Dawn/src/file/assetmanager.h

/**
 * Copyright (c) 2021 Dominic Masters
 * 
 * This software is released under the MIT License.
 * https://opensource.org/licenses/MIT
 */

#pragma once
#include "asset.h"
#include "../util/flags.h"
#include "../engine/thread.h"
#include "../display/shader.h"
#include "../display/texture.h"
#include "../display/scaledtexture.h"
#include "../display/font.h"
#include "../script/scripter.h"
#include "xml.h"

#define ASSET_MANAGER_ITEMS_MAX 64

#define ASSET_MANAGER_STATE_PENDING 0x00
#define ASSET_MANAGER_STATE_ASYNC_LOADING 0x01
#define ASSET_MANAGER_STATE_ASYNC_ERROR 0x02
#define ASSET_MANAGER_STATE_ASYNC_DONE 0x03
#define ASSET_MANAGER_STATE_SYNC_LOADING 0x04
#define ASSET_MANAGER_STATE_SYNC_ERROR 0x05
#define ASSET_MANAGER_STATE_SYNC_DONE 0x06

#define ASSET_MANAGER_TYPE_TEXTURE 0x00
#define ASSET_MANAGER_TYPE_FONT 0x01
#define ASSET_MANAGER_TYPE_SHADER 0x02
#define ASSET_MANAGER_TYPE_SCALED_TEXTURE 0x03
#define ASSET_MANAGER_TYPE_SCALE_TEXTURE 0x04

// Types
typedef struct {
  texture_t *texture;
  char *fileName;
  int32_t width, height;
  pixel_t *data;
} assetmanagertexture_t;

typedef struct {
  shader_t *shader;
  char *fileVert;
  char *fileFrag;
  char *dataVert;
  char *dataFrag;
} assetmanagershader_t;

typedef struct {
  font_t *font;
  char *fileName;
  char *data;
} assetmanagerfont_t;

typedef struct {
  scaledtexture_t *scaledTexture;
} assetmanagerscaledtexture_t;

typedef struct {
  scaledtexture_t *scaledTexture;
  texture_t *texture;
  uint8_t scale;
  pixel_t *data;
} assetmanagerscaletexture_t;


// Item
typedef union {
  assetmanagertexture_t texture;
  assetmanagershader_t shader;
  assetmanagerfont_t font;
  assetmanagerscaledtexture_t scaledTexture;
  assetmanagerscaletexture_t scaleTexture;
} assetmanagerassetdata_t;

typedef struct {
  uint8_t type;
  uint8_t state;
  assetmanagerassetdata_t data;
} assetmanageritem_t;


// Loader
typedef bool assetmanagerloader_t(assetmanageritem_t *item);

typedef struct {
  assetmanagerloader_t *loadAsync;
  assetmanagerloader_t *loadSync;
} assetmanagerloaderdefinition_t;


// Manager
typedef struct {
  thread_t thread;
  assetmanageritem_t items[ASSET_MANAGER_ITEMS_MAX];
  uint8_t itemCount;
  bool finished;
} assetmanager_t;

extern assetmanagerloaderdefinition_t ASSET_MANAGER_LOADERS[];


/**
 * Initialize the asset manager
 * 
 * @param manager Manager to initialize.
 */
void assetManagerInit(assetmanager_t *manager);

/**
 * Begin asynchronously loading all of the assets
 * 
 * @param manager Manager to begin async loading.
 */
void assetManagerStart(assetmanager_t *manager);

/**
 * Synchronously tick the asset manager. Some assets require some form of sync
 * operations, such as buffering to the GPU, so make sure this is called at a
 * good time for that task, such as right at the end of a frame.
 * 
 * @param manager Manager to synchronously tick.
 */
void assetManagerUpdate(assetmanager_t *manager);

/**
 * Returns whether or not the given item is finished.
 * 
 * @param item Item to check state of.
 * @return True if finished, otherwise false.
 */
bool assetManagerIsItemFinished(assetmanageritem_t *item);

/**
 * Gets the progress of the asset manager as a representation of 0-1 as a % that
 * has loaded.
 * 
 * @param manager Manager to check the state of.
 * @return The progress percent as a representation of 0-1
 */
float assetManagerProgressGet(assetmanager_t *manager);

/** Private Thread that is executed asynchronously */
int32_t _assetManagerThread(thread_t *thread);

/**
 * Private method, simply adds an item to the manager and resets the state.
 * 
 * @param manager Manager to add to.
 * @return The added and reset item.
 */
assetmanageritem_t * assetManagerItemAdd(assetmanager_t *manager);

/**
 * Queue a texture load onto the asset manager buffer.
 * 
 * @param manager Manager to queue on to.
 * @param texture Texture to push the result in to.
 * @param fileName Texture filename to load.
 * @return A pointer to the asset manager item for tracking.
 */
assetmanageritem_t * assetManagerLoadTexture(
  assetmanager_t *manager, texture_t *texture, char *fileName
);

bool _assetManagerLoaderTextureAsync(assetmanageritem_t *item);
bool _assetManagerLoaderTextureSync(assetmanageritem_t *item);

/**
 * Queue a font load onto the asset manager buffer.
 * 
 * @param manager Manager to queue on to.
 * @param font Font to push the result in to.
 * @param fileName Filename of the asset to load.
 * @return A pointer to the asset manager item for tracking.
 */
assetmanageritem_t * assetManagerLoadFont(
  assetmanager_t *manager, font_t *font, char *fileName
);

bool _assetManagerLoaderFontAsync(assetmanageritem_t *item);
bool _assetManagerLoaderFontSync(assetmanageritem_t *item);

/**
 * Queues a shader load onto the asset manager buffer.
 * 
 * @param manager Manager to queue on to.
 * @param shader Shader to push the result in to.
 * @param fileVert Vertex file in question to load.
 * @param fileFrag Fragment file in question to load.
 * @return A pointer to the asset manager item for tracking.
 */
assetmanageritem_t * assetManagerLoadShader(
  assetmanager_t *manager, shader_t *shader, char *fileVert, char *fileFrag
);

bool _assetManagerLoaderShaderAsync(assetmanageritem_t *item);
bool _assetManagerLoaderShaderSync(assetmanageritem_t *item);


assetmanageritem_t * assetManagerLoadScaledTexture(
  assetmanager_t *manager, scaledtexture_t *mt, char *path, char *file
);

bool _assetManagerLoaderScaledTextureAsync(assetmanageritem_t *item);




assetmanageritem_t * assetManagerLoadTextureScale(
  assetmanager_t *manager, scaledtexture_t *st, texture_t *text, uint8_t scale
);

bool _assetManagerLoaderTextureScaleAsync(assetmanageritem_t *item);
bool _assetManagerLoaderTextureScaleSync(assetmanageritem_t *item);