Canvas refactoring

appWasm.go

@@ -4,6 +4,8 @@ package rui
 
 import (
 	_ "embed"
+	"encoding/base64"
+	"path/filepath"
 	"strings"
 	"syscall/js"
 )
@@ -112,10 +114,46 @@ func (app *wasmApp) createSession() Session {
 	return session
 }
 
-func (app *wasmApp) init() {
+func (app *wasmApp) init(params AppParams) {
+
+	app.params = params
 
 	document := js.Global().Get("document")
 	body := document.Call("querySelector", "body")
+	head := document.Call("querySelector", "head")
+
+	meta := document.Call("createElement", "meta")
+	meta.Set("name", "viewport")
+	meta.Set("content", "width=device-width")
+	head.Call("appendChild", meta)
+
+	meta = document.Call("createElement", "base")
+	meta.Set("target", "_blank")
+	meta.Set("rel", "noopener")
+	head.Call("appendChild", meta)
+
+	if params.Icon != "" {
+		if image, ok := resources.images[params.Icon]; ok && image.fs != nil {
+			dataType := map[string]string{
+				".svg":  "data:image/svg+xml",
+				".png":  "data:image/png",
+				".jpg":  "data:image/jpg",
+				".jpeg": "data:image/jpg",
+				".gif":  "data:image/gif",
+			}
+			ext := strings.ToLower(filepath.Ext(params.Icon))
+			if prefix, ok := dataType[ext]; ok {
+				if data, err := image.fs.ReadFile(image.path); err == nil {
+					meta = document.Call("createElement", "link")
+					meta.Set("rel", "icon")
+					meta.Set("href", prefix+";base64,"+base64.StdEncoding.EncodeToString(data))
+					head.Call("appendChild", meta)
+				} else {
+					DebugLog(err.Error())
+				}
+			}
+		}
+	}
 
 	script := document.Call("createElement", "script")
 	script.Set("type", "text/javascript")
@@ -156,6 +194,11 @@ func (app *wasmApp) init() {
 	div.Set("download", "")
 	div.Set("style", "display: none;")
 	body.Call("appendChild", div)
+
+	if params.TitleColor != 0 {
+		app.brige.runFunc("setTitleColor", params.TitleColor.cssString())
+	}
+
 }
 
 // StartApp - create the new wasmApp and start it
@@ -168,11 +211,10 @@ func StartApp(addr string, createContentFunc func(Session) SessionContent, param
 	}
 
 	app := new(wasmApp)
-	app.params = params
 	app.createContentFunc = createContentFunc
 	app.brige = createWasmBrige()
 
-	app.init()
+	app.init(params)
 	<-app.close
 }
 

app_scripts.js

@@ -1796,3 +1796,16 @@ function getPropertyValue(answerID, elementId, name) {
 function appendStyles(styles) {
 	document.querySelector('style').textContent += styles
 }
+
+function getCanvasContext(elementId) {
+	const canvas = document.getElementById(elementId)
+	const ctx = canvas.getContext('2d');
+	const dpr = window.devicePixelRatio || 1;
+	//var gradient;
+	//var path;
+	//var img;
+	ctx.canvas.width = dpr * canvas.clientWidth;
+	ctx.canvas.height = dpr * canvas.clientHeight;
+	ctx.scale(dpr, dpr);
+	return ctx;
+}

canvas.go

@@ -1,7 +1,7 @@
 package rui
 
 import (
-	"fmt"
+	"math"
 	"strconv"
 	"strings"
 )
@@ -290,42 +290,24 @@ type Canvas interface {
 	// in the rectangle (dstX, dstY, dstWidth, dstHeight), scaling in height and width if necessary
 	DrawImageFragment(srcX, srcY, srcWidth, srcHeight, dstX, dstY, dstWidth, dstHeight float64, image Image)
 
-	finishDraw() string
+	finishDraw()
 }
 
 type canvasData struct {
-	view   CanvasView
+	view    CanvasView
-	script strings.Builder
+	session Session
 }
 
 func newCanvas(view CanvasView) Canvas {
 	canvas := new(canvasData)
 	canvas.view = view
-	canvas.script.Grow(4096)
+	canvas.session = view.Session()
-	canvas.script.WriteString(`const canvas = document.getElementById('`)
+	canvas.session.cavnasStart(view.htmlID())
-	canvas.script.WriteString(view.htmlID())
-	canvas.script.WriteString(`');
-const ctx = canvas.getContext('2d');
-const dpr = window.devicePixelRatio || 1;
-var gradient;
-var path;
-var img;
-ctx.canvas.width = dpr * canvas.clientWidth;
-ctx.canvas.height = dpr * canvas.clientHeight;
-ctx.scale(dpr, dpr);`)
-	/*
-	   	canvas.script.WriteString(strconv.FormatFloat(view.canvasWidth(), 'g', -1, 64))
-	   	canvas.script.WriteString(`;
-	   ctx.canvas.height = dpr * `)
-	   	canvas.script.WriteString(strconv.FormatFloat(view.canvasHeight(), 'g', -1, 64))
-	   	canvas.script.WriteString(";\nctx.scale(dpr, dpr);")
-	*/
 	return canvas
 }
 
