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.math.Vertex;
  12 import eu.svjatoslav.sixth.e3d.renderer.raster.Color;
  13 import eu.svjatoslav.sixth.e3d.renderer.raster.shapes.AbstractCoordinateShape;
  14
  15 import static eu.svjatoslav.sixth.e3d.geometry.Polygon.pointWithinPolygon;
  16
  17 /**
  18  * polygon with solid color.
  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(
  30                 new Vertex(point1),
  31                 new Vertex(point2),
  32                 new Vertex(point3)
  33         );
  34         this.color = color;
  35     }
  36
  37     public static void drawHorizontalLine(final LineInterpolator line1,
  38                                           final LineInterpolator line2, final int y,
  39                                           final RenderingContext renderBuffer, final Color color) {
  40
  41         int x1 = line1.getX(y);
  42         int x2 = line2.getX(y);
  43
  44         if (x1 > x2) {
  45             final int tmp = x1;
  46             x1 = x2;
  47             x2 = tmp;
  48         }
  49
  50         if (x1 < 0)
  51             x1 = 0;
  52
  53         if (x2 >= renderBuffer.width)
  54             x2 = renderBuffer.width - 1;
  55
  56         final int width = x2 - x1;
  57
  58         int offset = ((y * renderBuffer.width) + x1) * 4;
  59         final byte[] offScreenBufferBytes = renderBuffer.pixels;
  60
  61         final int polygonAlpha = color.a;
  62         final int b = color.b;
  63         final int g = color.g;
  64         final int r = color.r;
  65
  66         if (polygonAlpha == 255)
  67             for (int i = 0; i < width; i++) {
  68                 offScreenBufferBytes[offset] = (byte) 255;
  69                 offset++;
  70                 offScreenBufferBytes[offset] = (byte) b;
  71                 offset++;
  72                 offScreenBufferBytes[offset] = (byte) g;
  73                 offset++;
  74                 offScreenBufferBytes[offset] = (byte) r;
  75                 offset++;
  76             }
  77         else {
  78             final int backgroundAlpha = 255 - polygonAlpha;
  79
  80             final int blueWithAlpha = b * polygonAlpha;
  81             final int greenWithAlpha = g * polygonAlpha;
  82             final int redWithAlpha = r * polygonAlpha;
  83
  84             for (int i = 0; i < width; i++) {
  85                 offScreenBufferBytes[offset] = (byte) 255;
  86                 offset++;
  87                 offScreenBufferBytes[offset] = (byte) ((((offScreenBufferBytes[offset] & 0xff) * backgroundAlpha) + blueWithAlpha) / 256);
  88                 offset++;
  89                 offScreenBufferBytes[offset] = (byte) ((((offScreenBufferBytes[offset] & 0xff) * backgroundAlpha) + greenWithAlpha) / 256);
  90                 offset++;
  91                 offScreenBufferBytes[offset] = (byte) ((((offScreenBufferBytes[offset] & 0xff) * backgroundAlpha) + redWithAlpha) / 256);
  92                 offset++;
  93             }
  94
  95         }
  96
  97     }
  98
  99     public static void drawPolygon(final RenderingContext context,
 100                                    final Point2D onScreenPoint1, final Point2D onScreenPoint2,
 101                                    final Point2D onScreenPoint3,
 102                                    final MouseInteractionController mouseInteractionController,
 103                                    final Color color) {
 104
 105         onScreenPoint1.roundToInteger();
 106         onScreenPoint2.roundToInteger();
 107         onScreenPoint3.roundToInteger();
 108
 109         if (mouseInteractionController != null)
 110             if (context.getMouseEvent() != null)
 111                 if (pointWithinPolygon(context.getMouseEvent().coordinate,
 112                         onScreenPoint1, onScreenPoint2, onScreenPoint3))
 113                     context.setCurrentObjectUnderMouseCursor(mouseInteractionController);
 114
 115         if (color.isTransparent())
 116             return;
 117
 118         // find top-most point
 119         int yTop = (int) onScreenPoint1.y;
 120
 121         if (onScreenPoint2.y < yTop)
 122             yTop = (int) onScreenPoint2.y;
 123
 124         if (onScreenPoint3.y < yTop)
 125             yTop = (int) onScreenPoint3.y;
 126
 127         if (yTop < 0)
 128             yTop = 0;
 129
 130         // find bottom-most point
 131         int yBottom = (int) onScreenPoint1.y;
 132
 133         if (onScreenPoint2.y > yBottom)
 134             yBottom = (int) onScreenPoint2.y;
 135
 136         if (onScreenPoint3.y > yBottom)
 137             yBottom = (int) onScreenPoint3.y;
 138
 139         if (yBottom >= context.height)
 140             yBottom = context.height - 1;
 141
 142         // paint
 143         polygonBoundary1.setPoints(onScreenPoint1, onScreenPoint2);
 144         polygonBoundary2.setPoints(onScreenPoint1, onScreenPoint3);
 145         polygonBoundary3.setPoints(onScreenPoint2, onScreenPoint3);
 146
 147         final LineInterpolator[] is = new LineInterpolator[3];
 148         is[0] = polygonBoundary1;
 149         is[1] = polygonBoundary2;
 150         is[2] = polygonBoundary3;
 151
 152         java.util.Arrays.sort(is);
 153
 154         for (int y = yTop; y < yBottom; y++)
 155             if (is[0].containsY(y)) {
 156
 157                 if (is[1].containsY(y))
 158                     drawHorizontalLine(is[0], is[1], y, context, color);
 159                 else if (is[2].containsY(y))
 160                     drawHorizontalLine(is[0], is[2], y, context, color);
 161             } else if (is[1].containsY(y))
 162                 if (is[2].containsY(y))
 163                     drawHorizontalLine(is[1], is[2], y, context, color);
 164     }
 165
 166     public Color getColor() {
 167         return color;
 168     }
 169
 170     public void setColor(final Color color) {
 171         this.color = color;
 172     }
 173
 174     @Override
 175     public void paint(final RenderingContext renderBuffer) {
 176
 177         final Point2D onScreenPoint1 = coordinates[0].onScreenCoordinate;
 178         final Point2D onScreenPoint2 = coordinates[1].onScreenCoordinate;
 179         final Point2D onScreenPoint3 = coordinates[2].onScreenCoordinate;
 180
 181         drawPolygon(renderBuffer, onScreenPoint1, onScreenPoint2,
 182                 onScreenPoint3, mouseInteractionController, color);
 183
 184     }
 185
 186 }