SkPaint intercept API for SkTextBlob and horizontal text
Add getPosTextHIntercepts(), getTextBlobIntercepts().
Consolidate the implementation in GetTextIntercepts<> template.
BUG=chormium:581456
R=caryclark@google.com,reed@google.com
GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=2186663004
Review-Url: https://codereview.chromium.org/2186663004
diff --git a/gm/texteffects.cpp b/gm/texteffects.cpp
index e199594..f0d2752 100644
--- a/gm/texteffects.cpp
+++ b/gm/texteffects.cpp
@@ -9,6 +9,7 @@
#include "SkBlurMask.h"
#include "SkBlurMaskFilter.h"
#include "SkReadBuffer.h"
+#include "SkTextBlob.h"
#include "SkWriteBuffer.h"
#include "SkLayerRasterizer.h"
@@ -267,7 +268,7 @@
const char* fam[] = { "sans-serif", "serif", "monospace" };
const char test[] = "aAjJgGyY_|{-(~[,]qQ}pP}zZ";
SkPoint textPt = { 10, 80 };
- for (int font = 0; font < 3; ++font) {
+ for (size_t font = 0; font < SK_ARRAY_COUNT(fam); ++font) {
sk_tool_utils::set_portable_typeface(&paint, fam[font]);
for (SkScalar textSize = 100; textSize > 10; textSize -= 20) {
paint.setTextSize(textSize);
@@ -311,7 +312,7 @@
const char* fam[] = { "sans-serif", "serif", "monospace" };
const char test[] = "aAjJgGyY_|{-(~[,]qQ}pP}zZ";
SkPoint textPt = { 10, 80 };
- for (int font = 0; font < 3; ++font) {
+ for (size_t font = 0; font < SK_ARRAY_COUNT(fam); ++font) {
sk_tool_utils::set_portable_typeface(&paint, fam[font]);
for (SkScalar textSize = 100; textSize > 10; textSize -= 20) {
paint.setTextSize(textSize);
@@ -348,6 +349,114 @@
}
}
+namespace {
+
+sk_sp<const SkTextBlob> MakeFancyBlob(const SkPaint& paint, const char* text) {
+ SkPaint blobPaint(paint);
+
+ const size_t textLen = strlen(text);
+ const int glyphCount = blobPaint.textToGlyphs(text, textLen, nullptr);
+ SkAutoTArray<SkGlyphID> glyphs(glyphCount);
+ blobPaint.textToGlyphs(text, textLen, glyphs.get());
+
+ blobPaint.setTextEncoding(SkPaint::kGlyphID_TextEncoding);
+ const size_t glyphTextBytes = SkTo<uint32_t>(glyphCount) * sizeof(SkGlyphID);
+ const int widthCount = blobPaint.getTextWidths(glyphs.get(), glyphTextBytes, nullptr);
+ SkAssertResult(widthCount == glyphCount);
+
+ SkAutoTArray<SkScalar> widths(glyphCount);
+ blobPaint.getTextWidths(glyphs.get(), glyphTextBytes, widths.get());
+
+ SkTextBlobBuilder blobBuilder;
+ int glyphIndex = 0;
+ SkScalar advance = 0;
+
+ // Default-positioned run.
+ {
+ const int defaultRunLen = glyphCount / 3;
+ const SkTextBlobBuilder::RunBuffer& buf = blobBuilder.allocRun(blobPaint,
+ defaultRunLen,
+ advance, 0);
+ memcpy(buf.glyphs, glyphs.get(), SkTo<uint32_t>(defaultRunLen) * sizeof(SkGlyphID));
+
+ for (int i = 0; i < defaultRunLen; ++i) {
+ advance += widths[glyphIndex++];
+ }
+ }
+
+ // Horizontal-positioned run.
