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.gui.RenderingContext;
  15 import eu.svjatoslav.sixth.e3d.gui.humaninput.MouseInteractionController;
  16 import eu.svjatoslav.sixth.e3d.renderer.raster.Color;
  17 import eu.svjatoslav.sixth.e3d.renderer.raster.shapes.AbstractCoordinateShape;
  18
  19 import static eu.svjatoslav.sixth.e3d.geometry.Polygon.pointWithinPolygon;
  20
  21 public class SolidPolygon extends AbstractCoordinateShape {
  22
  23     private final static LineInterpolator polygonBoundary1 = new LineInterpolator();
  24     private final static LineInterpolator polygonBoundary2 = new LineInterpolator();
  25     private final static LineInterpolator polygonBoundary3 = new LineInterpolator();
  26     private Color color;
  27
  28     public SolidPolygon(final Point3D point1, final Point3D point2,
  29                         final Point3D point3, final Color color) {
  30         super(point1, point2, point3);
  31         this.color = color;
  32     }
  33
  34     public static void drawHorizontalLine(final LineInterpolator line1,
  35                                           final LineInterpolator line2, final int y,
  36                                           final RenderingContext renderBuffer, final Color color) {
  37
  38         int x1 = line1.getX(y);
  39         int x2 = line2.getX(y);
  40
  41         if (x1 > x2) {
  42             final int tmp = x1;
  43             x1 = x2;
  44             x2 = tmp;
  45         }
  46
  47         if (x1 < 0)
  48             x1 = 0;
  49
  50         if (x2 >= renderBuffer.width)
  51             x2 = renderBuffer.width - 1;
  52
  53         final int width = x2 - x1;
  54
  55         int offset = ((y * renderBuffer.width) + x1) * 4;
  56         final byte[] offSreenBufferBytes = renderBuffer.pixels;
  57
  58         final int polygonAlpha = color.a;
  59         final int b = color.b;
  60         final int g = color.g;
  61         final int r = color.r;
  62
  63         if (polygonAlpha == 255)
  64             for (int i = 0; i < width; i++) {
  65                 offSreenBufferBytes[offset] = (byte) 255;
  66                 offset++;
  67                 offSreenBufferBytes[offset] = (byte) b;
  68                 offset++;
  69                 offSreenBufferBytes[offset] = (byte) g;
  70                 offset++;
  71                 offSreenBufferBytes[offset] = (byte) r;
  72                 offset++;
  73             }
  74         else {
  75             final int backgroundAlpha = 255 - polygonAlpha;
  76
  77             final int blueWithAlpha = b * polygonAlpha;
  78             final int greenWithAlpha = g * polygonAlpha;
  79             final int redWithAlpha = r * polygonAlpha;
  80
  81             for (int i = 0; i < width; i++) {
  82                 offSreenBufferBytes[offset] = (byte) 255;
  83                 offset++;
  84                 offSreenBufferBytes[offset] = (byte) ((((offSreenBufferBytes[offset] & 0xff) * backgroundAlpha) + blueWithAlpha) / 256);
  85                 offset++;
  86                 offSreenBufferBytes[offset] = (byte) ((((offSreenBufferBytes[offset] & 0xff) * backgroundAlpha) + greenWithAlpha) / 256);
  87                 offset++;
  88                 offSreenBufferBytes[offset] = (byte) ((((offSreenBufferBytes[offset] & 0xff) * backgroundAlpha) + redWithAlpha) / 256);
  89                 offset++;
  90             }
  91
  92         }
  93
  94     }
  95
  96     public static void drawPolygon(final RenderingContext context,
  97                                    final Point2D onScreenPoint1, final Point2D onScreenPoint2,
  98                                    final Point2D onScreenPoint3,
  99                                    final MouseInteractionController mouseInteractionController,
 100                                    final Color color) {
 101
 102         onScreenPoint1.roundToInteger();
 103         onScreenPoint2.roundToInteger();
 104         onScreenPoint3.roundToInteger();
 105
 106         if (mouseInteractionController != null)
 107             if (context.getMouseEvent() != null)
 108                 if (pointWithinPolygon(context.getMouseEvent().coordinate,
 109                         onScreenPoint1, onScreenPoint2, onScreenPoint3))
 110                     context.setObjectUnderMouse(mouseInteractionController);
 111
 112         if (color.isTransparent())
 113             return;
 114
 115         // find top-most point
 116         int yTop = (int) onScreenPoint1.y;
 117
 118         if (onScreenPoint2.y < yTop)
 119             yTop = (int) onScreenPoint2.y;
 120
 121         if (onScreenPoint3.y < yTop)
 122             yTop = (int) onScreenPoint3.y;
 123
 124         if (yTop < 0)
 125             yTop = 0;
 126
 127         // find bottom-most point
 128         int yBottom = (int) onScreenPoint1.y;
 129
 130         if (onScreenPoint2.y > yBottom)
 131             yBottom = (int) onScreenPoint2.y;
 132
 133         if (onScreenPoint3.y > yBottom)
 134             yBottom = (int) onScreenPoint3.y;
 135
 136         if (yBottom >= context.height)
 137             yBottom = context.height - 1;
 138
 139         // paint
 140         polygonBoundary1.setPoints(onScreenPoint1, onScreenPoint2);
 141         polygonBoundary2.setPoints(onScreenPoint1, onScreenPoint3);
 142         polygonBoundary3.setPoints(onScreenPoint2, onScreenPoint3);
 143
 144         final LineInterpolator[] is = new LineInterpolator[3];
 145         is[0] = polygonBoundary1;
 146         is[1] = polygonBoundary2;
 147         is[2] = polygonBoundary3;
 148
 149         java.util.Arrays.sort(is);
 150
 151         for (int y = yTop; y < yBottom; y++)
 152             if (is[0].containsY(y)) {
 153
 154                 if (is[1].containsY(y))
 155                     drawHorizontalLine(is[0], is[1], y, context, color);
 156                 else if (is[2].containsY(y))
 157                     drawHorizontalLine(is[0], is[2], y, context, color);
 158             } else if (is[1].containsY(y))
 159                 if (is[2].containsY(y))
 160                     drawHorizontalLine(is[1], is[2], y, context, color);
 161     }
 162
 163     public Color getColor() {
 164         return color;
 165     }
 166
 167     public void setColor(final Color color) {
 168         this.color = color;
 169     }
 170
 171     @Override
 172     public void paint(final RenderingContext renderBuffer) {
 173
 174         final Point2D onScreenPoint1 = coordinates[0].onScreenCoordinate;
 175         final Point2D onScreenPoint2 = coordinates[1].onScreenCoordinate;
 176         final Point2D onScreenPoint3 = coordinates[2].onScreenCoordinate;
 177
 178         drawPolygon(renderBuffer, onScreenPoint1, onScreenPoint2,
 179                 onScreenPoint3, mouseInteractionController, color);
 180
 181     }
 182
 183 }