| /* |
| * Copyright (C) 2006 The Android Open Source Project |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| package android.graphics; |
| |
| import android.annotation.UnsupportedAppUsage; |
| |
| /** |
| * <p>This class contains the list of alpha compositing and blending modes |
| * that can be passed to {@link PorterDuffXfermode}, a specialized implementation |
| * of {@link Paint}'s {@link Paint#setXfermode(Xfermode) transfer mode}. |
| * All the available modes can be found in the {@link Mode} enum.</p> |
| * |
| * Consider using {@link BlendMode} instead as it provides a wider variety of tinting options |
| */ |
| public class PorterDuff { |
| /** |
| * {@usesMathJax} |
| * |
| * <h3>Porter-Duff</h3> |
| * |
| * <p>The name of the parent class is an homage to the work of Thomas Porter and |
| * Tom Duff, presented in their seminal 1984 paper titled "Compositing Digital Images". |
| * In this paper, the authors describe 12 compositing operators that govern how to |
| * compute the color resulting of the composition of a source (the graphics object |
| * to render) with a destination (the content of the render target).</p> |
| * |
| * <p>"Compositing Digital Images" was published in <em>Computer Graphics</em> |
| * Volume 18, Number 3 dated July 1984.</p> |
| * |
| * <p>Because the work of Porter and Duff focuses solely on the effects of the alpha |
| * channel of the source and destination, the 12 operators described in the original |
| * paper are called alpha compositing modes here.</p> |
| * |
| * <p>For convenience, this class also provides several blending modes, which similarly |
| * define the result of compositing a source and a destination but without being |
| * constrained to the alpha channel. These blending modes are not defined by Porter |
| * and Duff but have been included in this class for convenience purposes.</p> |
| * |
| * <h3>Diagrams</h3> |
| * |
| * <p>All the example diagrams presented below use the same source and destination |
| * images:</p> |
| * |
| * <table summary="Source and Destination" style="background-color: transparent;"> |
| * <tr> |
| * <td style="border: none; text-align: center;"> |
| * <img src="{@docRoot}reference/android/images/graphics/composite_SRC.png" /> |
| * <figcaption>Source image</figcaption> |
| * </td> |
| * <td style="border: none; text-align: center;"> |
| * <img src="{@docRoot}reference/android/images/graphics/composite_DST.png" /> |
| * <figcaption>Destination image</figcaption> |
| * </td> |
| * </tr> |
| * </table> |
| * |
| * <p>The order of drawing operations used to generate each diagram is shown in the |
| * following code snippet:</p> |
| * |
| * <pre class="prettyprint"> |
| * Paint paint = new Paint(); |
| * canvas.drawBitmap(destinationImage, 0, 0, paint); |
| * |
| * PorterDuff.Mode mode = // choose a mode |
| * paint.setXfermode(new PorterDuffXfermode(mode)); |
| * |
| * canvas.drawBitmap(sourceImage, 0, 0, paint); |
| * </pre> |
| |
| * |
| * <h3>Alpha compositing modes</h3> |
| * |
| * <table summary="Alpha compositing modes" style="background-color: transparent;"> |
| * <tr> |
| * <td style="border: none; text-align: center;"> |
