Extract drawing operations to Canvas interface (#1019)

* Revert "fonts: fix race condition (#963)"

This reverts commit 58155a8.

* Extract drawing operations to Canvas interface

* Add TTF versions of all fonts

* Fix buildifier errors by upgrading to latest

* Make DrawStringWrapped more generic

Move implementation details into `GGCanvas`.

cmd/render.go

@@ -4,7 +4,6 @@ import (
 	"context"
 	"fmt"
 	"image"
-	"io/ioutil"
 	"os"
 	"strings"
 	"time"
@@ -13,7 +12,7 @@ import (
 	"go.starlark.net/starlark"
 
 	"tidbyt.dev/pixlet/encode"
-	"tidbyt.dev/pixlet/globals"
+	pixletrender "tidbyt.dev/pixlet/render"
 	"tidbyt.dev/pixlet/runtime"
 	"tidbyt.dev/pixlet/starlarkutil"
 )
@@ -80,8 +79,8 @@ var RenderCmd = &cobra.Command{
 func render(cmd *cobra.Command, args []string) error {
 	script := args[0]
 
-	globals.Width = width
-	globals.Height = height
+	pixletrender.FrameWidth = width
+	pixletrender.FrameHeight = height
 
 	if !strings.HasSuffix(script, ".star") {
 		return fmt.Errorf("script file must have suffix .star: %s", script)
@@ -106,7 +105,7 @@ func render(cmd *cobra.Command, args []string) error {
 		config[split[0]] = strings.Join(split[1:], "=")
 	}
 
-	src, err := ioutil.ReadFile(script)
+	src, err := os.ReadFile(script)
 	if err != nil {
 		return fmt.Errorf("failed to read file %s: %w", script, err)
 	}
@@ -200,7 +199,7 @@ func render(cmd *cobra.Command, args []string) error {
 	if outPath == "-" {
 		_, err = os.Stdout.Write(buf)
 	} else {
-		err = ioutil.WriteFile(outPath, buf, 0644)
+		err = os.WriteFile(outPath, buf, 0644)
 	}
 
 	if err != nil {

docs/schema/location/example.star

@@ -1,6 +1,6 @@
+load("encoding/json.star", "json")
 load("render.star", "render")
 load("schema.star", "schema")
-load("encoding/json.star", "json")
 
 DEFAULT_LOCATION = """
 {

docs/schema/locationbased/example.star

@@ -1,6 +1,6 @@
+load("encoding/json.star", "json")
 load("render.star", "render")
 load("schema.star", "schema")
-load("encoding/json.star", "json")
 
 EXAMPLE_LOCATION = """
 {

docs/schema/oauth2/example.star

@@ -1,8 +1,8 @@
+load("encoding/json.star", "json")
 load("http.star", "http")
 load("render.star", "render")
 load("schema.star", "schema")
 load("secret.star", "secret")
-load("encoding/json.star", "json")
 
 OAUTH2_CLIENT_SECRET = secret.decrypt("your-client-secret")
 

docs/schema/photoselect/example.star

@@ -1,6 +1,6 @@
+load("encoding/base64.star", "base64")
 load("render.star", "render")
 load("schema.star", "schema")
-load("encoding/base64.star", "base64")
 
 def main(config):
     encoded = config.get("photo", DEFAULT_PHOTO)

examples/bitcoin.star

@@ -1,6 +1,6 @@
-load("render.star", "render")
-load("http.star", "http")
 load("encoding/base64.star", "base64")
+load("http.star", "http")
+load("render.star", "render")
 
 COINDESK_PRICE_URL = "https://api.coindesk.com/v1/bpi/currentprice.json"
 

examples/humanize.star

@@ -1,7 +1,7 @@
+load("humanize.star", "humanize")
 load("render.star", "render")
 load("schema.star", "schema")
 load("time.star", "time")
-load("humanize.star", "humanize")
 
