From ef63e47b94cbeb9fa0dc17382af7b19d9db27b9b Mon Sep 17 00:00:00 2001
From: James Ball <jhb119@ic.ac.uk>
Date: Thu, 5 Nov 2020 21:03:48 +0000
Subject: [PATCH] Add shape normalising function for correct rendering on
 oscilloscope

---
 src/audio/AudioClient.java | 11 +++++++++--
 src/parser/SvgParser.java  | 21 ++++++---------------
 src/shapes/Shapes.java     | 27 +++++++++++++++++++++++++++
 3 files changed, 42 insertions(+), 17 deletions(-)

diff --git a/src/audio/AudioClient.java b/src/audio/AudioClient.java
index 53a8d87..608805f 100644
--- a/src/audio/AudioClient.java
+++ b/src/audio/AudioClient.java
@@ -8,6 +8,9 @@ import java.util.ArrayList;
 import java.util.List;
 import java.util.concurrent.atomic.AtomicInteger;
 import java.util.stream.IntStream;
+import javax.xml.parsers.ParserConfigurationException;
+import org.xml.sax.SAXException;
+import parser.SvgParser;
 import shapes.Shape;
 import shapes.Shapes;
 import shapes.Vector2;
@@ -32,7 +35,8 @@ public class AudioClient {
   //
   // example:
   // osci-render models/cube.obj 3
-  public static void main(String[] programArgs) throws IOException {
+  public static void main(String[] programArgs)
+      throws IOException, ParserConfigurationException, SAXException {
     // TODO: Calculate weight of lines using depth.
     //  Reduce weight of lines drawn multiple times.
     //  Find intersections of lines to (possibly) improve line cleanup.
@@ -53,7 +57,10 @@ public class AudioClient {
     Vector3 rotation = new Vector3(0, OBJ_ROTATE_SPEED, OBJ_ROTATE_SPEED);
 
     System.out.println("Begin pre-render...");
-    List<List<? extends Shape>> frames = preRender(object, rotation, camera);
+    //List<List<? extends Shape>> frames = preRender(object, rotation, camera);
+    List<List<? extends Shape>> frames = new ArrayList<>();
+    List<Shape> frame = Shapes.normalizeShapes(new SvgParser("test/images/sine-wave.svg").getShapes());
+    frames.add(frame);
     System.out.println("Finish pre-render");
     System.out.println("Connecting to audio player");
     AudioPlayer player = new AudioPlayer(SAMPLE_RATE, frames, ROTATE_SPEED, TRANSLATION_SPEED,
diff --git a/src/parser/SvgParser.java b/src/parser/SvgParser.java
index dfa4af6..d8332bc 100644
--- a/src/parser/SvgParser.java
+++ b/src/parser/SvgParser.java
@@ -210,22 +210,13 @@ public class SvgParser extends FileParser {
     return shapes;
   }
 
-  private Vector2 scaledArguments(float arg1, float arg2) {
-    return new Vector2(arg1, arg2);
-//    return new Vector2(arg1, arg2)
-//        .scale(new Vector2((width / viewBoxWidth) / viewBoxWidth,
-//            -(height / viewBoxHeight) / viewBoxHeight)
-//        ).translate(new Vector2(-0.5, 0.5))
-//        .scale(2);
-  }
-
   // Parses moveto commands (M and m commands)
   private List<? extends Shape> parseMoveTo(List<Float> args, boolean isAbsolute) {
     if (args.size() % 2 != 0 || args.size() < 2) {
       throw new IllegalArgumentException("SVG moveto command has incorrect number of arguments.");
     }
 
-    Vector2 vec = scaledArguments(args.get(0), args.get(1));
+    Vector2 vec = new Vector2(args.get(0), args.get(1));
 
     if (isAbsolute) {
       currPoint = vec;
@@ -273,9 +264,9 @@ public class SvgParser extends FileParser {
       Vector2 newPoint;
 
       if (expectedArgs == 1) {
-        newPoint = scaledArguments(args.get(i), args.get(i));
+        newPoint = new Vector2(args.get(i), args.get(i));
       } else {
-        newPoint = scaledArguments(args.get(i), args.get(i + 1));
+        newPoint = new Vector2(args.get(i), args.get(i + 1));
       }
 
       if (isHorizontal && !isVertical) {
@@ -326,14 +317,14 @@ public class SvgParser extends FileParser {
               : prevQuadraticControlPoint.reflectRelativeToVector(currPoint);
         }
       } else {
-        controlPoint1 = scaledArguments(args.get(i), args.get(i + 1));
+        controlPoint1 = new Vector2(args.get(i), args.get(i + 1));
       }
 
       if (isCubic) {
-        controlPoint2 = scaledArguments(args.get(i + 2), args.get(i + 3));
+        controlPoint2 = new Vector2(args.get(i + 2), args.get(i + 3));
       }
 
-      Vector2 newPoint = scaledArguments(args.get(i + expectedArgs - 2),
+      Vector2 newPoint = new Vector2(args.get(i + expectedArgs - 2),
           args.get(i + expectedArgs - 1));
 
       if (!isAbsolute) {
diff --git a/src/shapes/Shapes.java b/src/shapes/Shapes.java
index 1232612..bfdf141 100644
--- a/src/shapes/Shapes.java
+++ b/src/shapes/Shapes.java
@@ -12,8 +12,35 @@ import org.jgrapht.graph.AsSubgraph;
 import org.jgrapht.graph.DefaultUndirectedWeightedGraph;
 import org.jgrapht.graph.DefaultWeightedEdge;
 
+// Helper functions for the Shape interface.
 public class Shapes {
 
+  // Normalises shapes between the coords -1 and 1 for proper scaling on an oscilloscope. May not
+  // work perfectly with curves that heavily deviate from their start and end points.
+  public static List<Shape> normalizeShapes(List<Shape> shapes) {
+    double maxVertex = 0;
+
+    for (Shape shape : shapes) {
+      Vector2 startVector = shape.nextVector(0);
+      Vector2 endVector = shape.nextVector(1);
+
+      double maxX = Math.max(Math.abs(startVector.getX()), Math.abs(endVector.getX()));
+      double maxY = Math.max(Math.abs(startVector.getY()), Math.abs(endVector.getY()));
+
+      maxVertex = Math.max(Math.max(maxX, maxY), maxVertex);
+    }
+
+    double factor = 2 / maxVertex;
+
+    for (int i = 0; i < shapes.size(); i++) {
+      shapes.set(i, shapes.get(i)
+          .scale(new Vector2(factor, -factor))
+          .translate(new Vector2(-1, 1)));
+    }
+
+    return shapes;
+  }
+
   public static List<Shape> generatePolygram(int sides, int angleJump, Vector2 start,
       double weight) {
     List<Shape> polygon = new ArrayList<>();