From d475003215828d8b78b79e5062b64cb9bc7fb58d Mon Sep 17 00:00:00 2001
From: King_DuckZ <king_duckz@gmx.com>
Date: Fri, 20 Mar 2020 01:43:50 +0100
Subject: [PATCH] Add frame() method.

---
 subprojects/memcard/include/memcard/block.hpp |  3 +++
 subprojects/memcard/src/block.cpp             | 21 +++++++++++++++----
 2 files changed, 20 insertions(+), 4 deletions(-)

diff --git a/subprojects/memcard/include/memcard/block.hpp b/subprojects/memcard/include/memcard/block.hpp
index ec277cb..d4cf491 100644
--- a/subprojects/memcard/include/memcard/block.hpp
+++ b/subprojects/memcard/include/memcard/block.hpp
@@ -33,6 +33,9 @@ public:
 	const data_type* begin() const { return m_begin; }
 	const data_type* end() const { return m_begin + size(); }
 
+	data_type* frame(unsigned int idx);
+	const data_type* frame(unsigned int idx) const;
+
 	static constexpr std::size_t size() { return 8192; }
 
 	const std::vector<uint8_t>& palette() const { return m_icon_palette; }
diff --git a/subprojects/memcard/src/block.cpp b/subprojects/memcard/src/block.cpp
index cdcf7b5..5410a6c 100644
--- a/subprojects/memcard/src/block.cpp
+++ b/subprojects/memcard/src/block.cpp
@@ -85,27 +85,40 @@ BasicBlock<Const>::BasicBlock (data_type* beg) :
 template <bool Const>
 BasicBlock<Const>::~BasicBlock() = default;
 
+template <bool Const>
+auto BasicBlock<Const>::frame(unsigned int idx) -> data_type* {
+	return const_cast<data_type*>(const_cast<const BasicBlock<Const>*>(this)->frame(idx));
+}
+
+template <bool Const>
+auto BasicBlock<Const>::frame(unsigned int idx) const -> const data_type* {
+	const constexpr unsigned int framesize = 128;
+	assert(idx * framesize + framesize <= this->size());
+	return this->begin() + framesize * idx;
+}
+
 template <bool Const>
 bool BasicBlock<Const>::has_magic() const {
 	const constexpr uint16_t magic = ('S' << 8) | 'C'; //0x5343 "SC"
-	return magic == static_cast<uint16_t>((m_begin[0] << 8) | m_begin[1]);
+	const data_type* const ptr = frame(0);
+	return magic == static_cast<uint16_t>((ptr[0] << 8) | ptr[1]);
 }
 
 template <bool Const>
 IconDisplayFlag BasicBlock<Const>::icon_display_flag() const {
-	const uint8_t val = m_begin[2];
+	const uint8_t val = frame(0)[2];
 	return static_cast<IconDisplayFlag>(val);
 }
 
 template <bool Const>
 int BasicBlock<Const>::block_count() const {
-	return m_begin[3];
+	return frame(0)[3];
 }
 
 template <bool Const>
 std::string BasicBlock<Const>::title() const {
 	char mem[64 + 1];
-	std::strncpy(mem, reinterpret_cast<const char*>(m_begin + 4), sizeof(mem) / sizeof(mem[0]));
+	std::strncpy(mem, reinterpret_cast<const char*>(frame(0) + 4), sizeof(mem) / sizeof(mem[0]));
 	std::string_view temp(mem, std::strlen(mem));
 	auto name = full_to_halfwidth_ascii(shiftjis_to_utf8(temp));