Fix issue #6. Added Ellipse, Circle and Elliptical Arc as mentioned.

Author: ashutoshshrm529

keywords.txt

@@ -34,6 +34,8 @@ point	KEYWORD2
 quad	KEYWORD2
 rect	KEYWORD2
 ellipse KEYWORD2
+circle KEYWORD2
+arc KEYWORD2
 
 text	KEYWORD2
 textFont	KEYWORD2

src/ArduinoGraphics.cpp

@@ -192,13 +192,13 @@ void ArduinoGraphics::ellipse(int x, int y, int width, int height)
 
   int x1 = x;
   int y1 = y;
-  int r1 = (width/2);
-  int r2 = (height/2);
+  int r1 = (int)(width/2);
+  int r2 = (int)(height/2);
   int x2 = x1 + r1 - 1;
 
-  for(x = x1; x <= x2; x++) {
-      y2 = y1 + sqrt((1 - ((x * x)/(r1 * r1)))) * r2;
-      for(y = y1; y <= y2; y++) {
+  for (x = x1; x <= x2; x++) {
+      y2 = (int) (y1 + sqrt((1 - ((x * x)/(r1 * r1)))) * r2);
+      for (y = y1; y <= y2; y++) {
           if ((y == y2) && _stroke) {
             // stroke
             set(x, y, _strokeR, _strokeG, _strokeB); // current point
@@ -216,6 +216,63 @@ void ArduinoGraphics::ellipse(int x, int y, int width, int height)
   }
 }
 
+void ArduinoGraphics::circle(int x, int y, int radius)
+{
+  if (!_stroke && !_fill) {
+    return;
+  }
+
+  int x1 = x;
+  int y1 = y;
+  int x2 = x1 + radius;
+
+  for (x = x1; x <= x2; x++) {
+      y2 = (int) y1 + sqrt((radius*radius)-(x*x)) ;
+      for (y = y1; y <= y2; y++) {
+          if ((y == y2) && _stroke) {
+            // stroke
+            set(x, y, _strokeR, _strokeG, _strokeB); // current point
+            set(x - (((x - x1) * 2)), y, _strokeR, _strokeG, _strokeB); // second reflection
+            set(x, y - (((y - y1) * 2)), _strokeR, _strokeG, _strokeB); // third reflection
+            set(x - (((x - x1) * 2)), y - (((y - y1) * 2)), _strokeR, _strokeG, _strokeB); // fourth reflection
+          } else if (_fill) {
+            // fill
+            set(x, y, _fillR, _fillG, _fillB); // current point
+            set(x - (((x - x1) * 2)), y, _fillR, _fillG, _fillB); // second reflection
+            set(x, y - (((y - y1) * 2)), _fillR, _fillG, _fillB); // third reflection
+            set(x - (((x - x1) * 2)), y - (((y - y1) * 2)), _fillR, _fillG, _fillB); // fourth reflection
+          }
+      }
+  }
+}
+
+void ArduinoGraphics::arc(int x, int y, int radiusX, int radiusY, int start, int stop);
+{
+  if (!_stroke && !_fill) {
+    return;
+  }
+
+  int x1 = x;
+  int y1 = y;
+
+  for(int a = start; a <= stop; a++) {
+
+      int x2 = (int)(x1 + (radiusX * cos(a)));
+      int y2 = (int)(y1 + (radiusY * sin(a)));
+
+      if (_stroke) {
+        // stroke
+        set(x2, y2, _strokeR, _strokeG, _strokeB);
+      }
+
+      if (_fill) {
+          for (int r = 0; r < a; r++) {
+              set((int)(x1 + (radiusX * cos(r))), (int)(y1 + (radiusY * sin(r))), _fillR, _fillG, _fillB);
+          }
+      }
+  }
+}
+
 void ArduinoGraphics::text(const char* str, int x, int y)
 {
   if (!_font || !_stroke) {

src/ArduinoGraphics.h

@@ -22,6 +22,8 @@
 
 #include <Arduino.h>
 
+#include <math.h> // added for sqrt, cos and sin functions
+
 #include "Font.h"
 #include "Image.h"
 
@@ -57,13 +59,14 @@ class ArduinoGraphics : public Print {
   void stroke(uint32_t color);
   void noStroke();
 
-  //virtual void arc(int x, int y, int width, int height, int start, int stop);
   virtual void line(int x1, int y1, int x2, int y2);
   virtual void point(int x, int y);
   //virtual void quad(int x1, int y1, int x2, int y2, int x3, int y3, int x4, int y4);
   //virtual void triangle(int x1, int y1, int x2, int y2, int x3, int y3);
   virtual void rect(int x, int y, int width, int height);
   virtual void ellipse(int x, int y, int width, int height);
+  virtual void circle(int x, int y, int radius);
+  virtual void arc(int x, int y, int radiusX, int radiusY, int start, int stop);
 
   virtual void text(const char* str, int x = 0, int y = 0);
   virtual void text(const String& str, int x = 0, int y = 0) { text(str.c_str(), x, y); }