diff --git a/CMakeLists.txt b/CMakeLists.txt
index 4636246..bea93b2 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -16,13 +16,13 @@ set(CMAKE_CXX_CLANG_TIDY "clang-tidy;-checks=*")
 set(CMAKE_CXX_CLANG_TIDY clang-tidy;-header-filter=.;-checks=*;)
 
 file(GLOB_RECURSE SOURCES src/*.cpp)
-file(GLOB_RECURSE HEADERS src/*.h)
+file(GLOB_RECURSE HEADERS src/*.hpp)
 file(GLOB_RECURSE TESTS test/*.cpp)
 
 set(LIB_PATH "${CMAKE_SOURCE_DIR}/../library")
 
 include_directories(${LIB_PATH}/include)
-add_executable(SimpleDraw ${SOURCES} ${HEADERS} main/main.cpp src/DrawRender.cpp src/DrawRender.h)
+add_executable(SimpleDraw ${SOURCES} ${HEADERS} main/main.cpp src/DrawRender.cpp src/DrawRender.hpp)
 
 target_link_libraries(SimpleDraw ${LIB_PATH}/lib/liblibrary.a)
 
diff --git a/main/main.cpp b/main/main.cpp
index 025e5f0..fa07588 100644
--- a/main/main.cpp
+++ b/main/main.cpp
@@ -2,59 +2,38 @@
 #include "../src/demo.h"
 #include "internal.hpp"
 #include "vkvm.hpp"
-#include "../src/DrawRender.h"
+#include "../src/DrawRender.hpp"
+#include <unistd.h>
 
 /**
  * @author: Shaohua Tong
- * @since: v0.0.0
- * A circle and squre is converted and displayed in the console.
- * Currently only to test.
+ * @since: v0.0.1
+ * Circle and Square and Mouse brush can show in GUI
  */
 void outPutPixel(int windowHeight, int windowWidth, vkvm::Color brushColor);
 
 int main() {
     vkvm::initialize(0);
 
-    /*************************set back to shared memory(only for test)********************************************/
-    int windowWidth = 30;
-    int windowHeight = 30;
-    int penWidth = 2;
-    vkvm::setWidth(windowWidth);
-    vkvm::setHeight(windowHeight);
-    //vkvm::setPenWIdth(penWidth); maybe
+    vkvm::registerEvent(vkvm::EventType::MouseDrag, [](){
+        std::cout << "drag" << std::endl;
+        vkvm::Color backgroundColor = vkvm::getBackgroundColor();
+        vkvm::Color penColor(160,180,123);
+        int penWidth = 10;
+        DrawRender drawRender(vkvm::getWidth(), vkvm::getHeight(), backgroundColor, penColor, penWidth);
+        drawRender.update(vkvm::getMousePosition(), BRUSH);
+    });
 
-    vkvm::Color penColor1(1, 1, 1);
-    vkvm::Color backgroudColor1(255, 255, 255);
-    vkvm::setForegroundColor(penColor1);
-    vkvm::setBackgroundColor(backgroudColor1);
-    /**************************get color, widnowsWidth, windowsHeightm, penColor, penWidth from shared memory****************************/
-    vkvm::Color penColor = vkvm::getForegroundColor();
-    vkvm::Color backgroundColor = vkvm::getBackgroundColor();
-    DrawRender drawRender(windowWidth, windowHeight, backgroundColor, penColor, penWidth);
-    /*************************get Mouseposition and update back to shared meomory********************************************/
-    std::string command;
-    std::cout << "DrawRender: ";
-    std::getline(std::cin, command);
+    vkvm::registerEvent(vkvm::EventType::MouseButton, [](){
+        vkvm::Color backgroundColor = vkvm::getBackgroundColor();
+        vkvm::Color penColor(160,180,123);
+        int penWidth = 10;
+        DrawRender drawRender(vkvm::getWidth(), vkvm::getHeight(), backgroundColor, penColor, penWidth);
+        drawRender.update(vkvm::getMousePosition(), CIRCLE);
+    });
 
-    //vkvm::getMousePosition();
-    vkvm::Coordinates mousePostiion;
-    mousePostiion.x = 15;
-    mousePostiion.y = 15;
-
-    while(command.compare("quit") != 0) {
-        if(command.compare("circle") == 0) {
-            drawRender.update(mousePostiion, CIRCLE);
-            outPutPixel(windowHeight, windowWidth, penColor);
-        }
-        if(command.compare("square") == 0) {
-            drawRender.update(mousePostiion, SQUARE);
-            outPutPixel(windowHeight, windowWidth, penColor);
-        }
-        if(command.compare("clear")) {
-            drawRender.clear();
-        }
-        std::cout << "DrawRender: ";
-        std::getline(std::cin, command);
+    while(1){
+        sleep(5);
     }
 
     return 0;
@@ -72,4 +51,6 @@ void outPutPixel(int windowHeight, int windowWidth, vkvm::Color penColor) {
         }
         std::cout << "\n";
     }
-}
\ No newline at end of file
+}
+
+
diff --git a/src/DrawRender.cpp b/src/DrawRender.cpp
index 8735225..93fa6a4 100644
--- a/src/DrawRender.cpp
+++ b/src/DrawRender.cpp
@@ -2,7 +2,7 @@
 // Created by shaohuatong on 21.11.19.
 //
 