| * <img src="{@docRoot}reference/android/images/graphics/composite_SRC.png" /> |
| * <figcaption>{@link #SRC Source}</figcaption> |
| * </td> |
| * <td style="border: none; text-align: center;"> |
| * <img src="{@docRoot}reference/android/images/graphics/composite_SRC_OVER.png" /> |
| * <figcaption>{@link #SRC_OVER Source Over}</figcaption> |
| * </td> |
| * <td style="border: none; text-align: center;"> |
| * <img src="{@docRoot}reference/android/images/graphics/composite_SRC_IN.png" /> |
| * <figcaption>{@link #SRC_IN Source In}</figcaption> |
| * </td> |
| * <td style="border: none; text-align: center;"> |
| * <img src="{@docRoot}reference/android/images/graphics/composite_SRC_ATOP.png" /> |
| * <figcaption>{@link #SRC_ATOP Source Atop}</figcaption> |
| * </td> |
| * </tr> |
| * <tr> |
| * <td style="border: none; text-align: center;"> |
| * <img src="{@docRoot}reference/android/images/graphics/composite_DST.png" /> |
| * <figcaption>{@link #DST Destination}</figcaption> |
| * </td> |
| * <td style="border: none; text-align: center;"> |
| * <img src="{@docRoot}reference/android/images/graphics/composite_DST_OVER.png" /> |
| * <figcaption>{@link #DST_OVER Destination Over}</figcaption> |
| * </td> |
| * <td style="border: none; text-align: center;"> |
| * <img src="{@docRoot}reference/android/images/graphics/composite_DST_IN.png" /> |
| * <figcaption>{@link #DST_IN Destination In}</figcaption> |
| * </td> |
| * <td style="border: none; text-align: center;"> |
| * <img src="{@docRoot}reference/android/images/graphics/composite_DST_ATOP.png" /> |
| * <figcaption>{@link #DST_ATOP Destination Atop}</figcaption> |
| * </td> |
| * </tr> |
| * <tr> |
| * <td style="border: none; text-align: center;"> |
| * <img src="{@docRoot}reference/android/images/graphics/composite_CLEAR.png" /> |
| * <figcaption>{@link #CLEAR Clear}</figcaption> |
| * </td> |
| * <td style="border: none; text-align: center;"> |
| * <img src="{@docRoot}reference/android/images/graphics/composite_SRC_OUT.png" /> |
| * <figcaption>{@link #SRC_OUT Source Out}</figcaption> |
| * </td> |
| * <td style="border: none; text-align: center;"> |
| * <img src="{@docRoot}reference/android/images/graphics/composite_DST_OUT.png" /> |
| * <figcaption>{@link #DST_OUT Destination Out}</figcaption> |
| * </td> |
| * <td style="border: none; text-align: center;"> |
| * <img src="{@docRoot}reference/android/images/graphics/composite_XOR.png" /> |
| * <figcaption>{@link #XOR Exclusive Or}</figcaption> |
| * </td> |
| * </tr> |
| * </table> |
| * |
| * <h3>Blending modes</h3> |
| * |
| * <table summary="Blending modes" style="background-color: transparent;"> |
| * <tr> |
| * <td style="border: none; text-align: center;"> |
| * <img src="{@docRoot}reference/android/images/graphics/composite_DARKEN.png" /> |
| * <figcaption>{@link #DARKEN Darken}</figcaption> |
| * </td> |
| * <td style="border: none; text-align: center;"> |
| * <img src="{@docRoot}reference/android/images/graphics/composite_LIGHTEN.png" /> |
| * <figcaption>{@link #LIGHTEN Lighten}</figcaption> |
| * </td> |
| * <td style="border: none; text-align: center;"> |
