src/main/java/eu/svjatoslav/sixth/e3d/renderer/raster/texture/TextureBitmap.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.texture;
   6
   7 import eu.svjatoslav.sixth.e3d.renderer.raster.Color;
   8
   9 public class TextureBitmap {
  10
  11     /**
  12      * Byte order: Alpha, Blue, Green, Red
  13      */
  14     public final byte[] bytes;
  15
  16     public final int width;
  17
  18     public final int height;
  19
  20     public double multiplicationFactor;
  21
  22     public TextureBitmap(final int width, final int height, final byte[] bytes,
  23                          final double multiplicationFactor) {
  24
  25         this.width = width;
  26         this.height = height;
  27         this.bytes = bytes;
  28         this.multiplicationFactor = multiplicationFactor;
  29     }
  30
  31     public TextureBitmap(final int width, final int height,
  32                          final double multiplicationFactor) {
  33
  34         this(width, height, new byte[width * height * 4], multiplicationFactor);
  35     }
  36
  37     /**
  38      * Transfer (render) one pixel from current {@link TextureBitmap} to target raster bitmap.
  39      *
  40      * @param sourceBitmapPixelAddress Pixel address within current {@link TextureBitmap} as indicated by its offset.
  41      * @param targetBitmap Bitmap of the target image where pixel should be rendered to.
  42      * @param targetBitmapPixelAddress Pixel location within target image where pixel should be rendered to.
  43      */
  44     public void drawPixel(int sourceBitmapPixelAddress,
  45                           final byte[] targetBitmap, int targetBitmapPixelAddress) {
  46
  47         final int textureAlpha = bytes[sourceBitmapPixelAddress] & 0xff;
  48
  49         if (textureAlpha == 0)
  50             return;
  51
  52         if (textureAlpha == 255) {
  53             // skip reading of background for fully opaque pixels
  54             targetBitmap[targetBitmapPixelAddress] = (byte) 255;
  55
  56             targetBitmapPixelAddress++;
  57             sourceBitmapPixelAddress++;
  58             targetBitmap[targetBitmapPixelAddress] = bytes[sourceBitmapPixelAddress];
  59
  60             targetBitmapPixelAddress++;
  61             sourceBitmapPixelAddress++;
  62             targetBitmap[targetBitmapPixelAddress] = bytes[sourceBitmapPixelAddress];
  63
  64             targetBitmapPixelAddress++;
  65             sourceBitmapPixelAddress++;
  66             targetBitmap[targetBitmapPixelAddress] = bytes[sourceBitmapPixelAddress];
  67             return;
  68         }
  69
  70         final int backgroundAlpha = 255 - textureAlpha;
  71         sourceBitmapPixelAddress++;
  72
  73         targetBitmap[targetBitmapPixelAddress] = (byte) 255;
  74         targetBitmapPixelAddress++;
  75
  76         targetBitmap[targetBitmapPixelAddress] = (byte) ((((targetBitmap[targetBitmapPixelAddress] & 0xff) * backgroundAlpha) + ((bytes[sourceBitmapPixelAddress] & 0xff) * textureAlpha)) / 256);
  77         sourceBitmapPixelAddress++;
  78         targetBitmapPixelAddress++;
  79
  80         targetBitmap[targetBitmapPixelAddress] = (byte) ((((targetBitmap[targetBitmapPixelAddress] & 0xff) * backgroundAlpha) + ((bytes[sourceBitmapPixelAddress] & 0xff) * textureAlpha)) / 256);
  81         sourceBitmapPixelAddress++;
  82         targetBitmapPixelAddress++;
  83
  84         targetBitmap[targetBitmapPixelAddress] = (byte) ((((targetBitmap[targetBitmapPixelAddress] & 0xff) * backgroundAlpha) + ((bytes[sourceBitmapPixelAddress] & 0xff) * textureAlpha)) / 256);
  85     }
  86
  87     public void drawPixel(final int x, final int y, final Color color) {
  88         int address = getAddress(x, y);
  89
  90         bytes[address] = (byte) color.a;
  91
  92         address++;
  93         bytes[address] = (byte) color.b;
  94
  95         address++;
  96         bytes[address] = (byte) color.g;
  97
  98         address++;
  99         bytes[address] = (byte) color.r;
 100     }
 101
 102     public void drawRectangle(int x1, final int y1, int x2, final int y2,
 103                               final Color color) {
 104
 105         if (x1 > x2) {
 106             final int tmp = x1;
 107             x1 = x2;
 108             x2 = tmp;
 109         }
 110
 111         if (y1 > y2) {
 112             final int tmp = x1;
 113             x1 = x2;
 114             x2 = tmp;
 115         }
 116
 117         for (int y = y1; y < y2; y++)
 118             for (int x = x1; x < x2; x++)
 119                 drawPixel(x, y, color);
 120     }
 121
 122     public void fillColor(final Color color) {
 123         int address = 0;
 124         while (address < bytes.length) {
 125             bytes[address] = (byte) color.a;
 126             address++;
 127
 128             bytes[address] = (byte) color.b;
 129             address++;
 130
 131             bytes[address] = (byte) color.g;
 132             address++;
 133
 134             bytes[address] = (byte) color.r;
 135             address++;
 136         }
 137     }
 138
 139     public int getAddress(int x, int y) {
 140         if (x < 0)
 141             x = 0;
 142
 143         if (x >= width)
 144             x = width - 1;
 145
 146         if (y < 0)
 147             y = 0;
 148
 149         if (y >= height)
 150             y = height - 1;
 151
 152         return ((y * width) + x) * 4;
 153     }
 154 }