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