gm/texteffects.cpp - platform/external/skia - Gitiles

 /*
  * Copyright 2011 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */

 #include "gm.h"
 #include "sk_tool_utils.h"

 #include "SkBlurMask.h"
 #include "SkBlurMaskFilter.h"
 #include "SkReadBuffer.h"
 #include "SkTextBlob.h"
 #include "SkTo.h"
 #include "SkWriteBuffer.h"

 #include "Sk2DPathEffect.h"

 static SkPath create_underline(const SkTDArray<SkScalar>& intersections,
         SkScalar last, SkScalar finalPos,
         SkScalar uPos, SkScalar uWidth, SkScalar textSize) {
     SkPath underline;
     SkScalar end = last;
     for (int index = 0; index < intersections.count(); index += 2) {
         SkScalar start = intersections[index] - uWidth;
         end = intersections[index + 1] + uWidth;
         if (start > last && last + textSize / 12 < start) {
             underline.moveTo(last, uPos);
             underline.lineTo(start, uPos);
         }
         last = end;
     }
     if (end < finalPos) {
         underline.moveTo(end, uPos);
         underline.lineTo(finalPos, uPos);
     }
     return underline;
 }

 namespace {

 sk_sp<SkTextBlob> MakeFancyBlob(const SkPaint& paint, const SkFont& font, const char* text) {
     const size_t textLen = strlen(text);
     const int glyphCount = font.countText(text, textLen, kUTF8_SkTextEncoding);
     SkAutoTArray<SkGlyphID> glyphs(glyphCount);
     font.textToGlyphs(text, textLen, kUTF8_SkTextEncoding, glyphs.get(), glyphCount);
     SkAutoTArray<SkScalar> widths(glyphCount);
     font.getWidths(glyphs.get(), glyphCount, widths.get());

     SkTextBlobBuilder blobBuilder;
     int glyphIndex = 0;
     SkScalar advance = 0;

     // Default-positioned run.
     {
         const int defaultRunLen = glyphCount / 3;
         const SkTextBlobBuilder::RunBuffer& buf = blobBuilder.allocRun(font,
                                                                        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(font,
                                                                            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(font, 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 blobBuilder.make();
 }

 } // 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) {
         for (SkScalar textSize = 100; textSize > 10; textSize -= 20) {
             SkFont skFont(
                     sk_tool_utils::create_portable_typeface(fam[font], SkFontStyle()), textSize);
             const SkScalar uWidth = textSize / 15;
             paint.setStrokeWidth(uWidth);
             paint.setStyle(SkPaint::kFill_Style);

             sk_sp<SkTextBlob> blob = MakeFancyBlob(paint, skFont, test);
             canvas->drawTextBlob(blob, blobOffset.x(), blobOffset.y(), paint);

             const SkScalar uPos = uWidth;
             const SkScalar bounds[2] = { uPos - uWidth / 2, uPos + uWidth / 2 };
             const int interceptCount = blob->getIntercepts(bounds, nullptr, &paint);
             SkASSERT(!(interceptCount % 2));

             SkTDArray<SkScalar> intercepts;
             intercepts.setCount(interceptCount);
             blob->getIntercepts(bounds, intercepts.begin(), &paint);

             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);
     }
 }

 ///////////////////////////////////////////////////////////////////////////////////////////////////

 static sk_sp<SkTextBlob> make_text(const SkFont& font, const SkGlyphID glyphs[], int count) {
     return SkTextBlob::MakeFromText(glyphs, count * sizeof(SkGlyphID), font,
                                     kGlyphID_SkTextEncoding);
 }

 static sk_sp<SkTextBlob> make_posh(const SkFont& font, const SkGlyphID glyphs[], int count,
                                    SkScalar spacing) {
     SkAutoTArray<SkScalar> xpos(count);
     font.getXPos(glyphs, count, xpos.get());
     for (int i = 1; i < count; ++i) {
         xpos[i] += spacing * i;
     }
     return SkTextBlob::MakeFromPosTextH(glyphs, count * sizeof(SkGlyphID), xpos.get(), 0, font,
                                         kGlyphID_SkTextEncoding);
 }

