From ea3c5e03fbccf2ef062be3174c45d2395644d29b Mon Sep 17 00:00:00 2001
From: Gary Talent <gary@drinkingtea.net>
Date: Fri, 4 Oct 2024 01:00:02 -0500
Subject: [PATCH] [olympic] Remove Ox from developer-handbook.md

---
 developer-handbook.md | 493 ++----------------------------------------
 1 file changed, 24 insertions(+), 469 deletions(-)

diff --git a/developer-handbook.md b/developer-handbook.md
index a2cb24e6..15e88578 100644
--- a/developer-handbook.md
+++ b/developer-handbook.md
@@ -1,4 +1,4 @@
-# Nostalgia Developer Handbook
+# Olympic Developer Handbook
 
 ## About
 
@@ -47,7 +47,7 @@ All components have a platform indicator next to them:
   * Ox - Library of things useful for portable bare metal and userland code. Not really that external...
     * clargs - Command Line Args processing (PG)
     * claw - Reads and writes Metal or Organic Claw with header to indicate which
-    * event - Qt-like signal system
+    * event - Qt-like signal system (PG)
     * fs - file system (PG)
 	 * logconn - connects logging to Bullock (P-)
     * mc - Metal Claw serialization, builds on model (PG)
@@ -59,6 +59,10 @@ All components have a platform indicator next to them:
   * teagba - GBA assembly startup code (mostly pulled from devkitPro under MPL
 	          2.0), and custom GBA hardware interop code (-G)
 
+Most GBA code is built on PC because it is small and helps to work on both
+projects with the same CMake build dir, but GBA code is never linked with any
+executables on PC.
+
 ## Platform Notes
 
 ### GBA
@@ -88,6 +92,7 @@ The GBA has two major resources for learning about its hardware:
 * Pointer and reference designators should be bound to the identifier name and
   not the type, unless there is not identifier name, in which case it should be
   bound to the type.
+* East const
 
 ### Write C++, Not C
 
@@ -160,479 +165,29 @@ classes in question.
 
