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improve LineLayer bevel joint

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This commit is contained in:
Hannes Janetzek 2014-02-21 04:14:37 +01:00
parent 60438b2925
commit 0ef16b6c5b
1 changed files with 129 additions and 41 deletions
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170
vtm/src/org/oscim/renderer/elements/LineLayer.java
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@ -30,7 +30,6 @@ import org.oscim.renderer.GLUtils;
import org.oscim.renderer.GLViewport;
import org.oscim.renderer.MapRenderer;
import org.oscim.theme.styles.Line;
import org.oscim.utils.FastMath;
import org.oscim.utils.pool.Inlist;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
@ -47,6 +46,16 @@ public final class LineLayer extends RenderElement {
private static final float COORD_SCALE = MapRenderer.COORD_SCALE;
/** scale factor mapping extrusion vector to short values */
public static final float DIR_SCALE = 2048;
/** maximal resoultion */
private static final float MIN_DIST = 1 / 8f;
/**
* not quite right.. need to go back so that additional
* bevel vertices are at least MIN_DIST apart
*/
//private static final float JOIN_BEVEL = MIN_DIST
/**
* mask for packing last two bits of extrusion vector with texture
* coordinates
@ -59,7 +68,7 @@ public final class LineLayer extends RenderElement {
public float scale = 1;
public boolean roundCap;
private float mMinDist = 1 / 8f;
private float mMinDist = MIN_DIST;
public float heightOffset;
@ -78,10 +87,10 @@ public final class LineLayer extends RenderElement {
}
/**
* For point reduction by minimal distance. Default is 1/4.
* For point reduction by minimal distance. Default is 1/8.
*/
public void setDropDistance(float minDist) {
mMinDist = minDist < 1 / 8f ? 1 / 8f : minDist;
mMinDist = Math.max(minDist, MIN_DIST);
}
public void addLine(GeometryBuffer geom) {
@ -99,8 +108,6 @@ public final class LineLayer extends RenderElement {
}
private void addLine(float[] points, short[] index, int numPoints, boolean closed) {
float x, y, nextX, nextY;
float a, ux, uy, vx, vy, wx, wy;
int tmax = Tile.SIZE + 4;
int tmin = -4;
@ -150,6 +157,13 @@ public final class LineLayer extends RenderElement {
}
for (int i = 0, pos = 0; i < n; i++) {
float ux, uy;
float vx, vy;
float wx, wy;
float x, y;
float nextX, nextY;
double a;
if (index != null)
length = index[i];
@ -331,7 +345,6 @@ public final class LineLayer extends RenderElement {
x = nextX;
y = nextY;
boolean flip = false;
/* Unit vector pointing back to previous node */
vx *= -1;
vy *= -1;
@ -353,7 +366,7 @@ public final class LineLayer extends RenderElement {
/* Unit vector pointing forward to next node */
wx = nextX - x;
wy = nextY - y;
a = (float) Math.sqrt(wx * wx + wy * wy);
a = Math.sqrt(wx * wx + wy * wy);
/* skip too short segmets */
if (a < mMinDist) {
numVertices -= 2;
@ -362,32 +375,116 @@ public final class LineLayer extends RenderElement {
wx /= a;
wy /= a;
/* Sum of these two vectors points */
double dotp = (wx * vx + wy * vy);
//log.debug("acos " + dotp);
if (dotp > 0.7) {
/* add bevel join to avoid miter going to infinity */
numVertices += 2;
//dotp = FastMath.clamp(dotp, -1, 1);
//double cos = Math.acos(dotp);
//log.debug("cos " + Math.toDegrees(cos));
//log.debug("back " + (mMinDist * 2 / Math.sin(cos + Math.PI / 2)));
float px, py;
if (dotp > 0.999) {
/* 360 degree angle, set points aside */
ux = vx + wx;
uy = vy + wy;
a = wx * uy - wy * ux;
if (a < 0.1 && a > -0.1) {
/* Almost straight */
ux = -wy;
uy = wx;
} else {
ux /= a;
uy /= a;
}
//log.debug("aside " + a + " " + ux + " " + uy);