 static sk_sp<SkTextBlob> make_pos(const SkFont& font, const SkGlyphID glyphs[], int count,
                                   SkScalar spacing) {
     SkAutoTArray<SkPoint> pos(count);
     font.getPos(glyphs, count, pos.get());
     for (int i = 1; i < count; ++i) {
         pos[i].fX += spacing * i;
     }
     return SkTextBlob::MakeFromPosText(glyphs, count * sizeof(SkGlyphID), pos.get(), font,
                                        kGlyphID_SkTextEncoding);
 }

 // widen the gaps with a margin (on each side of the gap), elimnating segments that go away
 static int trim_with_halo(SkScalar intervals[], int count, SkScalar margin) {
     SkASSERT(count > 0 && (count & 1) == 0);

     int n = count;
     SkScalar* stop = intervals + count;
     *intervals++ -= margin;
     while (intervals < stop - 1) {
         intervals[0] += margin;
         intervals[1] -= margin;
         if (intervals[0] >= intervals[1]) { // went away
             int remaining = stop - intervals - 2;
             SkASSERT(remaining >= 0 && (remaining & 1) == 1);
             if (remaining > 0) {
                 memmove(intervals, intervals + 2, remaining * sizeof(SkScalar));
             }
             stop -= 2;
             n -= 2;
         } else {
             intervals += 2;
         }
     }
     *intervals += margin;
     return n;
 }

 static void draw_blob_adorned(SkCanvas* canvas, sk_sp<SkTextBlob> blob) {
     SkPaint paint;

     canvas->drawTextBlob(blob.get(), 0, 0, paint);

     const SkScalar yminmax[] = { 8, 16 };
     int count = blob->getIntercepts(yminmax, nullptr);
     if (!count) {
         return;
     }

     SkAutoTArray<SkScalar> intervals(count);
     blob->getIntercepts(yminmax, intervals.get());
     count = trim_with_halo(intervals.get(), count, SkScalarHalf(yminmax[1] - yminmax[0]) * 1.5f);
     SkASSERT(count >= 2);

     const SkScalar y = SkScalarAve(yminmax[0], yminmax[1]);
     SkScalar end = 900;
     SkPath path;
     path.moveTo({0, y});
     for (int i = 0; i < count; i += 2) {
         path.lineTo(intervals[i], y).moveTo(intervals[i+1], y);
     }
     if (intervals[count - 1] < end) {
         path.lineTo(end, y);
     }

     paint.setAntiAlias(true);
     paint.setStyle(SkPaint::kStroke_Style);
     paint.setStrokeWidth(yminmax[1] - yminmax[0]);
     canvas->drawPath(path, paint);
 }

 DEF_SIMPLE_GM(textblob_intercepts, canvas, 940, 800) {
     const char text[] = "Hyjay {worlp}.";
     const size_t length = strlen(text);
     SkFont font;
     font.setTypeface(sk_tool_utils::create_portable_typeface());
     font.setSize(100);
     font.setEdging(SkFont::Edging::kAntiAlias);
     const int count = font.countText(text, length, kUTF8_SkTextEncoding);
     SkAutoTArray<SkGlyphID> glyphs(count);
     font.textToGlyphs(text, length, kUTF8_SkTextEncoding, glyphs.get(), count);

     auto b0 = make_text(font, glyphs.get(), count);

     canvas->translate(20, 120);
     draw_blob_adorned(canvas, b0);
     for (SkScalar spacing = 0; spacing < 30; spacing += 20) {
         auto b1 = make_posh(font, glyphs.get(), count, spacing);
         auto b2 = make_pos( font, glyphs.get(), count, spacing);
         canvas->translate(0, 150);
         draw_blob_adorned(canvas, b1);
         canvas->translate(0, 150);
         draw_blob_adorned(canvas, b2);
     }
 }
	/*
	* Copyright 2011 Google Inc.
	*
	* Use of this source code is governed by a BSD-style license that can be
	* found in the LICENSE file.
	*/

