From 85829e004f2a5bc5b0125c187c94205a3afc0759 Mon Sep 17 00:00:00 2001
From: David Williams <david@david-williams.info>
Date: Wed, 20 May 2009 20:09:34 +0000
Subject: [PATCH] Work on refactoring surface extractor.

---
 examples/OpenGL/OpenGLWidget.cpp              |  2 +-
 library/PolyVoxCore/include/VolumeIterator.h  |  1 +
 .../PolyVoxCore/include/VolumeIterator.inl    | 19 +++++++++++++++++++
 3 files changed, 21 insertions(+), 1 deletion(-)

diff --git a/examples/OpenGL/OpenGLWidget.cpp b/examples/OpenGL/OpenGLWidget.cpp
index 851c8124..d2f33202 100644
--- a/examples/OpenGL/OpenGLWidget.cpp
+++ b/examples/OpenGL/OpenGLWidget.cpp
@@ -64,7 +64,7 @@ void OpenGLWidget::setVolume(PolyVox::Volume<PolyVox::uint8_t>* volData)
 					Vector3DInt32 regUpperCorner(regionEndX, regionEndY, regionEndZ);
 
 					//Extract the surface for this region
-					extractSurface(m_volData, 1, PolyVox::Region(regLowerCorner, regUpperCorner), ispCurrent);
+					extractSurface(m_volData, 0, PolyVox::Region(regLowerCorner, regUpperCorner), ispCurrent);
 
 					//computeNormalsForVertices(m_volData, *ispCurrent, SOBEL_SMOOTHED);
 					//*ispCurrent = getSmoothedSurface(*ispCurrent);
diff --git a/library/PolyVoxCore/include/VolumeIterator.h b/library/PolyVoxCore/include/VolumeIterator.h
index 79fcdbaf..e47e00e6 100644
--- a/library/PolyVoxCore/include/VolumeIterator.h
+++ b/library/PolyVoxCore/include/VolumeIterator.h
@@ -47,6 +47,7 @@ namespace PolyVox
 		uint16_t getPosY(void) const;
 		uint16_t getPosZ(void) const;
 		VoxelType getSubSampledVoxel(uint8_t uLevel) const;
+		VoxelType getSubSampledVoxelWithBoundsCheck(uint8_t uLevel) const;
 		const Volume<VoxelType>& getVolume(void) const;
 		VoxelType getVoxel(void) const;			
 
diff --git a/library/PolyVoxCore/include/VolumeIterator.inl b/library/PolyVoxCore/include/VolumeIterator.inl
index d2b9e913..d70e0f58 100644
--- a/library/PolyVoxCore/include/VolumeIterator.inl
+++ b/library/PolyVoxCore/include/VolumeIterator.inl
@@ -163,6 +163,25 @@ namespace PolyVox
 		}
 	}
 
+	template <typename VoxelType>
+	VoxelType VolumeIterator<VoxelType>::getSubSampledVoxelWithBoundsCheck(uint8_t uLevel) const
+	{
+		const uint8_t uSize = 1 << uLevel;
+
+		if((mXPosInVolume >= 0) && (mXPosInVolume <= mVolume.getWidth() - uSize) &&
+			(mYPosInVolume >= 0) && (mYPosInVolume <= mVolume.getHeight() - uSize) &&
+			(mZPosInVolume >= 0) && (mZPosInVolume <= mVolume.getDepth() - uSize))
+		{
+			return getSubSampledVoxel(uLevel);
+		}
+		else
+		{
+			//If any voxel is outside then it's value will be zero, and so the minimum will be zero.
+			//No need to even look at the rest of the voxels.
+			return 0;
+		}
+	}
+
 	template <typename VoxelType>
 	const Volume<VoxelType>& VolumeIterator<VoxelType>::getVolume(void) const
 	{