Files
gio-patched/widget/index_test.go
T
Chris Waldon 73787b8478 text,widget: minimize loss of positional precision in shaping
This commit combs through the logic of computing glyph sizes and positions,
attempting to remove all unnecessary rounding and truncation. This is in
an effort to help text display consistently when different-length strings
are displayed near one another.

The specific problem prompting this change was end-aligned text stacked in
rows with a common suffix. If the rows displayed different values, they
would shape such that those final glyphs were at different fractional x
coordinates, and then they would be aligned with rounding that could display
them at different x positions in spite of the fact that both suffixes are
the same glyphs.

By removing rounding from Alignment.Align, the largest problem is fixed, but
I'm also removing other unnecessary loss of precision that can circumstantially
contribute to this sort of visual issue.

Signed-off-by: Chris Waldon <christopher.waldon.dev@gmail.com>
2023-04-05 11:32:35 -06:00

807 lines
25 KiB
Go

package widget
import (
"bytes"
"io"
"testing"
nsareg "eliasnaur.com/font/noto/sans/arabic/regular"
"gioui.org/font/opentype"
"gioui.org/text"
"golang.org/x/image/font/gofont/goregular"
"golang.org/x/image/math/fixed"
)
// makePosTestText returns two bidi samples of shaped text at the given
// font size and wrapped to the given line width. The runeLimit, if nonzero,
// truncates the sample text to ensure shorter output for expensive tests.
func makePosTestText(fontSize, lineWidth int, alignOpposite bool) (source string, bidiLTR, bidiRTL []text.Glyph) {
ltrFace, _ := opentype.Parse(goregular.TTF)
rtlFace, _ := opentype.Parse(nsareg.TTF)
shaper := text.NewShaper([]text.FontFace{
{
Font: text.Font{Typeface: "LTR"},
Face: ltrFace,
},
{
Font: text.Font{Typeface: "RTL"},
Face: rtlFace,
},
})
// bidiSource is crafted to contain multiple consecutive RTL runs (by
// changing scripts within the RTL).
bidiSource := "The quick سماء שלום لا fox تمط שלום غير the lazy dog."
ltrParams := text.Parameters{
Font: text.Font{Typeface: "LTR"},
PxPerEm: fixed.I(fontSize),
MaxWidth: lineWidth,
MinWidth: lineWidth,
Locale: english,
}
rtlParams := text.Parameters{
Alignment: text.End,
Font: text.Font{Typeface: "RTL"},
PxPerEm: fixed.I(fontSize),
MaxWidth: lineWidth,
MinWidth: lineWidth,
Locale: arabic,
}
if alignOpposite {
ltrParams.Alignment = text.End
rtlParams.Alignment = text.Start
}
shaper.LayoutString(ltrParams, bidiSource)
for g, ok := shaper.NextGlyph(); ok; g, ok = shaper.NextGlyph() {
bidiLTR = append(bidiLTR, g)
}
shaper.LayoutString(rtlParams, bidiSource)
for g, ok := shaper.NextGlyph(); ok; g, ok = shaper.NextGlyph() {
bidiRTL = append(bidiRTL, g)
}
return bidiSource, bidiLTR, bidiRTL
}
// makeAccountingTestText shapes text designed to stress rune accounting
// logic within the index.
func makeAccountingTestText(str string, fontSize, lineWidth int) (txt []text.Glyph) {
ltrFace, _ := opentype.Parse(goregular.TTF)
rtlFace, _ := opentype.Parse(nsareg.TTF)
shaper := text.NewShaper([]text.FontFace{{
Font: text.Font{Typeface: "LTR"},
Face: ltrFace,
},
{
Font: text.Font{Typeface: "RTL"},
Face: rtlFace,
},
})
params := text.Parameters{
PxPerEm: fixed.I(fontSize),
MaxWidth: lineWidth,
Locale: english,
}
shaper.LayoutString(params, str)
for g, ok := shaper.NextGlyph(); ok; g, ok = shaper.NextGlyph() {
txt = append(txt, g)
}
return txt
}
// getGlyphs shapes text as english.