-func (canvas *canvasData) finishDraw() string {
+func (canvas *canvasData) finishDraw() {
-	canvas.script.WriteString("\n")
+	canvas.session.cavnasFinish()
-	return canvas.script.String()
 }
 
 func (canvas *canvasData) View() CanvasView {
@@ -347,162 +329,102 @@ func (canvas *canvasData) Height() float64 {
 }
 
 func (canvas *canvasData) Save() {
-	canvas.script.WriteString("\nctx.save();")
+	canvas.session.callCanvasFunc("save")
 }
 
 func (canvas *canvasData) Restore() {
-	canvas.script.WriteString("\nctx.restore();")
+	canvas.session.callCanvasFunc("restore")
 }
 
 func (canvas *canvasData) ClipRect(x, y, width, height float64) {
-	canvas.script.WriteString("\nctx.beginPath();\nctx.rect(")
+	canvas.session.callCanvasFunc("beginPath")
-	canvas.script.WriteString(strconv.FormatFloat(x, 'g', -1, 64))
+	canvas.session.callCanvasFunc("rect", x, y, width, height)
-	canvas.script.WriteRune(',')
+	canvas.session.callCanvasFunc("clip")
-	canvas.script.WriteString(strconv.FormatFloat(y, 'g', -1, 64))
-	canvas.script.WriteRune(',')
-	canvas.script.WriteString(strconv.FormatFloat(width, 'g', -1, 64))
-	canvas.script.WriteRune(',')
-	canvas.script.WriteString(strconv.FormatFloat(height, 'g', -1, 64))
-	canvas.script.WriteString(");\nctx.clip();")
 }
 
 func (canvas *canvasData) ClipPath(path Path) {
-	canvas.script.WriteString(path.scriptText())
+	path.create(canvas.session)
-	canvas.script.WriteString("\nctx.clip();")
+	canvas.session.callCanvasFunc("clip")
 }
 
 func (canvas *canvasData) SetScale(x, y float64) {
-	canvas.script.WriteString("\nctx.scale(")
+	canvas.session.callCanvasFunc("scale", x, y)
-	canvas.script.WriteString(strconv.FormatFloat(x, 'g', -1, 64))
-	canvas.script.WriteRune(',')
-	canvas.script.WriteString(strconv.FormatFloat(y, 'g', -1, 64))
-	canvas.script.WriteString(");")
 }
 
 func (canvas *canvasData) SetTranslation(x, y float64) {
-	canvas.script.WriteString("\nctx.translate(")
+	canvas.session.callCanvasFunc("translate", x, y)
-	canvas.script.WriteString(strconv.FormatFloat(x, 'g', -1, 64))
-	canvas.script.WriteRune(',')
-	canvas.script.WriteString(strconv.FormatFloat(y, 'g', -1, 64))
-	canvas.script.WriteString(");")
 }
 
 func (canvas *canvasData) SetRotation(angle float64) {
-	canvas.script.WriteString("\nctx.rotate(")
+	canvas.session.callCanvasFunc("rotate", angle)
-	canvas.script.WriteString(strconv.FormatFloat(angle, 'g', -1, 64))
-	canvas.script.WriteString(");")
 }
 
 func (canvas *canvasData) SetTransformation(xScale, yScale, xSkew, ySkew, dx, dy float64) {
-	canvas.script.WriteString("\nctx.transform(")
+	canvas.session.callCanvasFunc("transform", xScale, ySkew, xSkew, yScale, dx, dy)
-	canvas.script.WriteString(strconv.FormatFloat(xScale, 'g', -1, 64))
-	canvas.script.WriteRune(',')
-	canvas.script.WriteString(strconv.FormatFloat(ySkew, 'g', -1, 64))
-	canvas.script.WriteRune(',')
-	canvas.script.WriteString(strconv.FormatFloat(xSkew, 'g', -1, 64))
-	canvas.script.WriteRune(',')
-	canvas.script.WriteString(strconv.FormatFloat(yScale, 'g', -1, 64))
-	canvas.script.WriteRune(',')
-	canvas.script.WriteString(strconv.FormatFloat(dx, 'g', -1, 64))
-	canvas.script.WriteRune(',')
-	canvas.script.WriteString(strconv.FormatFloat(dy, 'g', -1, 64))
-	canvas.script.WriteString(");")
 }
 
 func (canvas *canvasData) ResetTransformation() {
-	canvas.script.WriteString("\nctx.resetTransform();\nctx.scale(dpr, dpr);")
+	canvas.session.callCanvasFunc("resetTransform")
+	canvas.session.callCanvasFunc("scale", canvas.session.PixelRatio(), canvas.session.PixelRatio())
+	//canvas.session.callCanvasFunc("scale", angle)
+	// TODO canvas.script.WriteString("\nctx.resetTransform();\nctx.scale(dpr, dpr);")
 }
 
 func (canvas *canvasData) SetSolidColorFillStyle(color Color) {
-	canvas.script.WriteString("\nctx.fillStyle = \"")
+	canvas.session.updateCanvasProperty("fillStyle", color.cssString())
-	canvas.script.WriteString(color.cssString())
-	canvas.script.WriteString(`";`)
 }
 
 func (canvas *canvasData) SetSolidColorStrokeStyle(color Color) {
-	canvas.script.WriteString("\nctx.strokeStyle = \"")
+	canvas.session.updateCanvasProperty("strokeStyle", color.cssString())
-	canvas.script.WriteString(color.cssString())
-	canvas.script.WriteString(`";`)
 }
 
