hslt: misc improved functionality:

texture formats
matrix 2x2 inversion special case (wasn't called before)
more meaningful flags on vertex.

include/mitsuba/bidir/util.h

@@ -75,7 +75,7 @@ struct RestoreMeasureHelper {
 		: vertex(vertex), measure(vertex->measure) { }
 	~RestoreMeasureHelper() { vertex->measure = measure; }
 	PathVertex *vertex;
-	uint8_t measure;
+	EMeasure measure;
 };
 
 MTS_NAMESPACE_END

include/mitsuba/bidir/vertex.h

@@ -91,7 +91,7 @@ struct MTS_EXPORT_BIDIR PathVertex {
 	 *
 	 * \sa EVertexType
 	 */
-	uint8_t type : 7;
+	EVertexType type : 7;
 
 	/**
 	 * \brief Denotes whether this vertex \a only supports
@@ -129,7 +129,7 @@ struct MTS_EXPORT_BIDIR PathVertex {
 	 *
 	 * \sa EMeasure
 	 */
-	uint8_t measure;
+	EMeasure measure : 8;
 
 	/**
 	 * \brief When the current vertex supports sampling

include/mitsuba/core/frame.h

@@ -96,6 +96,12 @@ struct Frame {
 		return v.z;
 	}
 
+	/** \brief Assuming that the given direction is in the local coordinate
+	 * system, return the u and v coordinates of the vector 'v' */
+	inline static Vector2 uv(const Vector &v) {
+		return Vector2(v.x, v.y);
+	}
+
 	/** \brief Assuming that the given direction is in the local coordinate
 	 * system, return the squared sine of the angle between the normal and v */
 	inline static Float sinTheta2(const Vector &v) {

include/mitsuba/core/matrix.h

@@ -37,7 +37,7 @@ public:
 	/**
 	 * \brief Construct a new MxN matrix without initializing it.
 	 *
-	 * This construtor is useful when the matrix will either not
+	 * This constructor is useful when the matrix will either not
 	 * be used at all (it might be part of a larger data structure)
 	 * or initialized at a later point in time. Always make sure
 	 * that one of the two is the case! Otherwise your program will do
@@ -291,7 +291,7 @@ public:
 	 * and a permutation vector piv of length m so that A(piv,:) = L*U.
 	 * If m < n, then L is m-by-m and U is m-by-n.
 	 *
-	 * The LU decompostion with pivoting always exists, even if the matrix is
+	 * The LU decomposition with pivoting always exists, even if the matrix is
 	 * singular, so the constructor will never fail.
 	 * The primary use of the
 	 *
@@ -361,7 +361,7 @@ public:
 
 	T cholDet() const;
 
-	/// Check if the matrix is identically zeor
+	/// Check if the matrix is identically zero
 	inline bool isZero() const {
 		for (int i=0; i<M; ++i)
 			for (int j=0; j<N; ++j)
@@ -489,7 +489,7 @@ public:
 	}
 
 	/// Compute the inverse (Faster than Matrix::invert)
-	FINLINE bool invert(Matrix2x2 &target) const {
+	FINLINE bool invert2x2(Matrix2x2 &target) const {
 		Float det = m[0][0]*m[1][1] - m[0][1]*m[1][0];
 		if (std::abs(det) <= RCPOVERFLOW)
 			return false;
@@ -500,6 +500,22 @@ public:
 		target.m[1][0] = -m[1][0] * invDet;
 		return true;
 	}
+	FINLINE bool invert(Matrix2x2 &target) const {
+		return invert2x2(target);
+	}
+
+	 /// Compute the inverse with det (Faster than Matrix::invert)
+	 FINLINE bool invert2x2(Matrix2x2 &target, Float& det) const {
+		det = m[0][0]*m[1][1] - m[0][1]*m[1][0];
+		if(std::abs(det) <= RCPOVERFLOW)
+			return false;
+		Float invDet = 1/det;
+		target.m[0][0] = m[1][1] * invDet;
+		target.m[0][1] = -m[0][1] * invDet;
+		target.m[1][1] = m[0][0] * invDet;
+		target.m[1][0] = -m[1][0] * invDet;
+		return true;
+	 }
 
 	/// Matrix-vector multiplication
 	inline Vector2 operator*(const Vector2 &v) const {

include/mitsuba/core/ray.h

@@ -167,6 +167,13 @@ struct RayDifferential : public Ray {
 		ryDirection = d + (ryDirection - d) * amount;
 	}
 
+	void scaleDifferentialUV(const Vector2 amountUV) {
+		rxOrigin = o + (rxOrigin - o) * amountUV.x;
+		ryOrigin = o + (ryOrigin - o) * amountUV.y;
+		rxDirection = d + (rxDirection - d) * amountUV.x;
+		ryDirection = d + (ryDirection - d) * amountUV.y;
+	}
+
 	inline void operator=(const RayDifferential &ray) {
 		o = ray.o;
 		mint = ray.mint;

src/libhw/gltexture.cpp

@@ -362,7 +362,18 @@ void GLTexture::lookupGLConstants() {
 			return;
 	}
 
-	if (m_componentFormat == EFloat16) {
+  if (m_componentFormat == EUInt8) {
+		switch (m_pixelFormat) {
+		case ELuminance: m_internalFormat = GL_LUMINANCE8; break;
+		case ELuminanceAlpha: m_internalFormat = GL_LUMINANCE8_ALPHA8; break;
+		case ERGB: m_internalFormat = GL_RGB8; break;
+		case ERGBA: m_internalFormat = GL_RGBA8; break;
+		default:
+			Log(EError, "Unknown/unsupported pixel format!");
+			return;
+		}
+  }
+  else if (m_componentFormat == EFloat16) {
 		switch (m_pixelFormat) {
 			case ELuminance: m_internalFormat = GL_LUMINANCE16F_ARB; break;
 			case ELuminanceAlpha: m_internalFormat = GL_LUMINANCE_ALPHA16F_ARB; break;