 DEFAULT_COUNTER = "1337"
 DEFAULT_APPS = "42"

examples/qrcode.star

@@ -1,7 +1,7 @@
 load("cache.star", "cache")
 load("encoding/base64.star", "base64")
-load("render.star", "render")
 load("qrcode.star", "qrcode")
+load("render.star", "render")
 
 def main(config):
     url = "https://tidbyt.com?utm_source=pixlet_example"

examples/sunrise.star

@@ -1,8 +1,8 @@
+load("encoding/json.star", "json")
 load("render.star", "render")
 load("schema.star", "schema")
-load("time.star", "time")
-load("encoding/json.star", "json")
 load("sunrise.star", "sunrise")
+load("time.star", "time")
 
 DEFAULT_LOCATION = """
 {

fonts/fonts.go

@@ -0,0 +1,91 @@
+package fonts
+
+import (
+	"embed"
+	"fmt"
+	"log"
+	"strings"
+	"sync"
+
+	"github.com/zachomedia/go-bdf"
+)
+
+var (
+	//go:embed *.bdf *.ttf
+	files embed.FS
+
+	once      sync.Once
+	fontCache = map[string]*Font{}
+)
+
+type Font struct {
+	Name string
+	Font *bdf.Font
+
+	// BDF is the raw BDF font data.
+	BDF []byte
+
+	// TTF is the raw TTF font data.
+	TTF []byte
+}
+
+func loadFonts() {
+	fontFileInfos, err := files.ReadDir(".")
+	if err != nil {
+		fmt.Println("files.ReadDir()", err)
+		return
+	}
+
+	for _, ffi := range fontFileInfos {
+		if !strings.HasSuffix(ffi.Name(), ".bdf") {
+			continue
+		}
+
+		name := strings.TrimSuffix(ffi.Name(), ".bdf")
+
+		bdfBuf, err := files.ReadFile(name + ".bdf")
+		if err != nil {
+			fmt.Printf("files.ReadFile(): %s\n", err)
+			continue
+		}
+
+		ttfBuf, err := files.ReadFile(name + ".ttf")
+		if err != nil {
+			fmt.Printf("files.ReadFile(): %s\n", err)
+			continue
+		}
+
+		fnt, err := bdf.Parse(bdfBuf)
+		if err != nil {
+			fmt.Printf("bdf.Parse(%s): %s\n", ffi.Name(), err)
+		}
+
+		fontCache[name] = &Font{
+			Name: name,
+			Font: fnt,
+			BDF:  bdfBuf,
+			TTF:  ttfBuf,
+		}
+	}
+}
+
+func Names() []string {
+	once.Do(loadFonts)
+
+	fontNames := []string{}
+	for key := range fontCache {
+		fontNames = append(fontNames, key)
+	}
+	return fontNames
+}
+
+func GetFont(name string) *Font {
+	once.Do(loadFonts)
+
+	font, ok := fontCache[name]
+	if !ok {
+		log.Panicf("Unknown font '%s', the available fonts are: %v", name, Names())
+	}
+
+	return font
+}

render/animation.go

@@ -3,7 +3,7 @@ package render
 import (
 	"image"
 
-	"github.com/tidbyt/gg"
+	"tidbyt.dev/pixlet/render/canvas"
 )
 
 // Animations turns a list of children into an animation, where each
@@ -16,13 +16,15 @@ import (
 //
 // EXAMPLE BEGIN
 // render.Animation(
-//      children=[
-//           render.Box(width=10, height=10, color="#300"),
-//           render.Box(width=12, height=12, color="#500"),
-//           render.Box(width=14, height=14, color="#700"),
-//           render.Box(width=16, height=16, color="#900"),
-//           render.Box(width=18, height=18, color="#b00"),
-//      ],
+//
+//	children=[
+//	     render.Box(width=10, height=10, color="#300"),
+//	     render.Box(width=12, height=12, color="#500"),
+//	     render.Box(width=14, height=14, color="#700"),
+//	     render.Box(width=16, height=16, color="#900"),
+//	     render.Box(width=18, height=18, color="#b00"),
+//	],
+//
 // )
 // EXAMPLE END
 type Animation struct {
@@ -49,7 +51,7 @@ func (a Animation) PaintBounds(bounds image.Rectangle, frameIdx int) image.Recta
 	return a.Children[ModInt(frameIdx, len(a.Children))].PaintBounds(bounds, frameIdx)
 }
 
