Updated readability of the code.

[sixth-3d.git] / src / main / java / eu / svjatoslav / sixth / e3d / renderer / raster / shapes / basic / GlowingPoint.java

diff --git a/src/main/java/eu/svjatoslav/sixth/e3d/renderer/raster/shapes/basic/GlowingPoint.java b/src/main/java/eu/svjatoslav/sixth/e3d/renderer/raster/shapes/basic/GlowingPoint.java
index 2727a17..6541aca 100644 (file)
--- a/src/main/java/eu/svjatoslav/sixth/e3d/renderer/raster/shapes/basic/GlowingPoint.java
+++ b/src/main/java/eu/svjatoslav/sixth/e3d/renderer/raster/shapes/basic/GlowingPoint.java
@@ -1,12 +1,7 @@
 /*
- * Sixth 3D engine. Copyright ©2012-2018, Svjatoslav Agejenko, svjatoslav@svjatoslav.eu
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of version 3 of the GNU Lesser General Public License
- * or later as published by the Free Software Foundation.
- *
+ * Sixth 3D engine. Author: Svjatoslav Agejenko.
+ * This project is released under Creative Commons Zero (CC0) license.
  */
-
 package eu.svjatoslav.sixth.e3d.renderer.raster.shapes.basic;
 
 import eu.svjatoslav.sixth.e3d.geometry.Point3D;
@@ -17,15 +12,22 @@ import java.util.Collections;
 import java.util.Set;
 import java.util.WeakHashMap;
 
+import static java.lang.Math.pow;
+import static java.lang.Math.sqrt;
+
 public class GlowingPoint extends ForwardOrientedTexture {
 
-    private static final int TEXTURE_SIZE = 50;
+    private static final int TEXTURE_RESOLUTION_PIXELS = 100;
+    /**
+     * A set of all existing glowing points.
+     * Used to reuse textures of glowing points of the same color.
+     */
     private static final Set<GlowingPoint> glowingPoints = Collections.newSetFromMap(new WeakHashMap<>());
     private final Color color;
 
     public GlowingPoint(final Point3D point, final double pointSize,
                         final Color color) {
-        super(point, pointSize, getTexture(color));
+        super(point, computeScale(pointSize), getTexture(color));
         this.color = color;
 
         synchronized (glowingPoints) {
@@ -33,6 +35,15 @@ public class GlowingPoint extends ForwardOrientedTexture {
         }
     }
 
+
+    private static double computeScale(double pointSize) {
+        return pointSize / ((double) (TEXTURE_RESOLUTION_PIXELS / 50f));
+    }
+
+    /**
+     * Returns a texture for a glowing point of the given color.
+     * The texture is a circle with a gradient from transparent to the given color.
+     */
     private static Texture getTexture(final Color color) {
         // attempt to reuse texture from existing glowing point of the same color
         synchronized (glowingPoints) {
@@ -45,17 +56,21 @@ public class GlowingPoint extends ForwardOrientedTexture {
         return createTexture(color);
     }
 
+    /**
+     * Creates a texture for a glowing point of the given color.
+     * The texture is a circle with a gradient from transparent to the given color.
+     */
     private static Texture createTexture(final Color color) {
-        final Texture texture = new Texture(TEXTURE_SIZE, TEXTURE_SIZE, 1);
-        for (int x = 0; x < TEXTURE_SIZE; x++)
-            for (int y = 0; y < TEXTURE_SIZE; y++) {
+        final Texture texture = new Texture(TEXTURE_RESOLUTION_PIXELS, TEXTURE_RESOLUTION_PIXELS, 1);
+        int halfResolution = TEXTURE_RESOLUTION_PIXELS / 2;
+
+        for (int x = 0; x < TEXTURE_RESOLUTION_PIXELS; x++)
+            for (int y = 0; y < TEXTURE_RESOLUTION_PIXELS; y++) {
                 int address = texture.primaryBitmap.getAddress(x, y);
 
-                final int distance = (int) Math
-                        .sqrt((((TEXTURE_SIZE / 2) - x) * ((TEXTURE_SIZE / 2) - x))
-                                + (((TEXTURE_SIZE / 2) - y) * ((TEXTURE_SIZE / 2) - y)));
+                final int distanceFromCenter = (int) sqrt(pow(halfResolution - x, 2) + pow(halfResolution - y, 2));
 
-                int alpha = 255 - ((270 * distance) / (TEXTURE_SIZE / 2));
+                int alpha = 255 - ((270 * distanceFromCenter) / halfResolution);
                 if (alpha < 0)
                     alpha = 0;