+ {
+ const int horizontalRunLen = glyphCount / 3;
+ const SkTextBlobBuilder::RunBuffer& buf = blobBuilder.allocRunPosH(blobPaint,
+ horizontalRunLen,
+ 0);
+ memcpy(buf.glyphs, glyphs.get() + glyphIndex,
+ SkTo<uint32_t>(horizontalRunLen) * sizeof(SkGlyphID));
+ for (int i = 0; i < horizontalRunLen; ++i) {
+ buf.pos[i] = advance;
+ advance += widths[glyphIndex++];
+ }
+ }
+
+ // Full-positioned run.
+ {
+ const int fullRunLen = glyphCount - glyphIndex;
+ const SkTextBlobBuilder::RunBuffer& buf = blobBuilder.allocRunPos(blobPaint, fullRunLen);
+ memcpy(buf.glyphs, glyphs.get() + glyphIndex,
+ SkTo<uint32_t>(fullRunLen) * sizeof(SkGlyphID));
+ for (int i = 0; i < fullRunLen; ++i) {
+ buf.pos[i * 2 + 0] = advance; // x offset
+ buf.pos[i * 2 + 1] = 0; // y offset
+ advance += widths[glyphIndex++];
+ }
+ }
+
+ return sk_sp<const SkTextBlob>(blobBuilder.build());
+}
+
+} // anonymous ns
+
+DEF_SIMPLE_GM(fancyblobunderline, canvas, 1480, 1380) {
+ SkPaint paint;
+ paint.setAntiAlias(true);
+ const char* fam[] = { "sans-serif", "serif", "monospace" };
+ const char test[] = "aAjJgGyY_|{-(~[,]qQ}pP}zZ";
+ const SkPoint blobOffset = { 10, 80 };
+
+ for (size_t font = 0; font < SK_ARRAY_COUNT(fam); ++font) {
+ sk_tool_utils::set_portable_typeface(&paint, fam[font]);
+ for (SkScalar textSize = 100; textSize > 10; textSize -= 20) {
+ paint.setTextSize(textSize);
+ const SkScalar uWidth = textSize / 15;
+ paint.setStrokeWidth(uWidth);
+ paint.setStyle(SkPaint::kFill_Style);
+
+ sk_sp<const SkTextBlob> blob = MakeFancyBlob(paint, test);
+ canvas->drawTextBlob(blob.get(), blobOffset.x(), blobOffset.y(), paint);
+
+ const SkScalar uPos = uWidth;
+ const SkScalar bounds[2] = { uPos - uWidth / 2, uPos + uWidth / 2 };
+ const int interceptCount = paint.getTextBlobIntercepts(blob.get(), bounds, nullptr);
+ SkASSERT(!(interceptCount % 2));
+
+ SkTDArray<SkScalar> intercepts;
+ intercepts.setCount(interceptCount);
+ paint.getTextBlobIntercepts(blob.get(), bounds, intercepts.begin());
+
+ const SkScalar start = blob->bounds().left();
+ const SkScalar end = blob->bounds().right();
+ SkPath underline = create_underline(intercepts, start, end, uPos, uWidth, textSize);
+ underline.offset(blobOffset.x(), blobOffset.y());
+ paint.setStyle(SkPaint::kStroke_Style);
+ canvas->drawPath(underline, paint);
+
+ canvas->translate(0, textSize * 1.3f);
+ }
+
+ canvas->translate(0, 60);
+ }
+}
+
DEF_SIMPLE_GM(fancyunderlinebars, canvas, 1500, 460) {
SkPaint paint;
paint.setAntiAlias(true);
diff --git a/include/core/SkPaint.h b/include/core/SkPaint.h
index ef80b73..ea7eedd 100644
--- a/include/core/SkPaint.h
+++ b/include/core/SkPaint.h
@@ -33,6 +33,7 @@
struct SkScalerContextEffects;
class SkShader;
class SkSurfaceProps;
+class SkTextBlob;
class SkTypeface;
#define kBicubicFilterBitmap_Flag kHighQualityFilterBitmap_Flag
@@ -964,6 +965,40 @@
int getPosTextIntercepts(const void* text, size_t length, const SkPoint pos[],
const SkScalar bounds[2], SkScalar* intervals) const;
+ /** Return the number of intervals that intersect the intercept along the axis of the advance.