-#include "DrawRender.h"
+#include "DrawRender.hpp"
 #include <algorithm>
 
 DrawRender::DrawRender(int windowWidth, int windowHeight, vkvm::Color backgroundColor, vkvm::Color penColor, int penWidth)
@@ -13,8 +13,15 @@ DrawRender::DrawRender(int windowWidth, int windowHeight, vkvm::Color background
 }
 
 void DrawRender::update(vkvm::Coordinates mousePostion, int type) {
-    std::vector<std::vector<bool>> graphics = circleAndSquareCreator(mousePostion, type);
-    translateToSharedMemory(graphics, startX, startY, type);
+    if(type == BRUSH) {
+        std::vector<std::vector<bool>> circleBrush = brushCreator(mousePostion);
+        translateToSharedMemory(circleBrush, startX, startY, type);
+
+    }
+    else if(type == CIRCLE || type == SQUARE) {
+        std::vector<std::vector<bool>> graphics = circleAndSquareCreator(mousePostion, type);
+        translateToSharedMemory(graphics, startX, startY, type);
+    }
 }
 
 void DrawRender::clear() {
@@ -69,20 +76,49 @@ std::vector<std::vector<bool>> DrawRender::circleAndSquareCreator(vkvm::Coordina
     return circle;
 }
 
+std::vector<std::vector<bool>> DrawRender::brushCreator(vkvm::Coordinates mousePosition) {
+    std::vector<std::vector<bool>> circleBrush;
+    int x_draw = 0;
+    int y_draw = 0;
+    int distance = 0;
+    radius =  penWidth;
+    vkvm::Coordinates uperLeft;
+    vkvm::Coordinates bottomRight;
+    uperLeft.x = mousePosition.x - radius;
+    uperLeft.y = mousePosition.y - radius;
+    bottomRight.x = mousePosition.x + radius;
+    bottomRight.y = mousePosition.y + radius;
+
+    vkvm::Coordinates temp;
+    circleBrush.resize(2 * radius);
+    for(y_draw = 0; y_draw < 2 * radius; y_draw++) {
+        circleBrush[y_draw].resize(2 * radius);
+        for(x_draw = 0; x_draw < 2 * radius; x_draw++) {
+            temp.x = uperLeft.x + x_draw;
+            temp.y = uperLeft.y + y_draw;
+            distance = squareOfDistance(temp, mousePosition);
+            if( distance < (radius * radius)) {
+                circleBrush[y_draw][x_draw] = true;
+            }
+        }
+    }
+
+    startX = uperLeft.x;
+    startY = uperLeft.y;
+    return circleBrush;
+}
+
+
 void DrawRender::translateToSharedMemory(std::vector<std::vector<bool>> graphics, int startX, int startY, int type) {
     int x, y;
     int currentX = startX;
     int currentY = startY;
-
-    if(type == CIRCLE || type == SQUARE) {
+    if(type == CIRCLE || type == SQUARE || type == BRUSH) {
         for(y = 0; y < 2 * radius; y++) {
             for(x = 0; x < 2 * radius; x++) {
                 if(graphics[y][x]) {
                     vkvm::setPixel(currentX, currentY, penColor);
                 }
-                else {
-                    vkvm::setPixel(currentX, currentY, backgroundColor);
-                }
                 currentX++;
             }
             currentX = startX;
diff --git a/src/DrawRender.h b/src/DrawRender.hpp
similarity index 77%
rename from src/DrawRender.h
rename to src/DrawRender.hpp
index 9eaa8e1..543d238 100644
--- a/src/DrawRender.h
+++ b/src/DrawRender.hpp
@@ -1,8 +1,8 @@
 //
 // Created by shaohuatong on 21.11.19.
 //
-#ifndef SIMPLE_DRAW_DRAWRENDER_H
-#define SIMPLE_DRAW_DRAWRENDER_H
+#ifndef SIMPLE_DRAW_DRAWRENDER_HPP
+#define SIMPLE_DRAW_DRAWRENDER_HPP
 
 #include <string>
 #include <Color.hpp>
@@ -20,7 +20,7 @@ public:
     DrawRender(int windowWidth, int windowHeight, vkvm::Color defaultBackgroundColor, vkvm::Color penColor, int penWidth);
 
     void setType();
-    void update(vkvm::Coordinates mousePostion, int type);
+    void update(vkvm::Coordinates mousePosition, int type);
     void clear();
 
 private:
@@ -36,9 +36,13 @@ private:
     int radius;
     int startX;
     int startY;
+    bool turnOnBrush;
+
     std::vector<std::vector<bool>> circleAndSquareCreator(vkvm::Coordinates mousePosition, int type);
+    std::vector<std::vector<bool>> brushCreator(vkvm::Coordinates mousePosition);
+
     int squareOfDistance(vkvm::Coordinates x, vkvm::Coordinates y);
     void translateToSharedMemory(std::vector<std::vector<bool>> graphics, int startX, int startY, int Type);
 };
 
-#endif //SIMPLE_DRAW_DRAWRENDER_H
+#endif //SIMPLE_DRAW_DRAWRENDER_HPP