renderlayer.h

#ifndef RENDERLAYER_H
#define RENDERLAYER_H

#include <QDebug>
#include <QRectF>

#include "ogr_core.h"
#include "ogrsf_frmts.h"

//#include "ui_openglwindow.h"

#include <QMatrix4x4>
#include <QOpenGLBuffer>
#include <QOpenGLContext>
#include <QOpenGLFunctions>
#include <QOpenGLShaderProgram>
#include <QOpenGLVertexArrayObject>
#include <QtMath>

#include "gpc.h"
#include "rtreeindex.h"

// 头文件的互相引用，声明位置导致的问题。需要前置声明，并在CPP文件中包含定义。
// 在ui_openglwindow.h头文件中，Ui_OpenGLWindow出现在了类定义之前，所以要先声明
class Ui_OpenGLWindow;

class OpenGLWindow;

class RenderLayer {
 public:
  static Ui_OpenGLWindow *windowUi;
  static OpenGLWindow *window;

  RenderLayer(const char *str, int indexGrid = 5);

  ~RenderLayer();

  // 外接矩形
  OGREnvelope boundary;
  QRectF boundaryQ;

  // 依赖的图层
  OGRLayer *layer;
  QVector<OGRFeature *> features;

  // 建立网格索引的密度
  int indexGrid;
  // 网格索引数量，indexGrid^2
  int gridCount;
  // 每个网格，保存着要素的引用
  QVector<OGRFeature *> *gridArray;
  // 外接矩形数组，用来判断要素落在哪个网格内
  OGREnvelope *envelopeArray;

  // 顶点数组
  QVector<float> vertexVector;
  // 画面时，面的分隔数组
  QVector<int> vertexIndex;

  // 要素类型
  int geoType = 0;

  QOpenGLBuffer vboOrigin;
  QOpenGLVertexArrayObject vaoOrigin;

  QOpenGLBuffer vboTriangular;
  QOpenGLVertexArrayObject vaoTriangular;

  QOpenGLBuffer vboSelect;
  QOpenGLVertexArrayObject vaoSelect;

  QOpenGLBuffer vboDensity;
  QOpenGLVertexArrayObject vaoDensity;

  QOpenGLBuffer vboRTree;
  QOpenGLVertexArrayObject vaoRTree;

  QOpenGLShaderProgram *shader = nullptr;

  void renderInit(QOpenGLShaderProgram *shader);

  void render();

  float lineWidth = 2.f;

  void selectFeature(float x, float y);

  void selectFeature(float x, float y, float x2, float y2);

  QString queryString;
  bool concreteSelect = false;

  void calculateDensity(float radius = 0.1, float resolution = 300);

  void exportDensity(float x, float y, float dx, float dy, int xCount,
                     int yCount, QVector<float> data);

  float layerHeight = 0;

 private:
  RenderLayer(OGRLayer *layer, int indexGrid = 5);

  int appendFeature(OGRFeature *feature, QVector<float> &vertexVector,
                    QVector<int> &vertexIndex);

  // 三角化
  void triangulate();

  // 三角化结果
  QVector<float> triResult;
  QVector<int> triIndex;

  // 选择要素
  QVector<float> selectVertex;
  QVector<int> selectVertexIndex;

  QVector<float> densityVertex;

  QVector<float> RTreeVertex;

  RTreeIndex rindex;

  // 取随机数
  static float randF();

  float dx;
  float dy;
};

#endif  // RENDERLAYER_H