| * <img src="{@docRoot}reference/android/images/graphics/composite_MULTIPLY.png" /> |
| * <figcaption>{@link #MULTIPLY Multiply}</figcaption> |
| * </td> |
| * </tr> |
| * <tr> |
| * <td style="border: none; text-align: center;"> |
| * <img src="{@docRoot}reference/android/images/graphics/composite_SCREEN.png" /> |
| * <figcaption>{@link #SCREEN Screen}</figcaption> |
| * </td> |
| * <td style="border: none; text-align: center;"> |
| * <img src="{@docRoot}reference/android/images/graphics/composite_OVERLAY.png" /> |
| * <figcaption>{@link #OVERLAY Overlay}</figcaption> |
| * </td> |
| * </tr> |
| * </table> |
| * |
| * <h3>Compositing equations</h3> |
| * |
| * <p>The documentation of each individual alpha compositing or blending mode below |
| * provides the exact equation used to compute alpha and color value of the result |
| * of the composition of a source and destination.</p> |
| * |
| * <p>The result (or output) alpha value is noted \(\alpha_{out}\). The result (or output) |
| * color value is noted \(C_{out}\).</p> |
| */ |
| public enum Mode { |
| // these value must match their native equivalents. See SkXfermode.h |
| /** |
| * <p> |
| * <img src="{@docRoot}reference/android/images/graphics/composite_CLEAR.png" /> |
| * <figcaption>Destination pixels covered by the source are cleared to 0.</figcaption> |
| * </p> |
| * <p>\(\alpha_{out} = 0\)</p> |
| * <p>\(C_{out} = 0\)</p> |
| */ |
| CLEAR (0), |
| /** |
| * <p> |
| * <img src="{@docRoot}reference/android/images/graphics/composite_SRC.png" /> |
| * <figcaption>The source pixels replace the destination pixels.</figcaption> |
| * </p> |
| * <p>\(\alpha_{out} = \alpha_{src}\)</p> |
| * <p>\(C_{out} = C_{src}\)</p> |
| */ |
| SRC (1), |
| /** |
| * <p> |
| * <img src="{@docRoot}reference/android/images/graphics/composite_DST.png" /> |
| * <figcaption>The source pixels are discarded, leaving the destination intact.</figcaption> |
| * </p> |
| * <p>\(\alpha_{out} = \alpha_{dst}\)</p> |
| * <p>\(C_{out} = C_{dst}\)</p> |
| */ |
| DST (2), |
| /** |
| * <p> |
| * <img src="{@docRoot}reference/android/images/graphics/composite_SRC_OVER.png" /> |
| * <figcaption>The source pixels are drawn over the destination pixels.</figcaption> |
| * </p> |
| * <p>\(\alpha_{out} = \alpha_{src} + (1 - \alpha_{src}) * \alpha_{dst}\)</p> |
| * <p>\(C_{out} = C_{src} + (1 - \alpha_{src}) * C_{dst}\)</p> |
| */ |
| SRC_OVER (3), |
| /** |
| * <p> |
| * <img src="{@docRoot}reference/android/images/graphics/composite_DST_OVER.png" /> |
| * <figcaption>The source pixels are drawn behind the destination pixels.</figcaption> |
| * </p> |
| * <p>\(\alpha_{out} = \alpha_{dst} + (1 - \alpha_{dst}) * \alpha_{src}\)</p> |
| * <p>\(C_{out} = C_{dst} + (1 - \alpha_{dst}) * C_{src}\)</p> |
| */ |
| DST_OVER (4), |
| /** |
| * <p> |
| * <img src="{@docRoot}reference/android/images/graphics/composite_SRC_IN.png" /> |
| * <figcaption>Keeps the source pixels that cover the destination pixels, |
| * discards the remaining source and destination pixels.</figcaption> |
| * </p> |
| * <p>\(\alpha_{out} = \alpha_{src} * \alpha_{dst}\)</p> |
| * <p>\(C_{out} = C_{src} * \alpha_{dst}\)</p> |
