<?php

namespace App\System;

use App\Component\SunComponent;

use App\Renderer\DistanceFogRenderer;

use App\Renderer\SkyboxRenderer;

use App\Voxel\ChunkRenderer;

use GL\Math\{GLM, Quat, Vec2, Vec3};

use VISU\ECS\EntitiesInterface;

use VISU\ECS\SystemInterface;

use VISU\Geo\Transform;

use VISU\Graphics\GLState;

use VISU\Graphics\Rendering\Pass\BackbufferData;

use VISU\Graphics\Rendering\Pass\CameraData;

use VISU\Graphics\Rendering\Pass\ClearPass;

use VISU\Graphics\Rendering\RenderContext;

use VISU\Graphics\Rendering\Renderer\FullscreenTextureRenderer;

use VISU\Graphics\ShaderCollection;

use VISU\Graphics\TextureOptions;

class RenderingSystem implements SystemInterface

{

/**

* Fullscreen Texture Debug Renderer

*/

private FullscreenTextureRenderer $fullscreenRenderer;

/**

* Voxel Rendere

*/

private ChunkRenderer $voxelRenderer;

/**

* Skybox Renderer

*/

private SkyboxRenderer $skyboxRenderer;

/**

* Fog Renderer

*/

private DistanceFogRenderer $fogRenderer;

/**

* Constructor

*/

public function __construct(

private GLState $gl,

private ShaderCollection $shaders

)

{

$this->fullscreenRenderer = new FullscreenTextureRenderer($this->gl);

$this->voxelRenderer = new ChunkRenderer($this->gl, $this->shaders);

$this->skyboxRenderer = new SkyboxRenderer($this->gl, $this->shaders);

$this->fogRenderer = new DistanceFogRenderer($this->gl, $this->shaders);

}

/**

* Registers the system, this is where you should register all required components.

*

* @return void

*/

public function register(EntitiesInterface $entities) : void

{

$entities->registerComponent(Transform::class);

$entities->registerComponent(SunComponent::class);

// create a global sun entity

$entities->setSingleton(new SunComponent);

}

/**

* Unregisters the system, this is where you can handle any cleanup.

*

* @return void

*/

public function unregister(EntitiesInterface $entities) : void

{

}

/**

* Updates handler, this is where the game state should be updated.

*

* @return void

*/

public function update(EntitiesInterface $entities) : void

{

}

/**

* Handles rendering of the scene, here you can attach additional render passes,

* modify the render pipeline or customize rendering related data.

*

* @param RenderContext $context

*/

public function render(EntitiesInterface $entities, RenderContext $context) : void

{

// retrieve the backbuffer and clear it

$backbuffer = $context->data->get(BackbufferData::class)->target;

$context->pipeline->addPass(new ClearPass($backbuffer));

// fetch the camera data

$cameraData = $context->data->get(CameraData::class);

// attach scene related data

$context->data->set($entities->getSingleton(SunComponent::class));

// create an intermediate

$sceneRenderTarget = $context->pipeline->createRenderTarget('scene', $cameraData->resolutionX, $cameraData->resolutionY);

// depth

$sceneDepth = $context->pipeline->createDepthAttachment($sceneRenderTarget);

// scene color

$sceneColorOptions = new TextureOptions;

$sceneColorOptions->internalFormat = GL_RGB;

$sceneColor = $context->pipeline->createColorAttachment($sceneRenderTarget, 'sceneColor', $sceneColorOptions);

// scene position

$spaceTextureOptions = new TextureOptions;

$spaceTextureOptions->internalFormat = GL_RGB32F;

$spaceTextureOptions->generateMipmaps = false;

$scenePosition = $context->pipeline->createColorAttachment($sceneRenderTarget, 'scenePosition', $spaceTextureOptions);

// clear the scene render target

$context->pipeline->addPass(new ClearPass($sceneRenderTarget));

// render the chunks

$this->voxelRenderer->attachPass($context->pipeline, $sceneRenderTarget, $entities);

// render the skybox

$this->skyboxRenderer->attachPass($context->pipeline, $sceneRenderTarget);

// create an intermediate for post processing

$postProcessRenderTarget = $context->pipeline->createRenderTarget('postProcess', $cameraData->resolutionX, $cameraData->resolutionY);

$postProcessColor = $context->pipeline->createColorAttachment($postProcessRenderTarget, 'postProcessColor', $sceneColorOptions);

// render the fog

$this->fogRenderer->attachPass($context->pipeline, $postProcessRenderTarget, $sceneColor, $scenePosition);

// add a pass that renders the scene render target to the backbuffer

$this->fullscreenRenderer->attachPass($context->pipeline, $backbuffer, $postProcessColor);

}

}