vtm/vtm-android/jni/triangle/TriangleJni.c
Hannes Janetzek 83cd73156a split up
2013-10-09 01:56:08 +02:00

303 lines
8.2 KiB
C

#include <jni.h>
#include <string.h>
#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#include "triangle.h"
#include <android/log.h>
#define printf(...) __android_log_print(ANDROID_LOG_DEBUG, "Triangle", __VA_ARGS__)
// from www.ecse.rpi.edu/Homepages/wrf/Research/Short_Notes/pnpoly.html
#if 0
int pnpoly(int nvert, float *vert, float testx, float testy)
{
int i, j, c = 0;
for (i = 0, j = (nvert-1)*2; i < nvert * 2; j = i++)
{
if ( ((vert[i*2+1] > testy) != (vert[j*j+1] > testy)) &&
(testx < (vert[j*2]-vert[i*2])
* (testy - vert[i*2+1])
/ (vert[j*2+1]-vert[i*2+1]) + vert[i*2]) )
c = !c;
}
return c;
}
int compare_dups(const void *a, const void *b) {
int da = *((const long*) a);
int db = *((const long*) b);
return (da > db) - (da < db);
}
void shiftSegment(TriangleIO *in, int *seg, int pos) {
int size = (in->numberofsegments - pos - 1) * sizeof(int) * 2;
printf("shift %d - %d %d\n", size, in->numberofsegments, pos);
if (size > 0)
memmove(seg, seg + 2, size);
in->numberofsegments -= 1;
}
struct {
int p1;
int p2;
} segment;
#endif
static void printPoly(TriangleIO *in) {
// print poly format to check with triangle/showme
printf("%d 2 0 0\n", in->numberofpoints);
for (int j = 0; j < in->numberofpoints; j++)
printf("%d %f %f\n", j, in->pointlist[j*2], in->pointlist[j*2+1]);
int *seg = in->segmentlist;
printf("%d 0\n", in->numberofsegments);
for (int j = 0; j < in->numberofsegments; j++, seg += 2)
printf("%d %d %d\n", j, *seg, *(seg+1));
printf("%d 0\n", in->numberofholes);
for (int j = 0; j < in->numberofholes; j++) {
printf("%d %f %f\n", j, in->holelist[j*2], in->holelist[j*2+1]);
}
}
jint Java_org_oscim_renderer_sublayers_ExtrusionLayer_triangulate(JNIEnv *env, jclass c,
jfloatArray obj_points, jint pos, jint len, jint num_rings, jobject indice_buf, jint offset) {
jshort* indices = (jshort*) (*env)->GetDirectBufferAddress(env, indice_buf);
jboolean isCopy;
float* orig_points = (float*) (*env)->GetPrimitiveArrayCritical(env, obj_points, &isCopy);
if (orig_points == NULL)
return 0;
float *points = orig_points + pos;
TriangleIO in, out;
char buf[128];
memset(&in, 0, sizeof(TriangleIO));
in.numberofpoints = len >> 1;
in.pointlist = (float *) points;
// check if explicitly closed
if (in.pointlist[0] == in.pointlist[indices[0] - 2]
&& in.pointlist[1] == in.pointlist[indices[0] - 1]) {
int point = 0;
for (int i = 0; i < num_rings; i++) {
// remove last point in ring
indices[i] -= 2;
int last = point + (indices[i] >> 1);
if (in.numberofpoints - last > 1)
memmove(in.pointlist + (last * 2), in.pointlist + ((last + 1) * 2),
(in.numberofpoints - last - 1) * 2 * sizeof(float));
in.numberofpoints--;
point = last;
}
}
int dups = 0;
float *i_points = points;
int *skip_list = NULL;
// check for duplicate vertices and keep a list
// of dups and the first occurence
for (int i = 0; i < in.numberofpoints - 1; i++) {
float x = *i_points++;
float y = *i_points++;
float *j_points = i_points;
for (int j = i + 1; j < in.numberofpoints; j++, j_points += 2) {
if ((*j_points == x) && (*(j_points + 1) == y)) {
skip_list = realloc(skip_list, (dups + 2) * 2 * sizeof(int));
skip_list[dups * 2 + 0] = j;
skip_list[dups * 2 + 1] = i;
dups++;
}
}
}
in.segmentlist = (int *) malloc(in.numberofpoints * 2 * sizeof(int));
in.numberofsegments = in.numberofpoints;
in.numberofholes = num_rings - 1;
int *rings = NULL;
if (in.numberofholes > 0) {
in.holelist = (float *) malloc(in.numberofholes * 2 * sizeof(float));
rings = (int*) malloc(num_rings * sizeof(int));
}
int *seg = in.segmentlist;
float *hole = in.holelist;
// counter going through all points
int point;
// counter going through all rings
int ring;
// assign all points to segments for each ring
for (ring = 0, point = 0; ring < num_rings; ring++, point++) {
int len;
int num_points = indices[ring] >> 1;
if (rings)
rings[ring] = num_points;
// add holes: we need a point inside the hole...
