scons: Build progs together with everything else.

This is a substantial reorganization, This particular commit enables:
- building the progs for unices platforms
- glew is now built as a shared library (it is the default, and it is
inconvenient and pointless to shift away from that default)
- all progs get built by default
diff --git a/progs/SConscript b/progs/SConscript
index 66eaf9e..3b180d0 100644
--- a/progs/SConscript
+++ b/progs/SConscript
@@ -1,5 +1,43 @@
 SConscript([
     'util/SConscript',
+])
+
+Import('*')
+
+progs_env = env.Clone()
+
+if progs_env['platform'] == 'windows':
+    progs_env.Append(CPPDEFINES = ['NOMINMAX'])
+    progs_env.Prepend(LIBS = [
+        'winmm',
+        'kernel32',
+        'user32',
+        'gdi32',
+    ])
+
+# OpenGL
+if progs_env['platform'] == 'windows':
+    progs_env.Prepend(LIBS = ['glu32', 'opengl32'])
+else:
+    progs_env.Prepend(LIBS = ['GLU', 'GL'])
+
+# Glut
+progs_env.Prepend(LIBS = [glut])
+
+# GLEW
+progs_env.Prepend(LIBS = [glew])
+
+progs_env.Prepend(CPPPATH = [
+	'#progs/util',
+])
+
+progs_env.Prepend(LIBS = [
+	util,
+])
+
+Export('progs_env')
+
+SConscript([
     'demos/SConscript',
     'glsl/SConscript',
     'redbook/SConscript',
diff --git a/progs/SConstruct b/progs/SConstruct
deleted file mode 100644
index 4d268cc..0000000
--- a/progs/SConstruct
+++ /dev/null
@@ -1,65 +0,0 @@
-import os
-import os.path
-import sys
-
-env = Environment(
-    tools = ['generic'],
-    toolpath = ['../scons'],
-    ENV = os.environ,
-)
-
-
-# Use Mesa's headers and libs
-if 1:
-    build_topdir = 'build'
-    build_subdir = env['platform']
-    if env['machine'] != 'generic':
-        build_subdir += '-' + env['machine']
-    if env['debug']:
-        build_subdir += "-debug"
-    if env['profile']:
-        build_subdir += "-profile"
-    build_dir = os.path.join(build_topdir, build_subdir)
-
-    env.Append(CPPDEFINES = ['GLEW_STATIC'])
-    env.Append(CPPPATH = ['#../include'])
-    env.Append(LIBPATH = [
-        '#../' + build_dir + '/glew/',
-        '#../' + build_dir + '/glut/glx',
-    ])
-
-
-conf = Configure(env)
-
-# OpenGL
-if env['platform'] == 'windows':
-    env.Prepend(LIBS = ['glu32', 'opengl32'])
-else:
-    env.Prepend(LIBS = ['GLU', 'GL'])
-
-# Glut
-env['GLUT'] = False
-if conf.CheckCHeader('GL/glut.h'):
-    if env['platform'] == 'windows':
-        env['GLUT_LIB'] = 'glut32'
-    else:
-        env['GLUT_LIB'] = 'glut'
-    env['GLUT'] = True
-
-# GLEW
-env['GLEW'] = False
-if conf.CheckCHeader('GL/glew.h'):
-    env['GLEW_LIB'] = 'glew'
-    env['GLEW'] = True
-    env.Prepend(LIBS = ['glew'])
-
-conf.Finish()
-
-
-Export('env')
-
-SConscript(
-    'SConscript',
-    build_dir = env['build'],
-    duplicate = 0 # http://www.scons.org/doc/0.97/HTML/scons-user/x2261.html
-)
diff --git a/progs/demos/SConscript b/progs/demos/SConscript
index f851870..742dd66 100644
--- a/progs/demos/SConscript
+++ b/progs/demos/SConscript
@@ -1,84 +1,66 @@
 Import('*')
 
