Added drawPosTextOnPath method.
The drawPosTextOnPath method allows for text positioned on
a straight line to be drawn along a path.
This method can be used by layout engines to implement the
Canvas::drawTextOnPath method for complex scripts.
Change-Id: I2f9c22b8c97eeacb61cd6de7429ba875a1e7ade9
diff --git a/include/core/SkCanvas.h b/include/core/SkCanvas.h
index 8fba6cf..f88a8b9 100644
--- a/include/core/SkCanvas.h
+++ b/include/core/SkCanvas.h
@@ -581,6 +581,19 @@
const SkPath& path, const SkMatrix* matrix,
const SkPaint& paint);
+ /** Draw the text on path, with each character/glyph origin specified by the pos[]
+ array. The origin is interpreted by the Align setting in the paint.
+ @param text The text to be drawn
+ @param byteLength The number of bytes to read from the text parameter
+ @param pos Array of positions, used to position each character
+ @param paint The paint used for the text (e.g. color, size, style)
+ @param path The path to draw on
+ @param matrix The canvas matrix
+ */
+ void drawPosTextOnPath(const void* text, size_t byteLength,
+ const SkPoint pos[], const SkPaint& paint,
+ const SkPath& path, const SkMatrix* matrix);
+
/** Draw the picture into this canvas. This method effective brackets the
playback of the picture's draw calls with save/restore, so the state
of this canvas will be unchanged after this call. This contrasts with
diff --git a/include/core/SkDevice.h b/include/core/SkDevice.h
index 4d678c6..0d724ba 100644
--- a/include/core/SkDevice.h
+++ b/include/core/SkDevice.h
@@ -120,6 +120,9 @@
virtual void drawTextOnPath(const SkDraw&, const void* text, size_t len,
const SkPath& path, const SkMatrix* matrix,
const SkPaint& paint);
+ virtual void drawPosTextOnPath(const SkDraw& draw, const void* text, size_t len,
+ const SkPoint pos[], const SkPaint& paint,
+ const SkPath& path, const SkMatrix* matrix);
virtual void drawVertices(const SkDraw&, SkCanvas::VertexMode, int vertexCount,
const SkPoint verts[], const SkPoint texs[],
const SkColor colors[], SkXfermode* xmode,
diff --git a/include/core/SkDraw.h b/include/core/SkDraw.h
index 8214859..a86ef67 100644
--- a/include/core/SkDraw.h
+++ b/include/core/SkDraw.h
@@ -54,6 +54,9 @@
int scalarsPerPosition, const SkPaint& paint) const;
void drawTextOnPath(const char text[], size_t byteLength,
const SkPath&, const SkMatrix*, const SkPaint&) const;
+ void drawPosTextOnPath(const char text[], size_t byteLength,
+ const SkPoint pos[], const SkPaint& paint,
+ const SkPath& path, const SkMatrix* matrix) const;
void drawVertices(SkCanvas::VertexMode mode, int count,
const SkPoint vertices[], const SkPoint textures[],
const SkColor colors[], SkXfermode* xmode,
diff --git a/src/core/SkCanvas.cpp b/src/core/SkCanvas.cpp
index 23031c5..c01c343 100644
--- a/src/core/SkCanvas.cpp
+++ b/src/core/SkCanvas.cpp
@@ -1216,6 +1216,20 @@
ITER_END
}
+void SkCanvas::drawPosTextOnPath(const void* text, size_t byteLength,
+ const SkPoint pos[], const SkPaint& paint,
+ const SkPath& path, const SkMatrix* matrix) {
+
+ ITER_BEGIN(paint, SkDrawFilter::kText_Type)
+
+ while (iter.next()) {
+ iter.fDevice->drawPosTextOnPath(iter, text, byteLength, pos,
+ paint, path, matrix);
+ }
+
+ ITER_END
+}
+
void SkCanvas::drawVertices(VertexMode vmode, int vertexCount,
const SkPoint verts[], const SkPoint texs[],
const SkColor colors[], SkXfermode* xmode,
diff --git a/src/core/SkDevice.cpp b/src/core/SkDevice.cpp
index 139174d..8ce1bd8 100644
--- a/src/core/SkDevice.cpp
+++ b/src/core/SkDevice.cpp
@@ -92,6 +92,12 @@
draw.drawTextOnPath((const char*)text, len, path, matrix, paint);
}
+void SkDevice::drawPosTextOnPath(const SkDraw& draw, const void* text, size_t len,
+ const SkPoint pos[], const SkPaint& paint,
+ const SkPath& path, const SkMatrix* matrix) {
+ draw.drawPosTextOnPath((const char*)text, len, pos, paint, path, matrix);
+}
+
void SkDevice::drawVertices(const SkDraw& draw, SkCanvas::VertexMode vmode,
int vertexCount,
const SkPoint verts[], const SkPoint textures[],
diff --git a/src/core/SkDraw.cpp b/src/core/SkDraw.cpp
index 7f0cc15..a47d101 100644
--- a/src/core/SkDraw.cpp
+++ b/src/core/SkDraw.cpp
@@ -1854,6 +1854,68 @@
}
}
+void SkDraw::drawPosTextOnPath(const char text[], size_t byteLength,
+ const SkPoint pos[], const SkPaint& paint,
+ const SkPath& path, const SkMatrix* matrix) const {
+ // nothing to draw
+ if (text == NULL || byteLength == 0 || fClip->isEmpty() ||
+ (paint.getAlpha() == 0 && paint.getXfermode() == NULL)) {
+ return;
+ }
+
+ SkMatrix scaledMatrix;
+ SkPathMeasure meas(path, false);
+
+ SkMeasureCacheProc glyphCacheProc = paint.getMeasureCacheProc(
+ SkPaint::kForward_TextBufferDirection, true);
+
+ // Copied (modified) from SkTextToPathIter constructor to setup paint
+ SkPaint tempPaint(paint);
+
+ tempPaint.setLinearText(true);
+ tempPaint.setMaskFilter(NULL); // don't want this affecting our path-cache lookup
+
+ if (tempPaint.getPathEffect() == NULL && !(tempPaint.getStrokeWidth() > 0
+ && tempPaint.getStyle() != SkPaint::kFill_Style)) {
+ tempPaint.setStyle(SkPaint::kFill_Style);
+ tempPaint.setPathEffect(NULL);
+ }
+ // End copied from SkTextToPathIter constructor
+
+ // detach cache
+ SkGlyphCache* cache = tempPaint.detachCache(NULL);
+
+ // Must set scale, even if 1
+ SkScalar scale = SK_Scalar1;
+ scaledMatrix.setScale(scale, scale);
+
+ // Loop over all glyph ids
+ for (const char* stop = text + byteLength; text < stop; pos++) {
+
+ const SkGlyph& glyph = glyphCacheProc(cache, &text);
+ SkPath tmp;
+
+ const SkPath* glyphPath = cache->findPath(glyph);
+ if (glyphPath == NULL) {
+ continue;
+ }
+
+ SkMatrix m(scaledMatrix);
+ m.postTranslate(pos->fX, 0);
+
+ if (matrix) {
+ m.postConcat(*matrix);
+ }
+
+ morphpath(&tmp, *glyphPath, meas, m);
+ this->drawPath(tmp, tempPaint);
+
+ }
+
+ // re-attach cache
+ SkGlyphCache::AttachCache(cache);
+}
+
///////////////////////////////////////////////////////////////////////////////
struct VertState {
