Conditionalize debug tracing

[ctsim.git] / libctgraphics / bresenham.cpp

diff --git a/libctgraphics/bresenham.cpp b/libctgraphics/bresenham.cpp
index 43c8f349d2c68c42e1350fc9c73ebd8a085b2910..9d3077b33e3815c913b6e3344e49513302b10c91 100644 (file)
--- a/libctgraphics/bresenham.cpp
+++ b/libctgraphics/bresenham.cpp
@@ -1,8 +1,6 @@
 /*****************************************************************************
 **  This is part of the CTSim program
-**  Copyright (c) 1983-2001 Kevin Rosenberg
-**
-**  $Id$
+**  Copyright (c) 1983-2009 Kevin Rosenberg
 **
 **  This program is free software; you can redistribute it and/or modify
 **  it under the terms of the GNU General Public License (version 2) as
@@ -23,73 +21,71 @@
 // Foley & van Dam, "Fundementals of Interactive Computer Graphics", page 433
 
 
-
-void 
-bresenham (int x1, int y1, int x2, int y2)
-{
-  int delta_x = x2 - x1;
-  int dx_abs = (delta_x >= 0 ? delta_x : -delta_x);
-  
-  int delta_y = y2 - y1;
-  int dy_abs = (delta_y >= 0 ? delta_y : -delta_y);
-  
-  // draws a line when abs(dx) >= abs(dy) 
-  if (dx_abs > dy_abs) {
-    int count = dx_abs + 1;
-    int major_inc = (x1 <= x2 ? 1 : -1);
-    int min_inc = (delta_y >= 0 ? 1 : -1);     // determine direction of minor axis 
-    
-    int d = dy_abs * 2 - dx_abs;      // Put decision variable in d
-    int dinc1 = (dy_abs - dx_abs) * 2;
-    int dinc2 = 2 * dy_abs;
-    
-    bresx (x1, y1, major_inc, d, d1, d2);
-  } else {    //For plotting lines with abs(dy) > abs(sx)
-    int count = dy_abs + 1;
-    
-    int major_inc = (y1 <= y2 ? 1 : -1);
-    int min_inc = (delta_x >= 0 ? 1 : -1);      // check direction of minor axis
-        
-    int d = dx_abs * 2 - dy_abs;
-    dinc1 = (dx_abs - dy_abs) * 2;
-    dinc2 = 2 * dx_abs;
-    
-    bresy (x1, y1, major_inc, min_inc, count, d, d1, d2);
-  }
-}
-
-
-static void 
-bresx (int x, int y, int majorinc, int minorinc, int count, int d, int d1, int d2)
+static void
+bresx (int x, int y, int major_inc, int minor_inc, int count, int d, 
+       int dinc1, int dinc2, void(*fn)(const int, const int))
 {
   do {
-    setpixel();
-    x += majorinc;
-    
+    (*fn)(x,y);
+    x += major_inc;
+
     if (d < 0)
       d += dinc2;
     else {
       d += dinc1;
-      y += min_inc;
+      y += minor_inc;
     }
   } while (--count > 0);
 }
-  
-  
-static void 
-bresy (int x, int y, int majorinc, int minorinc, int count, int d, int d1, int d2)
+
+
+static void
+bresy (int x, int y, int major_inc, int minor_inc, int count, int d,
+       int dinc1, int dinc2, void(*fn)(const int, const int))
 {
   do {
-    setpixel();
-    y += majorinc;
-    
+    (*fn)(x,y);
+    y += major_inc;
+
     if (d < 0)
       d += dinc2;
     else {
       d += dinc1;
-      x += min_inc;
+      x += minor_inc;
     }
   } while (--count > 0);
 }
-  
-  
+
+void
+bresenham (int x1, int y1, int x2, int y2, void(*fn)(const int, const int))
+{0000
+  int delta_x = x2 - x1;
+  int dx_abs = (delta_x >= 0 ? delta_x : -delta_x);
+
+  int delta_y = y2 - y1;
+  int dy_abs = (delta_y >= 0 ? delta_y : -delta_y);
+
+  // draws a line when abs(dx) >= abs(dy)
+  if (dx_abs > dy_abs) {
+    int count = dx_abs + 1;
+    int major_inc = (x1 <= x2 ? 1 : -1);
+    int minor_inc = (delta_y >= 0 ? 1 : -1);     // determine direction of minor axis
+
+    int d = dy_abs * 2 - dx_abs;      // Put decision variable in d
+    int dinc1 = (dy_abs - dx_abs) * 2;
+    int dinc2 = 2 * dy_abs;
+
+    bresx (x1, y1, major_inc, minor_inc, count, d, dinc1, dinc2, fn);
+  } else {    //For plotting lines with abs(dy) > abs(sx)
+    int count = dy_abs + 1;
+
+    int major_inc = (y1 <= y2 ? 1 : -1);
+    int minor_inc = (delta_x >= 0 ? 1 : -1);      // check direction of minor axis
+
+    int d = dx_abs * 2 - dy_abs;
+    int dinc1 = (dx_abs - dy_abs) * 2;
+    int dinc2 = 2 * dx_abs;
+
+    bresy (x1, y1, major_inc, minor_inc, count, d, dinc1, dinc2, fn);
+  }
+}