func getGlyphs(fontSize, minWidth, lineWidth int, align text.Alignment, str string) (txt []text.Glyph) {
ltrFace, _ := opentype.Parse(goregular.TTF)
rtlFace, _ := opentype.Parse(nsareg.TTF)
shaper := text.NewShaper([]text.FontFace{{
Font: text.Font{Typeface: "LTR"},
Face: ltrFace,
},
{
Font: text.Font{Typeface: "RTL"},
Face: rtlFace,
},
})
params := text.Parameters{
PxPerEm: fixed.I(fontSize),
Alignment: align,
MinWidth: minWidth,
MaxWidth: lineWidth,
Locale: english,
}
shaper.LayoutString(params, str)
for g, ok := shaper.NextGlyph(); ok; g, ok = shaper.NextGlyph() {
txt = append(txt, g)
}
return txt
}
// TestIndexPositionWhitespace checks that the index correctly generates cursor positions
// for empty lines and the empty string.
func TestIndexPositionWhitespace(t *testing.T) {
type testcase struct {
name string
str string
align text.Alignment
expected []combinedPos
}
for _, tc := range []testcase{
{
name: "empty string",
str: "",
expected: []combinedPos{
{x: fixed.Int26_6(0), y: 16, ascent: fixed.Int26_6(968), descent: fixed.Int26_6(216)},
},
},
{
name: "just hard newline",
str: "\n",
expected: []combinedPos{
{x: fixed.Int26_6(0), y: 16, ascent: fixed.Int26_6(968), descent: fixed.Int26_6(216)},
{x: fixed.Int26_6(0), y: 35, ascent: fixed.Int26_6(968), descent: fixed.Int26_6(216), runes: 1, lineCol: screenPos{line: 1}},
},
},
{
name: "trailing newline",
str: "a\n",
expected: []combinedPos{
{x: fixed.Int26_6(0), y: 16, ascent: fixed.Int26_6(968), descent: fixed.Int26_6(216)},
{x: fixed.Int26_6(570), y: 16, ascent: fixed.Int26_6(968), descent: fixed.Int26_6(216), runes: 1, lineCol: screenPos{col: 1}},
{x: fixed.Int26_6(0), y: 35, ascent: fixed.Int26_6(968), descent: fixed.Int26_6(216), runes: 2, lineCol: screenPos{line: 1}},
},
},
{
name: "just blank line",
str: "\n\n",
expected: []combinedPos{
{x: fixed.Int26_6(0), y: 16, ascent: fixed.Int26_6(968), descent: fixed.Int26_6(216)},
{x: fixed.Int26_6(0), y: 35, ascent: fixed.Int26_6(968), descent: fixed.Int26_6(216), runes: 1, lineCol: screenPos{line: 1}},
{x: fixed.Int26_6(0), y: 54, ascent: fixed.Int26_6(968), descent: fixed.Int26_6(216), runes: 2, lineCol: screenPos{line: 2}},
},
},
{
name: "middle aligned blank lines",
str: "\n\n\nabc",
align: text.Middle,
expected: []combinedPos{
{x: fixed.Int26_6(832), y: 16, ascent: fixed.Int26_6(968), descent: fixed.Int26_6(216)},
{x: fixed.Int26_6(832), y: 35, ascent: fixed.Int26_6(968), descent: fixed.Int26_6(216), runes: 1, lineCol: screenPos{line: 1}},
{x: fixed.Int26_6(832), y: 54, ascent: fixed.Int26_6(968), descent: fixed.Int26_6(216), runes: 2, lineCol: screenPos{line: 2}},
{x: fixed.Int26_6(6), y: 73, ascent: fixed.Int26_6(968), descent: fixed.Int26_6(216), runes: 3, lineCol: screenPos{line: 3}},
{x: fixed.Int26_6(576), y: 73, ascent: fixed.Int26_6(968), descent: fixed.Int26_6(216), runes: 4, lineCol: screenPos{line: 3, col: 1}},
