multiple fixes: prevent crash from nil loca, fix Height metric, cache advances, more robust to bad kern issues

CONTRIBUTORS

@@ -27,10 +27,12 @@
 # Please keep the list sorted.
 
 Andrew Gerrand <adg@golang.org>
+Dmitri Shuralyov <dmitshur@golang.org>
 Jeff R. Allen <jra@nella.org> <jeff.allen@gmail.com>
 Maksim Kochkin <maxxarts@gmail.com>
 Michael Fogleman <fogleman@gmail.com>
 Nigel Tao <nigeltao@golang.org>
+Randall O'Reilly <oreilly@ucdavis.edu>
 Rémy Oudompheng <oudomphe@phare.normalesup.org> <remyoudompheng@gmail.com>
 Rob Pike <r@golang.org>
 Roger Peppe <rogpeppe@gmail.com>

Makefile

@@ -0,0 +1,75 @@
+# Basic Go makefile
+
+GOCMD=go
+GOBUILD=$(GOCMD) build
+GOCLEAN=$(GOCMD) clean
+GOTEST=$(GOCMD) test
+GOGET=$(GOCMD) get
+
+DIRS=`go list ./...`
+
+all: build
+
+build: 
+	@echo "GO111MODULE = $(value GO111MODULE)"
+	$(GOBUILD) -v $(DIRS)
+
+test: 
+	@echo "GO111MODULE = $(value GO111MODULE)"
+	$(GOTEST) -v $(DIRS)
+
+clean: 
+	@echo "GO111MODULE = $(value GO111MODULE)"
+	$(GOCLEAN) ./...
+
+fmts:
+	gofmt -s -w .
+
+vet:
+	@echo "GO111MODULE = $(value GO111MODULE)"
+	$(GOCMD) vet $(DIRS) | grep -v unkeyed
+
+tidy: export GO111MODULE = on
+tidy:
+	@echo "GO111MODULE = $(value GO111MODULE)"
+	go mod tidy
+
+mod-update: export GO111MODULE = on
+mod-update:
+	@echo "GO111MODULE = $(value GO111MODULE)"
+	go get -u ./...
+	go mod tidy
+
+# gopath-update is for GOPATH to get most things updated.
+# need to call it in a target executable directory
+gopath-update: export GO111MODULE = off
+gopath-update:
+	@echo "GO111MODULE = $(value GO111MODULE)"
+	go get -u ./...
+
+# NOTE: MUST update version number here prior to running 'make release' and edit this file! 
+VERS=v1.0.1
+PACKAGE=freetype
+GIT_COMMIT=`git rev-parse --short HEAD`
+VERS_DATE=`date -u +%Y-%m-%d\ %H:%M`
+VERS_FILE=version.go
+
+release:
+	/bin/rm -f $(VERS_FILE)
+	@echo "// WARNING: auto-generated by Makefile release target -- run 'make release' to update" > $(VERS_FILE)
+	@echo "" >> $(VERS_FILE)
+	@echo "package $(PACKAGE)" >> $(VERS_FILE)
+	@echo "" >> $(VERS_FILE)
+	@echo "const (" >> $(VERS_FILE)
+	@echo "	Version = \"$(VERS)\"" >> $(VERS_FILE)
+	@echo "	GitCommit = \"$(GIT_COMMIT)\" // the commit JUST BEFORE the release" >> $(VERS_FILE)
+	@echo "	VersionDate = \"$(VERS_DATE)\" // UTC" >> $(VERS_FILE)
+	@echo ")" >> $(VERS_FILE)
+	@echo "" >> $(VERS_FILE)
+	goimports -w $(VERS_FILE)
+	/bin/cat $(VERS_FILE)
+	git commit -am "$(VERS) release"
+	git tag -a $(VERS) -m "$(VERS) release"
+	git push
+	git push origin --tags
+

README

@@ -1,7 +1,7 @@
 The Freetype font rasterizer in the Go programming language.
 
 To download and install from source:
-$ go get github.com/golang/freetype
+$ go get github.com/tdewolff/freetype
 
 It is an incomplete port:
   * It only supports TrueType fonts, and not Type 1 fonts nor bitmap fonts.

example/capjoin/main.go

@@ -3,9 +3,11 @@
 // FreeType License or the GNU General Public License version 2 (or
 // any later version), both of which can be found in the LICENSE file.
 
+//go:build example
 // +build example
+
 //
-// This build tag means that "go install github.com/golang/freetype/..."
+// This build tag means that "go install ..."
 // doesn't install this example program. Use "go run main.go" to run it or "go
 // install -tags=example" to install it.
 
