Render themes: symbols on lines, fix #495

docs/Changelog.md

@@ -5,7 +5,8 @@
 - S3DB layer [#475](https://github.com/mapsforge/vtm/pull/475)
 - vtm-mvt module with MVT tile decoder [#481](https://github.com/mapsforge/vtm/pull/481)
 - OpenMapTiles MVT vector tiles [#482](https://github.com/mapsforge/vtm/issues/482)
-- Theme styles improvements [#479](https://github.com/mapsforge/vtm/pull/479)
+- Render themes: symbols on lines [#495](https://github.com/mapsforge/vtm/issues/495)
+- Render themes: styles improvements [#479](https://github.com/mapsforge/vtm/pull/479)
 - Internal render themes improvements [#488](https://github.com/mapsforge/vtm/pull/488)
 - Map view roll [#474](https://github.com/mapsforge/vtm/pull/474)
 - Fling animation improvements [#489](https://github.com/mapsforge/vtm/pull/489)

resources/rendertheme.xsd

@@ -234,6 +234,9 @@
         <xs:attribute name="symbol-width" type="xs:positiveInteger" use="optional" />
         <xs:attribute name="symbol-height" type="xs:positiveInteger" use="optional" />
         <xs:attribute name="symbol-percent" type="xs:positiveInteger" use="optional" />
+        <xs:attribute name="repeat" default="false" type="xs:boolean" use="optional" />
+        <xs:attribute name="repeat-gap" default="200" type="xs:float" use="optional" />
+        <xs:attribute name="repeat-start" default="30" type="xs:float" use="optional" />
     </xs:complexType>
 
     <xs:complexType name="extrusion">

vtm/src/org/oscim/layers/tile/vector/labeling/LabelTileLoaderHook.java

@@ -123,7 +123,16 @@ public class LabelTileLoaderHook implements TileLoaderThemeHook {
 
             LabelTileData ld = get(tile);
             if (element.type == LINE) {
-                // TODO
+                int offset = 0;
+                for (int i = 0, n = element.index.length; i < n; i++) {
+                    int length = element.index[i];
+                    if (length < 4)
+                        break;
+
+                    WayDecorator.renderSymbol(null, element.points, symbol,
+                            offset, length, ld);
+                    offset += length;
+                }
             } else if (element.type == POLY) {
                 PointF centroid = element.labelPosition;
                 if (!Parameters.POLY_SYMBOL) {

vtm/src/org/oscim/layers/tile/vector/labeling/WayDecorator.java

@@ -1,6 +1,7 @@
 /*
- * Copyright 2010, 2011, 2012 mapsforge.org
+ * Copyright 2010, 2011, 2012, 2013 mapsforge.org
  * Copyright 2013 Hannes Janetzek
+ * Copyright 2018 devemux86
  *
  * This file is part of the OpenScienceMap project (http://www.opensciencemap.org).
  *
@@ -18,13 +19,94 @@
 package org.oscim.layers.tile.vector.labeling;
 
 import org.oscim.core.Tile;
+import org.oscim.renderer.bucket.SymbolItem;
 import org.oscim.renderer.bucket.TextItem;
+import org.oscim.theme.styles.SymbolStyle;
 import org.oscim.theme.styles.TextStyle;
 import org.oscim.utils.geom.GeometryUtils;
 import org.oscim.utils.geom.LineClipper;
 