-func (canvas *canvasData) setLinearGradient(x0, y0 float64, color0 Color, x1, y1 float64, color1 Color, stopPoints []GradientPoint) {
+func (canvas *canvasData) createLinearGradient(x0, y0 float64, color0 Color, x1, y1 float64, color1 Color, stopPoints []GradientPoint) any {
-	canvas.script.WriteString("\ngradient = ctx.createLinearGradient(")
+
-	canvas.script.WriteString(strconv.FormatFloat(x0, 'g', -1, 64))
+	gradient := canvas.session.createCanvasVar("createLinearGradient", x0, y0, x1, y1)
-	canvas.script.WriteRune(',')
+	canvas.session.callCanvasVarFunc(gradient, "addColorStop", 0, color0.cssString())
-	canvas.script.WriteString(strconv.FormatFloat(y0, 'g', -1, 64))
-	canvas.script.WriteRune(',')
-	canvas.script.WriteString(strconv.FormatFloat(x1, 'g', -1, 64))
-	canvas.script.WriteRune(',')
-	canvas.script.WriteString(strconv.FormatFloat(y1, 'g', -1, 64))
-	canvas.script.WriteString(");\ngradient.addColorStop(0, '")
-	canvas.script.WriteString(color0.cssString())
-	canvas.script.WriteString("');")
 
 	for _, point := range stopPoints {
 		if point.Offset >= 0 && point.Offset <= 1 {
-			canvas.script.WriteString("\ngradient.addColorStop(")
+			canvas.session.callCanvasVarFunc(gradient, "addColorStop", point.Offset, point.Color.cssString())
-			canvas.script.WriteString(strconv.FormatFloat(point.Offset, 'g', -1, 64))
-			canvas.script.WriteString(", '")
-			canvas.script.WriteString(point.Color.cssString())
-			canvas.script.WriteString("');")
 		}
 	}
 
-	canvas.script.WriteString("\ngradient.addColorStop(1, '")
+	canvas.session.callCanvasVarFunc(gradient, "addColorStop", 1, color1.cssString())
-	canvas.script.WriteString(color1.cssString())
+	return gradient
-	canvas.script.WriteString("');")
 }
 
 func (canvas *canvasData) SetLinearGradientFillStyle(x0, y0 float64, color0 Color, x1, y1 float64, color1 Color, stopPoints []GradientPoint) {
-	canvas.setLinearGradient(x0, y0, color0, x1, y1, color1, stopPoints)
+	gradient := canvas.createLinearGradient(x0, y0, color0, x1, y1, color1, stopPoints)
-	canvas.script.WriteString("\nctx.fillStyle = gradient;")
+	canvas.session.updateCanvasProperty("fillStyle", gradient)
 }
 
 func (canvas *canvasData) SetLinearGradientStrokeStyle(x0, y0 float64, color0 Color, x1, y1 float64, color1 Color, stopPoints []GradientPoint) {
-	canvas.setLinearGradient(x0, y0, color0, x1, y1, color1, stopPoints)
+	gradient := canvas.createLinearGradient(x0, y0, color0, x1, y1, color1, stopPoints)
-	canvas.script.WriteString("\nctx.strokeStyle = gradient;")
+	canvas.session.updateCanvasProperty("strokeStyle", gradient)
 }
 
-func (canvas *canvasData) setRadialGradient(x0, y0, r0 float64, color0 Color, x1, y1, r1 float64, color1 Color, stopPoints []GradientPoint) {
+func (canvas *canvasData) createRadialGradient(x0, y0, r0 float64, color0 Color, x1, y1, r1 float64, color1 Color, stopPoints []GradientPoint) any {
-	canvas.script.WriteString("\ngradient = ctx.createRadialGradient(")
+	gradient := canvas.session.createCanvasVar("createRadialGradient", x0, y0, r0, x1, y1, r1)
-	canvas.script.WriteString(strconv.FormatFloat(x0, 'g', -1, 64))
+	canvas.session.callCanvasVarFunc(gradient, "addColorStop", 0, color0.cssString())
-	canvas.script.WriteRune(',')
-	canvas.script.WriteString(strconv.FormatFloat(y0, 'g', -1, 64))
-	canvas.script.WriteRune(',')
-	canvas.script.WriteString(strconv.FormatFloat(r0, 'g', -1, 64))
-	canvas.script.WriteRune(',')
-	canvas.script.WriteString(strconv.FormatFloat(x1, 'g', -1, 64))
-	canvas.script.WriteRune(',')
-	canvas.script.WriteString(strconv.FormatFloat(y1, 'g', -1, 64))
-	canvas.script.WriteRune(',')
-	canvas.script.WriteString(strconv.FormatFloat(r1, 'g', -1, 64))
-	canvas.script.WriteString(");\ngradient.addColorStop(0, '")
-	canvas.script.WriteString(color0.cssString())
-	canvas.script.WriteString("');")
 
 	for _, point := range stopPoints {
 		if point.Offset >= 0 && point.Offset <= 1 {
-			canvas.script.WriteString("\ngradient.addColorStop(")
+			canvas.session.callCanvasVarFunc(gradient, "addColorStop", point.Offset, point.Color.cssString())
-			canvas.script.WriteString(strconv.FormatFloat(point.Offset, 'g', -1, 64))
-			canvas.script.WriteString(", '")
-			canvas.script.WriteString(point.Color.cssString())
-			canvas.script.WriteString("');")
 		}
 	}
 