// this is just a heuristic, assuming that two
// 'parallel' lines have a distance of at least
// 1 unit. you'll notice when things went wrong
// when the hole is rendered instead of the poly
if (ring > 0) {
int k = point * 2;
float nx = in.pointlist[k++];
float ny = in.pointlist[k++];
float cx, cy, vx, vy;
// try to find a large enough segment
for (len = (point + num_points) * 2; k < len;) {
cx = nx;
cy = ny;
nx = in.pointlist[k++];
ny = in.pointlist[k++];
vx = nx - cx;
vy = ny - cy;
if (vx > 4 || vx < -4 || vy > 4 || vy < -4)
break;
}
float a = sqrt(vx * vx + vy * vy);
float ux = -vy / a;
float uy = vx / a;
float centerx = cx + vx / 2.0 - (ux * 0.1);
float centery = cy + vy / 2.0 - (uy * 0.1);
*hole++ = centerx;
*hole++ = centery;
}
// close ring
int last = point + (num_points - 1);
*seg++ = last;
*seg++ = point;
for (len = point + num_points - 1; point < len; point++) {
*seg++ = point;
*seg++ = point + 1;
}
}
if (dups) {
for (int i = 0; i < dups; i++) {
printf("duplicate points at %d, %d: %f,%f\n",
skip_list[i*2], skip_list[i*2+1],
in.pointlist[skip_list[i*2+1]*2],
in.pointlist[skip_list[i*2+1]*2+1]);
}
printPoly(&in);
// replace duplicate positions with first occurence
for (int i = 0; i < dups; i++) {
// position of the duplicate vertex
int pos = skip_list[i * 2] - i;
// first vertex
int replacement = skip_list[i * 2 + 1];
seg = in.segmentlist;
for (int j = 0; j < in.numberofsegments * 2; j++, seg++) {
if (*seg == pos) {
printf("%d: %d <- %d", j, pos, replacement);
*seg = replacement;
}
}
}
}
memset(&out, 0, sizeof(TriangleIO));
out.trianglelist = (INDICE*) indices;
// p - use polygon input, for CDT
// z - zero offset array offsets...
// P - no poly output
// N - no node output
// B - no bound output
// Q - be quiet!
TriangleOptions opt;
memset(&opt, 0, sizeof(TriangleOptions));
opt.dwyer = 1;
opt.steiner = -1;
opt.order = 1;
opt.maxarea = -1.0;
opt.poly = 1;
opt.usesegments = 1;
opt.nopolywritten = 1;
opt.nonodewritten = 1;
opt.nobound = 1;
opt.quiet = 1;
triangulate(&opt, &in, &out, (TriangleIO *) NULL);
if (in.numberofpoints < out.numberofpoints) {
// TODO rerun with 'nonodewritten = 0'
printf( "polygon input is bad! points in:%d out%d\n", in.numberofpoints, out.numberofpoints);
out.numberoftriangles = 0;
}
else {
// scale to stride and add offset
short stride = 2;
if (offset < 0)
offset = 0;
INDICE *tri = out.trianglelist;
for (int n = out.numberoftriangles * 3; n > 0; n--)
*tri++ = *tri * stride + offset;
// when a ring has an odd number of points one (or rather two)
// additional vertices will be added. so the following rings
// needs extra offset...
int start = offset;
for (int j = 0, m = in.numberofholes; j < m; j++) {
start += rings[j] * stride;
// even number of points?
if (!(rings[j] & 1))
continue;
tri = out.trianglelist;
int n = out.numberoftriangles * 3;
for (; n-- > 0; tri++)
if (*tri >= start)
*tri += stride;
start += stride;
}
}
(*env)->ReleasePrimitiveArrayCritical(env, obj_points, orig_points, JNI_ABORT);
free(in.segmentlist);
free(in.holelist);
free(rings);
free(skip_list);
return out.numberoftriangles;
}