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import unittest
import imath
import IECore
import IECoreScene
import IECoreImage
import IECoreGL
IECoreGL.init( False )
import os.path
import os
import shutil
import math

class OrientationTest( unittest.TestCase ) :

	## Makes a plane on the XY plane which appears with an anticlockwise winding order when
	# viewing down the negative Z axis.
	def makePlane( self ) :

		V = imath.V3f
		p = IECore.V3fVectorData( [ V( 1, -1, 0 ), V( 1, 1, 0 ), V( -1, 1, 0 ), V( -1, -1, 0 ) ] )
		nVerts = IECore.IntVectorData( [ 4 ] )
		vertIds = IECore.IntVectorData( [ 0, 1, 2, 3 ] )

		return IECoreScene.MeshPrimitive( nVerts, vertIds, "linear", p )

	def testAttribute( self ) :

		r = IECoreGL.Renderer()
		r.setOption( "gl:mode", IECore.StringData( "deferred" ) )
		r.worldBegin()
		self.assertEqual( r.getAttribute( "rightHandedOrientation" ), IECore.BoolData( True ) )
		r.setAttribute( "rightHandedOrientation", IECore.BoolData( False ) )
		self.assertEqual( r.getAttribute( "rightHandedOrientation" ), IECore.BoolData( False ) )
		r.worldEnd()

	def testMesh( self ) :

		"""Check that anticlockwise winding order is considered front facing by default."""

		outputFileName = os.path.join( os.path.dirname( __file__ ), "output", "testOrientation.tif" )

		# render a single sided plane that shouldn't be backface culled
		r = IECoreGL.Renderer()
		r.setOption( "gl:mode", IECore.StringData( "immediate" ) )
		r.display( outputFileName, "tiff", "rgba", {} )
		r.camera( "main", { "resolution" : IECore.V2iData( imath.V2i( 256 ) ) } )
		r.worldBegin()
		r.setAttribute( "doubleSided", IECore.BoolData( False ) )
		r.concatTransform( imath.M44f().translate( imath.V3f( 0, 0, -5 ) ) )
		self.makePlane().render( r )
		r.worldEnd()

		# check that something appears in the output image
		i = IECore.Reader.create( outputFileName ).read()
		dimensions = i.dataWindow.size() + imath.V2i( 1 )
		index = dimensions.x * int(dimensions.y * 0.5) + int(dimensions.x * 0.5)
		self.assertEqual( i["A"][index], 1 )

		# render a plane that should be backface culled
		r = IECoreGL.Renderer()
		r.setOption( "gl:mode", IECore.StringData( "immediate" ) )
		r.display( outputFileName, "tiff", "rgba", {} )
		r.camera( "main", { "resolution" : IECore.V2iData( imath.V2i( 256 ) ) } )
		r.worldBegin()
		r.setAttribute( "doubleSided", IECore.BoolData( False ) )
		r.concatTransform( imath.M44f().translate( imath.V3f( 0, 0, -5 ) ) )
		r.concatTransform( imath.M44f().rotate( imath.V3f( 0, math.pi, 0 ) ) )
		self.makePlane().render( r )
		r.worldEnd()

		# check that nothing appears in the output image
		i = IECore.Reader.create( outputFileName ).read()
		dimensions = i.dataWindow.size() + imath.V2i( 1 )
		index = dimensions.x * int(dimensions.y * 0.5) + int(dimensions.x * 0.5)
		self.assertEqual( i["A"][index], 0 )

	def METHOD_NAME( self ) :

		"""Check that flipping transforms are automatically compensated for."""

		outputFileName = os.path.join( os.path.dirname( __file__ ), "output", "testOrientation.tif" )

		# render a single sided plane that shouldn't be backface culled, even though
		# the negative transform has reversed the winding order
		r = IECoreGL.Renderer()
		r.setOption( "gl:mode", IECore.StringData( "immediate" ) )
		r.display( outputFileName, "tiff", "rgba", {} )
		r.camera( "main", { "resolution" : IECore.V2iData( imath.V2i( 256 ) ) } )
		r.worldBegin()
		self.assertEqual( r.getAttribute( "rightHandedOrientation" ), IECore.BoolData( True ) )
		r.setAttribute( "doubleSided", IECore.BoolData( False ) )
		r.concatTransform( imath.M44f().translate( imath.V3f( 0, 0, -5 ) ) )
		r.concatTransform( imath.M44f().scale( imath.V3f( -1, 1, 1 ) ) )
		self.assertEqual( r.getAttribute( "rightHandedOrientation" ), IECore.BoolData( False ) )
		self.makePlane().render( r )
		r.worldEnd()

		# check that something appears in the output image
		i = IECore.Reader.create( outputFileName ).read()
		dimensions = i.dataWindow.size() + imath.V2i( 1 )
		index = dimensions.x * int(dimensions.y * 0.5) + int(dimensions.x * 0.5)
		self.assertEqual( i["A"][index], 1 )

	def testFlippingTransformsAndTransformEnd( self ) :

		"""Check that flipped orientations are restored at transformEnd."""

		outputFileName = os.path.join( os.path.dirname( __file__ ), "output", "testOrientation.tif" )

		# render a single sided plane that shouldn't be backface culled, even though
		# the negative transform has reversed the winding order
		r = IECoreGL.Renderer()
		r.setOption( "gl:mode", IECore.StringData( "immediate" ) )
		r.display( outputFileName, "tiff", "rgba", {} )
		r.camera( "main", { "resolution" : IECore.V2iData( imath.V2i( 256 ) ) } )
		r.worldBegin()
		if 1 :

			self.assertEqual( r.getAttribute( "rightHandedOrientation" ), IECore.BoolData( True ) )
			r.setAttribute( "doubleSided", IECore.BoolData( False ) )
			r.concatTransform( imath.M44f().translate( imath.V3f( 0, 0, -5 ) ) )

			r.transformBegin()
			if 1 :

				r.concatTransform( imath.M44f().scale( imath.V3f( -1, 1, 1 ) ) )
				self.assertEqual( r.getAttribute( "rightHandedOrientation" ), IECore.BoolData( False ) )
				self.makePlane().render( r )

			r.transformEnd() ## \todo We need to fix our transformEnd implementation.

			self.assertEqual( r.getAttribute( "rightHandedOrientation" ), IECore.BoolData( True ) )

		r.worldEnd()

		# check that something appears in the output image
		i = IECore.Reader.create( outputFileName ).read()
		dimensions = i.dataWindow.size() + imath.V2i( 1 )
		index = dimensions.x * int(dimensions.y * 0.5) + int(dimensions.x * 0.5)
		self.assertEqual( i["A"][index], 1 )

	def setUp( self ) :

		if not os.path.isdir( os.path.join( "test", "IECoreGL", "output" ) ) :
			os.makedirs( os.path.join( "test", "IECoreGL", "output" ) )

	def tearDown( self ) :

		if os.path.isdir( os.path.join( "test", "IECoreGL", "output" ) ) :
			shutil.rmtree( os.path.join( "test", "IECoreGL", "output" ) )

if __name__ == "__main__":
    unittest.main()