{x: fixed.Int26_6(1146), y: 73, ascent: fixed.Int26_6(968), descent: fixed.Int26_6(216), runes: 5, lineCol: screenPos{line: 3, col: 2}},
{x: fixed.Int26_6(1658), y: 73, ascent: fixed.Int26_6(968), descent: fixed.Int26_6(216), runes: 6, lineCol: screenPos{line: 3, col: 3}},
},
},
{
name: "blank line",
str: "a\n\nb",
expected: []combinedPos{
{x: fixed.Int26_6(0), y: 16, ascent: fixed.Int26_6(968), descent: fixed.Int26_6(216)},
{x: fixed.Int26_6(570), y: 16, ascent: fixed.Int26_6(968), descent: fixed.Int26_6(216), runes: 1, lineCol: screenPos{col: 1}},
{x: fixed.Int26_6(0), y: 35, ascent: fixed.Int26_6(968), descent: fixed.Int26_6(216), runes: 2, lineCol: screenPos{line: 1}},
{x: fixed.Int26_6(0), y: 54, ascent: fixed.Int26_6(968), descent: fixed.Int26_6(216), runes: 3, lineCol: screenPos{line: 2}},
{x: fixed.Int26_6(570), y: 54, ascent: fixed.Int26_6(968), descent: fixed.Int26_6(216), runes: 4, lineCol: screenPos{line: 2, col: 1}},
},
},
} {
t.Run(tc.name, func(t *testing.T) {
glyphs := getGlyphs(16, 0, 200, tc.align, tc.str)
var gi glyphIndex
gi.reset()
for _, g := range glyphs {
gi.Glyph(g)
}
if len(gi.positions) != len(tc.expected) {
t.Errorf("expected %d positions, got %d", len(tc.expected), len(gi.positions))
}
for i := 0; i < min(len(gi.positions), len(tc.expected)); i++ {
actual := gi.positions[i]
expected := tc.expected[i]
if actual != expected {
t.Errorf("position %d: expected:\n%#+v, got:\n%#+v", i, expected, actual)
}
}
if t.Failed() {
printPositions(t, gi.positions)
printGlyphs(t, glyphs)
}
})
}
}
// TestIndexPositionBidi tests whether the index correct generates cursor positions for
// complex bidirectional text.
func TestIndexPositionBidi(t *testing.T) {
fontSize := 16
lineWidth := fontSize * 10
_, bidiLTRText, bidiRTLText := makePosTestText(fontSize, lineWidth, false)
type testcase struct {
name string
glyphs []text.Glyph
expectedXs []fixed.Int26_6
}
for _, tc := range []testcase{
{
name: "bidi ltr",
glyphs: bidiLTRText,
expectedXs: []fixed.Int26_6{
0, 626, 1196, 1766, 2051, 2621, 3191, 3444, 3956, 4468, 4753, 7133, 6330, 5738, 5440, 5019, 4753, // Positions on line 0.
3953, 3185, 2417, 1649, 881, 596, 298, 0, 3953, 4238, 4523, 5093, 5605, 5890, 7905, 7599, 7007, 6156, 5890, // Positions on line 1.
4660, 3892, 3124, 2356, 1588, 1303, 788, 406, 0, 4660, 4945, 5235, 5805, 6375, 6660, 6934, 7504, 8016, 8528, 8813, // Positions on line 2.
0, 570, 1140, 1710, 2034, // Positions on line 3.
},
},
{
name: "bidi rtl",
glyphs: bidiRTLText,
expectedXs: []fixed.Int26_6{
5368, 5994, 6564, 7134, 7419, 7989, 8559, 8812, 9324, 9836, 5368, 5102, 4299, 3707, 3409, 2988, 2722, 2108, 1494, 880, 266, 0, // Positions on line 0.
8801, 8503, 8205, 7939, 6572, 6857, 7427, 7939, 6572, 6306, 6000, 5408, 4557, 4291, 3677, 3063, 2449, 1835, 1569, 1054, 672, 266, 0, // Positions on line 1.
274, 564, 1134, 1704, 1989, 2263, 2833, 3345, 3857, 4142, 4712, 5282, 5852, 274, 0, // Positions on line 2.
