fixed dependencies

vendor/github.com/go-latex/latex/drawtex/canvas.go

@@ -0,0 +1,62 @@
+// Copyright ©2020 The go-latex 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 drawtex describes the graphics interface for drawing LaTeX.
+package drawtex // import "github.com/go-latex/latex/drawtex"
+
+import (
+	"github.com/go-latex/latex/font"
+	"golang.org/x/image/font/sfnt"
+)
+
+type Canvas struct {
+	ops []Op
+}
+
+func New() *Canvas {
+	return &Canvas{}
+}
+
+func (c *Canvas) RenderGlyph(x, y float64, infos Glyph) {
+	c.ops = append(c.ops, GlyphOp{x, y, infos})
+}
+
+func (c *Canvas) RenderRectFilled(x1, y1, x2, y2 float64) {
+	c.ops = append(c.ops, RectOp{x1, y1, x2, y2})
+}
+
+func (c *Canvas) Ops() []Op { return c.ops }
+
+type Op interface {
+	isOp()
+}
+
+type GlyphOp struct {
+	X, Y  float64
+	Glyph Glyph
+}
+
+func (GlyphOp) isOp() {}
+
+type RectOp struct {
+	X1, Y1 float64
+	X2, Y2 float64
+}
+
+func (RectOp) isOp() {}
+
+type Glyph struct {
+	Font       *sfnt.Font
+	Size       float64
+	Postscript string
+	Metrics    font.Metrics
+	Symbol     string
+	Num        sfnt.GlyphIndex
+	Offset     float64
+}
+
+var (
+	_ Op = (*GlyphOp)(nil)
+	_ Op = (*RectOp)(nil)
+)