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OBB2D optimizaitons

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This commit is contained in:
Hannes Janetzek 2014-01-24 05:29:54 +01:00
parent 77e2a6607c
commit 44fc754b6f
2 changed files with 144 additions and 129 deletions
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5
vtm/src/org/oscim/layers/tile/vector/labeling/Debug.java
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@ -24,7 +24,7 @@ import org.oscim.theme.styles.Line;
class Debug { class Debug {
private final static float[] mDebugPoints = new float[4]; private final static float[] mDebugPoints = new float[8];
static void addDebugBox(ElementLayers dbg, Label l, TextItem ti, int overlaps, boolean prev, static void addDebugBox(ElementLayers dbg, Label l, TextItem ti, int overlaps, boolean prev,
float scale) { float scale) {
@ -57,8 +57,9 @@ class Debug {
points[3] = (l.y + height * scale); points[3] = (l.y + height * scale);
ll.addLine(points, 4, false); ll.addLine(points, 4, false);
System.arraycopy(l.bbox.vec, 2, points, 0, 8);
if (l.bbox != null && overlaps != 3) { if (l.bbox != null && overlaps != 3) {
ll.addLine(l.bbox.corner, 8, true); ll.addLine(points, 8, true);
} }
} }

262
vtm/src/org/oscim/utils/OBB2D.java
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@ -17,115 +17,129 @@
package org.oscim.utils; package org.oscim.utils;
/** /**
* from http://www.flipcode.com/archives/2D_OBB_Intersection.shtml * ported from http://www.flipcode.com/archives/2D_OBB_Intersection.shtml
*
* @author Morgan McGuire morgan@cs.brown.edu
* @author Hannes Janetzek
*/ */
public class OBB2D { public class OBB2D {
/**
* Vector math for one array
*/
public static class Vec2 { public static class Vec2 {
public static void set(float[] v, int pos, float x, float y) { public static void set(float[] v, int pos, float x, float y) {
v[(pos << 1) + 0] = x; v[pos + 0] = x;
v[(pos << 1) + 1] = y; v[pos + 1] = y;
} }
public static float dot(float[] a, int apos, float[] b, int bpos) { public static float dot(float[] v, int a, int b) {
return a[apos << 1] * b[bpos << 1] + a[(apos << 1) + 1] * b[(bpos << 1) + 1]; return v[a] * v[b] + v[a + 1] * v[b + 1];
} }
public final static float lengthSquared(float[] v, int pos) { public final static float lengthSquared(float[] v, int pos) {
float x = v[(pos << 1) + 0]; float x = v[pos + 0];
float y = v[(pos << 1) + 1]; float y = v[pos + 1];
return x * x + y * y; return x * x + y * y;
} }
public final static void normalizeSquared(float[] v, int pos) { public final static void normalizeSquared(float[] v, int pos) {
float x = v[(pos << 1) + 0]; float x = v[pos + 0];
float y = v[(pos << 1) + 1]; float y = v[pos + 1];
float length = x * x + y * y; float length = x * x + y * y;
v[(pos << 1) + 0] = x / length; v[pos + 0] = x / length;
v[(pos << 1) + 1] = y / length; v[pos + 1] = y / length;
} }
public final static void normalize(float[] v, int pos) { public final static void normalize(float[] v, int pos) {
float x = v[(pos << 1) + 0]; float x = v[pos + 0];
float y = v[(pos << 1) + 1]; float y = v[pos + 1];
double length = Math.sqrt(x * x + y * y); double length = Math.sqrt(x * x + y * y);
v[(pos << 1) + 0] = (float) (x / length); v[pos + 0] = (float) (x / length);
v[(pos << 1) + 1] = (float) (y / length); v[pos + 1] = (float) (y / length);
} }
public final static float length(float[] v, int pos) { public final static float length(float[] v, int pos) {
float x = v[(pos << 1) + 0]; float x = v[pos + 0];
float y = v[(pos << 1) + 1]; float y = v[pos + 1];
return (float) Math.sqrt(x * x + y * y); return (float) Math.sqrt(x * x + y * y);
} }
public final static void add(float[] result, int rpos, float[] a, int apos, float[] b, public final static void add(float[] v, int r, int a, int b) {
int bpos) { v[r + 0] = v[a + 0] + v[b + 0];
result[(rpos << 1) + 0] = a[(apos << 1) + 0] + b[(bpos << 1) + 0]; v[r + 1] = v[a + 1] + v[b + 1];
result[(rpos << 1) + 1] = a[(apos << 1) + 1] + b[(bpos << 1) + 1];
} }
public final static void sub(float[] result, int rpos, float[] a, int apos, float[] b, public final static void sub(float[] v, int r, int a, int b) {
int bpos) { v[r + 0] = v[a + 0] - v[b + 0];
result[(rpos << 1) + 0] = a[(apos << 1) + 0] - b[(bpos << 1) + 0]; v[r + 1] = v[a + 1] - v[b + 1];
result[(rpos << 1) + 1] = a[(apos << 1) + 1] - b[(bpos << 1) + 1];
} }
public final static void mul(float[] v, int pos, float a) { public final static void mul(float[] v, int pos, float a) {
v[(pos << 1) + 0] *= a; v[pos + 0] *= a;
v[(pos << 1) + 1] *= a; v[pos + 1] *= a;
} }
} }
float originX;
float originY;
public final float[] vec = new float[4 * 2 + 2 * 2];
// Corners of the box, where 0 is the lower left. // Corners of the box, where 0 is the lower left.
