diff --git a/QT/linia/piksele.pro b/QT/linia/linia.pro
similarity index 90%
rename from QT/linia/piksele.pro
rename to QT/linia/linia.pro
index 5e870ab..39df8d0 100644
--- a/QT/linia/piksele.pro
+++ b/QT/linia/linia.pro
@@ -1,20 +1,20 @@
-#-------------------------------------------------
-#
-# Project created by QtCreator 2015-03-03T00:14:51
-#
-#-------------------------------------------------
-
-QT       += core gui
-
-greaterThan(QT_MAJOR_VERSION, 4): QT += widgets
-
-TARGET = piksele
-TEMPLATE = app
-
-OUTPUT += Console
-SOURCES += main.cpp\
-        mywindow.cpp
-
-HEADERS  += mywindow.h
-
-FORMS    += mywindow.ui
+#-------------------------------------------------
+#
+# Project created by QtCreator 2015-03-03T00:14:51
+#
+#-------------------------------------------------
+
+QT       += core gui
+
+greaterThan(QT_MAJOR_VERSION, 4): QT += widgets
+
+TARGET = linia
+TEMPLATE = app
+
+OUTPUT += Console
+SOURCES += main.cpp\
+        mywindow.cpp
+
+HEADERS  += mywindow.h
+
+FORMS    += mywindow.ui
diff --git a/QT/linia/mywindow.cpp b/QT/linia/mywindow.cpp
index 9133e25..8b291e4 100644
--- a/QT/linia/mywindow.cpp
+++ b/QT/linia/mywindow.cpp
@@ -5,9 +5,10 @@
 // Plik ten jest generowany automatycznie
 // z pliku XML "mywindow.ui"
 #include "ui_mywindow.h"
-
+#include <QColor>
 #include <QDebug>
 #include <iostream>
+#include<float.h> // for float,double macros
 // Definicja konstruktora, wywolujemy najpierw
 // konstruktor klasy nadrzednej, nastepnie tworzymy
 // obiekt klasy Ui_MyWindow reprezentujacy GUI
@@ -147,7 +148,7 @@ void MyWindow::mouseMoveEvent(QMouseEvent *event)
     x -= poczX;
     y -= poczY;
 
-    if(x >= szer || y >= wys || x < 0 || y < 0){
+    if(x >= szer || y >= wys || x < 0 || y < 0 || draw_finished){
         ApplyTempImage();
 
         active_img = img;
@@ -193,31 +194,43 @@ void MyWindow::DrawLine(int x1, int y1, int x2, int y2){
 
     UpdateTempImage();
 
+    unsigned char *ptr = img_tmp->bits();
+
     if(x1 > x2){
-        int tmpX = x1;
-        int tmpY = y1;
-        x1 = x2;
-        y1 = y2;
-        x2 = tmpX;
-        y2 = tmpY;
+        std::swap(x1, x2);
+        std::swap(y1, y2);
     }
-
-
-    int kolor = 255;
-    unsigned char *ptr;
-    int y = y2;
-    ptr = img_tmp->bits();
     float diff = x2 - x1;
-    float a = (y2 - y1) / diff;
-    for(int i = x1; i <= x2; i++){
-        int x = i;
-        y = a * (i - x1) + y1;
+    float a = diff != 0 ? (y2 - y1) / diff : FLT_MAX;
 
-        // Ustawiamy kolor kliknietego piksela na bialy lub czarny
-        ptr[szer*4*y + 4*x] = kolor;
-        ptr[szer*4*y + 4*x + 1] = kolor;
-        ptr[szer*4*y + 4*x + 2] = kolor;
-        ptr[szer*4*y + 4*x + 3] = 255;
+    if(abs(a) < 0.5f){
+        for(int x = x1; x <= x2; x++){
+            int x_form = x - x1;
+            int y = a * x_form + y1;
+
+            SetColor(ptr, QColor(255, 255, 255), x, y);
+        }
+    }
+    else{
+        if(y1 > y2){
+            std::swap(x1, x2);
+            std::swap(y1, y2);
+        }
+        float diff = x2 - x1;
+        float a = diff != 0 ? (y2 - y1) / diff : FLT_MAX;
+        for(int y = y1; y <= y2; y++){
+            int y_form = y - y1;
+            int x = ((float)(y_form) / a) + x1;
+
+            SetColor(ptr, QColor(255, 255, 255), x, y);
+        }
     }
 }
 
+void MyWindow::SetColor(unsigned char *ptr, QColor color, int x, int y){
+    ptr[szer*4*y + 4*x] = color.red();
+    ptr[szer*4*y + 4*x + 1] = color.green();
+    ptr[szer*4*y + 4*x + 2] = color.blue();
+    ptr[szer*4*y + 4*x + 3] = 255;
+}
+
diff --git a/QT/linia/mywindow.h b/QT/linia/mywindow.h
index dc96035..54adcc4 100644
--- a/QT/linia/mywindow.h
+++ b/QT/linia/mywindow.h
@@ -84,6 +84,7 @@ private:
     void DrawLine(int x1, int y1, int x2, int y2);
     void UpdateTempImage();
     void ApplyTempImage();
+    void SetColor(unsigned char *ptr, QColor color, int x, int y);
 
     // Deklaracje slotow, czyli funkcji wywolywanych
     // po wystapieniu zdarzen zwiazanych z GUI