},
},
} {
t.Run(tc.name, func(t *testing.T) {
var gi glyphIndex
gi.reset()
for _, g := range tc.glyphs {
gi.Glyph(g)
}
if len(gi.positions) != len(tc.expectedXs) {
t.Errorf("expected %d positions, got %d", len(tc.expectedXs), len(gi.positions))
}
lastRunes := 0
lastLine := 0
lastCol := -1
lastY := 0
for i := 0; i < min(len(gi.positions), len(tc.expectedXs)); i++ {
actualX := gi.positions[i].x
expectedX := tc.expectedXs[i]
if actualX != expectedX {
t.Errorf("position %d: expected x=%v(%d), got x=%v(%d)", i, expectedX, expectedX, actualX, actualX)
}
if r := gi.positions[i].runes; r < lastRunes {
t.Errorf("position %d: expected runes >= %d, got %d", i, lastRunes, r)
}
lastRunes = gi.positions[i].runes
if y := gi.positions[i].y; y < lastY {
t.Errorf("position %d: expected y>= %d, got %d", i, lastY, y)
}
lastY = gi.positions[i].y
if y := gi.positions[i].y; y < lastY {
t.Errorf("position %d: expected y>= %d, got %d", i, lastY, y)
}
lastY = gi.positions[i].y
if lineCol := gi.positions[i].lineCol; lineCol.line == lastLine && lineCol.col < lastCol {
t.Errorf("position %d: expected col >= %d, got %d", i, lastCol, lineCol.col)
}
lastCol = gi.positions[i].lineCol.col
if line := gi.positions[i].lineCol.line; line < lastLine {
t.Errorf("position %d: expected line >= %d, got %d", i, lastLine, line)
}
lastLine = gi.positions[i].lineCol.line
}
printPositions(t, gi.positions)
if t.Failed() {
printGlyphs(t, tc.glyphs)
}
})
}
}
func TestIndexPositionLines(t *testing.T) {
fontSize := 16
lineWidth := fontSize * 10
source1, bidiLTRText, bidiRTLText := makePosTestText(fontSize, lineWidth, false)
source2, bidiLTRTextOpp, bidiRTLTextOpp := makePosTestText(fontSize, lineWidth, true)
type testcase struct {
name string
source string
glyphs []text.Glyph
expectedLines []lineInfo
}
for _, tc := range []testcase{
{
name: "bidi ltr",
source: source1,
glyphs: bidiLTRText,
expectedLines: []lineInfo{
{
xOff: fixed.Int26_6(0),
yOff: 22,
glyphs: 15,
width: fixed.Int26_6(7133),
ascent: fixed.Int26_6(1407),
descent: fixed.Int26_6(756),
},
{
xOff: fixed.Int26_6(0),
yOff: 56,
glyphs: 15,
width: fixed.Int26_6(7905),
ascent: fixed.Int26_6(1407),
descent: fixed.Int26_6(756),
},
{
xOff: fixed.Int26_6(0),
yOff: 90,
glyphs: 18,
width: fixed.Int26_6(8813),
ascent: fixed.Int26_6(1407),
descent: fixed.Int26_6(756),
},
{
xOff: fixed.Int26_6(0),
yOff: 117,
glyphs: 4,
width: fixed.Int26_6(2034),
ascent: fixed.Int26_6(968),
descent: fixed.Int26_6(216),
},
},
},
{
name: "bidi rtl",
source: source1,
