imagedata.java

源码为Eclipse开源开发平台桌面开发工具SWT的源代码,

	int theByte;
	int mask;
	int n = putWidth;
	int i = startIndex;
	int srcX = x, srcY = y;
	if (depth == 1) {
		index = (y * bytesPerLine) + (x >> 3);
		while (n > 0) {
			mask = 1 << (7 - (srcX & 0x7));
			if ((pixels[i] & 0x1) == 1) {
				data[index] = (byte)((data[index] & 0xFF) | mask);
			} else {
				data[index] = (byte)((data[index] & 0xFF) & (mask ^ -1));
			}
			i++;
			n--;
			srcX++;
			if (srcX >= width) {
				srcY++;
				index = srcY * bytesPerLine;
				srcX = 0;
			} else {
				if (mask == 1) {
					index++;
				}
			}
		}
		return;
	}
	if (depth == 2) {
		byte [] masks = { (byte)0xFC, (byte)0xF3, (byte)0xCF, (byte)0x3F };
		index = (y * bytesPerLine) + (x >> 2);
		int offset = 3 - (x % 4);
		while (n > 0) {
			theByte = pixels[i] & 0x3;
			data[index] = (byte)((data[index] & masks[offset]) | (theByte << (offset * 2)));
			i++;
			n--;
			srcX++;
			if (srcX >= width) {
				srcY++;
				index = srcY * bytesPerLine;
				offset = 0;
				srcX = 0;
			} else {
				if (offset == 0) {
					index++;
					offset = 3;
				} else {
					offset--;
				}
			}
		}
		return;
	}
	if (depth == 4) {
		index = (y * bytesPerLine) + (x >> 1);
		boolean high = (x & 0x1) == 0;
		while (n > 0) {
			theByte = pixels[i] & 0x0F;
			if (high) {
				data[index] = (byte)((data[index] & 0x0F) | (theByte << 4));
			} else {
				data[index] = (byte)((data[index] & 0xF0) | theByte);
			}
			i++;
			n--;
			srcX++;
			if (srcX >= width) {
				srcY++;
				index = srcY * bytesPerLine;
				high = true;
				srcX = 0;
			} else {
				if (!high) index++;
				high = !high;
			}
		}
		return;
	}
	if (depth == 8) {
		index = (y * bytesPerLine) + x;
		for (int j = 0; j < putWidth; j++) {
			data[index] = (byte)(pixels[i] & 0xFF);
			i++;
			srcX++;
			if (srcX >= width) {
				srcY++;
				index = srcY * bytesPerLine;
				srcX = 0;
			} else {
				index++;
			}
		}
		return;
	}
	SWT.error(SWT.ERROR_UNSUPPORTED_DEPTH);
}

/**
 * Sets the pixel values starting at offset <code>x</code> in
 * scanline <code>y</code> in the receiver's data to the
 * values from the array <code>pixels</code> starting at
 * <code>startIndex</code>.
 *
 * @param x the x position of the pixel to set
 * @param y the y position of the pixel to set
 * @param putWidth the width of the pixels to set
 * @param pixels the pixels to set
 * @param startIndex the index at which to begin setting
 *
 * @exception IndexOutOfBoundsException if putWidth is too large
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_NULL_ARGUMENT - if pixels is null</li>
 *    <li>ERROR_INVALID_ARGUMENT - if x or y is out of bounds</li>
 *    <li>ERROR_INVALID_ARGUMENT - if putWidth is negative</li>
 * </ul>
 * @exception SWTException <ul>
 *    <li>ERROR_UNSUPPORTED_DEPTH if the depth is not one of 1, 2, 4, 8, 16, 24 or 32</li>
 * </ul>
 */
public void setPixels(int x, int y, int putWidth, int[] pixels, int startIndex) {
	if (pixels == null) SWT.error(SWT.ERROR_NULL_ARGUMENT);
	if (putWidth < 0 || x >= width || y >= height || x < 0 || y < 0) SWT.error(SWT.ERROR_INVALID_ARGUMENT);
	if (putWidth == 0) return;
	int index;
	int theByte;
	int mask;
	int n = putWidth;
	int i = startIndex;
	int pixel;
	int srcX = x, srcY = y;
	if (depth == 1) {
		index = (y * bytesPerLine) + (x >> 3);
		while (n > 0) {
			mask = 1 << (7 - (srcX & 0x7));
			if ((pixels[i] & 0x1) == 1) {
				data[index] = (byte)((data[index] & 0xFF) | mask);
			} else {
				data[index] = (byte)((data[index] & 0xFF) & (mask ^ -1));
			}
			i++;
			n--;
			srcX++;
			if (srcX >= width) {
				srcY++;
				index = srcY * bytesPerLine;
				srcX = 0;
			} else {
				if (mask == 1) {
					index++;
				}
			}
		}
		return;
	}
	if (depth == 2) {
		byte [] masks = { (byte)0xFC, (byte)0xF3, (byte)0xCF, (byte)0x3F };
		index = (y * bytesPerLine) + (x >> 2);
		int offset = 3 - (x % 4);
		while (n > 0) {
			theByte = pixels[i] & 0x3;
			data[index] = (byte)((data[index] & masks[offset]) | (theByte << (offset * 2)));
			i++;
			n--;
			srcX++;
			if (srcX >= width) {
				srcY++;
				index = srcY * bytesPerLine;
				offset = 3;
				srcX = 0;
			} else {
				if (offset == 0) {
					index++;
					offset = 3;
				} else {
					offset--;
				}
			}
		}
		return;
	}
	if (depth == 4) {
		index = (y * bytesPerLine) + (x >> 1);
		boolean high = (x & 0x1) == 0;
		while (n > 0) {
			theByte = pixels[i] & 0x0F;
			if (high) {
				data[index] = (byte)((data[index] & 0x0F) | (theByte << 4));
			} else {
				data[index] = (byte)((data[index] & 0xF0) | theByte);
			}
			i++;
			n--;
			srcX++;
			if (srcX >= width) {
				srcY++;
				index = srcY * bytesPerLine;
				high = true;
				srcX = 0;
			} else {
				if (!high) index++;
				high = !high;
			}
		}
		return;
	}
	if (depth == 8) {
		index = (y * bytesPerLine) + x;
		for (int j = 0; j < putWidth; j++) {
			data[index] = (byte)(pixels[i] & 0xFF);
			i++;
			srcX++;
			if (srcX >= width) {
				srcY++;
				index = srcY * bytesPerLine;
				srcX = 0;
			} else {
				index++;
			}
		}
		return;

