::arch::boot
 {
   extern "C" std::byte const multiboot_information_pointer;
-  extern "C" std::byte * vga_buffer_pointer;
 }  // namespace teachos::arch::boot
 
 #endif
\ No newline at end of file
diff --git a/source/arch/x86_64/include/arch/video/vga/text.hpp b/source/arch/x86_64/include/arch/video/vga/text.hpp
index 04b74d1..c9a79b8 100644
--- a/source/arch/x86_64/include/arch/video/vga/text.hpp
+++ b/source/arch/x86_64/include/arch/video/vga/text.hpp
@@ -1,12 +1,59 @@
 #ifndef TEACHOS_ARCH_X86_64_VIDEO_VGA_TEXT_HPP
 #define TEACHOS_ARCH_X86_64_VIDEO_VGA_TEXT_HPP
 
-#include <cstddef>
+#include <cstdint>
 #include <string_view>
 
 namespace teachos::arch::video::vga::text
 {
-  auto write(std::string_view text, std::byte color) -> void;
-}
+  enum struct color : std::uint8_t
+  {
+    black,
+    blue,
+    green,
+    cyan,
+    red,
+    purple,
+    brown,
+    gray,
+  };
+
+  enum struct foreground_flag : bool
+  {
+    none,
+    intense,
+  };
+
+  enum struct background_flag : bool
+  {
+    none,
+    blink_or_bright,
+  };
+
+  struct attribute
+  {
+    color foreground_color : 3;
+    enum foreground_flag foreground_flag : 1;
+    color bacground_color : 3;
+    enum background_flag background_flag : 1;
+  };
+
+  static_assert(sizeof(attribute) == 1);
+
+  namespace common_attributes
+  {
+    [[maybe_unused]]
+    auto constexpr gray_on_black = attribute{color::gray, foreground_flag::none, color::black, background_flag::none};
+
+    [[maybe_unused]]
+    auto constexpr green_on_black = attribute{color::green, foreground_flag::none, color::black, background_flag::none};
+
+    [[maybe_unused]]
+    auto constexpr white_on_red = attribute{color::gray, foreground_flag::intense, color::red, background_flag::none};
+  }
+
+  auto clear(attribute attribute = common_attributes::gray_on_black) -> void;
+  auto write(std::string_view code_points, attribute attribute) -> void;
+}  // namespace teachos::arch::video::vga::text
 
 #endif
\ No newline at end of file