src/main/java/eu/svjatoslav/sixth/e3d/renderer/raster/shapes/basic/GlowingPoint.java

   1 /*
   2  * Sixth 3D engine. Copyright ©2012-2018, Svjatoslav Agejenko, svjatoslav@svjatoslav.eu
   3  *
   4  * This program is free software; you can redistribute it and/or
   5  * modify it under the terms of version 3 of the GNU Lesser General Public License
   6  * or later as published by the Free Software Foundation.
   7  *
   8  */
   9
  10 package eu.svjatoslav.sixth.e3d.renderer.raster.shapes.basic;
  11
  12 import eu.svjatoslav.sixth.e3d.geometry.Point3D;
  13 import eu.svjatoslav.sixth.e3d.renderer.raster.Color;
  14 import eu.svjatoslav.sixth.e3d.renderer.raster.texture.Texture;
  15
  16 import java.util.Collections;
  17 import java.util.Set;
  18 import java.util.WeakHashMap;
  19
  20 import static java.lang.Math.pow;
  21 import static java.lang.Math.sqrt;
  22
  23 public class GlowingPoint extends ForwardOrientedTexture {
  24
  25     private static final int TEXTURE_RESOLUTION_PIXELS = 100;
  26     private static final Set<GlowingPoint> glowingPoints = Collections.newSetFromMap(new WeakHashMap<>());
  27     private final Color color;
  28
  29     public GlowingPoint(final Point3D point, final double pointSize,
  30                         final Color color) {
  31         super(point, computeScale(pointSize), getTexture(color));
  32         this.color = color;
  33
  34         synchronized (glowingPoints) {
  35             glowingPoints.add(this);
  36         }
  37     }
  38
  39     private static double computeScale(double pointSize) {
  40         return pointSize / ((double) (TEXTURE_RESOLUTION_PIXELS / 50f));
  41     }
  42
  43     private static Texture getTexture(final Color color) {
  44         // attempt to reuse texture from existing glowing point of the same color
  45         synchronized (glowingPoints) {
  46             for (GlowingPoint glowingPoint : glowingPoints)
  47                 if (color.equals(glowingPoint.color))
  48                     return glowingPoint.texture;
  49         }
  50
  51         // existing texture not found, creating new one
  52         return createTexture(color);
  53     }
  54
  55     private static Texture createTexture(final Color color) {
  56         final Texture texture = new Texture(TEXTURE_RESOLUTION_PIXELS, TEXTURE_RESOLUTION_PIXELS, 1);
  57         int halfResolution = TEXTURE_RESOLUTION_PIXELS / 2;
  58
  59         for (int x = 0; x < TEXTURE_RESOLUTION_PIXELS; x++)
  60             for (int y = 0; y < TEXTURE_RESOLUTION_PIXELS; y++) {
  61                 int address = texture.primaryBitmap.getAddress(x, y);
  62
  63                 final int distanceFromCenter = (int) sqrt(pow (halfResolution - x, 2) + pow (halfResolution - y, 2));
  64
  65                 int alpha = 255 - ((270 * distanceFromCenter) / halfResolution);
  66                 if (alpha < 0)
  67                     alpha = 0;
  68
  69                 texture.primaryBitmap.bytes[address] = (byte) alpha;
  70                 address++;
  71                 texture.primaryBitmap.bytes[address] = (byte) color.b;
  72                 address++;
  73                 texture.primaryBitmap.bytes[address] = (byte) color.g;
  74                 address++;
  75                 texture.primaryBitmap.bytes[address] = (byte) color.r;
  76             }
  77
  78         return texture;
  79     }
  80
  81 }