	}
	if (depth == 16) {
		index = (y * bytesPerLine) + (x * 2);
		for (int j = 0; j < putWidth; j++) {
			pixel = pixels[i];
			data[index] = (byte)(pixel & 0xFF);
			data[index + 1] = (byte)((pixel >> 8) & 0xFF);
			i++;
			srcX++;
			if (srcX >= width) {
				srcY++;
				index = srcY * bytesPerLine;
				srcX = 0;
			} else {
				index += 2;
			}
		}
		return;
	}
	if (depth == 24) {
		index = (y * bytesPerLine) + (x * 3);
		for (int j = 0; j < putWidth; j++) {
			pixel = pixels[i];
			data[index] = (byte)((pixel >> 16) & 0xFF);
			data[index + 1] = (byte)((pixel >> 8) & 0xFF);
			data[index + 2] = (byte)(pixel & 0xFF);
			i++;
			srcX++;
			if (srcX >= width) {
				srcY++;
				index = srcY * bytesPerLine;
				srcX = 0;
			} else {
				index += 3;
			}
		}
		return;
	}
	if (depth == 32) {
		index = (y * bytesPerLine) + (x * 4);
		for (int j = 0; j < putWidth; j++) {
			pixel = pixels[i];
			data[index] = (byte)((pixel >> 24) & 0xFF);
			data[index + 1] = (byte)((pixel >> 16) & 0xFF);
			data[index + 2] = (byte)((pixel >> 8) & 0xFF);
			data[index + 3] = (byte)(pixel & 0xFF);
			i++;
			srcX++;
			if (srcX >= width) {
				srcY++;
				index = srcY * bytesPerLine;
				srcX = 0;
			} else {
				index += 4;
			}
		}
		return;
	}
	SWT.error(SWT.ERROR_UNSUPPORTED_DEPTH);
}

/**
 * Returns a palette with 2 colors: black & white.
 */
static PaletteData bwPalette() {
	return new PaletteData(new RGB[] {new RGB(0, 0, 0), new RGB(255, 255, 255)});
}

/**
 * Gets the offset of the most significant bit for
 * the given mask.
 */
static int getMSBOffset(int mask) {
	for (int i = 31; i >= 0; i--) {
		if (((mask >> i) & 0x1) != 0) return i + 1;
	}
	return 0;
}

/**
 * Finds the closest match.
 */
static int closestMatch(int depth, byte red, byte green, byte blue, int redMask, int greenMask, int blueMask, byte[] reds, byte[] greens, byte[] blues) {
	if (depth > 8) {
		int rshift = 32 - getMSBOffset(redMask);
		int gshift = 32 - getMSBOffset(greenMask);
		int bshift = 32 - getMSBOffset(blueMask);
		return (((red << 24) >>> rshift) & redMask) |
			(((green << 24) >>> gshift) & greenMask) |
			(((blue << 24) >>> bshift) & blueMask);
	}
	int r, g, b;
	int minDistance = 0x7fffffff;
	int nearestPixel = 0;
	int n = reds.length;
	for (int j = 0; j < n; j++) {
		r = (reds[j] & 0xFF) - (red & 0xFF);
		g = (greens[j] & 0xFF) - (green & 0xFF);
		b = (blues[j] & 0xFF) - (blue & 0xFF);
		int distance = r*r + g*g + b*b;
		if (distance < minDistance) {
			nearestPixel = j;
			if (distance == 0) break;
			minDistance = distance;
		}
	}
	return nearestPixel;
}

