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

   1 /*
   2  * Sixth 3D engine. Author: Svjatoslav Agejenko.
   3  * This project is released under Creative Commons Zero (CC0) license.
   4  */
   5 package eu.svjatoslav.sixth.e3d.renderer.raster.shapes.basic;
   6
   7 import eu.svjatoslav.sixth.e3d.geometry.Point3D;
   8 import eu.svjatoslav.sixth.e3d.renderer.raster.Color;
   9 import eu.svjatoslav.sixth.e3d.renderer.raster.texture.Texture;
  10
  11 import java.util.Collections;
  12 import java.util.Set;
  13 import java.util.WeakHashMap;
  14
  15 import static java.lang.Math.pow;
  16 import static java.lang.Math.sqrt;
  17
  18 public class GlowingPoint extends ForwardOrientedTexture {
  19
  20     private static final int TEXTURE_RESOLUTION_PIXELS = 100;
  21     private static final Set<GlowingPoint> glowingPoints = Collections.newSetFromMap(new WeakHashMap<>());
  22     private final Color color;
  23
  24     public GlowingPoint(final Point3D point, final double pointSize,
  25                         final Color color) {
  26         super(point, computeScale(pointSize), getTexture(color));
  27         this.color = color;
  28
  29         synchronized (glowingPoints) {
  30             glowingPoints.add(this);
  31         }
  32     }
  33
  34     private static double computeScale(double pointSize) {
  35         return pointSize / ((double) (TEXTURE_RESOLUTION_PIXELS / 50f));
  36     }
  37
  38     private static Texture getTexture(final Color color) {
  39         // attempt to reuse texture from existing glowing point of the same color
  40         synchronized (glowingPoints) {
  41             for (GlowingPoint glowingPoint : glowingPoints)
  42                 if (color.equals(glowingPoint.color))
  43                     return glowingPoint.texture;
  44         }
  45
  46         // existing texture not found, creating new one
  47         return createTexture(color);
  48     }
  49
  50     private static Texture createTexture(final Color color) {
  51         final Texture texture = new Texture(TEXTURE_RESOLUTION_PIXELS, TEXTURE_RESOLUTION_PIXELS, 1);
  52         int halfResolution = TEXTURE_RESOLUTION_PIXELS / 2;
  53
  54         for (int x = 0; x < TEXTURE_RESOLUTION_PIXELS; x++)
  55             for (int y = 0; y < TEXTURE_RESOLUTION_PIXELS; y++) {
  56                 int address = texture.primaryBitmap.getAddress(x, y);
  57
  58                 final int distanceFromCenter = (int) sqrt(pow (halfResolution - x, 2) + pow (halfResolution - y, 2));
  59
  60                 int alpha = 255 - ((270 * distanceFromCenter) / halfResolution);
  61                 if (alpha < 0)
  62                     alpha = 0;
  63
  64                 texture.primaryBitmap.bytes[address] = (byte) alpha;
  65                 address++;
  66                 texture.primaryBitmap.bytes[address] = (byte) color.b;
  67                 address++;
  68                 texture.primaryBitmap.bytes[address] = (byte) color.g;
  69                 address++;
  70                 texture.primaryBitmap.bytes[address] = (byte) color.r;
  71             }
  72
  73         return texture;
  74     }
  75
  76 }