golang-image/font/font_test.go
Nigel Tao 3ba119400e font: fix rectangle-union for empty rectangles.
The bounding box of a string does not necessarily contain the origin.
Prior to this commit, BoundString(etc, "x") would call grow exactly
once, with the first argument being the (empty) zero rectangle.

Change-Id: Id7d4f6c250ac0749f6dae19d11f4e97f9c6f45bc
Reviewed-on: https://go-review.googlesource.com/34674
Reviewed-by: Dave Day <djd@golang.org>
2016-12-28 23:11:51 +00:00

66 lines
1.5 KiB
Go

// Copyright 2016 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package font
import (
"image"
"strings"
"testing"
"golang.org/x/image/math/fixed"
)
const toyAdvance = fixed.Int26_6(10 << 6)
type toyFace struct{}
func (toyFace) Close() error {
return nil
}
func (toyFace) Glyph(dot fixed.Point26_6, r rune) (image.Rectangle, image.Image, image.Point, fixed.Int26_6, bool) {
panic("unimplemented")
}
func (toyFace) GlyphBounds(r rune) (fixed.Rectangle26_6, fixed.Int26_6, bool) {
return fixed.Rectangle26_6{
Min: fixed.P(2, 0),
Max: fixed.P(6, 1),
}, toyAdvance, true
}
func (toyFace) GlyphAdvance(r rune) (fixed.Int26_6, bool) {
return toyAdvance, true
}
func (toyFace) Kern(r0, r1 rune) fixed.Int26_6 {
return 0
}
func (toyFace) Metrics() Metrics {
return Metrics{}
}
func TestBound(t *testing.T) {
wantBounds := []fixed.Rectangle26_6{
{Min: fixed.P(0, 0), Max: fixed.P(0, 0)},
{Min: fixed.P(2, 0), Max: fixed.P(6, 1)},
{Min: fixed.P(2, 0), Max: fixed.P(16, 1)},
{Min: fixed.P(2, 0), Max: fixed.P(26, 1)},
}
for i, wantBound := range wantBounds {
s := strings.Repeat("x", i)
gotBound, gotAdvance := BoundString(toyFace{}, s)
if gotBound != wantBound {
t.Errorf("i=%d: bound: got %v, want %v", i, gotBound, wantBound)
}
wantAdvance := toyAdvance * fixed.Int26_6(i)
if gotAdvance != wantAdvance {
t.Errorf("i=%d: advance: got %v, want %v", i, gotAdvance, wantAdvance)
}
}
}