From d80914966880b859b56ea7eef9ce192716c604fd Mon Sep 17 00:00:00 2001
From: Jan Philipp Timme <jan.philipp@timme.it>
Date: Wed, 6 Jan 2016 18:30:00 +0100
Subject: [PATCH] [TASK] Kind of begin hough transformation.

---
 hough_machine.cpp   | 98 ++++++++++++++++++++++++++++++++++++++++++---
 imageviewer-qt4.cpp |  3 ++
 2 files changed, 96 insertions(+), 5 deletions(-)

diff --git a/hough_machine.cpp b/hough_machine.cpp
index dd6852b..d12a86e 100644
--- a/hough_machine.cpp
+++ b/hough_machine.cpp
@@ -9,22 +9,110 @@
 
 #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;
 
   public:
-    HoughMachine() {
-
+    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;
+      }
     };
         
-    void convertToMonochrome(void) {
-
+    void run(int a_steps, int r_steps) {
+      this->reset();
+      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;
+      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(l > 0) {
+	    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 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);
+	}
+      }
     };
 
 };
diff --git a/imageviewer-qt4.cpp b/imageviewer-qt4.cpp
index 3215623..b2f5955 100644
--- a/imageviewer-qt4.cpp
+++ b/imageviewer-qt4.cpp
@@ -773,6 +773,9 @@ void ImageViewer::doUnsharpMasking(void) {
 void ImageViewer::runHoughTransformation(void) {
   logFile << "Let's run a hough transformation!" << std::endl;
   renewLogging();
+  HoughMachine* hm = new HoughMachine(original, working_copy);
+  hm->run(250, 250);
+  delete hm;
   updateImageDisplay();  
 }
 /****************************************************************************************