19066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project/* 29066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * Copyright (C) 2007 The Android Open Source Project 39066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * 49066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * Licensed under the Apache License, Version 2.0 (the "License"); 59066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * you may not use this file except in compliance with the License. 69066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * You may obtain a copy of the License at 79066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * 89066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * http://www.apache.org/licenses/LICENSE-2.0 99066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * 109066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * Unless required by applicable law or agreed to in writing, software 119066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * distributed under the License is distributed on an "AS IS" BASIS, 129066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 139066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * See the License for the specific language governing permissions and 149066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * limitations under the License. 159066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project */ 169066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project 179066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Projectpackage android.opengl; 189066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project 199066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project/** 209066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * A collection of utility methods for computing the visibility of triangle 219066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * meshes. 229066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * 239066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project */ 249066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Projectpublic class Visibility { 259066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project /** 269066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * Test whether a given triangle mesh is visible on the screen. The mesh 279066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * is specified as an indexed triangle list. 289066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * 299066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * @param ws the world space to screen space transform matrix, as an OpenGL 309066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * column matrix. 319066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * @param wsOffset an index into the ws array where the data starts. 329066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * @param positions the vertex positions (x, y, z). 339066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * @param positionsOffset the index in the positions array where the data 349066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * starts. 359066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * @param indices the indices of the triangle list. The indices are 369066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * expressed as chars because they are unsigned 16-bit values. 379066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * @param indicesOffset the index in the indices array where the index data 389066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * starts. 399066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * @param indexCount the number of indices in use. Typically a multiple of 409066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * three. If not a multiple of three, the remaining one or two indices will 419066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * be ignored. 429066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * @return 2 if all of the mesh is visible, 1 if some part of the mesh is 439066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * visible, 0 if no part is visible. 449066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * 459066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * @throws IllegalArgumentException if ws is null, wsOffset < 0, 469066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * positions is null, positionsOffset < 0, indices is null, 479066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * indicesOffset < 0, indicesOffset > indices.length - indexCount 489066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project */ 499066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project public static native int visibilityTest(float[] ws, int wsOffset, 509066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project float[] positions, int positionsOffset, char[] indices, 519066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project int indicesOffset, int indexCount); 529066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project 539066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project /** 549066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * Given an OpenGL ES ModelView-Projection matrix (which implicitly 559066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * describes a frustum) and a list of spheres, determine which spheres 569066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * intersect the frustum. 579066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * <p> 589066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * A ModelView-Projection matrix can be computed by multiplying the 599066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * a Projection matrix by the a ModelView matrix (in that order.). There 609066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * are several possible ways to obtain the current ModelView and 619066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * Projection matrices. The most generally applicable way is to keep 629066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * track of the current matrices in application code. If that is not 639066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * convenient, there are two optional OpenGL ES extensions which may 649066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * be used to read the current matrices from OpenGL ES: 659066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * <ul> 669066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * <li>GL10Ext.glQueryMatrixxOES 679066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * <li>GL11.GL_MODELVIEW_MATRIX_FLOAT_AS_INT_BITS_OES and 689066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * GL_PROJECTION_MATRIX_FLOAT_AS_INT_BITS_OES 699066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * </ul> 709066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * The problem with reading back the matrices is that your application 719066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * will only work with devices that support the extension(s) that 729066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * it uses. 739066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * <p> 749066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * A frustum is a six-sided truncated pyramid that defines the portion of 759066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * world space that is visible in the view. 769066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * <p> 779066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * Spheres are described as four floating point values: x, y, z, and r, in 789066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * world-space coordinates. R is the radius of the sphere. 799066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * <p> 809066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * @param mvp a float array containing the mode-view-projection matrix 819066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * @param mvpOffset The offset of the mvp data within the mvp array. 829066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * @param spheres a float array containing the sphere data. 839066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * @param spheresOffset an offset into the sphere array where the sphere 849066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * data starts 859066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * @param spheresCount the number of spheres to cull. 869066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * @param results an integer array containing the indices of the spheres 879066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * that are either contained entirely within or intersect the frustum. 889066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * @param resultsOffset an offset into the results array where the results 899066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * start. 909066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * @param resultsCapacity the number of array elements available for storing 919066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * results. 929066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * @return the number of spheres that intersected the frustum. Can be 939066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * larger than resultsCapacity, in which case only the first resultsCapacity 949066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * results are written into the results array. 959066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * 969066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * @throws IllegalArgumentException if mvp is null, mvpOffset < 0, 979066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * mvpOffset > mvp.length - 16, spheres is null, spheresOffset < 0, 989066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * spheresOffset > spheres.length - sphereCount, 999066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * results is null, resultsOffset < 0, resultsOffset > results.length - 1009066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * resultsCapacity. 1019066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project */ 1029066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project public static native int frustumCullSpheres(float[] mvp, int mvpOffset, 1039066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project float[] spheres, int spheresOffset, int spheresCount, 1049066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project int[] results, int resultsOffset, int resultsCapacity); 1059066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project 1069066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project /** 1079066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * Compute a bounding sphere for a set of points. It is approximately the 1089066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * minimal bounding sphere of an axis-aligned box that bounds the points. 1099066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * 1109066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * @param positions positions in x, y, z triples 1119066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * @param positionsOffset offset into positions array 1129066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * @param positionsCount number of position triples to process 1139066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * @param sphere array containing the output as (x, y, z, r) 1149066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * @param sphereOffset offset where the sphere data will be written 1159066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * 1169066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * @throws IllegalArgumentException if positions is null, 1179066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * positionsOffset < 0, positionsOffset > positions.length - positionsCount, 1189066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * sphere is null, sphereOffset < 0, sphereOffset > sphere.length - 4. 1199066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project */ 1209066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project public static native void computeBoundingSphere(float[] positions, 1219066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project int positionsOffset, int positionsCount, float[] sphere, 1229066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project int sphereOffset); 1239066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project} 124