glyphs: bidiRTLText,
expectedLines: []lineInfo{
{
xOff: fixed.Int26_6(0),
yOff: 22,
glyphs: 20,
width: fixed.Int26_6(9836),
ascent: fixed.Int26_6(1407),
descent: fixed.Int26_6(756),
},
{
xOff: fixed.Int26_6(0),
yOff: 56,
glyphs: 19,
width: fixed.Int26_6(8801),
ascent: fixed.Int26_6(1407),
descent: fixed.Int26_6(756),
},
{
xOff: fixed.Int26_6(0),
yOff: 90,
glyphs: 13,
width: fixed.Int26_6(5852),
ascent: fixed.Int26_6(1407),
descent: fixed.Int26_6(756),
},
},
},
{
name: "bidi ltr opposite alignment",
source: source2,
glyphs: bidiLTRTextOpp,
expectedLines: []lineInfo{
{
xOff: fixed.Int26_6(3107),
yOff: 22,
glyphs: 15,
width: fixed.Int26_6(7133),
ascent: fixed.Int26_6(1407),
descent: fixed.Int26_6(756),
},
{
xOff: fixed.Int26_6(2335),
yOff: 56,
glyphs: 15,
width: fixed.Int26_6(7905),
ascent: fixed.Int26_6(1407),
descent: fixed.Int26_6(756),
},
{
xOff: fixed.Int26_6(1427),
yOff: 90,
glyphs: 18,
width: fixed.Int26_6(8813),
ascent: fixed.Int26_6(1407),
descent: fixed.Int26_6(756),
},
{
xOff: fixed.Int26_6(8206),
yOff: 117,
glyphs: 4,
width: fixed.Int26_6(2034),
ascent: fixed.Int26_6(968),
descent: fixed.Int26_6(216),
},
},
},
{
name: "bidi rtl opposite alignment",
source: source2,
glyphs: bidiRTLTextOpp,
expectedLines: []lineInfo{
{
xOff: fixed.Int26_6(404),
yOff: 22,
glyphs: 20,
width: fixed.Int26_6(9836),
ascent: fixed.Int26_6(1407),
descent: fixed.Int26_6(756),
},
{
xOff: fixed.Int26_6(1439),
yOff: 56,
glyphs: 19,
width: fixed.Int26_6(8801),
ascent: fixed.Int26_6(1407),
descent: fixed.Int26_6(756),
},
{
xOff: fixed.Int26_6(4388),
yOff: 90,
glyphs: 13,
width: fixed.Int26_6(5852),
ascent: fixed.Int26_6(1407),
descent: fixed.Int26_6(756),
},
},
},
} {
t.Run(tc.name, func(t *testing.T) {
var gi glyphIndex
gi.reset()
for _, g := range tc.glyphs {
gi.Glyph(g)
}
if len(gi.lines) != len(tc.expectedLines) {
t.Errorf("expected %d lines, got %d", len(tc.expectedLines), len(gi.lines))
}
for i := 0; i < min(len(gi.lines), len(tc.expectedLines)); i++ {
actual := gi.lines[i]
expected := tc.expectedLines[i]
if actual != expected {
t.Errorf("line %d: expected:\n%#+v, got:\n%#+v", i, expected, actual)
}
}
})
}
}
// TestIndexPositionRunes checks for rune accounting errors in positions
// generated by the index.
func TestIndexPositionRunes(t *testing.T) {
fontSize := 16
lineWidth := fontSize * 10
// source is crafted to contain multiple consecutive RTL runs (by
// changing scripts within the RTL).
source := "The\nquick سماء של\nום لا fox\nتمط של\nום."