 ## Project Systems
 
-### Error Handling
-
-The GBA build has exceptions disabled.
-Instead of throwing exceptions, all engine code must return ```ox::Error```s.
-For the sake of consistency, try to stick to ```ox::Error``` in non-engine code
-as well, but non-engine code is free to use exceptions when they make sense.
-Nostalgia and Ox both use ```ox::Error``` to report errors. ```ox::Error``` is
-a struct that has overloaded operators to behave like an integer error code,
-plus some extra fields to enhance debuggability.
-If instantiated through the ```OxError(x)``` macro, it will also include the
-file and line of the error.
-The ```OxError(x)``` macro should only be used for the initial instantiation of
-an ```ox::Error```.
-
-In addition to ```ox::Error``` there is also the template ```ox::Result<T>```.
-```ox::Result``` simply wraps the type T value in a struct that also includes
-error information, which allows the returning of a value and an error without
-resorting to output parameters.
-
-If a function returns an ```ox::Error``` or ```ox::Result``` it should be
-declared as ```noexcept``` and all exceptions should be translated to an
-```ox::Error```.
-
-```ox::Result``` can be used as follows:
-
-```cpp
-ox::Result<int> foo(int i) noexcept {
-	if (i < 10) {
-		return i + 1; // implicitly calls ox::Result<T>::Result(T)
-	}
-	return OxError(1); // implicitly calls ox::Result<T>::Result(ox::Error)
-}
-
-int caller1() {
-	auto v = foo(argc);
-	if (v.error) {
-		return 1;
-	}
-	std::cout << v.value << '\n';
-	return 0;
-}
-
-int caller2() {
-	// it is also possible to capture the value and error in their own variables
-	auto [val, err] = foo(argc);
-	if (err) {
-		return 1;
-	}
-	std::cout << val << '\n';
-	return 0;
-}
-
-ox::Error caller3(int &i) {
-    return foo(i).moveTo(i);
-}
-
-ox::Error caller4(int &i) {
-    return foo(i).copyTo(i);
-}
-
-int caller5(int i) {
-    return foo(i).unwrap(); // unwrap will kill the program if there is an error
-}
-
-int caller6(int i) {
-    return foo(i).unwrapThrow(); // unwrap will throw if there is an error
-}
-
-int caller7(int i) {
-    return foo(i).or_value(0); // will return 0 if foo returned an error
-}
-
-ox::Result<uint64_t> caller8(int i) {
-    return foo(i).to<uint64_t>(); // will convert the result of foo to uint64_t
-}
-```
-
-Lastly, there are a few macros available to help in passing ```ox::Error```s
-back up the call stack, ```oxReturnError```, ```oxThrowError```, and
-```oxRequire```.
-
-```oxReturnError``` is by far the more helpful of the two.
-```oxReturnError``` will return an ```ox::Error``` if it is not 0 and
-```oxThrowError``` will throw an ```ox::Error``` if it is not 0.
-Because exceptions are disabled for GBA builds and thus cannot be used in the
-engine, ```oxThrowError``` is  only really useful at the boundary between
-engine libraries and Nostalgia Studio.
-
-Since ```ox::Error``` is always nodiscard, you must do something with them.
-In rare cases, you may not have anything you can do with them or you may know
-the code will never fail in that particular instance.
-This should be used sparingly.
-
-
-```cpp
-void studioCode() {
-	auto [val, err] = foo(1);
-	oxThrowError(err);
-	doStuff(val);
-}
-
-ox::Error engineCode() noexcept {
-	auto [val, err] = foo(1);
-	oxReturnError(err);
-	doStuff(val);
-	return {};
-}
-
-void anyCode() {
-    auto [val, err] = foo(1);
-    std::ignore = err;
-    doStuff(val);
-}
-```
-
