1 /*
2 * CAUTION: EXPERIMENTAL CODE
3 *
4 * This code is not to be used and will not be supported
5 * if it fails on you. DO NOT USE!
6 *
7 */
8
9 #include "SkPathUtils.h"
10
11 #include "SkPath.h"
12 #include "SkPathOps.h" // this can't be found, how do I link it?
13 #include "SkRegion.h"
14
15 typedef void (*line2path)(SkPath*, const char*, int, int);
16 #define SQRT_2 1.41421356237f
17 #define ON 0xFF000000 // black pixel
18 #define OFF 0x00000000 // transparent pixel
19
20 // assumes stride is in bytes
21 /*
22 static void FillRandomBits( int chars, char* bits ){
23 SkTime time;
24 SkRandom rand = SkRandom( time.GetMSecs() );
25
26 for (int i = 0; i < chars; ++i){
27 bits[i] = rand.nextU();
28 }
29 }OA
30 */
31
GetBit(const char * buffer,int x)32 static int GetBit( const char* buffer, int x ) {
33 int byte = x >> 3;
34 int bit = x & 7;
35
36 return buffer[byte] & (128 >> bit);
37 }
38
39 /*
40 static void Line2path_pixel(SkPath* path, const char* line,
41 int lineIdx, int width) {
42 for (int i = 0; i < width; ++i) {
43 // simply makes every ON pixel into a rect path
44 if (GetBit(line,i)) {
45 path->addRect(SkRect::MakeXYWH(i, lineIdx, 1, 1),
46 SkPath::kCW_Direction);
47 }
48 }
49 }
50
51 static void Line2path_pixelCircle(SkPath* path, const char* line,
52 int lineIdx, int width) {
53 for (int i = 0; i < width; ++i) {
54 // simply makes every ON pixel into a circle path
55 if (GetBit(line,i)) {
56 path->addCircle(i + SK_ScalarHalf,
57 lineIdx + SK_ScalarHalf,
58 SQRT_2 / 2.0f);
59 }
60 }
61 }
62 */
63
Line2path_span(SkPath * path,const char * line,int lineIdx,int width)64 static void Line2path_span(SkPath* path, const char* line,
65 int lineIdx, int width) {
66 bool inRun = 0;
67 int start = 1;
68
69 for (int i = 0; i < width; ++i) {
70 int curPixel = GetBit(line,i);
71
72 if ( (curPixel!=0) != inRun ) { // if transition
73 if (curPixel) { // if transition on
74 inRun = 1;
75 start = i; // mark beginning of span
76 }else { // if transition off add the span as a path
77 inRun = 0;
78 path->addRect(SkRect::MakeXYWH(SkIntToScalar(start), SkIntToScalar(lineIdx),
79 SkIntToScalar(i-start), SK_Scalar1),
80 SkPath::kCW_Direction);
81 }
82 }
83 }
84
85 if (inRun==1) { // close any open spans
86 int end = 0;
87 if ( GetBit(line,width-1) ) ++end;
88 path->addRect(SkRect::MakeXYWH(SkIntToScalar(start), SkIntToScalar(lineIdx),
89 SkIntToScalar(width - 1 + end - start), SK_Scalar1),
90 SkPath::kCW_Direction);
91 } else if ( GetBit(line, width - 1) ) { // if last pixel on add
92 path->addRect(SkRect::MakeXYWH(width - SK_Scalar1, SkIntToScalar(lineIdx),
93 SK_Scalar1, SK_Scalar1),
94 SkPath::kCW_Direction);
95 }
96 }
97
BitsToPath_Path(SkPath * path,const char * bitmap,int w,int h,int stride)98 void SkPathUtils::BitsToPath_Path(SkPath* path,
99 const char* bitmap,
100 int w, int h, int stride) {
101 // loop for every line in bitmap
102 for (int i = 0; i < h; ++i) {
103 // fn ptr handles each line separately
104 //l2p_fn(path, &bitmap[i*stride], i, w);
105 Line2path_span(path, &bitmap[i*stride], i, w);
106 }
107 Simplify(*path, path); // simplify resulting path.
108 }
109
BitsToPath_Region(SkPath * path,const char * bitmap,int w,int h,int stride)110 void SkPathUtils::BitsToPath_Region(SkPath* path,
111 const char* bitmap,
112 int w, int h, int stride) {
113 SkRegion region;
114
115 // loop for each line
116 for (int y = 0; y < h; ++y){
117 bool inRun = 0;
118 int start = 1;
119 const char* line = &bitmap[y * stride];
120
121 // loop for each pixel
122 for (int i = 0; i < w; ++i) {
123 int curPixel = GetBit(line,i);
124
125 if ( (curPixel!=0) != inRun ) { // if transition
126 if (curPixel) { // if transition on
127 inRun = 1;
128 start = i; // mark beginning of span
129 }else { // if transition off add the span as a path
130 inRun = 0;
131 //add here
132 region.op(SkIRect::MakeXYWH(start, y, i-start, 1),
133 SkRegion::kUnion_Op );
134 }
135 }
136 }
137 if (inRun==1) { // close any open spans
138 int end = 0;
139 if ( GetBit(line,w-1) ) ++end;
140 // add the thing here
141 region.op(SkIRect::MakeXYWH(start, y, w-1-start+end, 1),
142 SkRegion::kUnion_Op );
143
144 } else if ( GetBit(line,w-1) ) { // if last pixel on add rect
145 // add the thing here
146 region.op(SkIRect::MakeXYWH(w-1, y, 1, 1),
147 SkRegion::kUnion_Op );
148 }
149 }
150 // convert region to path
151 region.getBoundaryPath(path);
152 }
153