testText := makeAccountingTestText(source, fontSize, lineWidth)
type testcase struct {
name string
source string
glyphs []text.Glyph
expected []combinedPos
}
for _, tc := range []testcase{
{
name: "many newlines",
source: source,
glyphs: testText,
expected: []combinedPos{
{runes: 0, lineCol: screenPos{line: 0, col: 0}, runIndex: 0, towardOrigin: false},
{runes: 1, lineCol: screenPos{line: 0, col: 1}, runIndex: 0, towardOrigin: false},
{runes: 2, lineCol: screenPos{line: 0, col: 2}, runIndex: 0, towardOrigin: false},
{runes: 3, lineCol: screenPos{line: 0, col: 3}, runIndex: 0, towardOrigin: false},
{runes: 4, lineCol: screenPos{line: 1, col: 0}, runIndex: 0, towardOrigin: false},
{runes: 5, lineCol: screenPos{line: 1, col: 1}, runIndex: 0, towardOrigin: false},
{runes: 6, lineCol: screenPos{line: 1, col: 2}, runIndex: 0, towardOrigin: false},
{runes: 7, lineCol: screenPos{line: 1, col: 3}, runIndex: 0, towardOrigin: false},
{runes: 8, lineCol: screenPos{line: 1, col: 4}, runIndex: 0, towardOrigin: false},
{runes: 9, lineCol: screenPos{line: 1, col: 5}, runIndex: 0, towardOrigin: false},
{runes: 10, lineCol: screenPos{line: 1, col: 6}, runIndex: 0, towardOrigin: false},
{runes: 10, lineCol: screenPos{line: 1, col: 6}, runIndex: 1, towardOrigin: true},
{runes: 11, lineCol: screenPos{line: 1, col: 7}, runIndex: 1, towardOrigin: true},
{runes: 12, lineCol: screenPos{line: 1, col: 8}, runIndex: 1, towardOrigin: true},
{runes: 13, lineCol: screenPos{line: 1, col: 9}, runIndex: 1, towardOrigin: true},
{runes: 14, lineCol: screenPos{line: 1, col: 10}, runIndex: 1, towardOrigin: true},
{runes: 15, lineCol: screenPos{line: 1, col: 11}, runIndex: 1, towardOrigin: true},
{runes: 16, lineCol: screenPos{line: 1, col: 12}, runIndex: 2, towardOrigin: true},
{runes: 17, lineCol: screenPos{line: 1, col: 13}, runIndex: 2, towardOrigin: true},
{runes: 18, lineCol: screenPos{line: 2, col: 0}, runIndex: 0, towardOrigin: true},
{runes: 19, lineCol: screenPos{line: 2, col: 1}, runIndex: 0, towardOrigin: true},
{runes: 20, lineCol: screenPos{line: 2, col: 2}, runIndex: 0, towardOrigin: true},
{runes: 21, lineCol: screenPos{line: 2, col: 3}, runIndex: 0, towardOrigin: true},
{runes: 22, lineCol: screenPos{line: 2, col: 4}, runIndex: 1, towardOrigin: true},
{runes: 23, lineCol: screenPos{line: 2, col: 5}, runIndex: 1, towardOrigin: true},
{runes: 24, lineCol: screenPos{line: 2, col: 6}, runIndex: 1, towardOrigin: true},
{runes: 24, lineCol: screenPos{line: 2, col: 6}, runIndex: 2, towardOrigin: false},
{runes: 25, lineCol: screenPos{line: 2, col: 7}, runIndex: 2, towardOrigin: false},
{runes: 26, lineCol: screenPos{line: 2, col: 8}, runIndex: 2, towardOrigin: false},
{runes: 27, lineCol: screenPos{line: 2, col: 9}, runIndex: 2, towardOrigin: false},
{runes: 28, lineCol: screenPos{line: 3, col: 0}, runIndex: 0, towardOrigin: true},
{runes: 29, lineCol: screenPos{line: 3, col: 1}, runIndex: 0, towardOrigin: true},
{runes: 30, lineCol: screenPos{line: 3, col: 2}, runIndex: 0, towardOrigin: true},
{runes: 31, lineCol: screenPos{line: 3, col: 3}, runIndex: 0, towardOrigin: true},
