Rhythm Selection & Cleanup

include/vamp_protocol/page_control.hpp

@@ -1,6 +1,9 @@
 #pragma once
 
 #include <modulus/types.hpp>
+#include <cstddef>
+#include <cstdint>
+#include <string_view>
 
 
 namespace vamp_protocol {
@@ -12,6 +15,33 @@ constexpr std::char_t remote_previous_path[] = "/api/remote/previous";
 constexpr std::char_t remote_select_path[] = "/api/remote/select";
 constexpr std::char_t remote_heartbeat_path[] = "/api/remote/heartbeat";
 constexpr std::char_t remote_display_path[] = "/api/remote/display";
+constexpr std::char_t remote_title_path[] = "/api/remote/title";
+constexpr auto title_width = std::size_t{296};
+constexpr auto title_height = std::size_t{64};
+constexpr auto title_header_size = std::size_t{8};
+constexpr auto title_image_size = title_header_size + title_width * title_height / 2U;
+constexpr auto title_id_size = std::size_t{64};
+
+inline auto valid_title_id(std::string_view value) -> std::bool_t {
+  if (value.size() != title_id_size) {
+    return false;
+  }
+  for (auto character : value) {
+    if (!((character >= '0' && character <= '9') || (character >= 'a' && character <= 'f'))) {
+      return false;
+    }
+  }
+  return true;
+}
+
+// VPTI, little-endian uint16 dimensions, then row-major coverage, high nibble first.
+
+inline auto valid_title_image(std::string_view bytes) -> std::bool_t {
+  return bytes.size() == title_image_size && bytes.substr(0U, 4U) == "VPTI" &&
+         static_cast<std::uint8_t>(bytes[4]) == (title_width & 255U) &&
+         static_cast<std::uint8_t>(bytes[5]) == (title_width >> 8U) &&
+         static_cast<std::uint8_t>(bytes[6]) == title_height && bytes[7] == 0;
+}
 
 enum class page_command {
   PREVIOUS,