Normal quotes

50-06.md

@@ -14,7 +14,7 @@
     #include <stdio.h>
     #include <dos.h>
     #include <math.h>
-    #include “polygon.h”
+    #include "polygon.h"
     void main(void);
 
     /* Base offset of page to which to draw */
@@ -25,7 +25,7 @@
     /* Rectangle specifying extent to be erased in each page */
     struct Rect EraseRect[2] = { {0, 0, SCREEN_WIDTH, SCREEN_HEIGHT},
        {0, 0, SCREEN_WIDTH, SCREEN_HEIGHT} };
-    /* Transformation from polygon’s object space to world space.
+    /* Transformation from polygon's object space to world space.
        Initially set up to perform no rotation and to move the polygon
        into world space -140 units away from the origin down the Z axis.
        Given the viewing point, -140 down the Z axis means 140 units away
@@ -95,10 +95,10 @@
              switch (getch()) {
                 case 0x1B:     /* Esc to exit */
                    Done = 1; break;
-                case ‘A’: case ‘a’:      /* away (-Z) */
+                case ‘A': case ‘a':      /* away (-Z) */
                    PolyWorldXform[2][3] -= 3.0; break;
-                case ‘T’:      /* towards (+Z). Don’t allow to get too */
-                case ‘t’:      /* close, so Z clipping isn’t needed */
+                case ‘T':      /* towards (+Z). Don't allow to get too */
+                case ‘t':      /* close, so Z clipping isn't needed */
                    if (PolyWorldXform[2][3] < -40.0)
                          PolyWorldXform[2][3] += 3.0; break;
                 case 0:     /* extended code */