Adding my Bitmap2Path sample for 1on1 meeting.
BUG=
R=reed@google.com, borenet@google.com
Author: dierk@google.com
Review URL: https://chromiumcodereview.appspot.com/16829003
git-svn-id: http://skia.googlecode.com/svn/trunk@9843 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/src/utils/SkPathUtils.cpp b/src/utils/SkPathUtils.cpp
new file mode 100644
index 0000000..3d9bc08
--- /dev/null
+++ b/src/utils/SkPathUtils.cpp
@@ -0,0 +1,150 @@
+/*
+ * CAUTION: EXPERIMENTAL CODE
+ *
+ * This code is not to be used and will not be supported
+ * if it fails on you. DO NOT USE!
+ *
+ */
+
+#include "SkPathUtils.h"
+
+#include "SkPath.h"
+#include "SkPathOps.h" // this can't be found, how do I link it?
+#include "SkRegion.h"
+
+typedef void (*line2path)(SkPath*, const char*, int, int);
+#define SQRT_2 1.41421356237f
+#define ON 0xFF000000 // black pixel
+#define OFF 0x00000000 // transparent pixel
+
+// assumes stride is in bytes
+/*
+static void FillRandomBits( int chars, char* bits ){
+ SkTime time;
+ SkMWCRandom rand = SkMWCRandom( time.GetMSecs() );
+
+ for (int i = 0; i < chars; ++i){
+ bits[i] = rand.nextU();
+ }
+}OA
+*/
+
+static int GetBit( const char* buffer, int x ) {
+ int byte = x >> 3;
+ int bit = x & 7;
+
+ return buffer[byte] & (128 >> bit);
+}
+
+/*
+static void Line2path_pixel(SkPath* path, const char* line,
+ int lineIdx, int width) {
+ for (int i = 0; i < width; ++i) {
+ // simply makes every ON pixel into a rect path
+ if (GetBit(line,i)) {
+ path->addRect(SkRect::MakeXYWH(i, lineIdx, 1, 1),
+ SkPath::kCW_Direction);
+ }
+ }
+}
+
+static void Line2path_pixelCircle(SkPath* path, const char* line,
+ int lineIdx, int width) {
+ for (int i = 0; i < width; ++i) {
+ // simply makes every ON pixel into a circle path
+ if (GetBit(line,i)) {
+ path->addCircle(i + SK_ScalarHalf,
+ lineIdx + SK_ScalarHalf,
+ SkFloatToScalar(SQRT_2 / 2.0f));
+ }
+ }
+}
+*/
+
+static void Line2path_span(SkPath* path, const char* line,
+ int lineIdx, int width) {
+ bool inRun = 0;
+ int start = 1;
+
+ for (int i = 0; i < width; ++i) {
+ int curPixel = GetBit(line,i);
+
+ if ( (curPixel!=0) != inRun ) { // if transition
+ if (curPixel) { // if transition on
+ inRun = 1;
+ start = i; // mark beginning of span
+ }else { // if transition off add the span as a path
+ inRun = 0;
+ path->addRect(SkRect::MakeXYWH(start, lineIdx, i-start, 1),
+ SkPath::kCW_Direction);
+ }
+ }
+ }
+
+ if (inRun==1) { // close any open spans
+ int end = 0;
+ if ( GetBit(line,width-1) ) ++end;
+ path->addRect(SkRect::MakeXYWH(start, lineIdx,
+ width - 1 + end - start, 1),
+ SkPath::kCW_Direction);
+ } else if ( GetBit(line,width-1) ) { // if last pixel on add rect
+ path->addRect(SkRect::MakeXYWH(width-1, lineIdx, 1, 1),
+ SkPath::kCW_Direction);
+ }
+}
+
+void SkPathUtils::BitsToPath_Path(SkPath* path,
+ const char* bitmap,
+ int h, int w, int stride) {
+ // loop for every line in bitmap
+ for (int i = 0; i < h; ++i) {
+ // fn ptr handles each line separately
+ //l2p_fn(path, &bitmap[i*stride], i, w);
+ Line2path_span(path, &bitmap[i*stride], i, w);
+ }
+ Simplify(*path, path); // simplify resulting bitmap
+}
+
+void SkPathUtils::BitsToPath_Region(SkPath* path,
+ const char* bitmap,
+ int h, int w, int stride) {
+ SkRegion region;
+
+ // loop for each line
+ for (int y = 0; y < h; ++y){
+ bool inRun = 0;
+ int start = 1;
+ const char* line = &bitmap[y * stride];
+
+ // loop for each pixel
+ for (int i = 0; i < w; ++i) {
+ int curPixel = GetBit(line,i);
+
+ if ( (curPixel!=0) != inRun ) { // if transition
+ if (curPixel) { // if transition on
+ inRun = 1;
+ start = i; // mark beginning of span
+ }else { // if transition off add the span as a path
+ inRun = 0;
+ //add here
+ region.op(SkIRect::MakeXYWH(start, y, i-start, 1),
+ SkRegion::kUnion_Op );
+ }
+ }
+ }
+ if (inRun==1) { // close any open spans
+ int end = 0;
+ if ( GetBit(line,w-1) ) ++end;
+ // add the thing here
+ region.op(SkIRect::MakeXYWH(start, y, w-1-start+end, 1),
+ SkRegion::kUnion_Op );
+
+ } else if ( GetBit(line,w-1) ) { // if last pixel on add rect
+ // add the thing here
+ region.op(SkIRect::MakeXYWH(w-1, y, 1, 1),
+ SkRegion::kUnion_Op );
+ }
+ }
+ // convert region to path
+ region.getBoundaryPath(path);
+}