-Both macros will also take the ```ox::Result``` directly:
-
-```cpp
-void studioCode() {
-	auto valerr = foo(1);
-	oxThrowError(valerr);
-	doStuff(valerr.value);
-}
-
-ox::Error engineCode() noexcept {
-	auto valerr = foo(1);
-	oxReturnError(valerr);
-	doStuff(valerr.value);
-	return {};
-}
-```
-
-Ox also has the ```oxRequire``` macro, which will initialize a value if there is no error, and return if there is.
-It aims to somewhat emulate the ```?``` operator in Rust and Swift.
-
-Rust ```?``` operator:
-```rust
-fn f() -> Result<i32, i32> {
-  // do stuff
-}
-
-fn f2() -> Result<i32, i32> {
-  let i = f()?;
-  Ok(i + 4)
-}
-```
-
-```oxRequire```:
-```cpp
-ox::Result<int> f() noexcept {
-	// do stuff
-}
-
-ox::Result<int> f2() noexcept {
-	oxRequire(i, f()); // const auto [out, oxConcat(oxRequire_err_, __LINE__)] = x; oxReturnError(oxConcat(oxRequire_err_, __LINE__))
-	return i + 4;
-}
-```
-```oxRequire``` is not quite as versatile, but it should still cleanup a lot of otherwise less ideal code.
-
-```oxRequire``` also has variants for throwing the error and for making to value non-const:
-
-* ```oxRequireM``` - oxRequire Mutable
-* ```oxRequireT``` - oxRequire Throw
-* ```oxRequireMT``` - oxRequire Mutable Throw
-
-The throw variants of ```oxRequire``` are generally legacy code.
-```ox::Result::unwrapThrow``` is generally preferred now.
-
-### Logging and Output
-
-Ox provides for logging and debug prints via the ```oxTrace```, ```oxDebug```, and ```oxError``` macros.
-Each of these also provides a format variation.
-
-Ox also provide ```oxOut``` and ```oxErr``` for printing to stdout and stderr.
-These are intended for permanent messages and always go to stdout and stderr.
-
-Tracing functions do not go to stdout unless the OXTRACE environment variable is set.
-They also print with the channel that they are on, along with file and line.
-
-Debug statements go to stdout and go to the logger on the "debug" channel.
-Where trace statements are intended to be written with thoughtfulness,
-debug statements are intended to be quick and temporary insertions.
-Debug statements trigger compilation failures if OX_NODEBUG is enabled when CMake is run,
-as it is on Jenkins builds, so ```oxDebug``` statements should never be checked in.
-This makes ```oxDebug``` preferable to other forms of logging, as temporary prints should
-never be checked in.
-
-```oxError``` always prints.
-It includes file and line, and is prefixed with a red "ERROR:".
-It should generally be used conservatively.
-It shuld be used only when there is an error that is not technically fatal, but
-the user almost certainly wants to know about it.
-
-```oxTrace``` and ```oxTracef```:
-```cpp
-void f(int x, int y) { // x = 9, y = 4
-	oxTrace("nostalgia.core.sdl.gfx") << "f:" << x << y; // Output: "f: 9 4"
-	oxTracef("nostalgia.core.sdl.gfx", "f: {}, {}", x, y); // Output: "f: 9, 4"
-}
-```
-
-```oxDebug``` and ```oxDebugf```:
-```cpp
-void f(int x, int y) { // x = 9, y = 4
-	oxDebug() << "f:" << x << y; // Output: "f: 9 4"
-	oxDebugf("f: {}, {}", x, y); // Output: "f: 9, 4"
-}
-```
-
-```oxError``` and ```oxErrorf```:
-```cpp
-void f(int x, int y) { // x = 9, y = 4
-	oxError() << "f:" << x << y; // Output: "ERROR: (<file>:<line>): f: 9 4"
-	oxErrorf("f: {}, {}", x, y); // Output: "ERROR: (<file>:<line>): f: 9, 4"
-}
-```
+Olympic builds on Ox as its standard-ish library.
+Please read the [Ox documentation](deps/ox/ox-docs.md).
+The Ox way of doing things is the Olympic way of doing things.
 