+ * The return count is zero or a multiple of two, and is at most the number of glyphs * 2 in
+ * string. The caller may pass nullptr for intervals to determine the size of the interval
+ * array, or may conservatively pre-allocate an array with length * 2 entries. The computed
+ * intervals are cached by glyph to improve performance for multiple calls.
+ * This permits constructing an underline that skips the descenders.
+ *
+ * @param text The text.
+ * @param length Number of bytes of text.
+ * @param xpos Array of x-positions, used to position each character.
+ * @param constY The shared Y coordinate for all of the positions.
+ * @param bounds The lower and upper line parallel to the advance.
+ * @param array If not null, the glyph bounds contained by the advance parallel lines.
+ *
+ * @return The number of intersections, which may be zero.
+ */
+ int getPosTextHIntercepts(const void* text, size_t length, const SkScalar xpos[],
+ SkScalar constY, const SkScalar bounds[2], SkScalar* intervals) const;
+
+ /** Return the number of intervals that intersect the intercept along the axis of the advance.
+ * The return count is zero or a multiple of two, and is at most the number of glyphs * 2 in
+ * text blob. The caller may pass nullptr for intervals to determine the size of the interval
+ * array. The computed intervals are cached by glyph to improve performance for multiple calls.
+ * This permits constructing an underline that skips the descenders.
+ *
+ * @param blob The text blob.
+ * @param bounds The lower and upper line parallel to the advance.
+ * @param array If not null, the glyph bounds contained by the advance parallel lines.
+ *
+ * @return The number of intersections, which may be zero.
+ */
+ int getTextBlobIntercepts(const SkTextBlob* blob, const SkScalar bounds[2],
+ SkScalar* intervals) const;
+
/**
* Return a rectangle that represents the union of the bounds of all
* of the glyphs, but each one positioned at (0,0). This may be conservatively large, and
diff --git a/src/core/SkPaint.cpp b/src/core/SkPaint.cpp
index 528b1d0..07c10d5 100644
--- a/src/core/SkPaint.cpp
+++ b/src/core/SkPaint.cpp
@@ -27,12 +27,14 @@
#include "SkShader.h"
#include "SkStringUtils.h"
#include "SkStroke.h"
+#include "SkStrokeRec.h"
+#include "SkSurfacePriv.h"
+#include "SkTextBlob.h"
+#include "SkTextBlobRunIterator.h"
#include "SkTextFormatParams.h"
#include "SkTextToPathIter.h"
#include "SkTLazy.h"
#include "SkTypeface.h"
-#include "SkStrokeRec.h"
-#include "SkSurfacePriv.h"
#include "SkXfermode.h"
static inline uint32_t set_clear_mask(uint32_t bits, bool cond, uint32_t mask) {
@@ -1127,23 +1129,6 @@
}
}
-int SkPaint::getTextIntercepts(const void* textData, size_t length,
- SkScalar x, SkScalar y, const SkScalar bounds[2],
- SkScalar* array) const {
- SkASSERT(length == 0 || textData != nullptr);
- if (!length) {
- return 0;
- }
-
- const char* text = (const char*) textData;
- SkTextInterceptsIter iter(text, length, *this, bounds, x, y,
- SkTextInterceptsIter::TextType::kText);
- int count = 0;
- while (iter.next(array, &count)) {
- }
- return count;
-}
-
void SkPaint::getPosTextPath(const void* textData, size_t length,
