src/main/java/eu/svjatoslav/sixth/e3d/renderer/raster/shapes/basic/solidpolygon/SolidPolygon.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.solidpolygon;
  11
  12 import eu.svjatoslav.sixth.e3d.geometry.Point2D;
  13 import eu.svjatoslav.sixth.e3d.geometry.Point3D;
  14 import eu.svjatoslav.sixth.e3d.geometry.Polygon;
  15 import eu.svjatoslav.sixth.e3d.gui.RenderingContext;
  16 import eu.svjatoslav.sixth.e3d.gui.humaninput.MouseInteractionController;
  17 import eu.svjatoslav.sixth.e3d.renderer.raster.Color;
  18 import eu.svjatoslav.sixth.e3d.renderer.raster.shapes.AbstractCoordinateShape;
  19
  20 public class SolidPolygon extends AbstractCoordinateShape {
  21
  22     private final static LineInterpolator polygonBoundary1 = new LineInterpolator();
  23     private final static LineInterpolator polygonBoundary2 = new LineInterpolator();
  24     private final static LineInterpolator polygonBoundary3 = new LineInterpolator();
  25     private Color color;
  26
  27     public SolidPolygon(final Point3D point1, final Point3D point2,
  28                         final Point3D point3, final Color color) {
  29         super(point1, point2, point3);
  30         this.color = color;
  31     }
  32
  33     public static void drawHorizontalLine(final LineInterpolator line1,
  34                                           final LineInterpolator line2, final int y,
  35                                           final RenderingContext renderBuffer, final Color color) {
  36
  37         int x1 = line1.getX(y);
  38         int x2 = line2.getX(y);
  39
  40         if (x1 > x2) {
  41             final int tmp = x1;
  42             x1 = x2;
  43             x2 = tmp;
  44         }
  45
  46         if (x1 < 0)
  47             x1 = 0;
  48
  49         if (x2 >= renderBuffer.width)
  50             x2 = renderBuffer.width - 1;
  51
  52         final int width = x2 - x1;
  53
  54         int offset = ((y * renderBuffer.width) + x1) * 4;
  55         final byte[] offSreenBufferBytes = renderBuffer.pixels;
  56
  57         final int polygonAlpha = color.a;
  58         final int b = color.b;
  59         final int g = color.g;
  60         final int r = color.r;
  61
  62         if (polygonAlpha == 255)
  63             for (int i = 0; i < width; i++) {
  64                 offSreenBufferBytes[offset] = (byte) 255;
  65                 offset++;
  66                 offSreenBufferBytes[offset] = (byte) b;
  67                 offset++;
  68                 offSreenBufferBytes[offset] = (byte) g;
  69                 offset++;
  70                 offSreenBufferBytes[offset] = (byte) r;
  71                 offset++;
  72             }
  73         else {
  74             final int backgroundAlpha = 255 - polygonAlpha;
  75
  76             final int blueWithAlpha = b * polygonAlpha;
  77             final int greenWithAlpha = g * polygonAlpha;
  78             final int redWithAlpha = r * polygonAlpha;
  79
  80             for (int i = 0; i < width; i++) {
  81                 offSreenBufferBytes[offset] = (byte) 255;
  82                 offset++;
  83                 offSreenBufferBytes[offset] = (byte) ((((offSreenBufferBytes[offset] & 0xff) * backgroundAlpha) + blueWithAlpha) / 256);
  84                 offset++;
  85                 offSreenBufferBytes[offset] = (byte) ((((offSreenBufferBytes[offset] & 0xff) * backgroundAlpha) + greenWithAlpha) / 256);
  86                 offset++;
  87                 offSreenBufferBytes[offset] = (byte) ((((offSreenBufferBytes[offset] & 0xff) * backgroundAlpha) + redWithAlpha) / 256);
  88                 offset++;
  89             }
  90
  91         }
  92
  93     }
  94
  95     public static void drawPolygon(final RenderingContext context,
  96                                    final Point2D onScreenPoint1, final Point2D onScreenPoint2,
  97                                    final Point2D onScreenPoint3,
  98                                    final MouseInteractionController mouseInteractionController,
  99                                    final Color color) {
 100
 101         onScreenPoint1.roundToInteger();
 102         onScreenPoint2.roundToInteger();
 103         onScreenPoint3.roundToInteger();
 104
 105         if (mouseInteractionController != null)
 106             if (context.mouseClick != null)
 107                 if (Polygon.pointWithinPolygon(context.mouseClick.coordinate,
 108                         onScreenPoint1, onScreenPoint2, onScreenPoint3))
 109                     context.clickedItem = mouseInteractionController;
 110
 111         if (color.isTransparent())
 112             return;
 113
 114         // find top-most point
 115         int yTop = (int) onScreenPoint1.y;
 116
 117         if (onScreenPoint2.y < yTop)
 118             yTop = (int) onScreenPoint2.y;
 119
 120         if (onScreenPoint3.y < yTop)
 121             yTop = (int) onScreenPoint3.y;
 122
 123         if (yTop < 0)
 124             yTop = 0;
 125
 126         // find bottom-most point
 127         int yBottom = (int) onScreenPoint1.y;
 128
 129         if (onScreenPoint2.y > yBottom)
 130             yBottom = (int) onScreenPoint2.y;
 131
 132         if (onScreenPoint3.y > yBottom)
 133             yBottom = (int) onScreenPoint3.y;
 134
 135         if (yBottom >= context.height)
 136             yBottom = context.height - 1;
 137
 138         // paint
 139         polygonBoundary1.setPoints(onScreenPoint1, onScreenPoint2);
 140         polygonBoundary2.setPoints(onScreenPoint1, onScreenPoint3);
 141         polygonBoundary3.setPoints(onScreenPoint2, onScreenPoint3);
 142
 143         final LineInterpolator[] is = new LineInterpolator[3];
 144         is[0] = polygonBoundary1;
 145         is[1] = polygonBoundary2;
 146         is[2] = polygonBoundary3;
 147
 148         java.util.Arrays.sort(is);
 149
 150         for (int y = yTop; y < yBottom; y++)
 151             if (is[0].containsY(y)) {
 152
 153                 if (is[1].containsY(y))
 154                     drawHorizontalLine(is[0], is[1], y, context, color);
 155                 else if (is[2].containsY(y))
 156                     drawHorizontalLine(is[0], is[2], y, context, color);
 157             } else if (is[1].containsY(y))
 158                 if (is[2].containsY(y))
 159                     drawHorizontalLine(is[1], is[2], y, context, color);
 160     }
 161
 162     public Color getColor() {
 163         return color;
 164     }
 165
 166     public void setColor(final Color color) {
 167         this.color = color;
 168     }
 169
 170     @Override
 171     public void paint(final RenderingContext renderBuffer) {
 172
 173         final Point2D onScreenPoint1 = coordinates[0].onScreenCoordinate;
 174         final Point2D onScreenPoint2 = coordinates[1].onScreenCoordinate;
 175         final Point2D onScreenPoint3 = coordinates[2].onScreenCoordinate;
 176
 177         drawPolygon(renderBuffer, onScreenPoint1, onScreenPoint2,
 178                 onScreenPoint3, mouseInteractionController, color);
 179
 180     }
 181
 182 }