From bf28d19f208db02fa79061de5ee4f1478dff32af Mon Sep 17 00:00:00 2001
From: Yves Rizoud <yrizoud@gmail.com>
Date: Tue, 14 Jun 2011 21:52:20 +0000
Subject: [PATCH] Lua: Fixed drawdisk which was drawing a square instead of a
 circle (doh!). Radius can now be a multiple of 0.5 to draw circles of even
 sizes (r=0 -> 1x1, r=0.5 -> 2x2, r=1 -> 3x3 etc.)

git-svn-id: svn://pulkomandy.tk/GrafX2/trunk@1798 416bcca6-2ee7-4201-b75f-2eb2f807beb1
---
 src/factory.c | 26 ++++++++++++++++++++------
 src/graph.c   | 14 ++++++++++++++
 src/graph.h   |  2 ++
 src/special.c | 15 ---------------
 4 files changed, 36 insertions(+), 21 deletions(-)

diff --git a/src/factory.c b/src/factory.c
index 796dd910..156f9248 100644
--- a/src/factory.c
+++ b/src/factory.c
@@ -457,30 +457,44 @@ int L_DrawCircle(lua_State* L)
 
 int L_DrawDisk(lua_State* L)
 {
-  int center_x, center_y, r, c;
+  int center_x, center_y, diameter, c, r, even;
   long circle_limit;
   short x_pos,y_pos;
   short min_x,max_x,min_y,max_y;
+  double r_float;
 
   int nb_args = lua_gettop(L);
 
   LUA_ARG_LIMIT(4, "drawdisk");
   LUA_ARG_NUMBER(1, "drawdisk", center_x, INT_MIN, INT_MAX);
   LUA_ARG_NUMBER(2, "drawdisk", center_y, INT_MIN, INT_MAX);
-  LUA_ARG_NUMBER(3, "drawdisk", r, INT_MIN, INT_MAX);
+  LUA_ARG_NUMBER(3, "drawdisk", r_float, INT_MIN, INT_MAX);
   LUA_ARG_NUMBER(4, "drawdisk", c, INT_MIN, INT_MAX);
 
-  circle_limit = r*r;
+  if (r_float<0.0)
+    return 0;
+  diameter=(int)(floor(r_float*2.0+1.0));
+  r=diameter/2;
+  even=!(diameter&1);
+  
+  circle_limit = Circle_squared_diameter(diameter);
   
   // Compute clipping limits
-  min_x=center_x-r<0 ? 0 : center_x-r;
+  min_x=center_x-r+even<0 ? 0 : center_x-r+even;
   max_x=center_x+r>=Main_image_width? Main_image_width-1 : center_x+r;
-  min_y=center_y-r<0 ? 0 : center_y-r;
+  min_y=center_y-r+even<0 ? 0 : center_y-r+even;
   max_y=center_y+r>=Main_image_height? Main_image_height-1 : center_y+r;
 
   for (y_pos=min_y;y_pos<=max_y;y_pos++)
+  {
+    short y=(y_pos-center_y)*2-even;
     for (x_pos=min_x;x_pos<=max_x;x_pos++)
-      Pixel_in_current_screen(x_pos,y_pos,c,0);
+    {
+      short x=(x_pos-center_x)*2-even;
+      if (x*x+y*y <= circle_limit)
+        Pixel_in_current_screen(x_pos,y_pos,c,0);
+    }
+  }
 
   return 0;
 }
diff --git a/src/graph.c b/src/graph.c
index 06c99716..1bd0d9fb 100644
--- a/src/graph.c
+++ b/src/graph.c
@@ -1340,6 +1340,20 @@ void Draw_filled_circle(short center_x,short center_y,short radius,byte color)
   Update_part_of_screen(start_x,start_y,end_x+1-start_x,end_y+1-start_y);
 }
 
+int Circle_squared_diameter(int diameter)
+{
+  int result = diameter*diameter;
+  // Trick to make some circles rounder, even though
+  // mathematically incorrect.
+  if (diameter==3 || diameter==9)
+    return result-2;
+  if (diameter==11)
+    return result-6;
+  if (diameter==14)
+    return result-4;
+  
+  return result;
+}
 
   // -- Tracer général d'une ellipse vide -----------------------------------
 
diff --git a/src/graph.h b/src/graph.h
index 70c49d3c..5347a2d6 100644
--- a/src/graph.h
+++ b/src/graph.h
@@ -66,6 +66,8 @@ void Hide_empty_circle_preview (short center_x,short center_y,short radius);
 void Draw_empty_circle_general(short center_x,short center_y,short radius,byte color);
 void Draw_filled_circle         (short center_x,short center_y,short radius,byte color);
 
+int Circle_squared_diameter(int diameter);
+
 void Draw_empty_ellipse_permanent(short center_x,short center_y,short horizontal_radius,short vertical_radius,byte color);
 void Draw_empty_ellipse_preview  (short center_x,short center_y,short horizontal_radius,short vertical_radius,byte color);
 void Hide_empty_ellipse_preview (short center_x,short center_y,short horizontal_radius,short vertical_radius);
diff --git a/src/special.c b/src/special.c
index 6e3dc579..db8e14c0 100644
--- a/src/special.c
+++ b/src/special.c
@@ -37,21 +37,6 @@
 
 //---------------------- Modifier le pinceau spécial -------------------------
 
-int Circle_squared_diameter(int diameter)
-{
-  int result = diameter*diameter;
-  // Trick to make some circles rounder, even though
-  // mathematically incorrect.
-  if (diameter==3 || diameter==9)
-    return result-2;
-  if (diameter==11)
-    return result-6;
-  if (diameter==14)
-    return result-4;
-  
-  return result;
-}
-
 void Set_paintbrush_size(int width, int height)
 {
   int x_pos,y_pos;