feature to track down use of unitialized values (initialize vectors etc. with NaNs if a compile-time flag is set)

include/mitsuba/core/point.h

@@ -39,7 +39,11 @@ template <typename T> struct TPoint2 {
 	 * computations involving uninitialized memory, which will probably
 	 * lead to a difficult-to-find bug.
 	 */
+#if !defined(MTS_DEBUG_UNINITIALIZED)
 	TPoint2() { }
+#else
+	TPoint2() { x = y = std::numeric_limits<double>::quiet_NaN(); }
+#endif
 
 	/// Initialize the point with the specified X, Y and Z components
 	TPoint2(T x, T y) : x(x), y(y) {  }
@@ -221,7 +225,11 @@ template <typename T> struct TPoint3 {
 	 * computations involving uninitialized memory, which will probably
 	 * lead to a difficult-to-find bug.
 	 */
+#if !defined(MTS_DEBUG_UNINITIALIZED)
 	TPoint3() { }
+#else
+	TPoint3() { x = y = z = std::numeric_limits<double>::quiet_NaN(); }
+#endif
 
 	/// Initialize the point with the specified X, Y and Z components
 	TPoint3(T x, T y, T z) : x(x), y(y), z(z) {  }
@@ -406,7 +414,11 @@ template <typename T> struct TPoint4 {
 	 * computations involving uninitialized memory, which will probably
 	 * lead to a difficult-to-find bug.
 	 */
+#if !defined(MTS_DEBUG_UNINITIALIZED)
 	TPoint4() { }
+#else
+	TPoint4() { x = y = z = w = std::numeric_limits<double>::quiet_NaN(); }
+#endif
 
 	/// Initialize the point with the specified X, Y and Z components
 	TPoint4(T x, T y, T z, T w) : x(x), y(y), z(z), w(w) {  }

include/mitsuba/core/spectrum.h

@@ -104,7 +104,15 @@ private:
 struct MTS_EXPORT_CORE Spectrum {
 public:
 	/// Create a new spectral power distribution, but don't initialize the contents
+#if !defined(MTS_DEBUG_UNINITIALIZED)
 	inline Spectrum() { }
+#else
+	inline Spectrum() {
+		for (int i=0; i<SPECTRUM_SAMPLES; i++)
+			s[i] = std::numeric_limits<double>::quiet_NaN();
+	}
+#endif
+
 
 	/// Create a new spectral power distribution with all samples set to the given value
 	explicit inline Spectrum(Float v) {

include/mitsuba/core/vector.h

@@ -40,7 +40,11 @@ public:
 	 * computations involving uninitialized memory, which will probably
 	 * lead to a difficult-to-find bug.
 	 */
+#if !defined(MTS_DEBUG_UNINITIALIZED)
 	TVector2() { }
+#else
+	TVector2() { x = y = std::numeric_limits<double>::quiet_NaN(); }
+#endif
 
 	/// Initialize the vector with the specified X and Z components
 	TVector2(T x, T y) : x(x), y(y) {  }
@@ -222,7 +226,11 @@ public:
 	 * computations involving uninitialized memory, which will probably
 	 * lead to a difficult-to-find bug.
 	 */
+#if !defined(MTS_DEBUG_UNINITIALIZED)
 	TVector3() { }
+#else
+	TVector3() { x = y = z = std::numeric_limits<double>::quiet_NaN(); }
+#endif
 
 	/// Initialize the vector with the specified X, Y and Z components
 	TVector3(T x, T y, T z) : x(x), y(y), z(z) {  }
@@ -417,7 +425,11 @@ public:
 	 * computations involving uninitialized memory, which will probably
 	 * lead to a difficult-to-find bug.
 	 */
+#if !defined(MTS_DEBUG_UNINITIALIZED)
 	TVector4() { }
+#else
+	TVector4() { x = y = z = w = std::numeric_limits<double>::quiet_NaN(); }
+#endif
 
 	/// Initialize the vector with the specified X, Y and Z components
 	TVector4(T x, T y, T z, T w) : x(x), y(y), z(z), w(w) {  }

src/librender/shape.cpp

@@ -214,10 +214,13 @@ void Intersection::computePartials(const RayDifferential &ray) {
 	Float A[2][2], Bx[2], By[2], x[2];
 	int axes[2];
 
-	if (std::abs(geoFrame.n.x) > std::abs(geoFrame.n.y)
+	Float absX = std::abs(geoFrame.n.x),
-		&& std::abs(geoFrame.n.x) > std::abs(geoFrame.n.z)) {
+		  absY = std::abs(geoFrame.n.y),
+		  absZ = std::abs(geoFrame.n.z);
+
+	if (absX > absY && absX > absZ) {
 		axes[0] = 1; axes[1] = 2;
-	} else if (std::abs(geoFrame.n.y) > std::abs(geoFrame.n.z)) {
+	} else if (absY > absZ) {
 		axes[0] = 0; axes[1] = 2;
 	} else {
 		axes[0] = 0; axes[1] = 1;
@@ -227,6 +230,7 @@ void Intersection::computePartials(const RayDifferential &ray) {
 	A[0][1] = dpdv[axes[0]];
 	A[1][0] = dpdu[axes[1]];
 	A[1][1] = dpdv[axes[1]];
+
 	Bx[0] = px[axes[0]] - p[axes[0]];
 	Bx[1] = px[axes[1]] - p[axes[1]];
 	By[0] = py[axes[0]] - p[axes[0]];

src/librender/trimesh.cpp

@@ -170,7 +170,7 @@ void TriMesh::calculateTangentSpaceBasis(bool hasNormals, bool hasTexCoords, boo
 	
 	if (!hasNormals) {
 		for (unsigned int i=0; i<m_vertexCount; i++)
-			m_vertexBuffer[i].n = Normal(0.0, 0.0f, 0.0f);
+			m_vertexBuffer[i].n = Normal(0.0f);
 		for (unsigned int i=0; i<m_triangleCount; i++) {
 			const Point &v0 = m_vertexBuffer[m_triangles[i].idx[0]].p;
 			const Point &v1 = m_vertexBuffer[m_triangles[i].idx[1]].p;
@@ -219,11 +219,11 @@ void TriMesh::calculateTangentSpaceBasis(bool hasNormals, bool hasTexCoords, boo
 		int *sharers = new int[m_vertexCount];
 
 		for (unsigned int i=0; i<m_vertexCount; i++) {
-			m_vertexBuffer[i].dpdu = Vector(0.0, 0.0f, 0.0f);
+			m_vertexBuffer[i].dpdu = Vector(0.0f);
-			m_vertexBuffer[i].dpdv = Vector(0.0, 0.0f, 0.0f);
+			m_vertexBuffer[i].dpdv = Vector(0.0f);
 			if (m_vertexBuffer[i].n.isZero()) {
 				zeroNormals++;
-				m_vertexBuffer[i].n = Normal(1, 0, 0);
+				m_vertexBuffer[i].n = Normal(1.0f, 0.0f, 0.0f);
 			}
 			sharers[i] = 0;
 		}