@@ -21,7 +23,7 @@ import (
 	"log"
 	"os"
 
-	"github.com/golang/freetype/raster"
+	"github.com/goki/freetype/raster"
 	"golang.org/x/image/math/fixed"
 )
 

example/drawer/main.go

@@ -3,9 +3,11 @@
 // FreeType License or the GNU General Public License version 2 (or
 // any later version), both of which can be found in the LICENSE file.
 
+//go:build example
 // +build example
+
 //
-// This build tag means that "go install github.com/golang/freetype/..."
+// This build tag means that "go install ..."
 // doesn't install this example program. Use "go run main.go" to run it or "go
 // install -tags=example" to install it.
 
@@ -24,7 +26,7 @@ import (
 	"math"
 	"os"
 
-	"github.com/golang/freetype/truetype"
+	"github.com/goki/freetype/truetype"
 	"golang.org/x/image/font"
 	"golang.org/x/image/math/fixed"
 )

example/freetype/main.go

@@ -3,9 +3,11 @@
 // FreeType License or the GNU General Public License version 2 (or
 // any later version), both of which can be found in the LICENSE file.
 
+//go:build example
 // +build example
+
 //
-// This build tag means that "go install github.com/golang/freetype/..."
+// This build tag means that "go install ..."
 // doesn't install this example program. Use "go run main.go" to run it or "go
 // install -tags=example" to install it.
 
@@ -23,7 +25,7 @@ import (
 	"log"
 	"os"
 
-	"github.com/golang/freetype"
+	"github.com/goki/freetype"
 	"golang.org/x/image/font"
 )
 

example/gamma/main.go

@@ -3,9 +3,11 @@
 // FreeType License or the GNU General Public License version 2 (or
 // any later version), both of which can be found in the LICENSE file.
 
+//go:build example
 // +build example
+
 //
-// This build tag means that "go install github.com/golang/freetype/..."
+// This build tag means that "go install ..."
 // doesn't install this example program. Use "go run main.go" to run it or "go
 // install -tags=example" to install it.
 
@@ -20,7 +22,7 @@ import (
 	"log"
 	"os"
 
-	"github.com/golang/freetype/raster"
+	"github.com/goki/freetype/raster"
 	"golang.org/x/image/math/fixed"
 )
 

example/genbasicfont/main.go

@@ -3,9 +3,11 @@
 // FreeType License or the GNU General Public License version 2 (or
 // any later version), both of which can be found in the LICENSE file.
 
+//go:build example
 // +build example
+
 //
-// This build tag means that "go install github.com/golang/freetype/..."
+// This build tag means that "go install ..."
 // doesn't install this example program. Use "go run main.go" to run it or "go
 // install -tags=example" to install it.
 
@@ -26,7 +28,7 @@ import (
 	"strings"
 	"unicode"
 
-	"github.com/golang/freetype/truetype"
+	"github.com/goki/freetype/truetype"
 	"golang.org/x/image/font"
 	"golang.org/x/image/math/fixed"
 )

example/raster/main.go

@@ -3,9 +3,11 @@
 // FreeType License or the GNU General Public License version 2 (or
 // any later version), both of which can be found in the LICENSE file.
 
+//go:build example
 // +build example
+
 //
-// This build tag means that "go install github.com/golang/freetype/..."
+// This build tag means that "go install ..."
 // doesn't install this example program. Use "go run main.go" to run it or "go
 // install -tags=example" to install it.
 
@@ -21,7 +23,7 @@ import (
 	"log"
 	"os"
 
-	"github.com/golang/freetype/raster"
+	"github.com/goki/freetype/raster"
 	"golang.org/x/image/math/fixed"
 )
 

example/round/main.go

@@ -3,9 +3,11 @@
 // FreeType License or the GNU General Public License version 2 (or
 // any later version), both of which can be found in the LICENSE file.
 
+//go:build example
 // +build example
+
 //
-// This build tag means that "go install github.com/golang/freetype/..."
+// This build tag means that "go install ..."
 // doesn't install this example program. Use "go run main.go" to run it or "go
 // install -tags=example" to install it.
 
@@ -27,7 +29,7 @@ import (
 	"math"
 	"os"
 
-	"github.com/golang/freetype/raster"
+	"github.com/goki/freetype/raster"
 	"golang.org/x/image/math/fixed"
 )
 

example/truetype/main.go

@@ -3,9 +3,11 @@
 // FreeType License or the GNU General Public License version 2 (or
 // any later version), both of which can be found in the LICENSE file.
 