 public final class WayDecorator {
 
+    /**
+     * Mapsforge implementation.
+     */
+    public static void renderSymbol(LineClipper clipper, float[] coordinates, SymbolStyle symbol,
+                                    int pos, int len, LabelTileData ld) {
+        int skipPixels = (int) symbol.repeatStart;
+
+        // get the first way point coordinates
+        float previousX = coordinates[pos + 0];
+        float previousY = coordinates[pos + 1];
+
+        // draw the symbol on each way segment
+        float segmentLengthRemaining;
+        float segmentSkipPercentage;
+        float theta = 0;
+
+        for (int i = pos; i < pos + len - 2; i += 2) {
+            // get the current way point coordinates
+            float currentX = coordinates[i + 2];
+            float currentY = coordinates[i + 3];
+
+            // calculate the length of the current segment (Euclidean distance)
+            float diffX = currentX - previousX;
+            float diffY = currentY - previousY;
+            double segmentLengthInPixel = Math.sqrt(diffX * diffX + diffY * diffY);
+            segmentLengthRemaining = (float) segmentLengthInPixel;
+
+            while (segmentLengthRemaining - skipPixels > symbol.repeatStart) {
+                // calculate the percentage of the current segment to skip
+                segmentSkipPercentage = skipPixels / segmentLengthRemaining;
+
+                // move the previous point forward towards the current point
+                previousX += diffX * segmentSkipPercentage;
+                previousY += diffY * segmentSkipPercentage;
+
+                // TODO
+                /*if (rotate) {
+                    // if we do not rotate theta will be 0, which is correct
+                    theta = (float) Math.atan2(currentY - previousY, currentX - previousX);
+                }*/
+
+                float x = previousX;
+                float y = previousY;
+                if (x >= 0 && x <= Tile.SIZE && y >= 0 && y <= Tile.SIZE) {
+                    SymbolItem s = SymbolItem.pool.get();
+                    if (symbol.bitmap != null)
+                        s.set(x, y, symbol.bitmap, 0, true);
+                    else
+                        s.set(x, y, symbol.texture, 0, true);
+                    ld.symbols.push(s);
+                }
+
+                // check if the symbol should only be rendered once
+                if (!symbol.repeat) {
+                    return;
+                }
+
+                // recalculate the distances
+                diffX = currentX - previousX;
+                diffY = currentY - previousY;
+
+                // recalculate the remaining length of the current segment
+                segmentLengthRemaining -= skipPixels;
+
+                // set the amount of pixels to skip before repeating the symbol
+                skipPixels = (int) symbol.repeatGap;
+            }
+
+            skipPixels -= segmentLengthRemaining;
+            if (skipPixels < symbol.repeatStart) {
+                skipPixels = (int) symbol.repeatStart;
+            }
+
+            // set the previous way point coordinates for the next loop
+            previousX = currentX;
+            previousY = currentY;
+        }
+    }
+
     public static void renderText(LineClipper clipper, float[] coordinates, String label,
                                   TextStyle text, int pos, int len, LabelTileData ld) {
         //TextItem items = textItems;
@@ -82,7 +164,7 @@ public final class WayDecorator {
 
             int last = i;
 
-            // calculate the length of the current segment (Euclidian distance)
+            // calculate the length of the current segment (Euclidean distance)
             float vx = prevX - curX;
             float vy = prevY - curY;
             if (vx == 0 && vy == 0)

vtm/src/org/oscim/theme/XmlMapsforgeThemeBuilder.java

@@ -1123,6 +1123,15 @@ public class XmlMapsforgeThemeBuilder extends DefaultHandler {
             else if ("symbol-scaling".equals(name))
                 ; // no-op
 
+            else if ("repeat".equals(name))
+                b.repeat(Boolean.parseBoolean(value));
+
+            else if ("repeat-start".equals(name))
+                b.repeatStart = Float.parseFloat(value) * mScale;
+
+            else if ("repeat-gap".equals(name))
+                b.repeatGap = Float.parseFloat(value) * mScale;
+
             else
                 logUnknownAttribute(elementName, name, value, i);
         }

vtm/src/org/oscim/theme/XmlThemeBuilder.java

@@ -1,7 +1,7 @@
 /*
  * Copyright 2010, 2011, 2012 mapsforge.org
  * Copyright 2013 Hannes Janetzek
- * Copyright 2016-2017 devemux86
+ * Copyright 2016-2018 devemux86
  * Copyright 2016-2017 Longri
  * Copyright 2016 Andrey Novikov
  *
@@ -1100,6 +1100,15 @@ public class XmlThemeBuilder extends DefaultHandler {
             else if ("symbol-scaling".equals(name))
                 ; // no-op
 
