1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
2 /* vim: set ts=8 sts=2 et sw=2 tw=80: */
3 /* This Source Code Form is subject to the terms of the Mozilla Public
4  * License, v. 2.0. If a copy of the MPL was not distributed with this
5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
6 
7 #ifndef _MOZILLA_GFX_DATASURFACEHELPERS_H
8 #define _MOZILLA_GFX_DATASURFACEHELPERS_H
9 
10 #include "2D.h"
11 
12 #include "mozilla/UniquePtr.h"
13 
14 namespace mozilla {
15 namespace gfx {
16 
17 int32_t StrideForFormatAndWidth(SurfaceFormat aFormat, int32_t aWidth);
18 
19 /**
20  * Create a DataSourceSurface and init the surface with the |aData|. The stride
21  * of this source surface might be different from the input data's
22  * |aDataStride|. System will try to use the optimal one.
23  */
24 already_AddRefed<DataSourceSurface> CreateDataSourceSurfaceFromData(
25     const IntSize& aSize, SurfaceFormat aFormat, const uint8_t* aData,
26     int32_t aDataStride);
27 
28 /**
29  * Similar to CreateDataSourceSurfaceFromData(), but could setup the stride for
30  * this surface.
31  */
32 already_AddRefed<DataSourceSurface> CreateDataSourceSurfaceWithStrideFromData(
33     const IntSize& aSize, SurfaceFormat aFormat, int32_t aStride,
34     const uint8_t* aData, int32_t aDataStride);
35 
36 /**
37  * Copy the pixel data from aSrc and pack it into aDst. aSrcSize, aSrcStride
38  * and aBytesPerPixel give the size, stride and bytes per pixel for aSrc's
39  * surface. Callers are responsible for making sure that aDst is big enough to
40  * contain |aSrcSize.width * aSrcSize.height * aBytesPerPixel| bytes.
41  */
42 void CopySurfaceDataToPackedArray(uint8_t* aSrc, uint8_t* aDst,
43                                   IntSize aSrcSize, int32_t aSrcStride,
44                                   int32_t aBytesPerPixel);
45 
46 /**
47  * Convert aSurface to a packed buffer in BGRA format.
48  */
49 UniquePtr<uint8_t[]> SurfaceToPackedBGRA(DataSourceSurface* aSurface);
50 
51 /**
52  * Convert aSurface to a packed buffer in BGR format. The pixel data is
53  * returned in a buffer allocated with new uint8_t[]. The caller then has
54  * ownership of the buffer and is responsible for delete[]'ing it.
55  *
56  * This function is currently only intended for use with surfaces of format
57  * SurfaceFormat::B8G8R8X8 since the X components of the pixel data (if any)
58  * are simply dropped (no attempt is made to un-pre-multiply alpha from the
59  * color components).
60  */
61 uint8_t* SurfaceToPackedBGR(DataSourceSurface* aSurface);
62 
63 /**
64  * Clears all the bytes in a DataSourceSurface's data array to zero (so to
65  * transparent black for SurfaceFormat::B8G8R8A8, for example).
66  * Note that DataSourceSurfaces can be initialized to zero, which is
67  * more efficient than zeroing the surface after initialization.
68  */
69 void ClearDataSourceSurface(DataSourceSurface* aSurface);
70 
71 /**
72  * Multiplies aStride and aHeight and makes sure the result is limited to
73  * something sane. To keep things consistent, this should always be used
74  * wherever we allocate a buffer based on surface stride and height.
75  *
76  * @param aExtra Optional argument to specify an additional number of trailing
77  *   bytes (useful for creating intermediate surfaces for filters, for
78  *   example).
79  *
80  * @return The result of the multiplication if it is acceptable, or else zero.
81  */
82 size_t BufferSizeFromStrideAndHeight(int32_t aStride, int32_t aHeight,
83                                      int32_t aExtraBytes = 0);
84 
85 /**
86  * Multiplies aWidth, aHeight, aDepth and makes sure the result is limited to
87  * something sane. To keep things consistent, this should always be used
88  * wherever we allocate a buffer based on surface dimensions.
89  *
90  * @param aExtra Optional argument to specify an additional number of trailing
91  *   bytes (useful for creating intermediate surfaces for filters, for
92  *   example).
93  *
94  * @return The result of the multiplication if it is acceptable, or else zero.
95  */
96 size_t BufferSizeFromDimensions(int32_t aWidth, int32_t aHeight, int32_t aDepth,
97                                 int32_t aExtraBytes = 0);
98 /**
99  * Copy aSrcRect from aSrc to aDest starting at aDestPoint.
100  * @returns false if the copy is not successful or the aSrc's size is empty.
101  */
102 bool CopyRect(DataSourceSurface* aSrc, DataSourceSurface* aDest,
103               IntRect aSrcRect, IntPoint aDestPoint);
104 
105 /**
106  * Create a non aliasing copy of aSource. This creates a new DataSourceSurface
107  * using the factory and copies the bits.
108  *
109  * @return a dss allocated by Factory that contains a copy a aSource.
110  */
111 already_AddRefed<DataSourceSurface> CreateDataSourceSurfaceByCloning(
112     DataSourceSurface* aSource);
113 
114 /**
115  * Return the byte at aPoint.
116  */
117 uint8_t* DataAtOffset(DataSourceSurface* aSurface,
118                       const DataSourceSurface::MappedSurface* aMap,
119                       IntPoint aPoint);
120 
121 /**
122  * Check if aPoint is contained by the surface.
123  *
124  * @returns true if and only if aPoint is inside the surface.
125  */
126 bool SurfaceContainsPoint(SourceSurface* aSurface, const IntPoint& aPoint);
127 
128 }  // namespace gfx
129 }  // namespace mozilla
130 
131 #endif  // _MOZILLA_GFX_DATASURFACEHELPERS_H
132