Add PBRT formula

Signed-off-by: Adam Vandenberg <flangy@gmail.com>

Formula/pbrt.rb

@@ -0,0 +1,42 @@
+require 'formula'
+
+class Pbrt <Formula
+  head 'git://github.com/mmp/pbrt-v2.git'
+  homepage 'http://www.pbrt.org/'
+
+  depends_on 'openexr'
+  depends_on 'libtiff'
+  depends_on 'ilmbase'
+
+  def install
+    # Configure the Makefile
+    inreplace 'src/Makefile' do |contents|
+      openexr = Formula.factory('openexr')
+      libtiff = Formula.factory('libtiff')
+      ilmbase = Formula.factory('ilmbase')
+
+      # Enable Tiff support
+      contents.change_make_var! "HAVE_LIBTIFF", "1"
+
+      # Set LibTiff path
+      contents.change_make_var! "TIFF_INCLUDES", "-I#{libtiff.include}"
+      contents.change_make_var! "TIFF_LIBDIR", "-L#{libtiff.lib}"
+
+      # Set OpenEXR path
+      contents.change_make_var! "EXR_INCLUDES", "-I#{openexr.include}/OpenEXR -I#{ilmbase.include}/OpenEXR"
+      contents.change_make_var! "EXR_LIBDIR", "-L#{openexr.lib} -L#{ilmbase.lib}"
+
+      # Change settings if we are using a 32bit system
+      if MACOS_VERSION <= 10.5 or not Hardware.is_64_bit?
+        contents.change_make_var! "MARCH", "-m32 -msse2 -mfpmath=sse"
+      end
+    end
+
+    # Build and install
+    system "make -C src"
+    bin.install Dir['src/bin/*']
+
+    # Copy resources
+    prefix.install %w(dtrace exporters scenes)
+  end
+end