-	canvas.script.WriteString("\ngradient.addColorStop(1, '")
+	canvas.session.callCanvasVarFunc(gradient, "addColorStop", 1, color1.cssString())
-	canvas.script.WriteString(color1.cssString())
+	return gradient
-	canvas.script.WriteString("');")
 }
 
 func (canvas *canvasData) SetRadialGradientFillStyle(x0, y0, r0 float64, color0 Color, x1, y1, r1 float64, color1 Color, stopPoints []GradientPoint) {
-	canvas.setRadialGradient(x0, y0, r0, color0, x1, y1, r1, color1, stopPoints)
+	gradient := canvas.createRadialGradient(x0, y0, r0, color0, x1, y1, r1, color1, stopPoints)
-	canvas.script.WriteString("\nctx.fillStyle = gradient;")
+	canvas.session.updateCanvasProperty("fillStyle", gradient)
 }
 
 func (canvas *canvasData) SetRadialGradientStrokeStyle(x0, y0, r0 float64, color0 Color, x1, y1, r1 float64, color1 Color, stopPoints []GradientPoint) {
-	canvas.setRadialGradient(x0, y0, r0, color0, x1, y1, r1, color1, stopPoints)
+	gradient := canvas.createRadialGradient(x0, y0, r0, color0, x1, y1, r1, color1, stopPoints)
-	canvas.script.WriteString("\nctx.strokeStyle = gradient;")
+	canvas.session.updateCanvasProperty("strokeStyle", gradient)
 }
 
 func (canvas *canvasData) SetImageFillStyle(image Image, repeat int) {
@@ -528,89 +450,70 @@ func (canvas *canvasData) SetImageFillStyle(image Image, repeat int) {
 		return
 	}
 
-	canvas.script.WriteString("\nimg = images.get('")
+	canvas.session.callCanvasImageFunc(image.URL(), "fillStyle", "createPattern", repeatText)
-	canvas.script.WriteString(image.URL())
-	canvas.script.WriteString("');\nif (img) {\nctx.fillStyle = ctx.createPattern(img,'")
-	canvas.script.WriteString(repeatText)
-	canvas.script.WriteString("');\n}")
 }
 
 func (canvas *canvasData) SetLineWidth(width float64) {
 	if width > 0 {
-		canvas.script.WriteString("\nctx.lineWidth = '")
+		canvas.session.updateCanvasProperty("lineWidth", width)
-		canvas.script.WriteString(strconv.FormatFloat(width, 'g', -1, 64))
-		canvas.script.WriteString("';")
 	}
 }
 
 func (canvas *canvasData) SetLineJoin(join int) {
 	switch join {
 	case MiterJoin:
-		canvas.script.WriteString("\nctx.lineJoin = 'miter';")
+		canvas.session.updateCanvasProperty("lineJoin", "miter")
 
 	case RoundJoin:
-		canvas.script.WriteString("\nctx.lineJoin = 'round';")
+		canvas.session.updateCanvasProperty("lineJoin", "round")
 
 	case BevelJoin:
-		canvas.script.WriteString("\nctx.lineJoin = 'bevel';")
+		canvas.session.updateCanvasProperty("lineJoin", "bevel")
 	}
 }
 
 func (canvas *canvasData) SetLineCap(cap int) {
 	switch cap {
 	case ButtCap:
-		canvas.script.WriteString("\nctx.lineCap = 'butt';")
+		canvas.session.updateCanvasProperty("lineCap", "butt")
 
 	case RoundCap:
-		canvas.script.WriteString("\nctx.lineCap = 'round';")
+		canvas.session.updateCanvasProperty("lineCap", "round")
 
 	case SquareCap:
-		canvas.script.WriteString("\nctx.lineCap = 'square';")
+		canvas.session.updateCanvasProperty("lineCap", "square")
 	}
 }
 
 func (canvas *canvasData) SetLineDash(dash []float64, offset float64) {
-	canvas.script.WriteString("\nctx.setLineDash([")
+	canvas.session.callCanvasFunc("setLineDash", dash)
-	for i, d := range dash {
-		if i > 0 {
-			canvas.script.WriteString(",")
-		}
-		canvas.script.WriteString(strconv.FormatFloat(d, 'g', -1, 64))
-	}
-
-	canvas.script.WriteString("]);")
 	if offset >= 0 {
-		canvas.script.WriteString("\nctx.lineDashOffset = '")
+		canvas.session.updateCanvasProperty("lineDashOffset", offset)
-		canvas.script.WriteString(strconv.FormatFloat(offset, 'g', -1, 64))
-		canvas.script.WriteString("';")
 	}
 }
 
-func (canvas *canvasData) writeFont(name string, script *strings.Builder) {
+/*
-	names := strings.Split(name, ",")
+	func (canvas *canvasData) convertFont(name string) string {
-	lead := " "
+		buffer := allocStringBuilder()
-	for _, font := range names {
+		defer freeStringBuilder(buffer)
-		font = strings.Trim(font, " \n\"'")
+
-		script.WriteString(lead)
+		for i, font := range strings.Split(name, ",") {
-		lead = ","
+			font = strings.Trim(font, " \n\"'")
-		if strings.Contains(font, " ") {
+			if i > 0 {
-			script.WriteRune('"')
+				buffer.WriteRune(',')
-			script.WriteString(font)
+			}
-			script.WriteRune('"')
+			if strings.Contains(font, " ") {
-		} else {
+				buffer.WriteRune('"')
-			script.WriteString(font)
+				buffer.WriteString(font)
+				buffer.WriteRune('"')
+			} else {
+				buffer.WriteString(font)
+			}
 		}
 
+		return buffer.String()
 	}
-	script.WriteString("';")
+*/
-}
-
-func (canvas *canvasData) SetFont(name string, size SizeUnit) {
-	canvas.script.WriteString("\nctx.font = '")
-	canvas.script.WriteString(size.cssString("1rem", canvas.View().Session()))
-	canvas.writeFont(name, &canvas.script)
-}
-
 func (canvas *canvasData) fontWithParams(name string, size SizeUnit, params FontParams) string {
 	buffer := allocStringBuilder()
 	defer freeStringBuilder(buffer)
@@ -672,135 +575,76 @@ func (canvas *canvasData) fontWithParams(name string, size SizeUnit, params Font
 	return buffer.String()
 }
 
