From 32ba8bbae04ed417cd87ce52c1f07c6f1f22745d Mon Sep 17 00:00:00 2001
From: Hannes Janetzek <hannes.janetzek@gmail.com>
Date: Sun, 10 Feb 2013 12:17:39 +0100
Subject: [PATCH] use faster Math.abs utility, cleanups, comments
---
src/org/oscim/renderer/layer/LineLayer.java | 55 +++++++++++----------
src/org/oscim/utils/FastMath.java | 14 ++++++
2 files changed, 44 insertions(+), 25 deletions(-)
diff --git a/src/org/oscim/renderer/layer/LineLayer.java b/src/org/oscim/renderer/layer/LineLayer.java
index 7b0a2895..b5c0d22f 100644
--- a/src/org/oscim/renderer/layer/LineLayer.java
+++ b/src/org/oscim/renderer/layer/LineLayer.java
@@ -17,6 +17,7 @@ package org.oscim.renderer.layer;
import org.oscim.core.Tile;
import org.oscim.renderer.GLRenderer;
import org.oscim.theme.renderinstruction.Line;
+import org.oscim.utils.FastMath;
import org.oscim.view.MapView;
import android.graphics.Paint.Cap;
@@ -70,8 +71,8 @@ public final class LineLayer extends Layer {
float x, y, nextX, nextY;
float a, ux, uy, vx, vy, wx, wy;
- int tmax = Tile.TILE_SIZE + 10;
- int tmin = -10;
+ int tmax = Tile.TILE_SIZE + 4;
+ int tmin = -4;
boolean rounded = false;
boolean squared = false;
@@ -108,7 +109,6 @@ public final class LineLayer extends Layer {
roundCap = rounded;
for (int i = 0, pos = 0, n = index.length; i < n; i++) {
-
int length = index[i];
// check end-marker in indices
@@ -139,11 +139,12 @@ public final class LineLayer extends Layer {
vx = nextX - x;
vy = nextY - y;
+ // Unit vector to next node
a = (float) Math.sqrt(vx * vx + vy * vy);
+ vx /= a;
+ vy /= a;
- vx = (vx / a);
- vy = (vy / a);
-
+ // perpendicular on the first segment
ux = -vy;
uy = vx;
@@ -153,12 +154,17 @@ public final class LineLayer extends Layer {
opos = 0;
}
- short ox, oy, dx, dy;
int ddx, ddy;
- ox = (short) (x * COORD_SCALE);
- oy = (short) (y * COORD_SCALE);
+ // vertex point coordinate
+ short ox = (short) (x * COORD_SCALE);
+ short oy = (short) (y * COORD_SCALE);
+ // vertex extrusion vector, last two bit
+ // encode texture coord.
+ short dx, dy;
+
+ // when the endpoint is outside the tile region omit round caps.
boolean outside = (x < tmin || x > tmax || y < tmin || y > tmax);
if (opos == VertexPoolItem.SIZE) {
@@ -171,7 +177,6 @@ public final class LineLayer extends Layer {
// add first vertex twice
ddx = (int) ((ux - vx) * DIR_SCALE);
ddy = (int) ((uy - vy) * DIR_SCALE);
- // last two bit encode texture coord (-1)
dx = (short) (0 | ddx & DIR_MASK);
dy = (short) (2 | ddy & DIR_MASK);
@@ -310,8 +315,8 @@ public final class LineLayer extends Layer {
wx = nextX - x;
wy = nextY - y;
a = (float) Math.sqrt(wx * wx + wy * wy);
- wx = (wx / a);
- wy = (wy / a);
+ wx /= a;
+ wy /= a;
// Sum of these two vectors points
ux = vx + wx;
@@ -320,24 +325,23 @@ public final class LineLayer extends Layer {
// cross-product
a = wx * uy - wy * ux;
- // boolean split = false;
- if (a < 0.01f && a > -0.01f) {
+ if (FastMath.abs(a) < 0.01f) {
// Almost straight
ux = -wy;
uy = wx;
} else {
- ux = (ux / a);
- uy = (uy / a);
+ ux /= a;
+ uy /= a;
// avoid miter going to infinity.
// TODO add option for round joints
- if (ux > 4.0f || ux < -4.0f || uy > 4.0f || uy < -4.0f) {
+ if (FastMath.absMaxCmp(ux, uy, 4f)) {
ux = vx - wx;
uy = vy - wy;
a = -wy * ux + wx * uy;
- ux = (ux / a);
- uy = (uy / a);
+ ux /= a;
+ uy /= a;
flip = !flip;
}
}
@@ -349,8 +353,8 @@ public final class LineLayer extends Layer {
ddy = (int) (uy * DIR_SCALE);
if (flip) {
- ddx *= -1;
- ddy *= -1;
+ ddx = -ddx;
+ ddy = -ddy;
}
if (opos == VertexPoolItem.SIZE) {
si = si.next = VertexPool.get();
@@ -377,8 +381,9 @@ public final class LineLayer extends Layer {
x = nextX;
y = nextY;
- vx = -1 * wx;
- vy = -1 * wy;
+ // flip unit vector to point back
+ vx = -wx;
+ vy = -wy;
}
ux = vy;
@@ -401,8 +406,8 @@ public final class LineLayer extends Layer {
ddy = (int) (uy * DIR_SCALE);
if (flip) {
- ddx *= -1;
- ddy *= -1;
+ ddx = -ddx;
+ ddy = -ddy;
}
v[opos++] = ox;
diff --git a/src/org/oscim/utils/FastMath.java b/src/org/oscim/utils/FastMath.java
index a6a3e2e9..b8b257d7 100644
--- a/src/org/oscim/utils/FastMath.java
+++ b/src/org/oscim/utils/FastMath.java
@@ -54,4 +54,18 @@ public class FastMath {
return (pow > 0 ? (1 << pow) : (1.0f / (1 << -pow)));
}
+
+ public static float abs(float value){
+ return value < 0 ? -value : value;
+ }
+
+ public static float absMax(float value1, float value2){
+ float a1 = value1 < 0 ? -value1 : value1;
+ float a2 = value2 < 0 ? -value2 : value2;
+ return a2 < a1 ? a1 : a2;
+ }
+
+ public static boolean absMaxCmp(float value1, float value2, float cmp){
+ return value1 < -cmp || value1 > cmp || value2 < -cmp || value2 > cmp;
+ }
}