texteffects.cpp File Reference

#include "gm/gm.h"
#include "include/core/SkCanvas.h"
#include "include/core/SkFont.h"
#include "include/core/SkFontStyle.h"
#include "include/core/SkFontTypes.h"
#include "include/core/SkPaint.h"
#include "include/core/SkPath.h"
#include "include/core/SkPoint.h"
#include "include/core/SkRect.h"
#include "include/core/SkRefCnt.h"
#include "include/core/SkScalar.h"
#include "include/core/SkTextBlob.h"
#include "include/core/SkTypeface.h"
#include "include/core/SkTypes.h"
#include "include/private/base/SkTDArray.h"
#include "include/private/base/SkTemplates.h"
#include "include/private/base/SkTo.h"
#include "tools/ToolUtils.h"
#include "tools/fonts/FontToolUtils.h"
#include <string.h>

Go to the source code of this file.

Functions
static SkPath	create_underline (const SkTDArray< SkScalar > &intersections, SkScalar last, SkScalar finalPos, SkScalar uPos, SkScalar uWidth, SkScalar textSize)
	DEF_SIMPLE_GM (fancyblobunderline, canvas, 1480, 1380)
static sk_sp< SkTextBlob >	make_text (const SkFont &font, const SkGlyphID glyphs[], int count)
static sk_sp< SkTextBlob >	make_posh (const SkFont &font, const SkGlyphID glyphs[], int count, SkScalar spacing)
static sk_sp< SkTextBlob >	make_pos (const SkFont &font, const SkGlyphID glyphs[], int count, SkScalar spacing)
static int	trim_with_halo (SkScalar intervals[], int count, SkScalar margin)
static void	draw_blob_adorned (SkCanvas *canvas, sk_sp< SkTextBlob > blob)
	DEF_SIMPLE_GM (textblob_intercepts, canvas, 940, 800)

Function Documentation

create_underline()

static SkPath create_underline ( const SkTDArray< SkScalar > &  intersections, SkScalar  last, SkScalar  finalPos, SkScalar  uPos, SkScalar  uWidth, SkScalar  textSize  )

static

Definition at line 32 of file texteffects.cpp.

                                                           {
    SkPath underline;
    SkScalar end = last;
    for (int index = 0; index < intersections.size(); 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;
}

DEF_SIMPLE_GM() [1/2]

DEF_SIMPLE_GM	(	fancyblobunderline	,
		canvas	,
		1480	,
		1380
	)

Definition at line 112 of file texteffects.cpp.

                                                      {
    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 < std::size(fam); ++font) {
        for (SkScalar textSize = 100; textSize > 10; textSize -= 20) {
            SkFont skFont(ToolUtils::CreatePortableTypeface(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.resize(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);
    }
}

DEF_SIMPLE_GM() [2/2]

DEF_SIMPLE_GM	(	textblob_intercepts	,
		canvas	,
		940	,
		800
	)

Definition at line 240 of file texteffects.cpp.

                                                     {
    const char text[] = "Hyjay {worlp}.";
    const size_t length = strlen(text);
    SkFont font = ToolUtils::DefaultPortableFont();
    font.setSize(100);
    font.setEdging(SkFont::Edging::kAntiAlias);
    const int count = font.countText(text, length, SkTextEncoding::kUTF8);
    AutoTArray<SkGlyphID> glyphs(count);
    font.textToGlyphs(text, length, SkTextEncoding::kUTF8, 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);
    }
}

draw_blob_adorned()

static void draw_blob_adorned ( SkCanvas *  canvas, sk_sp< SkTextBlob >  blob  )

static

Definition at line 207 of file texteffects.cpp.

                                                                        {
    SkPaint paint;
 
    canvas->drawTextBlob(blob.get(), 0, 0, paint);
 
    const SkScalar yminmax[] = { 8, 16 };
    int count = blob->getIntercepts(yminmax, nullptr);
    if (!count) {
        return;
    }
 
    AutoTArray<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);
}

make_pos()

static sk_sp< SkTextBlob > make_pos ( const SkFont &  font, const SkGlyphID  glyphs[], int  count, SkScalar  spacing  )

static

Definition at line 170 of file texteffects.cpp.

                                                    {
    AutoTArray<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,
                                       SkTextEncoding::kGlyphID);
}

make_posh()

static sk_sp< SkTextBlob > make_posh ( const SkFont &  font, const SkGlyphID  glyphs[], int  count, SkScalar  spacing  )

static

Definition at line 159 of file texteffects.cpp.

                                                     {
    AutoTArray<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,
                                        SkTextEncoding::kGlyphID);
}

make_text()

static sk_sp< SkTextBlob > make_text ( const SkFont &  font, const SkGlyphID  glyphs[], int  count  )

static

Definition at line 154 of file texteffects.cpp.

                                                                                            {
    return SkTextBlob::MakeFromText(glyphs, count * sizeof(SkGlyphID), font,
                                    SkTextEncoding::kGlyphID);
}

trim_with_halo()

static int trim_with_halo ( SkScalar  intervals[], int  count, SkScalar  margin  )

static

Definition at line 182 of file texteffects.cpp.

                                                                            {
    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;
}