-func (canvas *canvasData) setFontWithParams(name string, size SizeUnit, params FontParams, script *strings.Builder) {
+func (canvas *canvasData) SetFont(name string, size SizeUnit) {
-	script.WriteString("\nctx.font = '")
+	canvas.session.updateCanvasProperty("font", canvas.fontWithParams(name, size, FontParams{}))
-	if params.Italic {
-		script.WriteString("italic ")
-	}
-	if params.SmallCaps {
-		script.WriteString("small-caps ")
-	}
-	if params.Weight > 0 && params.Weight <= 9 {
-		switch params.Weight {
-		case 4:
-			script.WriteString("normal ")
-		case 7:
-			script.WriteString("bold ")
-		default:
-			script.WriteString(strconv.Itoa(params.Weight * 100))
-			script.WriteRune(' ')
-		}
-	}
-
-	script.WriteString(size.cssString("1rem", canvas.View().Session()))
-	switch params.LineHeight.Type {
-	case Auto:
-
-	case SizeInPercent:
-		if params.LineHeight.Value != 100 {
-			script.WriteString("/")
-			script.WriteString(strconv.FormatFloat(params.LineHeight.Value/100, 'g', -1, 64))
-		}
-
-	case SizeInFraction:
-		if params.LineHeight.Value != 1 {
-			script.WriteString("/")
-			script.WriteString(strconv.FormatFloat(params.LineHeight.Value, 'g', -1, 64))
-		}
-
-	default:
-		script.WriteString("/")
-		script.WriteString(params.LineHeight.cssString("", canvas.View().Session()))
-	}
-
-	canvas.writeFont(name, script)
 }
 
 func (canvas *canvasData) SetFontWithParams(name string, size SizeUnit, params FontParams) {
-	canvas.setFontWithParams(name, size, params, &canvas.script)
+	canvas.session.updateCanvasProperty("font", canvas.fontWithParams(name, size, params))
 }
 
 func (canvas *canvasData) TextMetrics(text string, fontName string, fontSize SizeUnit, fontParams FontParams) TextMetrics {
-	view := canvas.View()
+	return canvas.session.canvasTextMetrics(canvas.view.htmlID(), canvas.fontWithParams(fontName, fontSize, fontParams), text)
-	return view.Session().canvasTextMetrics(view.htmlID(), canvas.fontWithParams(fontName, fontSize, fontParams), text)
 }
 
 func (canvas *canvasData) SetTextBaseline(baseline int) {
 	switch baseline {
 	case AlphabeticBaseline:
-		canvas.script.WriteString("\nctx.textBaseline = 'alphabetic';")
+		canvas.session.updateCanvasProperty("textBaseline", "alphabetic")
 	case TopBaseline:
-		canvas.script.WriteString("\nctx.textBaseline = 'top';")
+		canvas.session.updateCanvasProperty("textBaseline", "top")
 	case MiddleBaseline:
-		canvas.script.WriteString("\nctx.textBaseline = 'middle';")
+		canvas.session.updateCanvasProperty("textBaseline", "middle")
 	case BottomBaseline:
-		canvas.script.WriteString("\nctx.textBaseline = 'bottom';")
+		canvas.session.updateCanvasProperty("textBaseline", "bottom")
 	case HangingBaseline:
-		canvas.script.WriteString("\nctx.textBaseline = 'hanging';")
+		canvas.session.updateCanvasProperty("textBaseline", "hanging")
 	case IdeographicBaseline:
-		canvas.script.WriteString("\nctx.textBaseline = 'ideographic';")
+		canvas.session.updateCanvasProperty("textBaseline", "ideographic")
 	}
 }
 
 func (canvas *canvasData) SetTextAlign(align int) {
 	switch align {
 	case LeftAlign:
-		canvas.script.WriteString("\nctx.textAlign = 'left';")
+		canvas.session.updateCanvasProperty("textAlign", "left")
 	case RightAlign:
-		canvas.script.WriteString("\nctx.textAlign = 'right';")
+		canvas.session.updateCanvasProperty("textAlign", "right")
 	case CenterAlign:
-		canvas.script.WriteString("\nctx.textAlign = 'center';")
+		canvas.session.updateCanvasProperty("textAlign", "center")
 	case StartAlign:
-		canvas.script.WriteString("\nctx.textAlign = 'start';")
+		canvas.session.updateCanvasProperty("textAlign", "start")
 	case EndAlign:
-		canvas.script.WriteString("\nctx.textAlign = 'end';")
+		canvas.session.updateCanvasProperty("textAlign", "end")
 	}
 }
 
 func (canvas *canvasData) SetShadow(offsetX, offsetY, blur float64, color Color) {
 	if color.Alpha() > 0 && blur >= 0 {
-		canvas.script.WriteString("\nctx.shadowColor = '")
+		canvas.session.updateCanvasProperty("shadowColor", color.cssString())
-		canvas.script.WriteString(color.cssString())
+		canvas.session.updateCanvasProperty("shadowOffsetX", offsetX)
-		canvas.script.WriteString("';\nctx.shadowOffsetX = ")
+		canvas.session.updateCanvasProperty("shadowOffsetY", offsetY)
-		canvas.script.WriteString(strconv.FormatFloat(offsetX, 'g', -1, 64))
+		canvas.session.updateCanvasProperty("shadowBlur", blur)
-		canvas.script.WriteString(";\nctx.shadowOffsetY = ")
-		canvas.script.WriteString(strconv.FormatFloat(offsetY, 'g', -1, 64))
-		canvas.script.WriteString(";\nctx.shadowBlur = ")
-		canvas.script.WriteString(strconv.FormatFloat(blur, 'g', -1, 64))
-		canvas.script.WriteString(";")
 	}
 }
 