-if not env['GLUT']:
-    Return()
-
-env = env.Clone()
-
-env.Prepend(CPPPATH = [
-	'../util',
-])
-
-env.Prepend(LIBS = [
-	util,
-	'$GLUT_LIB'
-])
-
-if env['platform'] == 'windows':
-    env.Append(CPPDEFINES = ['NOMINMAX'])
-    env.Prepend(LIBS = ['winmm'])
-
 progs = [
-	'arbfplight',
-	'arbfslight',
-	'arbocclude',
-	'bounce',
-	'clearspd',
-	'copypix',
-	'cubemap',
-	'drawpix',
-	'engine',
-	'fbo_firecube',
-	'fire',
-	'fogcoord',
-	'fplight',
-	'fslight',
-	'gamma',
-	'gearbox',
-	'gears',
-	'geartrain',
-	'glinfo',
-	'gloss',
-	'gltestperf',
-	'ipers',
-	'isosurf',
-	'lodbias',
-	'morph3d',
-	'multiarb',
-	'paltex',
-	'pointblast',
-	'ray',
-	'readpix',
-	'reflect',
-	'renormal',
-	'shadowtex',
-	'singlebuffer',
-	'spectex',
-	'spriteblast',
-	'stex3d',
-	'teapot',
-	'terrain',
-	'tessdemo',
-	'texcyl',
-	'texenv',
-	'textures',
-	'trispd',
-	'tunnel',
-	'tunnel2',
-	'vao_demo',
-	'winpos',
-        'dinoshade',
-        'fbotexture',
-        'projtex',
+    'arbfplight',
+    'arbfslight',
+    'arbocclude',
+    'bounce',
+    'clearspd',
+    'copypix',
+    'cubemap',
+    'drawpix',
+    'engine',
+    'fbo_firecube',
+    'fire',
+    'fogcoord',
+    'fplight',
+    'fslight',
+    'gamma',
+    'gearbox',
+    'gears',
+    'geartrain',
+    'glinfo',
+    'gloss',
+    'gltestperf',
+    'ipers',
+    'isosurf',
+    'lodbias',
+    'morph3d',
+    'multiarb',
+    'paltex',
+    'pointblast',
+    'ray',
+    'readpix',
+    'reflect',
+    'renormal',
+    'shadowtex',
+    'singlebuffer',
+    'spectex',
+    'spriteblast',
+    'stex3d',
+    'teapot',
+    'terrain',
+    'tessdemo',
+    'texcyl',
+    'texenv',
+    'textures',
+    'trispd',
+    'tunnel',
+    'tunnel2',
+    'vao_demo',
+    'winpos',
+    'dinoshade',
+    'fbotexture',
+    'projtex',
 ]
 
 for prog in progs:
-    env.Program(
+    progs_env.Program(
         target = prog,
         source = prog + '.c',
     )
     
-env.Program(
+progs_env.Program(
     target = 'rain',
     source = [
         'rain.cxx',
diff --git a/progs/fp/SConscript b/progs/fp/SConscript
index a783185..113e11a 100644
--- a/progs/fp/SConscript
+++ b/progs/fp/SConscript
@@ -1,15 +1,4 @@
-Import('env')
-
-if not env['GLUT']:
-    Return()
-
-env = env.Clone()
-
-env.Prepend(CPPPATH = [
-	'../util',
-])
-
-env.Prepend(LIBS = ['$GLUT_LIB'])
+Import('*')
 
 progs = [
     'fp-tri',
@@ -24,7 +13,7 @@
 ]
 
 for prog in progs:
-    env.Program(
+    progs_env.Program(
         target = prog,
         source = [prog + '.c'],
     )
diff --git a/progs/glsl/SConscript b/progs/glsl/SConscript
index 7a4549c..8f2ebcf 100644
--- a/progs/glsl/SConscript
+++ b/progs/glsl/SConscript
@@ -1,23 +1,5 @@
 Import('*')
 
-if not env['GLUT']:
-    Return()
-
-env = env.Clone()
-
-env.Prepend(CPPPATH = [
-	'../util',
-])
-
-env.Prepend(LIBS = [
-	util,
-	'$GLUT_LIB'
-])
-
-if env['platform'] == 'windows':
-    env.Append(CPPDEFINES = ['NOMINMAX'])
-    env.Prepend(LIBS = ['winmm'])
-
 progs = [
       'array',
       'bitmap',
@@ -48,7 +30,7 @@
 ]
 
 for prog in progs:
-    env.Program(
+    progs_env.Program(
         target = prog,
         source = prog + '.c',
     )
diff --git a/progs/perf/SConscript b/progs/perf/SConscript
index a5ec9a7..691478a 100644
--- a/progs/perf/SConscript
+++ b/progs/perf/SConscript
@@ -1,11 +1,4 @@
-Import('env')
-
-if not env['GLUT']:
-    Return()
-
-env = env.Clone()
-
-env.Prepend(LIBS = ['$GLUT_LIB'])
+Import('*')
 
 progs = [
       'copytex',
@@ -21,7 +14,7 @@
 ]
 
 for prog in progs:
-    env.Program(
+    progs_env.Program(
         target = prog,
         source = [
             prog + '.c',
diff --git a/progs/redbook/SConscript b/progs/redbook/SConscript
index 242cb66..24d7cff 100644
--- a/progs/redbook/SConscript
+++ b/progs/redbook/SConscript
@@ -1,23 +1,5 @@
 Import('*')
 
