X-Git-Url: http://git.kpe.io/?p=ctsim.git;a=blobdiff_plain;f=libctgraphics%2Fbresenham.cpp;h=9d3077b33e3815c913b6e3344e49513302b10c91;hp=7327f6b9afde94985291935c574ba96fbb0e5c1c;hb=ceb0f76ad587384928188f875c2862a3cb66b2dd;hpb=8774e7b513e87e09ba599dfb120c525e2bae2498

diff --git a/libctgraphics/bresenham.cpp b/libctgraphics/bresenham.cpp
index 7327f6b..9d3077b 100644
--- a/libctgraphics/bresenham.cpp
+++ b/libctgraphics/bresenham.cpp
@@ -21,73 +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)
+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)
+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);
+  }
+}