+//go:build example
 // +build example
+
 //
-// This build tag means that "go install github.com/golang/freetype/..."
+// This build tag means that "go install ..."
 // doesn't install this example program. Use "go run main.go" to run it or "go
 // install -tags=example" to install it.
 
@@ -17,7 +19,7 @@ import (
 	"io/ioutil"
 	"log"
 
-	"github.com/golang/freetype/truetype"
+	"github.com/goki/freetype/truetype"
 	"golang.org/x/image/font"
 	"golang.org/x/image/math/fixed"
 )

freetype.go

@@ -6,15 +6,15 @@
 // The freetype package provides a convenient API to draw text onto an image.
 // Use the freetype/raster and freetype/truetype packages for lower level
 // control over rasterization and TrueType parsing.
-package freetype // import "github.com/golang/freetype"
+package freetype
 
 import (
 	"errors"
 	"image"
 	"image/draw"
 
-	"github.com/golang/freetype/raster"
-	"github.com/golang/freetype/truetype"
+	"github.com/goki/freetype/raster"
+	"github.com/goki/freetype/truetype"
 	"golang.org/x/image/font"
 	"golang.org/x/image/math/fixed"
 )
@@ -78,7 +78,7 @@ type Context struct {
 // PointToFixed converts the given number of points (as in "a 12 point font")
 // into a 26.6 fixed point number of pixels.
 func (c *Context) PointToFixed(x float64) fixed.Int26_6 {
-	return fixed.Int26_6(x * float64(c.dpi) * (64.0 / 72.0))
+	return fixed.Int26_6(0.5 + (x * c.dpi * 64 / 72))
 }
 
 // drawContour draws the given closed contour with the given offset.
@@ -260,7 +260,7 @@ func (c *Context) DrawString(s string, p fixed.Point26_6) (fixed.Point26_6, erro
 // recalc recalculates scale and bounds values from the font size, screen
 // resolution and font metrics, and invalidates the glyph cache.
 func (c *Context) recalc() {
-	c.scale = fixed.Int26_6(c.fontSize * c.dpi * (64.0 / 72.0))
+	c.scale = fixed.Int26_6(0.5 + (c.fontSize * c.dpi * 64 / 72))
 	if c.f == nil {
 		c.r.SetBounds(0, 0)
 	} else {
@@ -332,10 +332,12 @@ func (c *Context) SetClip(clip image.Rectangle) {
 
 // NewContext creates a new Context.
 func NewContext() *Context {
-	return &Context{
+	c := &Context{
 		r:        raster.NewRasterizer(0, 0),
 		fontSize: 12,
 		dpi:      72,
 		scale:    12 << 6,
 	}
+	c.r.UseNonZeroWinding = true // needed for font rendering
+	return c
 }

freetype_test.go

@@ -12,6 +12,8 @@ import (
 	"runtime"
 	"strings"
 	"testing"
+
+	"golang.org/x/image/math/fixed"
 )
 
 func BenchmarkDrawString(b *testing.B) {
@@ -57,3 +59,26 @@ func BenchmarkDrawString(b *testing.B) {
 	mallocs = ms.Mallocs - mallocs
 	b.Logf("%d iterations, %d mallocs per iteration\n", b.N, int(mallocs)/b.N)
 }
+
+func TestScaling(t *testing.T) {
+	c := NewContext()
+	for _, tc := range [...]struct {
+		in   float64
+		want fixed.Int26_6
+	}{
+		{in: 12, want: fixed.I(12)},
+		{in: 11.992, want: fixed.I(12) - 1},
+		{in: 11.993, want: fixed.I(12)},
+		{in: 12.007, want: fixed.I(12)},
+		{in: 12.008, want: fixed.I(12) + 1},
+		{in: 86.4, want: fixed.Int26_6(86<<6 + 26)}, // Issue https://github.com/golang/freetype/issues/85.
+	} {
+		c.SetFontSize(tc.in)
+		if got, want := c.scale, tc.want; got != want {
+			t.Errorf("scale after SetFontSize(%v) = %v, want %v", tc.in, got, want)
+		}
+		if got, want := c.PointToFixed(tc.in), tc.want; got != want {
+			t.Errorf("PointToFixed(%v) = %v, want %v", tc.in, got, want)
+		}
+	}
+}

go.mod

@@ -0,0 +1,5 @@
+module github.com/goki/freetype
+
+go 1.18
+
+require golang.org/x/image v0.6.0