-if not env['GLUT']:
-    Return()
-
-env = env.Clone()
-
-env.Prepend(CPPPATH = [
-	'../util',
-])
-
-env.Prepend(LIBS = [
-	util,
-	'$GLUT_LIB'
-])
-
-if env['platform'] == 'windows':
-    env.Append(CPPDEFINES = ['NOMINMAX'])
-    env.Prepend(LIBS = ['winmm'])
-
 progs = [
     'aaindex',
     'aapoly',
@@ -85,7 +67,7 @@
 ]
 
 for prog in progs:
-    env.Program(
+    progs_env.Program(
         target = prog,
         source = prog + '.c',
     )
diff --git a/progs/samples/SConscript b/progs/samples/SConscript
index 7a8a0d62..134dfa9 100644
--- a/progs/samples/SConscript
+++ b/progs/samples/SConscript
@@ -1,23 +1,5 @@
 Import('*')
 
-if not env['GLUT']:
-    Return()
-
-env = env.Clone()
-
-env.Prepend(CPPPATH = [
-	'../util',
-])
-
-env.Prepend(LIBS = [
-	util,
-	'$GLUT_LIB'
-])
-
-if env['platform'] == 'windows':
-    env.Append(CPPDEFINES = ['NOMINMAX'])
-    env.Prepend(LIBS = ['winmm'])
-
 progs = [
     'accum',
     'bitmap1',
@@ -52,7 +34,7 @@
 ]
 
 for prog in progs:
-    env.Program(
+    progs_env.Program(
         target = prog,
         source = prog + '.c',
     )
diff --git a/progs/tests/SConscript b/progs/tests/SConscript
index ae6488b..e2c6538 100644
--- a/progs/tests/SConscript
+++ b/progs/tests/SConscript
@@ -1,23 +1,5 @@
 Import('*')
 
-if not env['GLUT']:
-    Return()
-
-env = env.Clone()
-
-env.Prepend(CPPPATH = [
-	'../util',
-])
-
-env.Prepend(LIBS = [
-	util,
-	'$GLUT_LIB'
-])
-
-if env['platform'] == 'windows':
-    env.Append(CPPDEFINES = ['NOMINMAX'])
-    env.Prepend(LIBS = ['winmm'])
-
 linux_progs = [
     'api_speed',
 ]
@@ -140,7 +122,7 @@
 ]
 
 for prog in progs:
-    env.Program(
+    progs_env.Program(
         target = prog,
         source = prog + '.c',
     )
diff --git a/progs/trivial/SConscript b/progs/trivial/SConscript
index 9a1f357..613383c 100644
--- a/progs/trivial/SConscript
+++ b/progs/trivial/SConscript
@@ -1,11 +1,4 @@
-Import('env')
-
-if not env['GLUT']:
-    Return()
-
-env = env.Clone()
-
-env.Prepend(LIBS = ['$GLUT_LIB'])
+Import('*')
 
 progs = [
     'clear-fbo-tex',
@@ -154,7 +147,7 @@
 ]
 
 for prog in progs:
-    prog = env.Program(
+    prog = progs_env.Program(
         target = prog,
         source = prog + '.c',
     )
diff --git a/progs/vp/SConscript b/progs/vp/SConscript
index 640c5dd..787cb79 100644
--- a/progs/vp/SConscript
+++ b/progs/vp/SConscript
@@ -1,13 +1,6 @@
-Import('env')
+Import('*')
 
-if not env['GLUT']:
-    Return()
-
-env = env.Clone()
-
-env.Prepend(LIBS = ['$GLUT_LIB'])
-
-env.Program(
+progs_env.Program(
         target = 'vp-tris',
         source = ['vp-tris.c'],
     )
diff --git a/progs/vpglsl/SConscript b/progs/vpglsl/SConscript
index 640c5dd..787cb79 100644
--- a/progs/vpglsl/SConscript
+++ b/progs/vpglsl/SConscript
@@ -1,13 +1,6 @@
-Import('env')
+Import('*')
 
-if not env['GLUT']:
-    Return()
-
-env = env.Clone()
-
-env.Prepend(LIBS = ['$GLUT_LIB'])
-
-env.Program(
+progs_env.Program(
         target = 'vp-tris',
         source = ['vp-tris.c'],
     )
diff --git a/progs/wgl/SConscript b/progs/wgl/SConscript
index 31f6167..248cc53 100644
--- a/progs/wgl/SConscript
+++ b/progs/wgl/SConscript
@@ -1,25 +1,17 @@
 Import('*')
 
-if env['platform'] != 'windows':
+if progs_env['platform'] != 'windows':
     Return()
 
-env = env.Clone()
-
-env.Append(LIBS = [
-    'kernel32',
-    'user32',
-    'gdi32',
-])
-
 progs = [
     'sharedtex_mt',
     'wglthreads',
 ]
 
 for prog in progs:
-    env.Program(
+    progs_env.Program(
         target = prog,
         source = prog + '/' + prog + '.c',
     )
 
-env.Program('wglinfo', ['wglinfo.c'])
+progs_env.Program('wglinfo', ['wglinfo.c'])