CG2_Tasks/hough_machine.cpp

#ifndef HOUGH_MACHINE_C
#define HOUGH_MACHINE_C

#include <QtGlobal>
#include <QMainWindow>
#include <QColor>

#include <iostream>

#include <math.h>

#include "lazy_image.cpp"

class HoughMachine {
  
  private:
    LazyImage* original;
    LazyImage* working_copy;
    
    int x_center;
    int y_center;
    int n_ang;
    double d_ang;
    int n_rad;
    double d_rad;
    int* hough_arr;
    
    int matching_threshold;

  public:
    HoughMachine(LazyImage* original, LazyImage* working_copy) {
      this->original = original;
      this->working_copy = working_copy;
      this->hough_arr = NULL;
    };
    
    ~HoughMachine() {
      this->reset();
    };
    
    void reset(void) {
      this->x_center = 0;
      this->y_center = 0;
      this->n_ang = 0;
      this->d_ang = 0;
      this->n_rad = 0;
      this->d_rad = 0;
      if(this->hough_arr != NULL) {
	free(this->hough_arr);
	this->hough_arr = NULL;
      }
      this->matching_threshold = 0;
    };
    
    void setMatchingThreshold(int matching_threshold) {
      // If negative, pixels greater than the absolute value match.
      // If positive, pixels less than the absolute value match.
      this->matching_threshold = matching_threshold;
    };
        
    void run(int a_steps, int r_steps) {
      this->x_center = this->original->width()/2;
      this->y_center = this->original->height()/2;
      this->n_ang = a_steps;
      this->d_ang = M_PI / this->n_ang;
      this->n_rad = r_steps;
      double r_max = sqrt(pow(this->x_center, 2) + pow(this->y_center, 2));
      this->d_rad = (2*r_max)/this->n_rad;
      this->hough_arr = (int*) malloc(sizeof(int) * this->n_ang * this->n_rad);
      for(int i=0; i< this->n_ang*this->n_rad; i++) this->hough_arr[i] = 0;
      std::cout << "Hough params: x_center: " << this->x_center << ", y_center: " << this->y_center << std::endl;
      std::cout << "n_ang: " << this->n_ang << ", d_ang: " << this->d_ang << std::endl;
      std::cout << "n_rad: " << this->n_rad << ", d_rad: " << this->d_rad << ", r_max: " << r_max << std::endl;
      this->fillHoughAccumulator();
      this->debugShow();
    };
    
    void fillHoughAccumulator() {
      for(int v=0; v<this->original->height(); v++) {
	for(int u=0; u<this->original->width(); u++) {
	  QColor pixel = QColor::fromRgb(this->original->getPixel(u, v, LazyImage::DEFAULT));
	  int h, s, l;
	  pixel.getHsl(&h, &s, &l);
	  if(this->matching_threshold > 0) {
	    int threshold = this->matching_threshold;
	    std::cout << "Comparing " << l << " < " << threshold << std::endl;
	    if(l < threshold) this->doPixel(u, v);
	  } else {
	    int threshold = -this->matching_threshold;
	    std::cout << "Comparing " << l << " > " << threshold << std::endl;
	    if(l > threshold) this->doPixel(u, v);
	  }
	}
      }
    };
    
    void doPixel(int u, int v) {
      int x = u - this->x_center;
      int y = v - this->y_center;
      for(int a=0; a<this->n_ang; a++) {
	double theta = this->d_ang * a;
	int r = (int) qRound( (x*cos(theta) + y*sin(theta)) / this->d_rad ) + this->n_rad / 2;
	if(r >= 0 && r < this->n_rad) {
	  this->hough_arr[a*this->n_ang+r] += 1;
	}
      }
    };
    
    void drawLines(int n) {
      // TODO: Sort stuff in hough_arr by value, get the n top values and draw them using bresenham.
      
    };
    
    void debugShow() {
      std::cout << "Dimensions: " << this->n_ang << " x " << this->n_rad << " | " << std::endl;
      
      int max_value = 0;
      for(int i=0; i<this->n_ang*this->n_rad; i++) {
	int current_value = this->hough_arr[i];
	if(current_value > max_value) max_value = current_value;
      }
      
      for(int x=0; x<this->n_ang; x++) {
	for(int y=0; y<this->n_rad; y++) {
	  int value = qRound(255.0*this->hough_arr[x*this->n_ang+y] / max_value);
	  if(value < 0) {
	    std::cout << value << std::endl;
	    value = 0;
	  }    
	  if(value > 255) {
	    std::cout << value << std::endl;
	    value = 255;
	  }
	  int color = QColor::fromRgb(value, value, value).rgb();
	  this->working_copy->getImage()->setPixel(x,y,color);
	}
      }
    };

};


#endif