1 /*
2  * Copyright (C) 2007 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 package android.graphics;
18 
19 import android.annotation.NonNull;
20 
21 /**
22  * Shader used to draw a bitmap as a texture. The bitmap can be repeated or
23  * mirrored by setting the tiling mode.
24  */
25 public class BitmapShader extends Shader {
26     /**
27      * Prevent garbage collection.
28      */
29     /*package*/ Bitmap mBitmap;
30 
31     private int mTileX;
32     private int mTileY;
33 
34     /*
35      *  This is cache of the last value from the Paint of bitmap-filtering.
36      *  In the future, BitmapShaders will carry their own (expanded) data for this
37      *  (e.g. including mipmap options, or bicubic weights)
38      *
39      *  When that happens, this bool will become those extended values, and we will
40      *  need to track whether this Shader was created with those new constructors,
41      *  or from the current "legacy" constructor, which (for compatibility) will
42      *  still need to know the Paint's setting.
43      *
44      *  When the filter Paint setting is finally gone, we will be able to remove
45      *  the filterFromPaint parameter currently being passed to createNativeInstance()
46      *  and shouldDiscardNativeInstance(), as shaders will always know their filter
47      *  settings.
48      */
49     private boolean mFilterFromPaint;
50 
51     /**
52      * Call this to create a new shader that will draw with a bitmap.
53      *
54      * @param bitmap The bitmap to use inside the shader
55      * @param tileX The tiling mode for x to draw the bitmap in.
56      * @param tileY The tiling mode for y to draw the bitmap in.
57      */
BitmapShader(@onNull Bitmap bitmap, @NonNull TileMode tileX, @NonNull TileMode tileY)58     public BitmapShader(@NonNull Bitmap bitmap, @NonNull TileMode tileX, @NonNull TileMode tileY) {
59         this(bitmap, tileX.nativeInt, tileY.nativeInt);
60     }
61 
BitmapShader(Bitmap bitmap, int tileX, int tileY)62     private BitmapShader(Bitmap bitmap, int tileX, int tileY) {
63         if (bitmap == null) {
64             throw new IllegalArgumentException("Bitmap must be non-null");
65         }
66         mBitmap = bitmap;
67         mTileX = tileX;
68         mTileY = tileY;
69         mFilterFromPaint = false;
70     }
71 
72     /** @hide */
73     @Override
createNativeInstance(long nativeMatrix, boolean filterFromPaint)74     protected long createNativeInstance(long nativeMatrix, boolean filterFromPaint) {
75         mFilterFromPaint = filterFromPaint;
76         return nativeCreate(nativeMatrix, mBitmap.getNativeInstance(), mTileX, mTileY,
77                             mFilterFromPaint);
78     }
79 
80     /** @hide */
81     @Override
shouldDiscardNativeInstance(boolean filterFromPaint)82     protected boolean shouldDiscardNativeInstance(boolean filterFromPaint) {
83         return mFilterFromPaint != filterFromPaint;
84     }
85 
nativeCreate(long nativeMatrix, long bitmapHandle, int shaderTileModeX, int shaderTileModeY, boolean filter)86     private static native long nativeCreate(long nativeMatrix, long bitmapHandle,
87             int shaderTileModeX, int shaderTileModeY, boolean filter);
88 }
89 
90