-func (a Animation) Paint(dc *gg.Context, bounds image.Rectangle, frameIdx int) {
+func (a Animation) Paint(dc canvas.Canvas, bounds image.Rectangle, frameIdx int) {
 	if len(a.Children) == 0 {
 		return
 	}

render/animation/positioned.go

@@ -4,9 +4,8 @@ import (
 	"image"
 	"math"
 
-	"github.com/tidbyt/gg"
-
 	"tidbyt.dev/pixlet/render"
+	"tidbyt.dev/pixlet/render/canvas"
 )
 
 // Animate a widget from start to end coordinates.
@@ -22,7 +21,6 @@ import (
 // DOC(Curve): Easing curve to use, default is 'linear'
 // DOC(Delay): Delay before animation in frames
 // DOC(Hold): Delay after animation in frames
-//
 type AnimatedPositioned struct {
 	render.Widget
 	Child    render.Widget `starlark:"child,required"`
@@ -40,7 +38,7 @@ func (o AnimatedPositioned) PaintBounds(bounds image.Rectangle, frameIdx int) im
 	return bounds
 }
 
-func (o AnimatedPositioned) Paint(dc *gg.Context, bounds image.Rectangle, frameIdx int) {
+func (o AnimatedPositioned) Paint(dc canvas.Canvas, bounds image.Rectangle, frameIdx int) {
 	var position float64
 
 	if frameIdx < o.Delay {

render/animation/rotate.go

@@ -1,19 +1,22 @@
 package animation
 
 import (
-	"github.com/tidbyt/gg"
+	"math"
+
+	"tidbyt.dev/pixlet/render/canvas"
 )
 
 // Transform by rotating by a given angle in degrees.
 //
 // DOC(Angle): Angle to rotate by in degrees
-//
 type Rotate struct {
 	Angle float64 `starlark:"angle,required"`
 }
 
-func (self Rotate) Apply(ctx *gg.Context, origin Vec2f, rounding Rounding) {
-	ctx.RotateAbout(gg.Radians(self.Angle), origin.X, origin.Y)
+func (self Rotate) Apply(ctx canvas.Canvas, origin Vec2f, rounding Rounding) {
+	ctx.Translate(origin.X, origin.Y)
+	ctx.Rotate(self.Angle * math.Pi / 180)
+	ctx.Translate(-origin.X, -origin.Y)
 }
 
 func (self Rotate) Interpolate(other Transform, progress float64) (result Transform, ok bool) {

render/animation/scale.go

@@ -1,20 +1,19 @@
 package animation
 
-import (
-	"github.com/tidbyt/gg"
-)
+import "tidbyt.dev/pixlet/render/canvas"
 
 // Transform by scaling by a given factor.
 //
 // DOC(X): Horizontal scale factor
 // DOC(Y): Vertical scale factor
-//
 type Scale struct {
 	Vec2f
 }
 
-func (self Scale) Apply(ctx *gg.Context, origin Vec2f, rounding Rounding) {
-	ctx.ScaleAbout(self.X, self.Y, origin.X, origin.Y)
+func (self Scale) Apply(ctx canvas.Canvas, origin Vec2f, rounding Rounding) {
+	ctx.Translate(origin.X, origin.Y)
+	ctx.Scale(self.X, self.Y)
+	ctx.Translate(-origin.X, -origin.Y)
 }
 
 func (self Scale) Interpolate(other Transform, progress float64) (result Transform, ok bool) {

render/animation/transform.go

@@ -1,11 +1,11 @@
 package animation
 
 import (
-	"github.com/tidbyt/gg"
+	"tidbyt.dev/pixlet/render/canvas"
 )
 
 type Transform interface {
-	Apply(ctx *gg.Context, origin Vec2f, rounding Rounding)
+	Apply(ctx canvas.Canvas, origin Vec2f, rounding Rounding)
 	Interpolate(other Transform, progress float64) (result Transform, ok bool)
 }