Initial source commit

minorGems/graphics/3d/LathePrimitive3D.h

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+/*
+ * Modification History
+ *
+ * 2001-January-9		Jason Rohrer
+ * Created.  Copied from LathePrimitiveGL, which this class will replace.
+ *
+ * 2001-January-19		Jason Rohrer
+ * Changed to support multi-texturing internally, though this primitive
+ * type doesn't use it.
+ *
+ * 2001-January-21		Jason Rohrer
+ * Fixed a bug in the constructor.
+ *
+ * 2001-January-31		Jason Rohrer
+ * Got rid of an unused variable.
+ *
+ * 2001-March-11   Jason Rohrer
+ * Fixed a bug in the texture map anchor points. 
+ */
+ 
+ 
+#ifndef LATHE_PRIMITIVE_3D_INCLUDED
+#define LATHE_PRIMITIVE_3D_INCLUDED 
+
+#include "Primitive3D.h"
+ 
+/**
+ * Primitive 3D lathe object.
+ *
+ * Made of a curve rotated around an axis.
+ *
+ * @author Jason Rohrer 
+ */
+class LathePrimitive3D : public Primitive3D { 
+	
+	public:
+		
+		
+		/**
+		 * Constructs a LathePrimitive.  The lathe curve is rotated
+		 * about the y axis.
+		 *
+		 * No parameters are copied, so they should not be destroyed
+		 * or re-accessed by caller.  All are destroyed when the 
+		 * primitive is destroyed.
+		 *
+		 * @param inNumCurvePoints number of points in curve to be lathed.
+		 * @param inCurvePoints points to be lathed.  All z components
+		 *   are set to 0 before lathing, so only x and y values matter.
+		 * @param inNumLatheSteps the number of quad segments around
+		 *   the circumference of the lathed object.  For example,
+		 *   setting to 4 (with a lathe angle of 2pi)
+		 *   will produce an extruded square object.
+		 * @param inNetLatheAngle total angle to sweep during lathing,
+		 *   in (0,2pi].
+		 * @param inTexture the texture to map onto the lathed object.
+		 *   Texture is anchored by its corners to the ends of the lath
+		 *   curve at the beginning and end of the lathe sweep
+		 */
+		LathePrimitive3D( int inNumCurvePoints, Vector3D **inCurvePoints,
+			int inNumLatheSteps, double inNetLatheAngle,
+			RGBAImage *inTexture );
+		
+	};
+
+
+
+inline LathePrimitive3D::LathePrimitive3D( int inNumCurvePoints, 
+	Vector3D **inCurvePoints,
+	int inNumLatheSteps, double inNetLatheAngle,
+	RGBAImage *inTexture ) {
+	
+	// first, set Primitve3D members
+	mHigh = inNumCurvePoints;
+	mWide = inNumLatheSteps + 1;
+	mNumVertices = mHigh * mWide;
+	
+	mNumTextures = 1;
+	mTexture = new RGBAImage*[1];
+	mTexture[0] = inTexture;
+	
+	
+	double stepAngle = inNetLatheAngle / inNumLatheSteps;
+	
+	int i;
+	
+	// first, set all z values for control points to 0
+	for( i=0; i<inNumCurvePoints; i++ ) {
+		inCurvePoints[i]->mZ = 0;
+		}
+	
+	mVertices = new Vector3D*[mNumVertices];
+	
+	mAnchorX = new double*[1];
+	mAnchorY = new double*[1];
+	mAnchorX[0] = new double[mNumVertices];
+	mAnchorY[0] = new double[mNumVertices];
+	
+	// anchor at texture corners, and step linearly through texture
+	double anchorYStep = 1.0 / ( mHigh - 1 );
+	double anchorXStep = 1.0 / ( mWide - 1 );
+	
+	for( int y=0; y<mHigh; y++ ) {
+		for( int x=0; x<mWide; x++ ) {
+			int index = y * mWide + x;
+			
+			mAnchorX[0][index] = anchorXStep * x;
+			mAnchorY[0][index] = anchorYStep * y;
+			
+			// copy curve into each lathe step
+			mVertices[index] = new Vector3D( inCurvePoints[y] );
+			
+			// rotate the copied curve by x steps around y-axis
+			Angle3D *latheRotation = new Angle3D( 0, stepAngle * x, 0 );
+			mVertices[index]->reverseRotate( latheRotation );
+			
+			delete latheRotation;
+			}
+		
+		// cleanup as we go along
+		delete inCurvePoints[y];
+		}
+		 
+	delete [] inCurvePoints;
+	
+	generateNormals();	
+	}
+
+#endif