| */ |
| SRC_IN (5), |
| /** |
| * <p> |
| * <img src="{@docRoot}reference/android/images/graphics/composite_DST_IN.png" /> |
| * <figcaption>Keeps the destination pixels that cover source pixels, |
| * discards the remaining source and destination pixels.</figcaption> |
| * </p> |
| * <p>\(\alpha_{out} = \alpha_{src} * \alpha_{dst}\)</p> |
| * <p>\(C_{out} = C_{dst} * \alpha_{src}\)</p> |
| */ |
| DST_IN (6), |
| /** |
| * <p> |
| * <img src="{@docRoot}reference/android/images/graphics/composite_SRC_OUT.png" /> |
| * <figcaption>Keeps the source pixels that do not cover destination pixels. |
| * Discards source pixels that cover destination pixels. Discards all |
| * destination pixels.</figcaption> |
| * </p> |
| * <p>\(\alpha_{out} = (1 - \alpha_{dst}) * \alpha_{src}\)</p> |
| * <p>\(C_{out} = (1 - \alpha_{dst}) * C_{src}\)</p> |
| */ |
| SRC_OUT (7), |
| /** |
| * <p> |
| * <img src="{@docRoot}reference/android/images/graphics/composite_DST_OUT.png" /> |
| * <figcaption>Keeps the destination pixels that are not covered by source pixels. |
| * Discards destination pixels that are covered by source pixels. Discards all |
| * source pixels.</figcaption> |
| * </p> |
| * <p>\(\alpha_{out} = (1 - \alpha_{src}) * \alpha_{dst}\)</p> |
| * <p>\(C_{out} = (1 - \alpha_{src}) * C_{dst}\)</p> |
| */ |
| DST_OUT (8), |
| /** |
| * <p> |
| * <img src="{@docRoot}reference/android/images/graphics/composite_SRC_ATOP.png" /> |
| * <figcaption>Discards the source pixels that do not cover destination pixels. |
| * Draws remaining source pixels over destination pixels.</figcaption> |
| * </p> |
| * <p>\(\alpha_{out} = \alpha_{dst}\)</p> |
| * <p>\(C_{out} = \alpha_{dst} * C_{src} + (1 - \alpha_{src}) * C_{dst}\)</p> |
| */ |
| SRC_ATOP (9), |
| /** |
| * <p> |
| * <img src="{@docRoot}reference/android/images/graphics/composite_DST_ATOP.png" /> |
| * <figcaption>Discards the destination pixels that are not covered by source pixels. |
| * Draws remaining destination pixels over source pixels.</figcaption> |
| * </p> |
| * <p>\(\alpha_{out} = \alpha_{src}\)</p> |
| * <p>\(C_{out} = \alpha_{src} * C_{dst} + (1 - \alpha_{dst}) * C_{src}\)</p> |
| */ |
| DST_ATOP (10), |
| /** |
| * <p> |
| * <img src="{@docRoot}reference/android/images/graphics/composite_XOR.png" /> |
| * <figcaption>Discards the source and destination pixels where source pixels |
| * cover destination pixels. Draws remaining source pixels.</figcaption> |
| * </p> |
| * <p>\(\alpha_{out} = (1 - \alpha_{dst}) * \alpha_{src} + (1 - \alpha_{src}) * \alpha_{dst}\)</p> |
| * <p>\(C_{out} = (1 - \alpha_{dst}) * C_{src} + (1 - \alpha_{src}) * C_{dst}\)</p> |
| */ |
| XOR (11), |
| /** |
| * <p> |
| * <img src="{@docRoot}reference/android/images/graphics/composite_DARKEN.png" /> |
| * <figcaption>Retains the smallest component of the source and |
| * destination pixels.</figcaption> |
| * </p> |
| * <p>\(\alpha_{out} = \alpha_{src} + \alpha_{dst} - \alpha_{src} * \alpha_{dst}\)</p> |
| * <p>\(C_{out} = (1 - \alpha_{dst}) * C_{src} + (1 - \alpha_{src}) * C_{dst} + min(C_{src}, C_{dst})\)</p> |
| */ |
| DARKEN (16), |
| /** |
| * <p> |
