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1 /* | |
2 * Copyright 2014 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 SkPatchGrid_DEFINED | |
9 #define SkPatchGrid_DEFINED | |
10 | |
11 #include "SkPatch.h" | |
12 #include "SkCanvas.h" | |
egdaniel
2014/08/08 18:45:41
annoying nit: but alphabetize these please
dandov
2014/08/08 19:00:55
Done.
| |
13 | |
14 /** | |
15 * Class that represents a grid of patches. Adjacent patches share their corners and a color is | |
16 * specified at each one of them. The colors are bilinearly interpolated across the patch. | |
17 * | |
18 * This implementation defines a bidimensional array of patches. There are 3 arr ays to store the | |
19 * control points of the patches to avoid storing repeated data since there are several points | |
20 * shared between adjacent patches. | |
21 * | |
22 * The array fCornerPts stores the corner control points of the patches. | |
23 * The array fHrzPts holds the intermidiate control points of the top and bottom curves of a patch. | |
24 * The array fVrtPts holds the intermidiate control points of the left and right curves of a patch. | |
25 * The array fCornerColors holds the corner colors in the same format as fCorner Pts. | |
26 * | |
27 * fCornerPts fHrzPts fVrtPts | |
28 * -------------- ------------------- -------------- | |
29 * | C0 | C1 | C2 | | H0 | H1 | H2 | H3 | | V0 | V1 | V2 | | |
30 * -------------- ------------------ --------------- | |
31 * | C3 | C4 | C5 | | H4 | H5 | H6 | H7 | | V4 | V5 | V6 | | |
32 * -------------- ------------------- -------------- | |
33 * | C6 | C7 | C8 | | H8 | H9 | H10| H11| | V6 | V7 | V8 | | |
34 * -------------- ------------------- -------------- | |
35 * | V9 | V10| V11| | |
36 * -------------- | |
37 * | |
38 * With the above configuration we would have a 2x2 grid of patches: | |
39 * H0 H1 H2 H3 | |
40 * / \/ \ | |
41 * C0-------C1-------C2 | |
42 * /| | |\ | |
43 * v0 | v1 | v2 | |
44 * v3 | V4 | v5 | |
45 * \| | |/ | |
46 * C3-H4-H5-C4-H6-H7-C5 | |
47 * /| | |\ | |
48 * v6 | v7 | v8 | |
49 * v9 | v10 | v11 | |
50 * \| | |/ | |
51 * C6-------C7-------C8 | |
52 * \ / \ / | |
53 * H8 H9 H10 H11 | |
54 * | |
55 * When trying to get a patch at a certain position it justs builds it with the corresponding | |
56 * points. | |
57 * When adding a patch it tries to add the points at their corresponding positio n trying to comply | |
58 * with the adjacent points or overwriting them. | |
59 * | |
60 * Based the idea on the SVG2 spec for mesh gradients in which a grid of patches is build as in the | |
61 * the following example: | |
62 * <meshGradient x="100" y="100"> | |
63 * <meshRow> | |
64 * <meshPatch> | |
65 * <stop .../> | |
66 * Up to four stops in first patch. See details below. | |
67 * </meshPatch> | |
68 * <meshPatch> | |
69 * Any number of meshPatches in row. | |
70 * </meshPatch> | |
71 * </meshRow> | |
72 * <meshRow> | |
73 * Any number of meshRows, each with the same number of meshPatches as in the first row. | |
74 * </meshRow> | |
75 * </meshGradient> | |
76 */ | |
77 class SkPatchGrid { | |
78 | |
79 public: | |
80 SkPatchGrid(int rows, int cols); | |
81 | |
82 ~SkPatchGrid(); | |
83 | |
84 /** | |
85 * Add a patch at location (x,y) overwriting the previous patch and shared p oints. | |
86 */ | |
87 bool setPatch(int x, int y, const SkPatch& patch); | |
88 bool setPatch(int x, int y, const SkPoint ctrlPts[12], const SkColor colors[ 4]); | |
89 | |
90 /** | |
91 * Get patch at location (x,y). If the patch is not NULL it sets patch's | |
92 * control points and colors to the corresponding values. | |
93 */ | |
94 bool getPatch(int x, int y, SkPatch* patch) const; | |
95 | |
96 /** | |
97 * Resets the grid of patches to contain rows and cols of patches. | |
98 */ | |
99 void reset(int rows, int cols); | |
100 | |
101 /** | |
102 * Draws the grid of patches. The patches are drawn starting at patch (0,0) drawing columns, so | |
103 * for a 2x2 grid the order would be (0,0)->(0,1)->(1,0)->(1,1). The order f ollows the order | |
104 * of the parametric coordinates of the coons patch. | |
105 */ | |
106 void draw(SkCanvas* canvas, SkPaint& paint); | |
107 | |
108 /** | |
109 * Get the dimensions of the grid of patches. | |
110 */ | |
111 SkISize getDimensions() const { | |
112 return SkISize::Make(fCols, fRows); | |
113 } | |
114 | |
115 private: | |
116 int fRows, fCols; | |
117 SkPoint* fCornerPts; | |
118 SkColor* fCornerColors; | |
119 SkPoint* fHrzCtrlPts; | |
120 SkPoint* fVrtCtrlPts; | |
121 }; | |
122 | |
123 | |
124 #endif | |
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