modules/midp-lcdui/src/main/java/cc/squirreljme/runtime/lcdui/gfx/SingleBuffer.java

   1 // -*- Mode: Java; indent-tabs-mode: t; tab-width: 4 -*-
   2 // ---------------------------------------------------------------------------
   3 // SquirrelJME
   4 //     Copyright (C) Stephanie Gawroriski <xer@multiphasicapps.net>
   5 // ---------------------------------------------------------------------------
   6 // SquirrelJME is under the GNU General Public License v3+, or later.
   7 // See license.mkd for licensing and copyright information.
   8 // ---------------------------------------------------------------------------
   9
  10 package cc.squirreljme.runtime.lcdui.gfx;
  11
  12 import cc.squirreljme.jvm.mle.constants.UIPixelFormat;
  13 import cc.squirreljme.runtime.lcdui.mle.PencilGraphics;
  14 import java.util.Arrays;
  15 import javax.microedition.lcdui.Graphics;
  16
  17 /**
  18  * Represents a single buffer for use with {@link DoubleBuffer}.
  19  *
  20  * @since 2022/02/25
  21  */
  22 public final class SingleBuffer
  23 {
  24         /** The color to fill with on resizes. */
  25         private final int fillColor;
  26
  27         /** Available pixels. */
  28         private volatile int[] _pixels =
  29                 new int[1];
  30
  31         /** The width of the buffer. */
  32         private volatile int _width =
  33                 1;
  34
  35         /** The height of the buffer. */
  36         private volatile int _height =
  37                 1;
  38
  39         /**
  40          * Initializes the single buffer.
  41          *
  42          * @param __resizeFillColor The color to fill with when resizing.
  43          * @since 2022/02/25
  44          */
  45         public SingleBuffer(int __resizeFillColor)
  46         {
  47                 this.fillColor = __resizeFillColor;
  48         }
  49
  50         /**
  51          * Clears the buffer to the fill color.
  52          *
  53          * @since 2022/02/25
  54          */
  55         public void clear()
  56         {
  57                 Arrays.fill(this._pixels, this.fillColor);
  58         }
  59
  60         /**
  61          * Copies from the source buffer.
  62          *
  63          * @param __source The source buffer.
  64          * @throws NullPointerException On null arguments.
  65          * @since 2022/02/25
  66          */
  67         public void copyFrom(SingleBuffer __source)
  68                 throws NullPointerException
  69         {
  70                 if (__source == null)
  71                         throw new NullPointerException("NARG");
  72
  73                 // Get destination parameters
  74                 int[] destPixels = this._pixels;
  75                 int destLimit = destPixels.length;
  76
  77                 // Get source parameters
  78                 int[] srcPixels = __source._pixels;
  79                 int srcWidth = __source._width;
  80                 int srcHeight = __source._height;
  81                 int srcArea = srcWidth * srcHeight;
  82
  83                 // If the source is larger, we need a new and bigger array but we
  84                 // can just automatically copy that array over
  85                 if (srcArea > destLimit)
  86                         this._pixels = Arrays.copyOf(srcPixels, srcArea);
  87
  88                 // Only copy what is needed
  89                 else
  90                         System.arraycopy(srcPixels, 0,
  91                                 destPixels, 0, srcArea);
  92
  93                 // Copy the parameters over
  94                 this._width = srcWidth;
  95                 this._height = srcHeight;
  96         }
  97
  98         /**
  99          * Returns a graphics object for drawing into the off-screen buffer. If
 100          * the screen size varies, then the contents of the graphics buffer is
 101          * undefined.
 102          *
 103          * @param __width The buffer width.
 104          * @param __height The buffer height.
 105          * @return The graphics to draw onto the image.
 106          * @throws IllegalArgumentException If the width and/or height are invalid.
 107          * @since 2022/02/25
 108          */
 109         public Graphics getGraphics(int __width, int __height)
 110                 throws IllegalArgumentException
 111         {
 112                 // {@squirreljme.error EB31 Invalid buffer dimensions.}
 113                 if (__width <= 0 || __height <= 0)
 114                         throw new IllegalArgumentException("EB31");
 115
 116                 int[] pixels = this._pixels;
 117
 118                 // Do we need to resize the buffer?
 119                 int currentLimit = pixels.length;
 120                 int wantedArea = __width * __height;
 121                 if (wantedArea > currentLimit)
 122                 {
 123                         this._pixels = (pixels = new int[wantedArea]);
 124
 125                         // Fill resized area accordingly
 126                         Arrays.fill(pixels, this.fillColor);
 127                 }
 128
 129                 // Set new parameters
 130                 this._width = __width;
 131                 this._height = __height;
 132
 133                 // Create graphics to wrap it, alpha is not used for buffers!
 134                 return PencilGraphics.hardwareGraphics(UIPixelFormat.INT_RGB888,
 135                         __width, __height,
 136                         pixels, 0, null,
 137                         0, 0, __width, __height);
 138         }
 139
 140         /**
 141          * Paints this buffer onto the target graphics instance.
 142          *
 143          * @param __g The graphics to paint onto.
 144          * @since 2022/02/25
 145          */
 146         public void paint(Graphics __g)
 147         {
 148                 // The fastest way to draw onto the screen is to do a direct draw
 149                 // from the RGB pixel data
 150                 int pw = this._width;
 151                 __g.drawRGB(this._pixels, 0, pw, 0, 0,
 152                         pw, this._height, false);
 153         }
 154 }