src/main/java/eu/svjatoslav/sixth/e3d/renderer/raster/shapes/basic/solidpolygon/SolidPolygon.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.solidpolygon;
   6
   7 import eu.svjatoslav.sixth.e3d.geometry.Point2D;
   8 import eu.svjatoslav.sixth.e3d.geometry.Point3D;
   9 import eu.svjatoslav.sixth.e3d.gui.RenderingContext;
  10 import eu.svjatoslav.sixth.e3d.gui.humaninput.MouseInteractionController;
  11 import eu.svjatoslav.sixth.e3d.renderer.raster.Color;
  12 import eu.svjatoslav.sixth.e3d.renderer.raster.shapes.AbstractCoordinateShape;
  13
  14 import static eu.svjatoslav.sixth.e3d.geometry.Polygon.pointWithinPolygon;
  15
  16 /**
  17  * polygon with solid color.
  18  */
  19 public class SolidPolygon extends AbstractCoordinateShape {
  20
  21     private final static LineInterpolator polygonBoundary1 = new LineInterpolator();
  22     private final static LineInterpolator polygonBoundary2 = new LineInterpolator();
  23     private final static LineInterpolator polygonBoundary3 = new LineInterpolator();
  24     private Color color;
  25
  26     public SolidPolygon(final Point3D point1, final Point3D point2,
  27                         final Point3D point3, final Color color) {
  28         super(point1, point2, point3);
  29         this.color = color;
  30     }
  31
  32     public static void drawHorizontalLine(final LineInterpolator line1,
  33                                           final LineInterpolator line2, final int y,
  34                                           final RenderingContext renderBuffer, final Color color) {
  35
  36         int x1 = line1.getX(y);
  37         int x2 = line2.getX(y);
  38
  39         if (x1 > x2) {
  40             final int tmp = x1;
  41             x1 = x2;
  42             x2 = tmp;
  43         }
  44
  45         if (x1 < 0)
  46             x1 = 0;
  47
  48         if (x2 >= renderBuffer.width)
  49             x2 = renderBuffer.width - 1;
  50
  51         final int width = x2 - x1;
  52
  53         int offset = ((y * renderBuffer.width) + x1) * 4;
  54         final byte[] offSreenBufferBytes = renderBuffer.pixels;
  55
  56         final int polygonAlpha = color.a;
  57         final int b = color.b;
  58         final int g = color.g;
  59         final int r = color.r;
  60
  61         if (polygonAlpha == 255)
  62             for (int i = 0; i < width; i++) {
  63                 offSreenBufferBytes[offset] = (byte) 255;
  64                 offset++;
  65                 offSreenBufferBytes[offset] = (byte) b;
  66                 offset++;
  67                 offSreenBufferBytes[offset] = (byte) g;
  68                 offset++;
  69                 offSreenBufferBytes[offset] = (byte) r;
  70                 offset++;
  71             }
  72         else {
  73             final int backgroundAlpha = 255 - polygonAlpha;
  74
  75             final int blueWithAlpha = b * polygonAlpha;
  76             final int greenWithAlpha = g * polygonAlpha;
  77             final int redWithAlpha = r * polygonAlpha;
  78
  79             for (int i = 0; i < width; i++) {
  80                 offSreenBufferBytes[offset] = (byte) 255;
  81                 offset++;
  82                 offSreenBufferBytes[offset] = (byte) ((((offSreenBufferBytes[offset] & 0xff) * backgroundAlpha) + blueWithAlpha) / 256);
  83                 offset++;
  84                 offSreenBufferBytes[offset] = (byte) ((((offSreenBufferBytes[offset] & 0xff) * backgroundAlpha) + greenWithAlpha) / 256);
  85                 offset++;
  86                 offSreenBufferBytes[offset] = (byte) ((((offSreenBufferBytes[offset] & 0xff) * backgroundAlpha) + redWithAlpha) / 256);
  87                 offset++;
  88             }
  89
  90         }
  91
  92     }
  93
  94     public static void drawPolygon(final RenderingContext context,
  95                                    final Point2D onScreenPoint1, final Point2D onScreenPoint2,
  96                                    final Point2D onScreenPoint3,
  97                                    final MouseInteractionController mouseInteractionController,
  98                                    final Color color) {
  99
 100         onScreenPoint1.roundToInteger();
 101         onScreenPoint2.roundToInteger();
 102         onScreenPoint3.roundToInteger();
 103
 104         if (mouseInteractionController != null)
 105             if (context.getMouseEvent() != null)
 106                 if (pointWithinPolygon(context.getMouseEvent().coordinate,
 107                         onScreenPoint1, onScreenPoint2, onScreenPoint3))
 108                     context.setCurrentObjectUnderMouseCursor(mouseInteractionController);
 109
 110         if (color.isTransparent())
 111             return;
 112
 113         // find top-most point
 114         int yTop = (int) onScreenPoint1.y;
 115
 116         if (onScreenPoint2.y < yTop)
 117             yTop = (int) onScreenPoint2.y;
 118
 119         if (onScreenPoint3.y < yTop)
 120             yTop = (int) onScreenPoint3.y;
 121
 122         if (yTop < 0)
 123             yTop = 0;
 124
 125         // find bottom-most point
 126         int yBottom = (int) onScreenPoint1.y;
 127
 128         if (onScreenPoint2.y > yBottom)
 129             yBottom = (int) onScreenPoint2.y;
 130
 131         if (onScreenPoint3.y > yBottom)
 132             yBottom = (int) onScreenPoint3.y;
 133
 134         if (yBottom >= context.height)
 135             yBottom = context.height - 1;
 136
 137         // paint
 138         polygonBoundary1.setPoints(onScreenPoint1, onScreenPoint2);
 139         polygonBoundary2.setPoints(onScreenPoint1, onScreenPoint3);
 140         polygonBoundary3.setPoints(onScreenPoint2, onScreenPoint3);
 141
 142         final LineInterpolator[] is = new LineInterpolator[3];
 143         is[0] = polygonBoundary1;
 144         is[1] = polygonBoundary2;
 145         is[2] = polygonBoundary3;
 146
 147         java.util.Arrays.sort(is);
 148
 149         for (int y = yTop; y < yBottom; y++)
 150             if (is[0].containsY(y)) {
 151
 152                 if (is[1].containsY(y))
 153                     drawHorizontalLine(is[0], is[1], y, context, color);
 154                 else if (is[2].containsY(y))
 155                     drawHorizontalLine(is[0], is[2], y, context, color);
 156             } else if (is[1].containsY(y))
 157                 if (is[2].containsY(y))
 158                     drawHorizontalLine(is[1], is[2], y, context, color);
 159     }
 160
 161     public Color getColor() {
 162         return color;
 163     }
 164
 165     public void setColor(final Color color) {
 166         this.color = color;
 167     }
 168
 169     @Override
 170     public void paint(final RenderingContext renderBuffer) {
 171
 172         final Point2D onScreenPoint1 = coordinates[0].onScreenCoordinate;
 173         final Point2D onScreenPoint2 = coordinates[1].onScreenCoordinate;
 174         final Point2D onScreenPoint3 = coordinates[2].onScreenCoordinate;
 175
 176         drawPolygon(renderBuffer, onScreenPoint1, onScreenPoint2,
 177                 onScreenPoint3, mouseInteractionController, color);
 178
 179     }
 180
 181 }