+            else if ("repeat".equals(name))
+                b.repeat(Boolean.parseBoolean(value));
+
+            else if ("repeat-start".equals(name))
+                b.repeatStart = Float.parseFloat(value) * mScale;
+
+            else if ("repeat-gap".equals(name))
+                b.repeatGap = Float.parseFloat(value) * mScale;
+
             else
                 logUnknownAttribute(elementName, name, value, i);
         }

vtm/src/org/oscim/theme/styles/SymbolStyle.java

@@ -1,7 +1,7 @@
 /*
  * Copyright 2010, 2011, 2012 mapsforge.org
  * Copyright 2013 Hannes Janetzek
- * Copyright 2016-2017 devemux86
+ * Copyright 2016-2018 devemux86
  * Copyright 2017 Longri
  *
  * This file is part of the OpenScienceMap project (http://www.opensciencemap.org).
@@ -27,6 +27,9 @@ import org.oscim.renderer.atlas.TextureRegion;
  */
 public final class SymbolStyle extends RenderStyle<SymbolStyle> {
 
+    public static final float REPEAT_START_DEFAULT = 30f;
+    public static final float REPEAT_GAP_DEFAULT = 200f;
+
     public final Bitmap bitmap;
     public final TextureRegion texture;
     public final int hash;
@@ -35,6 +38,10 @@ public final class SymbolStyle extends RenderStyle<SymbolStyle> {
     public final int symbolHeight;
     public final int symbolPercent;
 
+    public final boolean repeat;
+    public final float repeatStart;
+    public final float repeatGap;
+
     public SymbolStyle(Bitmap bitmap) {
         this(bitmap, null, 0);
     }
@@ -55,6 +62,10 @@ public final class SymbolStyle extends RenderStyle<SymbolStyle> {
         this.symbolWidth = 0;
         this.symbolHeight = 0;
         this.symbolPercent = 100;
+
+        this.repeat = false;
+        this.repeatStart = REPEAT_START_DEFAULT;
+        this.repeatGap = REPEAT_GAP_DEFAULT;
     }
 
     public SymbolStyle(SymbolBuilder<?> b) {
@@ -67,6 +78,10 @@ public final class SymbolStyle extends RenderStyle<SymbolStyle> {
         this.symbolWidth = b.symbolWidth;
         this.symbolHeight = b.symbolHeight;
         this.symbolPercent = b.symbolPercent;
+
+        this.repeat = b.repeat;
+        this.repeatStart = b.repeatStart;
+        this.repeatGap = b.repeatGap;
     }
 
     @Override
@@ -100,6 +115,10 @@ public final class SymbolStyle extends RenderStyle<SymbolStyle> {
         public int symbolHeight;
         public int symbolPercent;
 
+        public boolean repeat;
+        public float repeatStart;
+        public float repeatGap;
+
         public SymbolBuilder() {
         }
 
@@ -117,6 +136,10 @@ public final class SymbolStyle extends RenderStyle<SymbolStyle> {
             this.symbolHeight = symbol.symbolHeight;
             this.symbolPercent = symbol.symbolPercent;
 
+            this.repeat = symbol.repeat;
+            this.repeatStart = symbol.repeatStart;
+            this.repeatGap = symbol.repeatGap;
+
             return self();
         }
 
@@ -150,6 +173,21 @@ public final class SymbolStyle extends RenderStyle<SymbolStyle> {
             return self();
         }
 
+        public T repeat(boolean repeat) {
+            this.repeat = repeat;
+            return self();
+        }
+
+        public T repeatStart(float repeatStart) {
+            this.repeatStart = repeatStart;
+            return self();
+        }
+
+        public T repeatGap(float repeatGap) {
+            this.repeatGap = repeatGap;
+            return self();
+        }
+
         public T reset() {
             cat = null;
 
@@ -161,6 +199,10 @@ public final class SymbolStyle extends RenderStyle<SymbolStyle> {
             symbolHeight = 0;
             symbolPercent = 100;
 
+            repeat = false;
+            repeatStart = REPEAT_START_DEFAULT;
+            repeatGap = REPEAT_GAP_DEFAULT;
+
             return self();
         }