public final float[] corner = new float[4 * 2]; //public final float[] corner = new float[ 4 * 2];
private final static int CORNER_X = 0;
private final static int CORNER_Y = CORNER_X + 1;
private final static int CORNER_0 = CORNER_X;
private final static int CORNER_1 = CORNER_X + 2;
//private final static int CORNER_2 = CORNER_X + 4;
private final static int CORNER_3 = CORNER_X + 6;
// Two edges of the box extended away from corner[0]. // Two edges of the box extended away from origin[CORNER_X + 0].
public final float[] axis = new float[2 * 2]; //public final float[] axis = new float[2 * 2];
private final static int AXIS_X = 2 * 4;
private final static int AXIS_Y = AXIS_X + 1;
// origin[a] = corner[0].dot(axis[a]); private final static int AXIS_1 = AXIS_X;
public final float[] origin = new float[2]; private final static int AXIS_2 = AXIS_X + 2;
// Returns true if other overlaps one dimension of this. // Returns true if other overlaps one dimension of this.
private boolean overlaps1Way(OBB2D other) { private boolean overlaps1Way(OBB2D other) {
for (int a = 0; a < 2; a++) { for (int a = 0; a <= 2; a += 2) {
float ax = axis[a * 2]; float ax = vec[AXIS_X + a];
float ay = axis[a * 2 + 1]; float ay = vec[AXIS_Y + a];
// dot product // dot product
float t = ax * other.corner[0] + ay * other.corner[1]; float t = ax * other.vec[CORNER_X] + ay * other.vec[CORNER_Y];
// Find the extent of box 2 on axis a // Find the extent of box 2 on axis a
float tMin = t; float tMin = t;
float tMax = t; float tMax = t;
for (int c = 2; c < 8; c += 2) { for (int c = CORNER_X + 2; c < 8; c += 2) {
t = ax * other.corner[c] + ay * other.corner[c + 1]; t = ax * other.vec[c] + ay * other.vec[c + 1];
if (t < tMin) { if (t < tMin)
tMin = t; tMin = t;
} else if (t > tMax) { else if (t > tMax)
tMax = t; tMax = t;
} }
}
// We have to subtract off the origin // We have to subtract off the origin
// See if [tMin, tMax] intersects [0, 1] // See if [tMin, tMax] intersects [0, 1]
if ((tMin > 1 + origin[a]) || (tMax < origin[a])) { if (a == 0) {
if ((tMin > 1 + originX) || (tMax < originX))
// There was no intersection along this dimension; // There was no intersection along this dimension;
// the boxes cannot possibly overlap. // the boxes cannot possibly overlap.
return false; return false;
} else {
if ((tMin > 1 + originY) || (tMax < originY))
return false;
} }
} }
@ -137,42 +151,42 @@ public class OBB2D {
// Updates the axes after the corners move. Assumes the // Updates the axes after the corners move. Assumes the
// corners actually form a rectangle. // corners actually form a rectangle.
private void computeAxes() { private void computeAxes() {
Vec2.sub(axis, 0, corner, 1, corner, 0); Vec2.sub(vec, AXIS_1, CORNER_1, CORNER_0);
Vec2.sub(axis, 1, corner, 3, corner, 0); Vec2.sub(vec, AXIS_2, CORNER_3, CORNER_0);
// Make the length of each axis 1/edge length so we know any // Make the length of each axis 1/edge length so we know any
// dot product must be less than 1 to fall within the edge. // dot product must be less than 1 to fall within the edge.
