Support rendering image subregions.

This is the first step to supporting distributed renders.

1 files changed, 61 insertions, 31 deletions

diff --git a/dimension/dimension.in b/dimension/dimension.in
index f8cb114..b81f44b 100644
--- a/dimension/dimension.in
+++ b/dimension/dimension.in
@@ -19,36 +19,19 @@
 # along with this program.  If not, see <http://www.gnu.org/licenses/>. #
 #########################################################################
 
-import argparse
-import os.path
-import sys
-
-# Display a progress bar
-def progress_bar(str, progress):
-  if not _args.quiet:
-    print(str, end = ' ')
-    sys.stdout.flush()
-
-    term_width = terminal_width()
-    width = term_width - (len(str) + 1)%term_width
-    for i in range(width):
-      progress.wait(i/width)
-      print('.', end = '')
-      sys.stdout.flush()
-
-    print()
-    sys.stdout.flush()
-
-  progress.finish()
+import argparse as _argparse
+import re as _re
+import os.path as _path
+import sys as _sys
 
 # Specialized parser to print --version output to stdout rather than stderr,
 # to pass distcheck
-class _DimensionArgumentParser(argparse.ArgumentParser):
+class _DimensionArgumentParser(_argparse.ArgumentParser):
   def exit(self, status = 0, message = None):
     if message:
-      file = sys.stdout if status == 0 else sys.stderr
+      file = _sys.stdout if status == 0 else _sys.stderr
       file.write(message)
-    sys.exit(status)
+    _sys.exit(status)
 
 # Parse the command line
 _parser = _DimensionArgumentParser(
@@ -56,7 +39,7 @@ _parser = _DimensionArgumentParser(
            "@PACKAGE_URL@\n"
            "Copyright (C) 2009-2011 Tavian Barnes <@PACKAGE_BUGREPORT@>\n"
            "Licensed under the GNU General Public License",
-  formatter_class = argparse.RawDescriptionHelpFormatter,
+  formatter_class = _argparse.RawDescriptionHelpFormatter,
   conflict_handler = "resolve", # For -h as height instead of help
 )
 
@@ -67,6 +50,9 @@ _parser.add_argument("-w", "--width", action = "store", type = int,
                      default = 768, help = "image width")
 _parser.add_argument("-h", "--height", action = "store", type = int,
                      default = 480, help = "image height")
+_parser.add_argument("--region", action = "store", type = str,
+                     default = None,
+                     help = "subregion to render, as \"((x1, y1), (x2, y2))\"")
 
 _parser.add_argument("-v", "--verbose", action = "store_true",
                      help = "print more information")
@@ -85,23 +71,63 @@ _parser.add_argument("input", action = "store", type = str,
 
 # Debugging/testing options
 _parser.add_argument("--strict", action = "store_true",
-                     help = argparse.SUPPRESS)
+                     help = _argparse.SUPPRESS)
 
 _args = _parser.parse_args()
 
+# Calculate subregion
+if _args.region is None:
+  _args.region_x = 0
+  _args.region_y = 0
+  _args.region_width = _args.width
+  _args.region_height = _args.height
+else:
+  _pattern = r"^\s*\(\s*\(\s*(\d*)\s*,\s*(\d*)\s*\)\s*,\s*\(\s*(\d*)\s*,\s*(\d*)\s*\)\s*\)\s*$"
+  _match = _re.match(_pattern, _args.region)
+  if _match is None:
+    raise RuntimeError("range specified in invalid format.")
+  _args.region_x = int(_match.group(1))
+  _args.region_y = int(_match.group(2))
+  _args.region_width = int(_match.group(3)) - _args.region_x
+  _args.region_height = int(_match.group(4)) - _args.region_y
+  if _args.region_x + _args.region_width >= _args.width:
+    raise RuntimeError("region exceeds width of image.")
+  if _args.region_y + _args.region_height >= _args.height:
+    raise RuntimeError("region exceeds height of image.")
+
 # Default output is basename(input).png
 if _args.output is None:
-  _noext = os.path.splitext(os.path.basename(_args.input))[0]
+  _noext = _path.splitext(_path.basename(_args.input))[0]
   _args.output = _noext + ".png"
 
 # Imports available to scripts
 from math import *
 from dimension import *
 
+# Display a progress bar
+def _progress_bar(str, progress):
+  if not _args.quiet:
+    print(str, end = ' ')
+    _sys.stdout.flush()
+
+    term_width = terminal_width()
+    width = term_width - (len(str) + 1)%term_width
+    for i in range(width):
+      progress.wait(i/width)
+      print('.', end = '')
+      _sys.stdout.flush()
+
+    print()
+    _sys.stdout.flush()
+
+  progress.finish()
+
 # --strict option
 die_on_warnings(_args.strict)
 
-# Defaults
+# Defaults/available variables
+image_width      = _args.width
+image_height     = _args.height
 objects          = []
 lights           = []
 camera           = PerspectiveCamera()
@@ -121,7 +147,7 @@ with open(_args.input) as _fh:
 parse_timer.complete()
 
 # Make the canvas
-canvas = Canvas(width = _args.width, height = _args.height)
+canvas = Canvas(width = _args.region_width, height = _args.region_height)
 canvas.optimize_PNG()
 
 # Make the scene object
@@ -129,6 +155,10 @@ scene = Scene(canvas  = canvas,
               objects = objects,
               lights  = lights,
               camera  = camera)
+scene.region_x        = _args.region_x
+scene.region_y        = _args.region_y
+scene.outer_width     = _args.width
+scene.outer_height    = _args.height
 scene.default_texture = default_texture
 scene.background      = background
 if sky_sphere is not None:
@@ -145,11 +175,11 @@ if scene.nthreads == 1:
   render_message = "Rendering scene"
 else:
   render_message = "Rendering scene (using %d threads)" % scene.nthreads
-progress_bar(render_message, scene.raytrace_async())
+_progress_bar(render_message, scene.raytrace_async())
 
 # Write the output file
 export_timer = Timer()
-progress_bar("Writing %s" % _args.output, canvas.write_PNG_async(_args.output))
+_progress_bar("Writing %s" % _args.output, canvas.write_PNG_async(_args.output))
 export_timer.complete()
 
 # Print execution times