{runes: 32, lineCol: screenPos{line: 3, col: 4}, runIndex: 0, towardOrigin: true},
{runes: 33, lineCol: screenPos{line: 3, col: 5}, runIndex: 1, towardOrigin: true},
{runes: 34, lineCol: screenPos{line: 3, col: 6}, runIndex: 1, towardOrigin: true},
{runes: 35, lineCol: screenPos{line: 4, col: 0}, runIndex: 0, towardOrigin: true},
{runes: 36, lineCol: screenPos{line: 4, col: 1}, runIndex: 0, towardOrigin: true},
{runes: 37, lineCol: screenPos{line: 4, col: 2}, runIndex: 0, towardOrigin: true},
{runes: 38, lineCol: screenPos{line: 4, col: 3}, runIndex: 0, towardOrigin: true},
},
},
} {
t.Run(tc.name, func(t *testing.T) {
var gi glyphIndex
gi.reset()
for _, g := range tc.glyphs {
gi.Glyph(g)
}
if len(gi.positions) != len(tc.expected) {
t.Errorf("expected %d positions, got %d", len(tc.expected), len(gi.positions))
}
for i := 0; i < min(len(gi.positions), len(tc.expected)); i++ {
actual := gi.positions[i]
expected := tc.expected[i]
if expected.runes != actual.runes {
t.Errorf("position %d: expected runes=%d, got %d", i, expected.runes, actual.runes)
}
if expected.lineCol != actual.lineCol {
t.Errorf("position %d: expected lineCol=%v, got %v", i, expected.lineCol, actual.lineCol)
}
if expected.runIndex != actual.runIndex {
t.Errorf("position %d: expected runIndex=%d, got %d", i, expected.runIndex, actual.runIndex)
}
if expected.towardOrigin != actual.towardOrigin {
t.Errorf("position %d: expected towardOrigin=%v, got %v", i, expected.towardOrigin, actual.towardOrigin)
}
}
printPositions(t, gi.positions)
if t.Failed() {
printGlyphs(t, tc.glyphs)
}
})
}
}
func printPositions(t *testing.T, positions []combinedPos) {
t.Helper()
for i, p := range positions {
t.Logf("positions[%2d] = {runes: %2d, line: %2d, col: %2d, x: %5d, y: %3d}", i, p.runes, p.lineCol.line, p.lineCol.col, p.x, p.y)
}
}
func printGlyphs(t *testing.T, glyphs []text.Glyph) {
t.Helper()
for i, g := range glyphs {
t.Logf("glyphs[%2d] = {ID: 0x%013x, Flags: %4s, Advance: %4d(%6v), Runes: %d, Y: %3d, X: %4d(%6v)} ", i, g.ID, g.Flags, g.Advance, g.Advance, g.Runes, g.Y, g.X, g.X)
}
}
func TestGraphemeReaderNext(t *testing.T) {
latinDoc := bytes.NewReader([]byte(latinDocument))
arabicDoc := bytes.NewReader([]byte(arabicDocument))
emojiDoc := bytes.NewReader([]byte(emojiDocument))
complexDoc := bytes.NewReader([]byte(complexDocument))
type testcase struct {
name string
input *bytes.Reader
read func() ([]rune, bool)
}
var pr graphemeReader
for _, tc := range []testcase{
{
name: "latin",
input: latinDoc,
read: pr.next,
},
{
name: "arabic",
input: arabicDoc,
read: pr.next,
},
{
name: "emoji",
input: emojiDoc,
read: pr.next,
},
{
name: "complex",
input: complexDoc,
read: pr.next,
},
} {
t.Run(tc.name, func(t *testing.T) {
pr.SetSource(tc.input)
runes := []rune{}
var paragraph []rune
ok := true
for ok {
paragraph, ok = tc.read()
if ok && len(paragraph) > 0 && paragraph[len(paragraph)-1] != '\n' {
}
for i, r := range paragraph {
if i == len(paragraph)-1 {
if r != '\n' && ok {
t.Error("non-final paragraph does not end with newline")
}
} else if r == '\n' {
t.Errorf("paragraph[%d] contains newline", i)
}
}
runes = append(runes, paragraph...)