Vec2.normalizeSquared(axis, 0); Vec2.normalizeSquared(vec, AXIS_1);
origin[0] = Vec2.dot(corner, 0, axis, 0); originX = Vec2.dot(vec, CORNER_0, AXIS_1);
Vec2.normalizeSquared(axis, 1); Vec2.normalizeSquared(vec, AXIS_2);
origin[1] = Vec2.dot(corner, 0, axis, 1); originY = Vec2.dot(vec, CORNER_0, AXIS_2);
}
public OBB2D(float cx, float cy, float w, float h, float angle) {
float rcos = (float) Math.cos(angle);
float rsin = (float) Math.sin(angle);
float[] tmp = new float[4 * 2];
Vec2.set(tmp, 0, rcos, rsin);
Vec2.set(tmp, 1, -rsin, rcos);
Vec2.mul(tmp, 0, w / 2);
Vec2.mul(tmp, 1, h / 2);
Vec2.add(tmp, 2, tmp, 0, tmp, 1);
Vec2.sub(tmp, 3, tmp, 0, tmp, 1);
Vec2.set(tmp, 0, cx, cy);
Vec2.sub(corner, 0, tmp, 0, tmp, 3);
Vec2.add(corner, 1, tmp, 0, tmp, 3);
Vec2.add(corner, 2, tmp, 0, tmp, 2);
Vec2.sub(corner, 3, tmp, 0, tmp, 2);
computeAxes();
} }
// public OBB2D(float cx, float cy, float w, float h, float angle) {
// float rcos = (float) Math.cos(angle);
// float rsin = (float) Math.sin(angle);
//
// float[] tmp = new float[4 * 2];
// Vec2.set(tmp, 0, rcos, rsin);
// Vec2.set(tmp, 1, -rsin, rcos);
//
// Vec2.mul(tmp, 0, w / 2);
// Vec2.mul(tmp, 1, h / 2);
//
// Vec2.add(tmp, 2, tmp, 0, tmp, 1);
// Vec2.sub(tmp, 3, tmp, 0, tmp, 1);
//
// Vec2.set(tmp, 0, cx, cy);
//
// Vec2.sub(origin, CORNER_X + 0, tmp, 0, tmp, 3);
// Vec2.add(origin, CORNER_X + 2, tmp, 0, tmp, 3);
// Vec2.add(origin, CORNER_X + 4, tmp, 0, tmp, 2);
// Vec2.sub(origin, CORNER_X + 6, tmp, 0, tmp, 2);
//
// computeAxes();
// }
//
public OBB2D() { public OBB2D() {
} }
@ -185,17 +199,17 @@ public class OBB2D {
float ux = (float) -asin * height / 2; float ux = (float) -asin * height / 2;
float uy = (float) acos * height / 2; float uy = (float) acos * height / 2;
corner[0] = cx + (vx - ux); vec[CORNER_X] = cx + (vx - ux);
corner[1] = cy + (vy - uy); vec[CORNER_Y] = cy + (vy - uy);
corner[2] = cx + (-vx - ux); vec[CORNER_X + 2] = cx + (-vx - ux);
corner[3] = cy + (-vy - uy); vec[CORNER_Y + 2] = cy + (-vy - uy);
corner[4] = cx + (-vx + ux); vec[CORNER_X + 4] = cx + (-vx + ux);
corner[5] = cy + (-vy + uy); vec[CORNER_Y + 4] = cy + (-vy + uy);
corner[6] = cx + (vx + ux); vec[CORNER_X + 6] = cx + (vx + ux);
corner[7] = cy + (vy + uy); vec[CORNER_Y + 6] = cy + (vy + uy);
computeAxes(); computeAxes();
} }
@ -219,17 +233,17 @@ public class OBB2D {
ux *= hh; ux *= hh;
uy *= hh; uy *= hh;
corner[0] = cx - (vx - ux); vec[CORNER_X] = cx - (vx - ux);
corner[1] = cy - (vy - uy); vec[CORNER_Y] = cy - (vy - uy);
corner[2] = cx + (vx - ux); vec[CORNER_X + 2] = cx + (vx - ux);
corner[3] = cy + (vy - uy); vec[CORNER_Y + 2] = cy + (vy - uy);
corner[4] = cx + (vx + ux); vec[CORNER_X + 4] = cx + (vx + ux);
corner[5] = cy + (vy + uy); vec[CORNER_Y + 4] = cy + (vy + uy);
corner[6] = cx - (vx + ux); vec[CORNER_X + 6] = cx - (vx + ux);
corner[7] = cy - (vy + uy); vec[CORNER_Y + 6] = cy - (vy + uy);
computeAxes(); computeAxes();
} }
@ -251,17 +265,17 @@ public class OBB2D {
vx *= hw; vx *= hw;
vy *= hw; vy *= hw;
