render_particles.h

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 *  * Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
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#ifndef __RENDER_PARTICLES__
#define __RENDER_PARTICLES__

#include <EGL/egl.h>
#include <EGL/eglext.h>
#include <GLES3/gl31.h>

#include <cstdio>

typedef float matrix4[4][4];
typedef float vector3[3];

// check for OpenGL errors
inline void checkGLErrors(const char *s) {
  EGLenum error;

  while ((error = glGetError()) != GL_NO_ERROR) {
    fprintf(stderr, "%s: error - %d\n", s, error);
  }
}

class ParticleRenderer {
 public:
  ParticleRenderer(unsigned int windowWidth = 720,
                   unsigned int windowHeight = 480);
  ~ParticleRenderer();

  void setPositions(float *pos, int numParticles);
  void setPositions(double *pos, int numParticles);
  void setBaseColor(float color[4]);
  void setColors(float *color, int numParticles);
  void setPBO(unsigned int pbo, int numParticles, bool fp64);

  enum DisplayMode {
    PARTICLE_POINTS,
    PARTICLE_SPRITES,
    PARTICLE_SPRITES_COLOR,
    PARTICLE_NUM_MODES
  };

  void display();

  void setPointSize(float size) { m_pointSize = size; }
  void setSpriteSize(float size) { m_spriteSize = size; }

  void setCameraPos(vector3 camera_pos) {
    m_camera[0] = camera_pos[0];
    m_camera[1] = camera_pos[1];
    m_camera[2] = camera_pos[2];
  }

  void resetPBO();

 protected:  // methods
  void _initGL();
  void _createTexture(int resolution);

 protected:  // data
  float *m_pos;
  double *m_pos_fp64;
  int m_numParticles;

  float m_pointSize;
  float m_spriteSize;
  vector3 m_camera;

  unsigned int m_vertexShader;
  unsigned int m_vertexShaderPoints;
  unsigned int m_fragmentShader;
  unsigned int m_programPoints;
  unsigned int m_programSprites;
  unsigned int m_texture;
  unsigned int m_pbo;
  unsigned int m_vboColor;
  unsigned int m_windowWidth;
  unsigned int m_windowHeight;

  float m_baseColor[4];

  bool m_bFp64Positions;
};

#endif  //__ RENDER_PARTICLES__