video-shader-toys/apps/LoopThroughWithOpenGLCompositing/RuntimeHost.h

#pragma once

#include "RuntimeJson.h"

#include <chrono>
#include <filesystem>
#include <map>
#include <mutex>
#include <string>
#include <vector>

enum class ShaderParameterType
{
	Float,
	Vec2,
	Color,
	Boolean,
	Enum
};

struct ShaderParameterOption
{
	std::string value;
	std::string label;
};

struct ShaderParameterDefinition
{
	std::string id;
	std::string label;
	ShaderParameterType type = ShaderParameterType::Float;
	std::vector<double> defaultNumbers;
	std::vector<double> minNumbers;
	std::vector<double> maxNumbers;
	std::vector<double> stepNumbers;
	bool defaultBoolean = false;
	std::string defaultEnumValue;
	std::vector<ShaderParameterOption> enumOptions;
};

struct ShaderParameterValue
{
	std::vector<double> numberValues;
	bool booleanValue = false;
	std::string enumValue;
};

struct ShaderPackage
{
	std::string id;
	std::string displayName;
	std::string description;
	std::string category;
	std::string entryPoint;
	std::filesystem::path directoryPath;
	std::filesystem::path shaderPath;
	std::filesystem::path manifestPath;
	std::vector<ShaderParameterDefinition> parameters;
	std::filesystem::file_time_type shaderWriteTime;
	std::filesystem::file_time_type manifestWriteTime;
};

struct RuntimeRenderState
{
	std::string activeShaderId;
	std::vector<ShaderParameterDefinition> parameterDefinitions;
	std::map<std::string, ShaderParameterValue> parameterValues;
	double timeSeconds = 0.0;
	double frameCount = 0.0;
	double mixAmount = 1.0;
	double bypass = 0.0;
	unsigned inputWidth = 0;
	unsigned inputHeight = 0;
	unsigned outputWidth = 0;
	unsigned outputHeight = 0;
};

class RuntimeHost
{
public:
	RuntimeHost();

	bool Initialize(std::string& error);

	bool PollFileChanges(bool& registryChanged, bool& reloadRequested, std::string& error);
	bool ManualReloadRequested();
	void ClearReloadRequest();

	bool SelectShader(const std::string& shaderId, std::string& error);
	bool UpdateParameter(const std::string& shaderId, const std::string& parameterId, const JsonValue& newValue, std::string& error);
	bool SetBypass(bool bypassEnabled, std::string& error);
	bool SetMixAmount(double mixAmount, std::string& error);

	void SetCompileStatus(bool succeeded, const std::string& message);
	void SetSignalStatus(bool hasSignal, unsigned width, unsigned height, const std::string& modeName);
	void AdvanceFrame();

	bool BuildActiveFragmentShaderSource(std::string& fragmentShaderSource, std::string& error);
	RuntimeRenderState GetRenderState(unsigned outputWidth, unsigned outputHeight) const;
	std::string BuildStateJson() const;

	const std::filesystem::path& GetRepoRoot() const { return mRepoRoot; }
	const std::filesystem::path& GetUiRoot() const { return mUiRoot; }
	const std::filesystem::path& GetRuntimeRoot() const { return mRuntimeRoot; }
	unsigned short GetServerPort() const { return mServerPort; }
	void SetServerPort(unsigned short port);
	bool AutoReloadEnabled() const { return mAutoReloadEnabled; }

private:
	struct AppConfig
	{
		std::string shaderLibrary = "shaders";
		unsigned short serverPort = 8080;
		bool autoReload = true;
	};

	struct PersistentState
	{
		std::string activeShaderId;
		double mixAmount = 1.0;
		bool bypass = false;
		std::map<std::string, std::map<std::string, ShaderParameterValue>> parameterValuesByShader;
	};

	bool LoadConfig(std::string& error);
	bool LoadPersistentState(std::string& error);
	bool SavePersistentState(std::string& error) const;
	bool ScanShaderPackages(std::string& error);
	bool ParseShaderManifest(const std::filesystem::path& manifestPath, ShaderPackage& shaderPackage, std::string& error) const;
	bool NormalizeAndValidateValue(const ShaderParameterDefinition& definition, const JsonValue& value, ShaderParameterValue& normalizedValue, std::string& error) const;
	ShaderParameterValue DefaultValueForDefinition(const ShaderParameterDefinition& definition) const;
	void EnsureParameterDefaultsLocked(ShaderPackage& shaderPackage);
	std::string BuildWrapperSlangSource(const ShaderPackage& shaderPackage) const;
	bool FindSlangCompiler(std::filesystem::path& compilerPath, std::string& error) const;
	bool RunSlangCompiler(const std::filesystem::path& wrapperPath, const std::filesystem::path& outputPath, std::string& error) const;
	bool PatchGeneratedGlsl(std::string& shaderText, std::string& error) const;
	std::string ReadTextFile(const std::filesystem::path& path, std::string& error) const;
	bool WriteTextFile(const std::filesystem::path& path, const std::string& contents, std::string& error) const;
	bool ResolvePaths(std::string& error);
	JsonValue BuildStateValue() const;
	JsonValue SerializeParameterValue(const ShaderParameterDefinition& definition, const ShaderParameterValue& value) const;

private:
	mutable std::mutex mMutex;
	AppConfig mConfig;
	PersistentState mPersistentState;
	std::filesystem::path mRepoRoot;
	std::filesystem::path mUiRoot;
	std::filesystem::path mShaderRoot;
	std::filesystem::path mRuntimeRoot;
	std::filesystem::path mRuntimeStatePath;
	std::filesystem::path mConfigPath;
	std::filesystem::path mWrapperPath;
	std::filesystem::path mGeneratedGlslPath;
	std::filesystem::path mPatchedGlslPath;
	std::map<std::string, ShaderPackage> mPackagesById;
	std::vector<std::string> mPackageOrder;
	std::string mActiveShaderId;
	bool mReloadRequested;
	bool mCompileSucceeded;
	std::string mCompileMessage;
	bool mHasSignal;
	unsigned mSignalWidth;
	unsigned mSignalHeight;
	std::string mSignalModeName;
	unsigned short mServerPort;
	bool mAutoReloadEnabled;
	double mMixAmount;
	bool mBypass;
	std::chrono::steady_clock::time_point mStartTime;
	std::chrono::steady_clock::time_point mLastScanTime;
	uint64_t mFrameCounter;
};