 func (canvas *canvasData) ResetShadow() {
-	canvas.script.WriteString("\nctx.shadowColor = 'rgba(0,0,0,0)';\nctx.shadowOffsetX = 0;\nctx.shadowOffsetY = 0;\nctx.shadowBlur = 0;")
+	canvas.session.updateCanvasProperty("shadowColor", "rgba(0,0,0,0)")
-}
+	canvas.session.updateCanvasProperty("shadowOffsetX", 0)
-
+	canvas.session.updateCanvasProperty("shadowOffsetY", 0)
-func (canvas *canvasData) writeRectArgs(x, y, width, height float64) {
+	canvas.session.updateCanvasProperty("shadowBlur", 0)
-	canvas.script.WriteString(strconv.FormatFloat(x, 'g', -1, 64))
-	canvas.script.WriteRune(',')
-	canvas.script.WriteString(strconv.FormatFloat(y, 'g', -1, 64))
-	canvas.script.WriteRune(',')
-	canvas.script.WriteString(strconv.FormatFloat(width, 'g', -1, 64))
-	canvas.script.WriteRune(',')
-	canvas.script.WriteString(strconv.FormatFloat(height, 'g', -1, 64))
 }
 
 func (canvas *canvasData) ClearRect(x, y, width, height float64) {
-	canvas.script.WriteString("\nctx.clearRect(")
+	canvas.session.callCanvasFunc("clearRect", x, y, width, height)
-	canvas.writeRectArgs(x, y, width, height)
-	canvas.script.WriteString(");")
 }
 
 func (canvas *canvasData) FillRect(x, y, width, height float64) {
-	canvas.script.WriteString("\nctx.fillRect(")
+	canvas.session.callCanvasFunc("fillRect", x, y, width, height)
-	canvas.writeRectArgs(x, y, width, height)
-	canvas.script.WriteString(");")
 }
 
 func (canvas *canvasData) StrokeRect(x, y, width, height float64) {
-	canvas.script.WriteString("\nctx.strokeRect(")
+	canvas.session.callCanvasFunc("strokeRect", x, y, width, height)
-	canvas.writeRectArgs(x, y, width, height)
-	canvas.script.WriteString(");")
 }
 
 func (canvas *canvasData) FillAndStrokeRect(x, y, width, height float64) {
@@ -808,7 +652,7 @@ func (canvas *canvasData) FillAndStrokeRect(x, y, width, height float64) {
 	canvas.StrokeRect(x, y, width, height)
 }
 
-func (canvas *canvasData) writeRoundedRect(x, y, width, height, r float64) {
+func (canvas *canvasData) createRoundedRect(x, y, width, height, r float64) {
 	left := strconv.FormatFloat(x, 'g', -1, 64)
 	top := strconv.FormatFloat(y, 'g', -1, 64)
 	right := strconv.FormatFloat(x+width, 'g', -1, 64)
@@ -818,104 +662,65 @@ func (canvas *canvasData) writeRoundedRect(x, y, width, height, r float64) {
 	rightR := strconv.FormatFloat(x+width-r, 'g', -1, 64)
 	bottomR := strconv.FormatFloat(y+height-r, 'g', -1, 64)
 	radius := strconv.FormatFloat(r, 'g', -1, 64)
-	canvas.script.WriteString("\nctx.beginPath();\nctx.moveTo(")
+
-	canvas.script.WriteString(left)
+	canvas.session.callCanvasFunc("beginPath")
-	canvas.script.WriteRune(',')
+	canvas.session.callCanvasFunc("moveTo", left, topR)
-	canvas.script.WriteString(topR)
+	canvas.session.callCanvasFunc("arc", leftR, topR, radius, math.Pi, math.Pi*3/2)
-	canvas.script.WriteString(");\nctx.arc(")
+	canvas.session.callCanvasFunc("lineTo", rightR, top)
-	canvas.script.WriteString(leftR)
+	canvas.session.callCanvasFunc("arc", rightR, topR, radius, math.Pi*3/2, math.Pi*2)
-	canvas.script.WriteRune(',')
+	canvas.session.callCanvasFunc("lineTo", right, bottomR)
-	canvas.script.WriteString(topR)
+	canvas.session.callCanvasFunc("arc", rightR, bottomR, radius, 0, math.Pi/2)
-	canvas.script.WriteRune(',')
+	canvas.session.callCanvasFunc("lineTo", leftR, bottom)
-	canvas.script.WriteString(radius)
+	canvas.session.callCanvasFunc("arc", leftR, bottomR, radius, math.Pi/2, math.Pi)
-	canvas.script.WriteString(",Math.PI,Math.PI*3/2);\nctx.lineTo(")
+	canvas.session.callCanvasFunc("closePath")
-	canvas.script.WriteString(rightR)
-	canvas.script.WriteRune(',')
-	canvas.script.WriteString(top)
-	canvas.script.WriteString(");\nctx.arc(")
-	canvas.script.WriteString(rightR)
-	canvas.script.WriteRune(',')
-	canvas.script.WriteString(topR)
-	canvas.script.WriteRune(',')
-	canvas.script.WriteString(radius)
-	canvas.script.WriteString(",Math.PI*3/2,Math.PI*2);\nctx.lineTo(")
-	canvas.script.WriteString(right)
-	canvas.script.WriteRune(',')
-	canvas.script.WriteString(bottomR)
-	canvas.script.WriteString(");\nctx.arc(")
-	canvas.script.WriteString(rightR)
-	canvas.script.WriteRune(',')
-	canvas.script.WriteString(bottomR)
-	canvas.script.WriteRune(',')
-	canvas.script.WriteString(radius)
-	canvas.script.WriteString(",0,Math.PI/2);\nctx.lineTo(")
-	canvas.script.WriteString(leftR)
-	canvas.script.WriteRune(',')
-	canvas.script.WriteString(bottom)
-	canvas.script.WriteString(");\nctx.arc(")
-	canvas.script.WriteString(leftR)
-	canvas.script.WriteRune(',')
-	canvas.script.WriteString(bottomR)
-	canvas.script.WriteRune(',')
-	canvas.script.WriteString(radius)
-	canvas.script.WriteString(",Math.PI/2,Math.PI);\nctx.closePath();")
 }
 