corner[0] = cx - vx - ux; vec[CORNER_X] = cx - vx - ux;
corner[1] = cy - vy - uy; vec[CORNER_Y] = cy - vy - uy;
corner[2] = cx + vx - ux; vec[CORNER_X + 2] = cx + vx - ux;
corner[3] = cy + vy - uy; vec[CORNER_Y + 2] = cy + vy - uy;
corner[4] = cx + vx + ux; vec[CORNER_X + 4] = cx + vx + ux;
corner[5] = cy + vy + uy; vec[CORNER_Y + 4] = cy + vy + uy;
corner[6] = cx - vx + ux; vec[CORNER_X + 6] = cx - vx + ux;
corner[7] = cy - vy + uy; vec[CORNER_Y + 6] = cy - vy + uy;
computeAxes(); computeAxes();
} }
@ -284,17 +298,17 @@ public class OBB2D {
vx *= hw; vx *= hw;
vy *= hw; vy *= hw;
corner[0] = cx - vx - ux; vec[CORNER_X + 0] = cx - vx - ux;
corner[1] = cy - vy - uy; vec[CORNER_Y + 0] = cy - vy - uy;
corner[2] = cx + vx - ux; vec[CORNER_X + 2] = cx + vx - ux;
corner[3] = cy + vy - uy; vec[CORNER_Y + 2] = cy + vy - uy;
corner[4] = cx + vx + ux; vec[CORNER_X + 4] = cx + vx + ux;
corner[5] = cy + vy + uy; vec[CORNER_Y + 4] = cy + vy + uy;
corner[6] = cx - vx + ux; vec[CORNER_X + 6] = cx - vx + ux;
corner[7] = cy - vy + uy; vec[CORNER_Y + 6] = cy - vy + uy;
computeAxes(); computeAxes();
} }
@ -305,26 +319,26 @@ public class OBB2D {
float hw = width / 2; float hw = width / 2;
float hh = height / 2; float hh = height / 2;
corner[0] = cx - hw; vec[CORNER_X] = cx - hw;
corner[1] = cy - hh; vec[CORNER_Y] = cy - hh;
corner[2] = cx - hw; vec[CORNER_X + 2] = cx - hw;
corner[3] = cy + hh; vec[CORNER_Y + 2] = cy + hh;
corner[4] = cx + hw; vec[CORNER_X + 4] = cx + hw;
corner[5] = cy + hh; vec[CORNER_Y + 4] = cy + hh;
corner[6] = cx + hw; vec[CORNER_X + 6] = cx + hw;
corner[7] = cy - hh; vec[CORNER_Y + 6] = cy - hh;
axis[0] = 0; vec[AXIS_X + 0] = 0;
axis[1] = 1 / height; vec[AXIS_X + 1] = 1 / height;
axis[2] = 1 / width; vec[AXIS_X + 2] = 1 / width;
axis[3] = 0; vec[AXIS_X + 3] = 0;
origin[0] = corner[1] * axis[1]; vec[0] = vec[CORNER_Y] * vec[AXIS_Y];
origin[1] = corner[2] * axis[2]; vec[1] = vec[CORNER_X + 2] * vec[AXIS_X + 2];
} }
// Returns true if the intersection of the boxes is non-empty. // Returns true if the intersection of the boxes is non-empty.
@ -334,12 +348,12 @@ public class OBB2D {
// // For testing purposes. // // For testing purposes.
// void moveTo(Vec2 center) { // void moveTo(Vec2 center) {
// Vec2 centroid = (corner[0] + corner[1] + corner[2] + corner[3]) / 4; // Vec2 centroid = (origin[CORNER_X + 0] + origin[CORNER_X + 1] + origin[CORNER_X + 2] + origin[CORNER_X + 3]) / 4;
// //
// Vec2 translation = center - centroid; // Vec2 translation = center - centroid;
// //
// for (int c = 0; c < 4; ++c) { // for (int c = 0; c < 4; ++c) {
// corner[c] += translation; // origin[CORNER_X + c] += translation;
// } // }
// //
// computeAxes(); // computeAxes();
@ -348,7 +362,7 @@ public class OBB2D {
// void render() { // void render() {
// glBegin(GL_LINES); // glBegin(GL_LINES);
// for (int c = 0; c < 5; ++c) { // for (int c = 0; c < 5; ++c) {
// glVertex2fv(corner[c & 3]); // glVertex2fv(origin[CORNER_X + c & 3]);
// } // }
// glEnd(); // glEnd();
// } // }