| * <img src="{@docRoot}reference/android/images/graphics/composite_LIGHTEN.png" /> |
| * <figcaption>Retains the largest component of the source and |
| * destination pixel.</figcaption> |
| * </p> |
| * <p>\(\alpha_{out} = \alpha_{src} + \alpha_{dst} - \alpha_{src} * \alpha_{dst}\)</p> |
| * <p>\(C_{out} = (1 - \alpha_{dst}) * C_{src} + (1 - \alpha_{src}) * C_{dst} + max(C_{src}, C_{dst})\)</p> |
| */ |
| LIGHTEN (17), |
| /** |
| * <p> |
| * <img src="{@docRoot}reference/android/images/graphics/composite_MULTIPLY.png" /> |
| * <figcaption>Multiplies the source and destination pixels.</figcaption> |
| * </p> |
| * <p>\(\alpha_{out} = \alpha_{src} * \alpha_{dst}\)</p> |
| * <p>\(C_{out} = C_{src} * C_{dst}\)</p> |
| */ |
| MULTIPLY (13), |
| /** |
| * <p> |
| * <img src="{@docRoot}reference/android/images/graphics/composite_SCREEN.png" /> |
| * <figcaption>Adds the source and destination pixels, then subtracts the |
| * source pixels multiplied by the destination.</figcaption> |
| * </p> |
| * <p>\(\alpha_{out} = \alpha_{src} + \alpha_{dst} - \alpha_{src} * \alpha_{dst}\)</p> |
| * <p>\(C_{out} = C_{src} + C_{dst} - C_{src} * C_{dst}\)</p> |
| */ |
| SCREEN (14), |
| /** |
| * <p> |
| * <img src="{@docRoot}reference/android/images/graphics/composite_ADD.png" /> |
| * <figcaption>Adds the source pixels to the destination pixels and saturates |
| * the result.</figcaption> |
| * </p> |
| * <p>\(\alpha_{out} = max(0, min(\alpha_{src} + \alpha_{dst}, 1))\)</p> |
| * <p>\(C_{out} = max(0, min(C_{src} + C_{dst}, 1))\)</p> |
| */ |
| ADD (12), |
| /** |
| * <p> |
| * <img src="{@docRoot}reference/android/images/graphics/composite_OVERLAY.png" /> |
| * <figcaption>Multiplies or screens the source and destination depending on the |
| * destination color.</figcaption> |
| * </p> |
| * <p>\(\alpha_{out} = \alpha_{src} + \alpha_{dst} - \alpha_{src} * \alpha_{dst}\)</p> |
| * <p>\(\begin{equation} |
| * C_{out} = \begin{cases} 2 * C_{src} * C_{dst} & 2 * C_{dst} \lt \alpha_{dst} \\ |
| * \alpha_{src} * \alpha_{dst} - 2 (\alpha_{dst} - C_{src}) (\alpha_{src} - C_{dst}) & otherwise \end{cases} |
| * \end{equation}\)</p> |
| */ |
| OVERLAY (15); |
| |
| Mode(int nativeInt) { |
| this.nativeInt = nativeInt; |
| } |
| |
| /** |
| * @hide |
| */ |
| @UnsupportedAppUsage |
| public final int nativeInt; |
| } |
| |
| /** |
| * @hide |
| */ |
| public static int modeToInt(Mode mode) { |
| return mode.nativeInt; |
| } |
| |
| /** |
| * @hide |
| */ |
| public static Mode intToMode(int val) { |
| switch (val) { |
| default: |
| case 0: return Mode.CLEAR; |
| case 1: return Mode.SRC; |
| case 2: return Mode.DST; |
| case 3: return Mode.SRC_OVER; |
| case 4: return Mode.DST_OVER; |
| case 5: return Mode.SRC_IN; |
| case 6: return Mode.DST_IN; |
| case 7: return Mode.SRC_OUT; |
| case 8: return Mode.DST_OUT; |
| case 9: return Mode.SRC_ATOP; |
| case 10: return Mode.DST_ATOP; |
| case 11: return Mode.XOR; |
| case 16: return Mode.DARKEN; |
| case 17: return Mode.LIGHTEN; |
| case 13: return Mode.MULTIPLY; |
| case 14: return Mode.SCREEN; |
| case 12: return Mode.ADD; |
| case 15: return Mode.OVERLAY; |
| } |
| } |
| } |