 func (canvas *canvasData) FillRoundedRect(x, y, width, height, r float64) {
-	canvas.writeRoundedRect(x, y, width, height, r)
+	canvas.createRoundedRect(x, y, width, height, r)
-	canvas.script.WriteString("\nctx.fill();")
+	canvas.session.callCanvasFunc("fill")
 }
 
 func (canvas *canvasData) StrokeRoundedRect(x, y, width, height, r float64) {
-	canvas.writeRoundedRect(x, y, width, height, r)
+	canvas.createRoundedRect(x, y, width, height, r)
-	canvas.script.WriteString("\nctx.stroke();")
+	canvas.session.callCanvasFunc("stroke")
 }
 
 func (canvas *canvasData) FillAndStrokeRoundedRect(x, y, width, height, r float64) {
-	canvas.writeRoundedRect(x, y, width, height, r)
+	canvas.createRoundedRect(x, y, width, height, r)
-	canvas.script.WriteString("\nctx.fill();\nctx.stroke();")
+	canvas.session.callCanvasFunc("fill")
+	canvas.session.callCanvasFunc("stroke")
 }
 
-func (canvas *canvasData) writeEllipse(x, y, radiusX, radiusY, rotation float64) {
+func (canvas *canvasData) createEllipse(x, y, radiusX, radiusY, rotation float64) {
-	yText := strconv.FormatFloat(y, 'g', -1, 64)
+	canvas.session.callCanvasFunc("beginPath")
-	canvas.script.WriteString("\nctx.beginPath();\nctx.moveTo(")
+	canvas.session.callCanvasFunc("moveTo", x+radiusX, y)
-	canvas.script.WriteString(strconv.FormatFloat(x+radiusX, 'g', -1, 64))
+	canvas.session.callCanvasFunc("ellipse", x, y, radiusX, radiusY, rotation, 0, math.Pi*2)
-	canvas.script.WriteRune(',')
+	//canvas.session.callCanvasFunc("closePath")
-	canvas.script.WriteString(yText)
-	canvas.script.WriteString(");\nctx.ellipse(")
-	canvas.script.WriteString(strconv.FormatFloat(x, 'g', -1, 64))
-	canvas.script.WriteRune(',')
-	canvas.script.WriteString(yText)
-	canvas.script.WriteRune(',')
-	canvas.script.WriteString(strconv.FormatFloat(radiusX, 'g', -1, 64))
-	canvas.script.WriteRune(',')
-	canvas.script.WriteString(strconv.FormatFloat(radiusY, 'g', -1, 64))
-	canvas.script.WriteRune(',')
-	canvas.script.WriteString(strconv.FormatFloat(rotation, 'g', -1, 64))
-	canvas.script.WriteString(",0,Math.PI*2);")
 }
 
 func (canvas *canvasData) FillEllipse(x, y, radiusX, radiusY, rotation float64) {
 	if radiusX >= 0 && radiusY >= 0 {
-		canvas.writeEllipse(x, y, radiusX, radiusY, rotation)
+		canvas.createEllipse(x, y, radiusX, radiusY, rotation)
-		canvas.script.WriteString("\nctx.fill();")
+		canvas.session.callCanvasFunc("fill")
 	}
 }
 
 func (canvas *canvasData) StrokeEllipse(x, y, radiusX, radiusY, rotation float64) {
 	if radiusX >= 0 && radiusY >= 0 {
-		canvas.writeEllipse(x, y, radiusX, radiusY, rotation)
+		canvas.createEllipse(x, y, radiusX, radiusY, rotation)
-		canvas.script.WriteString("\nctx.stroke();")
+		canvas.session.callCanvasFunc("stroke")
 	}
 }
 
 func (canvas *canvasData) FillAndStrokeEllipse(x, y, radiusX, radiusY, rotation float64) {
 	if radiusX >= 0 && radiusY >= 0 {
-		canvas.writeEllipse(x, y, radiusX, radiusY, rotation)
+		canvas.createEllipse(x, y, radiusX, radiusY, rotation)
-		canvas.script.WriteString("\nctx.fill();\nctx.stroke();")
+		canvas.session.callCanvasFunc("fill")
+		canvas.session.callCanvasFunc("stroke")
 	}
 }
 