px = x - ux * MIN_DIST * 2;
py = y - uy * MIN_DIST * 2;
x = x + ux * MIN_DIST * 2;
y = y + uy * MIN_DIST * 2;
} else {
//log.debug("back");
/* go back by min dist */
px = x + vx * MIN_DIST * 2;
py = y + vy * MIN_DIST * 2;
/* go forward by min dist */
x = x + wx * MIN_DIST * 2;
y = y + wy * MIN_DIST * 2;
}
/* Unit vector pointing forward to next node */
wx = x - px;
wy = y - py;
a = Math.sqrt(wx * wx + wy * wy);
wx /= a;
wy /= a;
ux = vx + wx;
uy = vy + wy;
a = wx * uy - wy * ux;
if (a < 0.01 && a > -0.01) {
ux = -wy;
uy = wx;
} else {
ux /= a;
uy /= a;
}
ox = (short) (px * COORD_SCALE);
oy = (short) (py * COORD_SCALE);
ddx = (int) (ux * DIR_SCALE);
ddy = (int) (uy * DIR_SCALE);
if (opos == SIZE) {
si = pool.getNext(si);
v = si.vertices;
opos = 0;
}
v[opos++] = ox;
v[opos++] = oy;
v[opos++] = (short) (0 | ddx & DIR_MASK);
v[opos++] = (short) (1 | ddy & DIR_MASK);
if (opos == SIZE) {
si = pool.getNext(si);
v = si.vertices;
opos = 0;
}
v[opos++] = ox;
v[opos++] = oy;
v[opos++] = (short) (2 | -ddx & DIR_MASK);
v[opos++] = (short) (1 | -ddy & DIR_MASK);
/* flip unit vector to point back */
vx = -wx;
vy = -wy;
/* Unit vector pointing forward to next node */
wx = nextX - x;
wy = nextY - y;
a = Math.sqrt(wx * wx + wy * wy);
wx /= a;
wy /= a;
}
ux = vx + wx;
uy = vy + wy;
/* cross-product */
a = wx * uy - wy * ux;
if (FastMath.abs(a) < 0.01f) {
if (a < 0.01 && a > -0.01) {
/* Almost straight */
ux = -wy;
uy = wx;
} else {
ux /= a;
uy /= a;
/* avoid miter going to infinity.
* TODO add option for round joints */
if (FastMath.absMaxCmp(ux, uy, 4f)) {
ux = vx - wx;
uy = vy - wy;
a = -wy * ux + wx * uy;
ux /= a;
uy /= a;
flip = !flip;
}
}
ox = (short) (x * COORD_SCALE);
@ -396,10 +493,6 @@ public final class LineLayer extends RenderElement {
ddx = (int) (ux * DIR_SCALE);
ddy = (int) (uy * DIR_SCALE);
if (flip) {
ddx = -ddx;
ddy = -ddy;
}
if (opos == SIZE) {
si = pool.getNext(si);
v = si.vertices;
@ -448,11 +541,6 @@ public final class LineLayer extends RenderElement {
ddx = (int) (ux * DIR_SCALE);
ddy = (int) (uy * DIR_SCALE);
if (flip) {
ddx = -ddx;
ddy = -ddy;
}
v[opos++] = ox;
v[opos++] = oy;
v[opos++] = (short) (0 | ddx & DIR_MASK);
@ -479,8 +567,8 @@ public final class LineLayer extends RenderElement {
ddx = (int) ((ux - vx) * DIR_SCALE);
ddy = (int) ((uy - vy) * DIR_SCALE);
dx = (short) (0 | (flip ? -ddx : ddx) & DIR_MASK);
dy = (short) (0 | (flip ? -ddy : ddy) & DIR_MASK);
dx = (short) (0 | ddx & DIR_MASK);
dy = (short) (0 | ddy & DIR_MASK);
v[opos++] = ox;
v[opos++] = oy;
@ -496,8 +584,8 @@ public final class LineLayer extends RenderElement {
/* add last vertex twice */
ddx = (int) (-(ux + vx) * DIR_SCALE);
ddy = (int) (-(uy + vy) * DIR_SCALE);
dx = (short) (2 | (flip ? -ddx : ddx) & DIR_MASK);
dy = (short) (0 | (flip ? -ddy : ddy) & DIR_MASK);
dx = (short) (2 | ddx & DIR_MASK);
dy = (short) (0 | ddy & DIR_MASK);
v[opos++] = ox;
v[opos++] = oy;
@ -532,8 +620,8 @@ public final class LineLayer extends RenderElement {
v[opos++] = ox;
v[opos++] = oy;
v[opos++] = (short) (0 | (flip ? -ddx : ddx) & DIR_MASK);
v[opos++] = (short) (1 | (flip ? -ddy : ddy) & DIR_MASK);
v[opos++] = (short) (0 | ddx & DIR_MASK);
v[opos++] = (short) (1 | ddy & DIR_MASK);
if (opos == SIZE) {
si = pool.getNext(si);
@ -544,8 +632,8 @@ public final class LineLayer extends RenderElement {
/* add last vertex twice */
ddx = (int) (-(ux + vx) * DIR_SCALE);
ddy = (int) (-(uy + vy) * DIR_SCALE);
dx = (short) (2 | (flip ? -ddx : ddx) & DIR_MASK);
dy = (short) (1 | (flip ? -ddy : ddy) & DIR_MASK);
dx = (short) (2 | ddx & DIR_MASK);
dy = (short) (1 | ddy & DIR_MASK);
v[opos++] = ox;
v[opos++] = oy;