}
tc.input.Seek(0, 0)
b, _ := io.ReadAll(tc.input)
asRunes := []rune(string(b))
if len(asRunes) != len(runes) {
t.Errorf("expected %d runes, got %d", len(asRunes), len(runes))
}
for i := 0; i < max(len(asRunes), len(runes)); i++ {
if i < min(len(asRunes), len(runes)) {
if runes[i] != asRunes[i] {
t.Errorf("expected runes[%d]=%d, got %d", i, asRunes[i], runes[i])
}
} else if i < len(asRunes) {
t.Errorf("expected runes[%d]=%d, got nothing", i, asRunes[i])
} else if i < len(runes) {
t.Errorf("expected runes[%d]=nothing, got %d", i, runes[i])
}
}
})
}
}
func TestGraphemeReaderGraphemes(t *testing.T) {
latinDoc := bytes.NewReader([]byte(latinDocument))
arabicDoc := bytes.NewReader([]byte(arabicDocument))
emojiDoc := bytes.NewReader([]byte(emojiDocument))
complexDoc := bytes.NewReader([]byte(complexDocument))
type testcase struct {
name string
input *bytes.Reader
read func() []int
}
var pr graphemeReader
for _, tc := range []testcase{
{
name: "latin",
input: latinDoc,
read: pr.Graphemes,
},
{
name: "arabic",
input: arabicDoc,
read: pr.Graphemes,
},
{
name: "emoji",
input: emojiDoc,
read: pr.Graphemes,
},
{
name: "complex",
input: complexDoc,
read: pr.Graphemes,
},
} {
t.Run(tc.name, func(t *testing.T) {
pr.SetSource(tc.input)
graphemes := []int{}
for g := tc.read(); len(g) > 0; g = tc.read() {
if len(graphemes) > 0 && g[0] != graphemes[len(graphemes)-1] {
t.Errorf("expected first boundary in new paragraph %d to match final boundary in previous %d", g[0], graphemes[len(graphemes)-1])
}
if len(graphemes) > 0 {
// Drop duplicated boundary.
g = g[1:]
}
graphemes = append(graphemes, g...)
}
tc.input.Seek(0, 0)
b, _ := io.ReadAll(tc.input)
asRunes := []rune(string(b))
if len(asRunes)+1 < len(graphemes) {
t.Errorf("expected <= %d graphemes, got %d", len(asRunes)+1, len(graphemes))
}
for i := 0; i < len(graphemes)-1; i++ {
if graphemes[i] >= graphemes[i+1] {
t.Errorf("graphemes[%d](%d) >= graphemes[%d](%d)", i, graphemes[i], i+1, graphemes[i+1])
}
}
})
}
}
func BenchmarkGraphemeReaderNext(b *testing.B) {
latinDoc := bytes.NewReader([]byte(latinDocument))
arabicDoc := bytes.NewReader([]byte(arabicDocument))
emojiDoc := bytes.NewReader([]byte(emojiDocument))
complexDoc := bytes.NewReader([]byte(complexDocument))
type testcase struct {
name string
input *bytes.Reader
read func() ([]rune, bool)
}
pr := &graphemeReader{}
for _, tc := range []testcase{
{
name: "latin",
input: latinDoc,
read: pr.next,
},
{
name: "arabic",
input: arabicDoc,
read: pr.next,
},
{
name: "emoji",
input: emojiDoc,
read: pr.next,
},
{
name: "complex",
input: complexDoc,
read: pr.next,
},
} {
var paragraph []rune = make([]rune, 4096)
b.Run(tc.name, func(b *testing.B) {
b.ResetTimer()
for i := 0; i < b.N; i++ {
pr.SetSource(tc.input)
ok := true
for ok {
paragraph, ok = tc.read()
_ = paragraph
}
_ = paragraph
}
})
}
}
func BenchmarkGraphemeReaderGraphemes(b *testing.B) {
latinDoc := bytes.NewReader([]byte(latinDocument))
arabicDoc := bytes.NewReader([]byte(arabicDocument))
emojiDoc := bytes.NewReader([]byte(emojiDocument))
complexDoc := bytes.NewReader([]byte(complexDocument))
type testcase struct {
name string
input *bytes.Reader
read func() []int
}
pr := &graphemeReader{}
for _, tc := range []testcase{
{
name: "latin",
input: latinDoc,
read: pr.Graphemes,
},
{
name: "arabic",
input: arabicDoc,
read: pr.Graphemes,
},
{
name: "emoji",
input: emojiDoc,
read: pr.Graphemes,
},
{
name: "complex",
input: complexDoc,
read: pr.Graphemes,
},
} {
b.Run(tc.name, func(b *testing.B) {
b.ResetTimer()
for i := 0; i < b.N; i++ {
pr.SetSource(tc.input)
for g := tc.read(); len(g) > 0; g = tc.read() {
_ = g
}
}
})
}
}