package org.andresoviedo.app.util.math; import android.opengl.Matrix; import org.andresoviedo.app.model3D.entities.BoundingBox; /** * Utility class to calculate 3D stuff * * @author andresoviedo */ public class Math3DUtils { /** * Calculate face normal * * @param v0 * @param v1 * @param v2 * @return */ public static float[] calculateFaceNormal2(float[] v0, float[] v1, float[] v2) { // calculate perpendicular vector to the face. That is to calculate the cross product of v1-v0 x v2-v0 float[] va = new float[]{v1[0] - v0[0], v1[1] - v0[1], v1[2] - v0[2]}; float[] vb = new float[]{v2[0] - v0[0], v2[1] - v0[1], v2[2] - v0[2]}; float[] n = new float[]{va[1] * vb[2] - va[2] * vb[1], va[2] * vb[0] - va[0] * vb[2], va[0] * vb[1] - va[1] * vb[0]}; float modul = Matrix.length(n[0], n[1], n[2]); float[] vn = new float[]{n[0] / modul, n[1] / modul, n[2] / modul}; return vn; } /** * Calculate the 2 vectors, that is a line (x1,y1,z1-x2,y2,z2} corresponding to the normal of the specified face. * The calculated line will be positioned exactly in the middle of the face * * @param v0 the first vector of the face * @param v1 the second vector of the face * @param v2 the third vector of the face * @return the 2 vectors (line) corresponding to the face normal */ public static float[][] calculateFaceNormal(float[] v0, float[] v1, float[] v2) { // calculate perpendicular vector to the face. That is to calculate the cross product of v1-v0 x v2-v0 float[] va = new float[]{v1[0] - v0[0], v1[1] - v0[1], v1[2] - v0[2]}; float[] vb = new float[]{v2[0] - v0[0], v2[1] - v0[1], v2[2] - v0[2]}; float[] n = new float[]{va[1] * vb[2] - va[2] * vb[1], va[2] * vb[0] - va[0] * vb[2], va[0] * vb[1] - va[1] * vb[0]}; float modul = Matrix.length(n[0], n[1], n[2]); float[] vn = new float[]{n[0] / modul, n[1] / modul, n[2] / modul}; // calculate center of the face float[] faceCenter = calculateFaceCenter(v0, v1, v2); float[] vn2 = new float[]{faceCenter[0] + vn[0], faceCenter[1] + vn[1], faceCenter[2] + vn[2]}; @SuppressWarnings("unused") String msg = "fNormal(" + v0[0] + "," + v0[1] + "," + v0[2] + "#" + v1[0] + "," + v1[1] + "," + v1[2] + "#" + v2[0] + "," + v2[1] + "," + v2[2] + ")#normal(" + vn[0] + "," + vn[1] + "," + vn[2] + ") center(" + faceCenter[0] + "," + faceCenter[1] + "," + faceCenter[2] + ") to(" + vn2[0] + "," + vn2[1] + "," + vn2[2] + ")"; // Log.d("ObjectV4", msg); return new float[][]{faceCenter, vn2}; } public static float[] calculateFaceCenter(float[] v0, float[] v1, float[] v2) { return new float[]{(v0[0] + v1[0] + v2[0]) / 3, (v0[1] + v1[1] + v2[1]) / 3, (v0[2] + v1[2] + v2[2]) / 3}; } /** * Calculates the distance of the intersection between the specified ray and the target, or return -1 if the ray * doesn't intersect the target * * @param rayPoint1 where the ray starts * @param rayPoint2 where the ray ends * @param target where is the object to intersect * @param precision the radius to test for intersection * @return the distance of intersection * @deprecated */ public static float calculateDistanceOfIntersection(float[] rayPoint1, float[] rayPoint2, float[] target, float precision) { float raySteps = 100f; float objHalfWidth = precision / 2; float length = Matrix.length(rayPoint2[0] - rayPoint1[0], rayPoint2[1] - rayPoint1[1], rayPoint2[2] - rayPoint1[2]); float lengthDiff = length / raySteps; float xDif = (rayPoint2[0] - rayPoint1[0]) / raySteps; float yDif = (rayPoint2[1] - rayPoint1[1]) / raySteps; float zDif = (rayPoint2[2] - rayPoint1[2]) / raySteps; for (int i = 0; i < raySteps; i++) { // @formatter:off if ((rayPoint1[0] + (xDif * i)) > target[0] - objHalfWidth && (rayPoint1[0] + (xDif * i)) < target[0] + objHalfWidth && (rayPoint1[1] + (yDif * i)) > target[1] - objHalfWidth && (rayPoint1[1] + (yDif * i)) < target[1] + objHalfWidth && (rayPoint1[2] + (zDif * i)) > target[2] - objHalfWidth && (rayPoint1[2] + (zDif * i)) < target[2] + objHalfWidth) { // @formatter:on // Log.v(TouchController.TAG, "HIT: i[" + i + "] wz[" + (rayPoint1[2] + (zDif * i)) + "]"); // return new Object[] { i * lengthDiff, new float[] { rayPoint1[0] + (xDif * i), // rayPoint1[1] + (yDif * i), rayPoint1[2] + (zDif * i) } }; return i * lengthDiff; } } return -1; } /** * Substract 2 vertex: a-b * * @param a * @param b * @return a-b */ public static float[] substract(float[] a, float[] b) { return new float[]{a[0] - b[0], a[1] - b[1], a[2] - b[2]}; } /** * Divide 2 vertex: a/b * * @param a * @param b * @return a/b */ public static float[] divide(float[] a, float[] b) { return new float[]{a[0] / b[0], a[1] / b[1], a[2] / b[2]}; } /** * Divide vertex: a/b * * @param a * @param b * @return a/b */ public static float[] divide(float[] a, float b) { return new float[]{a[0] / b, a[1] / b, a[2] / b}; } /** * Get the min of both vertex * * @param a * @param b * @return min of both vertex */ public static float[] min(float[] a, float[] b) { return new float[]{Math.min(a[0], b[0]), Math.min(a[1], b[1]), Math.min(a[2], b[2])}; } /** * Get the max of both vertex * * @param a * @param b * @return max of both vertex */ public static float[] max(float[] a, float[] b) { return new float[]{Math.max(a[0], b[0]), Math.max(a[1], b[1]), Math.max(a[2], b[2])}; } /** * Normalize the specified vector * * @param a */ public static void normalize(float[] a) { float length = Matrix.length(a[0], a[1], a[2]); a[0] = a[0] / length; a[1] = a[1] / length; a[2] = a[2] / length; } public static float[] crossProduct(float[] a, float[] b){ // AxB = (AyBz − AzBy, AzBx − AxBz, AxBy − AyBx) //(r)[0] = (a)[1] * (b)[2] - (b)[1] * (a)[2]; \ //(r)[1] = (a)[2] * (b)[0] - (b)[2] * (a)[0]; \ //(r)[2] = (a)[0] * (b)[1] - (b)[0] * (a)[1]; float x = a[1]*b[2] - a[2]*b[1]; float y = a[2]*b[0] - a[0]*b[2]; float z = a[0]*b[1] - a[1]*b[0]; return new float[]{x,y,z}; } public static float dotProduct(float[] a, float[] b){ // a1b1+a2b2+a3b3 return a[0]*b[0]+a[1]*b[1]+a[2]*b[2]; } public static float[] multiply(float[] a, float t){ return new float[]{a[0]*t, a[1]*t, a[2]*t}; } public static float[] add(float[] a, float[] b){ return new float[]{a[0]+b[0], a[1]+b[1], a[2]+b[2]}; } }