const SkPoint pos[], SkPath* path) const {
SkASSERT(length == 0 || textData != nullptr);
@@ -1173,22 +1158,89 @@
}
}
-int SkPaint::getPosTextIntercepts(const void* textData, size_t length, const SkPoint pos[],
- const SkScalar bounds[2], SkScalar* array) const {
- SkASSERT(length == 0 || textData != nullptr);
+template <SkTextInterceptsIter::TextType TextType, typename Func>
+int GetTextIntercepts(const SkPaint& paint, const void* text, size_t length,
+ const SkScalar bounds[2], SkScalar* array, Func posMaker) {
+ SkASSERT(length == 0 || text != nullptr);
if (!length) {
return 0;
}
- const char* text = (const char*) textData;
- SkTextInterceptsIter iter(text, length, *this, bounds, pos[0].fX, pos[0].fY,
- SkTextInterceptsIter::TextType::kPosText);
+ const SkPoint pos0 = posMaker(0);
+ SkTextInterceptsIter iter(static_cast<const char*>(text), length, paint, bounds,
+ pos0.x(), pos0.y(), TextType);
+
int i = 0;
int count = 0;
while (iter.next(array, &count)) {
- i++;
- iter.setPosition(pos[i].fX, pos[i].fY);
+ if (TextType == SkTextInterceptsIter::TextType::kPosText) {
+ const SkPoint pos = posMaker(++i);
+ iter.setPosition(pos.x(), pos.y());
+ }
}
+
+ return count;
+}
+
+int SkPaint::getTextIntercepts(const void* textData, size_t length,
+ SkScalar x, SkScalar y, const SkScalar bounds[2],
+ SkScalar* array) const {
+
+ return GetTextIntercepts<SkTextInterceptsIter::TextType::kText>(
+ *this, textData, length, bounds, array, [&x, &y] (int) -> SkPoint {
+ return SkPoint::Make(x, y);
+ });
+}
+
+int SkPaint::getPosTextIntercepts(const void* textData, size_t length, const SkPoint pos[],
+ const SkScalar bounds[2], SkScalar* array) const {
+
+ return GetTextIntercepts<SkTextInterceptsIter::TextType::kPosText>(
+ *this, textData, length, bounds, array, [&pos] (int i) -> SkPoint {
+ return pos[i];
+ });
+}
+
+int SkPaint::getPosTextHIntercepts(const void* textData, size_t length, const SkScalar xpos[],
+ SkScalar constY, const SkScalar bounds[2],
+ SkScalar* array) const {
+
+ return GetTextIntercepts<SkTextInterceptsIter::TextType::kPosText>(
+ *this, textData, length, bounds, array, [&xpos, &constY] (int i) -> SkPoint {
+ return SkPoint::Make(xpos[i], constY);
+ });
+}
+
+int SkPaint::getTextBlobIntercepts(const SkTextBlob* blob, const SkScalar bounds[2],
+ SkScalar* intervals) const {
+ int count = 0;
+ SkPaint runPaint(*this);
+
+ SkTextBlobRunIterator it(blob);
+ while (!it.done()) {
+ it.applyFontToPaint(&runPaint);
+ const size_t runByteCount = it.glyphCount() * sizeof(SkGlyphID);
+ SkScalar* runIntervals = intervals ? intervals + count : nullptr;
+
+ switch (it.positioning()) {
+ case SkTextBlob::kDefault_Positioning:
+ count += runPaint.getTextIntercepts(it.glyphs(), runByteCount, it.offset().x(),
+ it.offset().y(), bounds, runIntervals);
+ break;
+ case SkTextBlob::kHorizontal_Positioning:
+ count += runPaint.getPosTextHIntercepts(it.glyphs(), runByteCount, it.pos(),
+ it.offset().y(), bounds, runIntervals);
+ break;
+ case SkTextBlob::kFull_Positioning:
+ count += runPaint.getPosTextIntercepts(it.glyphs(), runByteCount,
+ reinterpret_cast<const SkPoint*>(it.pos()),
+ bounds, runIntervals);
+ break;
+ }
+
+ it.next();
+ }
+
return count;
}