xref: /aosp_15_r20/external/skia/src/core/SkImagePriv.h (revision c8dee2aa9b3f27cf6c858bd81872bdeb2c07ed17)
1 /*
2  * Copyright 2012 Google Inc.
3  *
4  * Use of this source code is governed by a BSD-style license that can be
5  * found in the LICENSE file.
6  */
7 
8 #ifndef SkImagePriv_DEFINED
9 #define SkImagePriv_DEFINED
10 
11 #include "include/core/SkImage.h"
12 #include "include/core/SkSurface.h"
13 #include "include/core/SkTileMode.h"
14 
15 class SkPixelRef;
16 
17 enum SkCopyPixelsMode {
18     kIfMutable_SkCopyPixelsMode,  //!< only copy src pixels if they are marked mutable
19     kAlways_SkCopyPixelsMode,     //!< always copy src pixels (even if they are marked immutable)
20     kNever_SkCopyPixelsMode,      //!< never copy src pixels (even if they are marked mutable)
21 };
22 
23 // Convenience function to return a shader that implements the shader+image behavior defined for
24 // drawImage/Bitmap where the paint's shader is ignored when the bitmap is a color image, but
25 // properly compose them together when it is an alpha image. This allows the returned paint to
26 // be assigned to a paint clone without discarding the original behavior.
27 sk_sp<SkShader> SkMakeBitmapShaderForPaint(const SkPaint& paint, const SkBitmap& src,
28                                            SkTileMode, SkTileMode, const SkSamplingOptions&,
29                                            const SkMatrix* localMatrix, SkCopyPixelsMode);
30 
31 // Given arguments for a call to SkCanvas::drawImageRect, modify the SkPaint and return a
32 // possibly adjusted 'dst' SkRect such that calling SkCanvas::drawRect(newDst, *paint) produces
33 // visually equivalent results to the original drawImageRect() call.
34 SkRect SkModifyPaintAndDstForDrawImageRect(const SkImage* image,
35                                            const SkSamplingOptions&,
36                                            SkRect src,
37                                            SkRect dst,
38                                            bool strictSrcSubset,
39                                            SkPaint* paint);
40 
41 /**
42  *  Examines the bitmap to decide if it can share the existing pixelRef, or
43  *  if it needs to make a deep-copy of the pixels.
44  *
45  *  The bitmap's pixelref will be shared if either the bitmap is marked as
46  *  immutable, or CopyPixelsMode allows it. Shared pixel refs are also
47  *  locked when kLocked_SharedPixelRefMode is specified.
48  *
49  *  Passing kLocked_SharedPixelRefMode allows the image's peekPixels() method
50  *  to succeed, but it will force any lazy decodes/generators to execute if
51  *  they exist on the pixelref.
52  *
53  *  It is illegal to call this with a texture-backed bitmap.
54  *
55  *  If the bitmap's colortype cannot be converted into a corresponding
56  *  SkImageInfo, or the bitmap's pixels cannot be accessed, this will return
57  *  nullptr.
58  */
59 extern SK_SPI sk_sp<SkImage> SkMakeImageFromRasterBitmap(const SkBitmap&, SkCopyPixelsMode);
60 
61 // Given an image created from SkNewImageFromBitmap, return its pixelref. This
62 // may be called to see if the surface and the image share the same pixelref,
63 // in which case the surface may need to perform a copy-on-write.
64 extern const SkPixelRef* SkBitmapImageGetPixelRef(const SkImage* rasterImage);
65 
66 #endif
67