 ### File I/O
 
-All engine file I/O should go through nostalgia::core::Context, which should go
-through ox::FileSystem. Similarly, all studio file I/O should go thorough
-nostalgia::studio::Project, which should go through ox::FileSystem.
+All engine file I/O should go through Keel, which should go through
+```ox::FileSystem```.
+Similarly, all studio file I/O should go thorough
+```nostalgia::studio::Project```, which should go through ```ox::FileSystem```.
 
-ox::FileSystem abstracts away differences between conventional storage devices
-and ROM.
+```ox::FileSystem``` abstracts away differences between conventional storage
+devices and ROM.
 
-### Model System
+Olympic files are generally just [Claw objects](deps/ox/ox-docs.md#serialization).
 
-Ox has a model system that provides a sort of manual reflection mechanism.
+#### Keel
 
-Models require a model function for the type that you want to model.
-It is also good to provide a type name and type version number, though that is not required.
+Keel, as its name implies, is a foundational component of Olympic.
+Keel is the asset management system.
 
-The model function takes an instance of the type it is modelling and a template
-parameter type.
-The template parameter type must implement the API used in the models, but it
-can do anything with the data provided to it.
+Keel provides for the following needs:
 
-Here is an example from the Nostalgia/Core package:
-
-```cpp
-struct NostalgiaPalette {
-	static constexpr auto TypeName = "net.drinkingtea.nostalgia.core.NostalgiaPalette";
-	static constexpr auto TypeVersion = 1;
-	ox::Vector<Color16> colors;
-};
-
-struct NostalgiaGraphic {
-	static constexpr auto TypeName = "net.drinkingtea.nostalgia.core.NostalgiaGraphic";
-	static constexpr auto TypeVersion = 1;
-	int8_t bpp = 0;
-	// rows and columns are really only used by TileSheetEditor
-	int rows = 1;
-	int columns = 1;
-	ox::FileAddress defaultPalette;
-	NostalgiaPalette pal;
-	ox::Vector<uint8_t> pixels;
-};
-
-template<typename T>
-constexpr ox::Error model(T *h, ox::CommonPtrWith<NostalgiaPalette> auto *pal) noexcept {
-	h->template setTypeInfo<NostalgiaPalette>();
-	// it is also possible to provide the type name and type version as function arguments
-	//h->setTypeInfo("net.drinkingtea.nostalgia.core.NostalgiaPalette", 1);
-	oxReturnError(h->field("colors", &pal->colors));
-	return {};
-}
-
-template<typename T>
-constexpr ox::Error model(T *h, ox::CommonPtrWith<NostalgiaGraphic> auto *ng) noexcept {
-	h->template setTypeInfo<NostalgiaGraphic>();
-	oxReturnError(h->field("bpp", &ng->bpp));
-	oxReturnError(h->field("rows", &ng->rows));
-	oxReturnError(h->field("columns", &ng->columns));
-	oxReturnError(h->field("defaultPalette", &ng->defaultPalette));
-	oxReturnError(h->field("pal", &ng->pal));
-	oxReturnError(h->field("pixels", &ng->pixels));
-	return {};
-}
-```
-
-The model system also provides for unions:
-
-```cpp
-
-#include <ox/model/types.hpp>
-
-class FileAddress {
-
-	template<typename T>
-	friend constexpr Error model(T*, ox::CommonPtrWith<FileAddress> auto*) noexcept;
-
-	public:
-		static constexpr auto TypeName = "net.drinkingtea.ox.FileAddress";
-
-		union Data {
-			static constexpr auto TypeName = "net.drinkingtea.ox.FileAddress.Data";
-			char *path;
-			const char *constPath;
-			uint64_t inode;
-		};
-
-	protected:
-		FileAddressType m_type = FileAddressType::None;
-		Data m_data;
-
-};
-
-template<typename T>
-constexpr Error model(T *h, ox::CommonPtrWith<FileAddress::Data> auto *obj) noexcept {
-	h->template setTypeInfo<FileAddress::Data>();
-	oxReturnError(h->fieldCString("path", &obj->path));
-	oxReturnError(h->fieldCString("constPath", &obj->path));
-	oxReturnError(h->field("inode", &obj->inode));
-	return {};
-}
-
-template<typename T>
-constexpr Error model(T *io, ox::CommonPtrWith<FileAddress> auto *fa) noexcept {
-	io->template setTypeInfo<FileAddress>();
-	// cannot read from object in Reflect operation
-	if constexpr(ox_strcmp(T::opType(), OpType::Reflect) == 0) {
