commit c05b9172560c3b4db45ec5f6739a0f87cef5c849
Author: John Denker <jsd@av8n.com>
Date:   Wed Jan 21 13:16:07 2015 -0700

    suppress some compiler warnings

diff --git a/src/screen.cpp b/src/screen.cpp
index aa7055a..cfde637 100644
--- a/src/screen.cpp
+++ b/src/screen.cpp
@@ -162,7 +162,7 @@ void Screen::set_pixel (const vect3d& p, const color& c)
   x = (size_t)prec2double((space_width/2 + sx) * dw);
   y = (size_t)prec2double((space_height/2 + sy) * dh);
 
-  if ( x >= width || y >= height || zbuf && zbuf[y * width + x] <= z )
+  if ( x >= width || y >= height || (zbuf && zbuf[y * width + x] <= z) )
       return;
 
   if ( zbuf )
@@ -437,7 +437,8 @@ void Screen::draw_line (const vect3d& p0, const vect3d& p1, const color& c)
   while (true)
     {
       size_t x, y;
-      vect3d p0s1 = p0 + v * tinc;
+//xx unused:
+//xx      vect3d p0s1 = p0 + v * tinc;
       translate (p0 + v * tinc, x, y);
       if ( x != x0 || y != y0 )
         {