// Copyright (c) 2023 Dominic Masters
// 
// This software is released under the MIT License.
// https://opensource.org/licenses/MIT

#include "SimpleRenderTargetQuad.hpp"
#include "scene/Scene.hpp"

using namespace Dawn;

SimpleRenderTargetQuad::SimpleRenderTargetQuad(SceneItem *i) :
  SceneItemComponent(i)
{
}

void SimpleRenderTargetQuad::onRenderTargetResized(
  RenderTarget *target, float_t w, float_t h
) {
  assertTrue(target == this->renderTarget);
  // Update mesh
  QuadMesh::bufferQuadMesh(
    &this->meshHost->mesh,
    glm::vec2(0, 0), glm::vec2(0, 0),
    glm::vec2(w, h), glm::vec2(1, 1),
    0, 0
  );
}


void SimpleRenderTargetQuad::setRenderTarget(RenderTarget *rt) {
  assertTrue(rt != this->renderTarget);

  // Remove old event listener
  if(this->renderTarget != nullptr) {
    this->renderTarget->eventRenderTargetResized.removeListener(
      this, &SimpleRenderTargetQuad::onRenderTargetResized
    );
  }

  this->renderTarget = rt;

  // Add new event listener.
  if(rt != nullptr) {
    rt->eventRenderTargetResized.addListener(
      this, &SimpleRenderTargetQuad::onRenderTargetResized
    );
  }
}

std::vector<SceneItemComponent*> SimpleRenderTargetQuad::getDependencies() {
  return std::vector<SceneItemComponent*>{
    (this->meshHost = this->item->getComponent<MeshHost>())
  };
}

void SimpleRenderTargetQuad::onStart() {
  assertNotNull(this->meshHost);

  // Create quad mesh
  this->meshHost->mesh.createBuffers(QUAD_VERTICE_COUNT, QUAD_INDICE_COUNT);

  // Perform first resize.
  if(this->renderTarget != nullptr) {
    QuadMesh::bufferQuadMesh(
      &this->meshHost->mesh,
      glm::vec2(0, 0),
      glm::vec2(0, 0),
      glm::vec2(this->renderTarget->getWidth(), this->renderTarget->getHeight()),
      glm::vec2(1,1),
      0, 0
    );
  }
}

SimpleRenderTargetQuad::~SimpleRenderTargetQuad() {
  if(this->renderTarget != nullptr) {
    this->renderTarget->eventRenderTargetResized.removeListener(
      this, &SimpleRenderTargetQuad::onRenderTargetResized
    );
  }
}