Squashed 'deps/nostalgia/' content from commit 9cb6bd4a

git-subtree-dir: deps/nostalgia
git-subtree-split: 9cb6bd4a32e9f39a858f72443ff5c6d40489fe22

deps/teagba/src/gfx.cpp

@@ -0,0 +1,32 @@
+/*
+ * Copyright 2016 - 2023 Gary Talent (gary@drinkingtea.net). All rights reserved.
+ */
+
+#include <teagba/addresses.hpp>
+#include <teagba/bios.hpp>
+#include <teagba/irq.hpp>
+
+#include <teagba/gfx.hpp>
+
+namespace teagba {
+
+static ox::Array<GbaSpriteAttrUpdate, 128> g_spriteBuffer;
+
+GbaSpriteAttrUpdate &spriteAttr(size_t i) noexcept {
+	return g_spriteBuffer[i];
+}
+
+void addSpriteUpdate(const GbaSpriteAttrUpdate &upd) noexcept {
+	const auto ie = REG_IE; // disable vblank interrupt handler
+	REG_IE = REG_IE & static_cast<uint16_t>(~teagba::Int_vblank); // disable vblank interrupt handler
+	g_spriteBuffer[upd.idx] = upd;
+	REG_IE = ie; // enable vblank interrupt handler
+}
+
+void applySpriteUpdates() noexcept {
+	for (auto const&oa : g_spriteBuffer) {
+		MEM_OAM[oa.idx] = std::bit_cast<uint64_t>(oa);
+	}
+}
+
+}