static final byte[] convertPad(byte[] data, int width, int height, int depth, int pad, int newPad) {
	if (pad == newPad) return data;
	int stride = (width * depth + 7) / 8;
	int bpl = (stride + (pad - 1)) / pad * pad;	
	int newBpl = (stride + (newPad - 1)) / newPad * newPad;
	byte[] newData = new byte[height * newBpl];
	int srcIndex = 0, destIndex = 0;
	for (int y = 0; y < height; y++) {
		System.arraycopy(data, srcIndex, newData, destIndex, stride);
		srcIndex += bpl;
		destIndex += newBpl;
	}
	return newData;
}

/**
 * Blit operation bits to be OR'ed together to specify the desired operation.
 */
static final int
	BLIT_SRC = 1,     // copy source directly, else applies logic operations
	BLIT_ALPHA = 2,   // enable alpha blending
	BLIT_DITHER = 4;  // enable dithering in low color modes

/**
 * Alpha mode, values 0 - 255 specify global alpha level
 */
static final int
	ALPHA_OPAQUE = 255,           // Fully opaque (ignores any alpha data)
	ALPHA_TRANSPARENT = 0,        // Fully transparent (ignores any alpha data)
	ALPHA_CHANNEL_SEPARATE = -1,  // Use alpha channel from separate alphaData
	ALPHA_CHANNEL_SOURCE = -2,    // Use alpha channel embedded in sourceData
	ALPHA_MASK_UNPACKED = -3,     // Use transparency mask formed by bytes in alphaData (non-zero is opaque)
	ALPHA_MASK_PACKED = -4,       // Use transparency mask formed by packed bits in alphaData
	ALPHA_MASK_INDEX = -5,        // Consider source palette indices transparent if in alphaData array
	ALPHA_MASK_RGB = -6;          // Consider source RGBs transparent if in RGB888 format alphaData array

/**
 * Byte and bit order constants.
 */
static final int LSB_FIRST = 0;
static final int MSB_FIRST = 1;

/**
 * Data types (internal)
 */
private static final int
	// direct / true color formats with arbitrary masks & shifts
	TYPE_GENERIC_8 = 0,
	TYPE_GENERIC_16_MSB = 1,
	TYPE_GENERIC_16_LSB = 2,
	TYPE_GENERIC_24 = 3,
	TYPE_GENERIC_32_MSB = 4,
	TYPE_GENERIC_32_LSB = 5,
	// palette indexed color formats
	TYPE_INDEX_8 = 6,
	TYPE_INDEX_4 = 7,
	TYPE_INDEX_2 = 8,
	TYPE_INDEX_1_MSB = 9,
	TYPE_INDEX_1_LSB = 10;

/**
 * Blits a direct palette image into a direct palette image.
 * <p>
 * Note: When the source and destination depth, order and masks
 * are pairwise equal and the blitter operation is BLIT_SRC,
 * the masks are ignored.  Hence when not changing the image
 * data format, 0 may be specified for the masks.
 * </p>
 * 
 * @param op the blitter operation: a combination of BLIT_xxx flags
 *        (see BLIT_xxx constants)
 * @param srcData the source byte array containing image data
 * @param srcDepth the source depth: one of 8, 16, 24, 32
 * @param srcStride the source number of bytes per line
 * @param srcOrder the source byte ordering: one of MSB_FIRST or LSB_FIRST;
 *        ignored if srcDepth is not 16 or 32
 * @param srcX the top-left x-coord of the source blit region
 * @param srcY the top-left y-coord of the source blit region
 * @param srcWidth the width of the source blit region
 * @param srcHeight the height of the source blit region
 * @param srcRedMask the source red channel mask
 * @param srcGreenMask the source green channel mask
 * @param srcBlueMask the source blue channel mask
 * @param alphaMode the alpha blending or mask mode, may be
 *        an integer 0-255 for global alpha; ignored if BLIT_ALPHA
 *        not specified in the blitter operations
 *        (see ALPHA_MODE_xxx constants)
 * @param alphaData the alpha blending or mask data, varies depending
 *        on the value of alphaMode and sometimes ignored
 * @param alphaStride the alpha data number of bytes per line
 * @param alphaX the top-left x-coord of the alpha blit region
 * @param alphaY the top-left y-coord of the alpha blit region
 * @param destData the destination byte array containing image data
 * @param destDepth the destination depth: one of 8, 16, 24, 32
 * @param destStride the destination number of bytes per line