-		int8_t type = 0;
-		oxReturnError(io->field("type", &type));
-		oxReturnError(io->field("data", UnionView(&fa->m_data, 0)));
-	} else {
-		auto type = static_cast<int8_t>(fa->m_type);
-		oxReturnError(io->field("type", &type));
-		fa->m_type = static_cast<FileAddressType>(type);
-		oxReturnError(io->field("data", UnionView(&fa->m_data, static_cast<int>(fa->m_type))));
-	}
-	return {};
-}
-
-```
-
-There are also macros in ```<ox/model/def.hpp>``` for simplifying the declaration of models:
-
-```cpp
-oxModelBegin(NostalgiaGraphic)
-	oxModelField(bpp)
-	oxModelField(rows)
-	oxModelField(columns)
-	oxModelField(defaultPalette)
-	oxModelField(pal)
-	oxModelField(pixels)
-oxModelEnd()
-```
-
-### Serialization
-
-Using the model system, Ox provides for serialization.
-Ox has MetalClaw and OrganicClaw as its serialization format options.
-MetalClaw is a custom binary format designed for minimal size.
-OrganicClaw is a wrapper around JsonCpp, chosen because it technically
-implements a superset of JSON.
-OrganicClaw requires support for 64 bit integers, whereas normal JSON
-technically does not.
-
-These formats do not currently support floats.
-
-There is also a wrapper format called Claw that provides a header at the
-beginning of the file and can dynamically switch between the two depending on
-what the header says is present.
-The Claw header also includes information about the type and type version of
-the data.
-
-Claw header: ```M1;net.drinkingtea.nostalgia.core.NostalgiaPalette;1;```
-
-That reads:
-
-* Format is Metal Claw, version 1
-* Type ID is net.drinkingtea.nostalgia.core.NostalgiaPalette
-* Type version is 1
-
-Except when the data is exported for loading on the GBA, Claw is always used as
-a wrapper around the bare formats.
-
-#### Metal Claw Example
-
-##### Read
-
-```cpp
-#include <ox/mc/read.hpp>
-
-ox::Result<NostalgiaPalette> loadPalette1(ox::BufferView const&buff) noexcept {
-	return ox::readMC<NostalgiaPalette>(buff);
-}
-
-ox::Result<NostalgiaPalette> loadPalette2(ox::BufferView const&buff) noexcept {
-	NostalgiaPalette pal;
-	oxReturnError(ox::readMC(buff, pal));
-	return pal;
-}
-```
-
-##### Write
-
-```cpp
-#include <ox/mc/write.hpp>
-
-ox::Result<ox::Buffer> writeSpritePalette1(NostalgiaPalette const&pal) noexcept {
-	ox::Buffer buffer(ox::units::MB);
-	std::size_t sz = 0;
-	oxReturnError(ox::writeMC(buffer.data(), buffer.size(), pal, &sz));
-	buffer.resize(sz);
-	return buffer;
-}
-
-ox::Result<ox::Buffer> writeSpritePalette2(NostalgiaPalette const&pal) noexcept {
-	return ox::writeMC(pal);
-}
-```
-
-#### Organic Claw Example
-
-##### Read
-
-```cpp
-#include <ox/oc/read.hpp>
-
-ox::Result<NostalgiaPalette> loadPalette1(ox::BufferView const&buff) noexcept {
-	return ox::readOC<NostalgiaPalette>(buff);
-}
-
-ox::Result<NostalgiaPalette> loadPalette2(ox::BufferView const&buff) noexcept {
-	NostalgiaPalette pal;
-	oxReturnError(ox::readOC(buff, &pal));
-	return pal;
-}
-```
-
-##### Write
-
-```cpp
-#include <ox/oc/write.hpp>
-
-ox::Result<ox::Buffer> writeSpritePalette1(NostalgiaPalette const&pal) noexcept {
-	ox::Buffer buffer(ox::units::MB);
-	oxReturnError(ox::writeOC(buffer.data(), buffer.size(), pal));
-	return buffer;
-}
-
-ox::Result<ox::Buffer> writeSpritePalette2(NostalgiaPalette const&pal) noexcept {
-	return ox::writeOC(pal);
-}
-```
-
-#### Claw Example
-
-##### Read
-
-```cpp
-#include <ox/claw/read.hpp>
-
-ox::Result<NostalgiaPalette> loadPalette1(ox::BufferView const&buff) noexcept {
-	return ox::readClaw<NostalgiaPalette>(buff);
-}
-
-ox::Result<NostalgiaPalette> loadPalette2(ox::BufferView const&buff) noexcept {
-	NostalgiaPalette pal;
-	oxReturnError(ox::readClaw(buff, pal));
-	return pal;
-}
-```
-
-##### Write
-
-```cpp
-#include <ox/claw/write.hpp>
-
-ox::Result<ox::Buffer> writeSpritePalette(NostalgiaPalette const&pal) noexcept {
-	return ox::writeClaw(pal);
-}
-```
+* Type conversion
+* Asset bundling
+* Asset loading (including flyweighting on PC and preloading to ROM on the GBA)