michael@0: /*
michael@0:  *  CAUTION: EXPERIMENTAL CODE
michael@0:  *
michael@0:  *  This code is not to be used and will not be supported
michael@0:  *  if it fails on you. DO NOT USE!
michael@0:  *
michael@0:  */
michael@0: 
michael@0: #include "SkPathUtils.h"
michael@0: 
michael@0: #include "SkPath.h"
michael@0: #include "SkPathOps.h" // this can't be found, how do I link it?
michael@0: #include "SkRegion.h"
michael@0: 
michael@0: typedef void (*line2path)(SkPath*, const char*, int, int);
michael@0: #define SQRT_2 1.41421356237f
michael@0: #define ON  0xFF000000 // black pixel
michael@0: #define OFF 0x00000000 // transparent pixel
michael@0: 
michael@0: // assumes stride is in bytes
michael@0: /*
michael@0: static void FillRandomBits( int chars, char* bits ){
michael@0:     SkTime time;
michael@0:     SkRandom rand = SkRandom( time.GetMSecs() );
michael@0: 
michael@0:     for (int i = 0; i < chars; ++i){
michael@0:         bits[i] = rand.nextU();
michael@0:     }
michael@0: }OA
michael@0: */
michael@0: 
michael@0: static int GetBit( const char* buffer, int x ) {
michael@0:     int byte = x >> 3;
michael@0:     int bit = x & 7;
michael@0: 
michael@0:     return buffer[byte] & (128 >> bit);
michael@0: }
michael@0: 
michael@0: /*
michael@0: static void Line2path_pixel(SkPath* path, const char* line,
michael@0:                             int lineIdx, int width) {
michael@0:     for (int i = 0; i < width; ++i) {
michael@0:         // simply makes every ON pixel into a rect path
michael@0:         if (GetBit(line,i)) {
michael@0:             path->addRect(SkRect::MakeXYWH(i, lineIdx, 1, 1),
michael@0:                           SkPath::kCW_Direction);
michael@0:         }
michael@0:     }
michael@0: }
michael@0: 
michael@0: static void Line2path_pixelCircle(SkPath* path, const char* line,
michael@0:                                   int lineIdx, int width) {
michael@0:     for (int i = 0; i < width; ++i) {
michael@0:         // simply makes every ON pixel into a circle path
michael@0:         if (GetBit(line,i)) {
michael@0:             path->addCircle(i + SK_ScalarHalf,
michael@0:                             lineIdx + SK_ScalarHalf,
michael@0:                             SQRT_2 / 2.0f);
michael@0:         }
michael@0:     }
michael@0: }
michael@0: */
michael@0: 
michael@0: static void Line2path_span(SkPath* path, const char* line,
michael@0:                            int lineIdx, int width) {
michael@0:     bool inRun = 0;
michael@0:     int start = 1;
michael@0: 
michael@0:     for (int i = 0; i < width; ++i) {
michael@0:         int curPixel = GetBit(line,i);
michael@0: 
michael@0:         if ( (curPixel!=0) != inRun ) { // if transition
michael@0:             if (curPixel) { // if transition on
michael@0:                 inRun = 1;
michael@0:                 start = i; // mark beginning of span
michael@0:             }else { // if transition off add the span as a path
michael@0:                 inRun = 0;
michael@0:                 path->addRect(SkRect::MakeXYWH(SkIntToScalar(start), SkIntToScalar(lineIdx),
michael@0:                                                SkIntToScalar(i-start), SK_Scalar1),
michael@0:                               SkPath::kCW_Direction);
michael@0:             }
michael@0:         }
michael@0:     }
michael@0: 
michael@0:     if (inRun==1) { // close any open spans
michael@0:         int end = 0;
michael@0:         if ( GetBit(line,width-1) ) ++end;
michael@0:         path->addRect(SkRect::MakeXYWH(SkIntToScalar(start), SkIntToScalar(lineIdx),
michael@0:                                        SkIntToScalar(width - 1 + end - start), SK_Scalar1),
michael@0:                       SkPath::kCW_Direction);
michael@0:     } else if ( GetBit(line, width - 1) ) { // if last pixel on add
michael@0:         path->addRect(SkRect::MakeXYWH(width - SK_Scalar1, SkIntToScalar(lineIdx),
michael@0:                                        SK_Scalar1, SK_Scalar1),
michael@0:                       SkPath::kCW_Direction);
michael@0:     }
michael@0: }
michael@0: 
michael@0: void SkPathUtils::BitsToPath_Path(SkPath* path,
michael@0:                         const char* bitmap,
michael@0:                         int w, int h, int stride) {
michael@0:     // loop for every line in bitmap
michael@0:     for (int i = 0; i < h; ++i) {
michael@0:         // fn ptr handles each line separately
michael@0:         //l2p_fn(path, &bitmap[i*stride], i, w);
michael@0:         Line2path_span(path, &bitmap[i*stride], i, w);
michael@0:     }
michael@0:     Simplify(*path, path); // simplify resulting path.
michael@0: }
michael@0: 
michael@0: void SkPathUtils::BitsToPath_Region(SkPath* path,
michael@0:                                const char* bitmap,
michael@0:                                int w, int h, int stride) {
michael@0:     SkRegion region;
michael@0: 
michael@0:     // loop for each line
michael@0:     for (int y = 0; y < h; ++y){
michael@0:         bool inRun = 0;
michael@0:         int start = 1;
michael@0:         const char* line = &bitmap[y * stride];
michael@0: 
michael@0:         // loop for each pixel
michael@0:         for (int i = 0; i < w; ++i) {
michael@0:             int curPixel = GetBit(line,i);
michael@0: 
michael@0:             if ( (curPixel!=0) != inRun ) { // if transition
michael@0:                 if (curPixel) { // if transition on
michael@0:                     inRun = 1;
michael@0:                     start = i; // mark beginning of span
michael@0:                 }else { // if transition off add the span as a path
michael@0:                     inRun = 0;
michael@0:                     //add here
michael@0:                     region.op(SkIRect::MakeXYWH(start, y, i-start, 1),
michael@0:                               SkRegion::kUnion_Op );
michael@0:                 }
michael@0:             }
michael@0:         }
michael@0:         if (inRun==1) { // close any open spans
michael@0:             int end = 0;
michael@0:             if ( GetBit(line,w-1) ) ++end;
michael@0:             // add the thing here
michael@0:             region.op(SkIRect::MakeXYWH(start, y, w-1-start+end, 1),
michael@0:                       SkRegion::kUnion_Op );
michael@0: 
michael@0:         } else if ( GetBit(line,w-1) ) { // if last pixel on add rect
michael@0:             // add the thing here
michael@0:             region.op(SkIRect::MakeXYWH(w-1, y, 1, 1),
michael@0:                       SkRegion::kUnion_Op );
michael@0:         }
michael@0:     }
michael@0:     // convert region to path
michael@0:     region.getBoundaryPath(path);
michael@0: }