	#include "gm.h"
	#include "sk_tool_utils.h"

	#include "SkBlurMask.h"
	#include "SkBlurMaskFilter.h"
	#include "SkReadBuffer.h"
	#include "SkTextBlob.h"
	#include "SkTo.h"
	#include "SkWriteBuffer.h"

	#include "Sk2DPathEffect.h"

	static SkPath create_underline(const SkTDArray<SkScalar>& intersections,
	SkScalar last, SkScalar finalPos,
	SkScalar uPos, SkScalar uWidth, SkScalar textSize) {
	SkPath underline;
	SkScalar end = last;
	for (int index = 0; index < intersections.count(); index += 2) {
	SkScalar start = intersections[index] - uWidth;
	end = intersections[index + 1] + uWidth;
	if (start > last && last + textSize / 12 < start) {
	underline.moveTo(last, uPos);
	underline.lineTo(start, uPos);
	}
	last = end;
	}
	if (end < finalPos) {
	underline.moveTo(end, uPos);
	underline.lineTo(finalPos, uPos);
	}
	return underline;
	}

	namespace {

	sk_sp<SkTextBlob> MakeFancyBlob(const SkPaint& paint, const SkFont& font, const char* text) {
	const size_t textLen = strlen(text);
	const int glyphCount = font.countText(text, textLen, kUTF8_SkTextEncoding);
	SkAutoTArray<SkGlyphID> glyphs(glyphCount);
	font.textToGlyphs(text, textLen, kUTF8_SkTextEncoding, glyphs.get(), glyphCount);
	SkAutoTArray<SkScalar> widths(glyphCount);
	font.getWidths(glyphs.get(), glyphCount, widths.get());

	SkTextBlobBuilder blobBuilder;
	int glyphIndex = 0;
	SkScalar advance = 0;

	// Default-positioned run.
	{
	const int defaultRunLen = glyphCount / 3;
	const SkTextBlobBuilder::RunBuffer& buf = blobBuilder.allocRun(font,
	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(font,
	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(font, 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 blobBuilder.make();
	}

	} // 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) {
	for (SkScalar textSize = 100; textSize > 10; textSize -= 20) {
	SkFont skFont(
	sk_tool_utils::create_portable_typeface(fam[font], SkFontStyle()), textSize);
	const SkScalar uWidth = textSize / 15;
	paint.setStrokeWidth(uWidth);
	paint.setStyle(SkPaint::kFill_Style);

	sk_sp<SkTextBlob> blob = MakeFancyBlob(paint, skFont, test);
	canvas->drawTextBlob(blob, blobOffset.x(), blobOffset.y(), paint);

	const SkScalar uPos = uWidth;
	const SkScalar bounds[2] = { uPos - uWidth / 2, uPos + uWidth / 2 };
	const int interceptCount = blob->getIntercepts(bounds, nullptr, &paint);
	SkASSERT(!(interceptCount % 2));

	SkTDArray<SkScalar> intercepts;
	intercepts.setCount(interceptCount);
	blob->getIntercepts(bounds, intercepts.begin(), &paint);

	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);
	}
	}

	///////////////////////////////////////////////////////////////////////////////////////////////////

	static sk_sp<SkTextBlob> make_text(const SkFont& font, const SkGlyphID glyphs[], int count) {
	return SkTextBlob::MakeFromText(glyphs, count * sizeof(SkGlyphID), font,
	kGlyphID_SkTextEncoding);
	}

	static sk_sp<SkTextBlob> make_posh(const SkFont& font, const SkGlyphID glyphs[], int count,
	SkScalar spacing) {
	SkAutoTArray<SkScalar> xpos(count);
	font.getXPos(glyphs, count, xpos.get());
	for (int i = 1; i < count; ++i) {
	xpos[i] += spacing * i;
	}
	return SkTextBlob::MakeFromPosTextH(glyphs, count * sizeof(SkGlyphID), xpos.get(), 0, font,
	kGlyphID_SkTextEncoding);
	}

	static sk_sp<SkTextBlob> make_pos(const SkFont& font, const SkGlyphID glyphs[], int count,
	SkScalar spacing) {
	SkAutoTArray<SkPoint> pos(count);
	font.getPos(glyphs, count, pos.get());
	for (int i = 1; i < count; ++i) {
	pos[i].fX += spacing * i;
	}
	return SkTextBlob::MakeFromPosText(glyphs, count * sizeof(SkGlyphID), pos.get(), font,
	kGlyphID_SkTextEncoding);
	}

	// widen the gaps with a margin (on each side of the gap), elimnating segments that go away
	static int trim_with_halo(SkScalar intervals[], int count, SkScalar margin) {
	SkASSERT(count > 0 && (count & 1) == 0);

	int n = count;
	SkScalar* stop = intervals + count;
	*intervals++ -= margin;
	while (intervals < stop - 1) {
	intervals[0] += margin;
	intervals[1] -= margin;
	if (intervals[0] >= intervals[1]) { // went away
	int remaining = stop - intervals - 2;
	SkASSERT(remaining >= 0 && (remaining & 1) == 1);
	if (remaining > 0) {
	memmove(intervals, intervals + 2, remaining * sizeof(SkScalar));
	}
	stop -= 2;
	n -= 2;
	} else {
	intervals += 2;
	}
	}
	*intervals += margin;
	return n;
	}

	static void draw_blob_adorned(SkCanvas* canvas, sk_sp<SkTextBlob> blob) {
	SkPaint paint;

	canvas->drawTextBlob(blob.get(), 0, 0, paint);

	const SkScalar yminmax[] = { 8, 16 };
	int count = blob->getIntercepts(yminmax, nullptr);
	if (!count) {
	return;
	}

	SkAutoTArray<SkScalar> intervals(count);
	blob->getIntercepts(yminmax, intervals.get());
	count = trim_with_halo(intervals.get(), count, SkScalarHalf(yminmax[1] - yminmax[0]) * 1.5f);
	SkASSERT(count >= 2);

	const SkScalar y = SkScalarAve(yminmax[0], yminmax[1]);
	SkScalar end = 900;
	SkPath path;
	path.moveTo({0, y});
	for (int i = 0; i < count; i += 2) {
	path.lineTo(intervals[i], y).moveTo(intervals[i+1], y);
	}
	if (intervals[count - 1] < end) {
	path.lineTo(end, y);
	}

	paint.setAntiAlias(true);
	paint.setStyle(SkPaint::kStroke_Style);
	paint.setStrokeWidth(yminmax[1] - yminmax[0]);
	canvas->drawPath(path, paint);
	}

	DEF_SIMPLE_GM(textblob_intercepts, canvas, 940, 800) {
	const char text[] = "Hyjay {worlp}.";
	const size_t length = strlen(text);
	SkFont font;
	font.setTypeface(sk_tool_utils::create_portable_typeface());
	font.setSize(100);
	font.setEdging(SkFont::Edging::kAntiAlias);
	const int count = font.countText(text, length, kUTF8_SkTextEncoding);
	SkAutoTArray<SkGlyphID> glyphs(count);
	font.textToGlyphs(text, length, kUTF8_SkTextEncoding, glyphs.get(), count);

	auto b0 = make_text(font, glyphs.get(), count);

	canvas->translate(20, 120);
	draw_blob_adorned(canvas, b0);
	for (SkScalar spacing = 0; spacing < 30; spacing += 20) {
	auto b1 = make_posh(font, glyphs.get(), count, spacing);
	auto b2 = make_pos( font, glyphs.get(), count, spacing);
	canvas->translate(0, 150);
	draw_blob_adorned(canvas, b1);
	canvas->translate(0, 150);
	draw_blob_adorned(canvas, b2);
	}
	}