+/*
 func (canvas *canvasData) writePointArgs(x, y float64) {
 	canvas.script.WriteString(strconv.FormatFloat(x, 'g', -1, 64))
 	canvas.script.WriteRune(',')
@@ -947,101 +752,59 @@ func (canvas *canvasData) writeStringArgs(text string, script *strings.Builder)
 		}
 	}
 }
+*/
 
 func (canvas *canvasData) FillText(x, y float64, text string) {
-	canvas.script.WriteString("\nctx.fillText('")
+	canvas.session.callCanvasFunc("fillText", text, x, y)
-	canvas.writeStringArgs(text, &canvas.script)
-	canvas.script.WriteString(`',`)
-	canvas.writePointArgs(x, y)
-	canvas.script.WriteString(");")
 }
 
 func (canvas *canvasData) StrokeText(x, y float64, text string) {
-	canvas.script.WriteString("\nctx.strokeText('")
+	canvas.session.callCanvasFunc("strokeText", text, x, y)
-	canvas.writeStringArgs(text, &canvas.script)
-	canvas.script.WriteString(`',`)
-	canvas.writePointArgs(x, y)
-	canvas.script.WriteString(");")
 }
 
 func (canvas *canvasData) FillPath(path Path) {
-	canvas.script.WriteString(path.scriptText())
+	path.create(canvas.session)
-	canvas.script.WriteString("\nctx.fill();")
+	canvas.session.callCanvasFunc("fill")
 }
 
 func (canvas *canvasData) StrokePath(path Path) {
-	canvas.script.WriteString(path.scriptText())
+	path.create(canvas.session)
-	canvas.script.WriteString("\nctx.stroke();")
+	canvas.session.callCanvasFunc("stroke")
 }
 
 func (canvas *canvasData) FillAndStrokePath(path Path) {
-	canvas.script.WriteString(path.scriptText())
+	path.create(canvas.session)
-	canvas.script.WriteString("\nctx.fill();\nctx.stroke();")
+	canvas.session.callCanvasFunc("fill")
+	canvas.session.callCanvasFunc("stroke")
 }
 
 func (canvas *canvasData) DrawLine(x0, y0, x1, y1 float64) {
-	canvas.script.WriteString("\nctx.beginPath();\nctx.moveTo(")
+	canvas.session.callCanvasFunc("beginPath")
-	canvas.script.WriteString(strconv.FormatFloat(x0, 'g', -1, 64))
+	canvas.session.callCanvasFunc("moveTo", x0, y0)
-	canvas.script.WriteRune(',')
+	canvas.session.callCanvasFunc("lineTo", x1, y1)
-	canvas.script.WriteString(strconv.FormatFloat(y0, 'g', -1, 64))
+	canvas.session.callCanvasFunc("stroke")
-	canvas.script.WriteString(");\nctx.lineTo(")
-	canvas.script.WriteString(strconv.FormatFloat(x1, 'g', -1, 64))
-	canvas.script.WriteRune(',')
-	canvas.script.WriteString(strconv.FormatFloat(y1, 'g', -1, 64))
-	canvas.script.WriteString(");\nctx.stroke();")
 }
 
 func (canvas *canvasData) DrawImage(x, y float64, image Image) {
 	if image == nil || image.LoadingStatus() != ImageReady {
 		return
 	}
-	canvas.script.WriteString("\nimg = images.get('")
+
-	canvas.script.WriteString(image.URL())
+	canvas.session.callCanvasImageFunc(image.URL(), "", "drawImage", x, y)
-	canvas.script.WriteString("');\nif (img) {\nctx.drawImage(img,")
-	canvas.script.WriteString(strconv.FormatFloat(x, 'g', -1, 64))
-	canvas.script.WriteRune(',')
-	canvas.script.WriteString(strconv.FormatFloat(y, 'g', -1, 64))
-	canvas.script.WriteString(");\n}")
 }
 
 func (canvas *canvasData) DrawImageInRect(x, y, width, height float64, image Image) {
 	if image == nil || image.LoadingStatus() != ImageReady {
 		return
 	}
-	canvas.script.WriteString("\nimg = images.get('")
+
-	canvas.script.WriteString(image.URL())
+	canvas.session.callCanvasImageFunc(image.URL(), "", "drawImage", x, y, width, height)
-	canvas.script.WriteString("');\nif (img) {\nctx.drawImage(img,")
-	canvas.script.WriteString(strconv.FormatFloat(x, 'g', -1, 64))
-	canvas.script.WriteRune(',')
-	canvas.script.WriteString(strconv.FormatFloat(y, 'g', -1, 64))
-	canvas.script.WriteRune(',')
-	canvas.script.WriteString(strconv.FormatFloat(width, 'g', -1, 64))
-	canvas.script.WriteRune(',')
-	canvas.script.WriteString(strconv.FormatFloat(height, 'g', -1, 64))
-	canvas.script.WriteString(");\n}")
 }
 
 func (canvas *canvasData) DrawImageFragment(srcX, srcY, srcWidth, srcHeight, dstX, dstY, dstWidth, dstHeight float64, image Image) {
 	if image == nil || image.LoadingStatus() != ImageReady {
 		return
 	}
-	canvas.script.WriteString("\nimg = images.get('")
+
-	canvas.script.WriteString(image.URL())
+	canvas.session.callCanvasImageFunc(image.URL(), "", "drawImage", srcX, srcY, srcWidth, srcHeight, dstX, dstY, dstWidth, dstHeight)
-	canvas.script.WriteString("');\nif (img) {\nctx.drawImage(img,")
-	canvas.script.WriteString(strconv.FormatFloat(srcX, 'g', -1, 64))
-	canvas.script.WriteRune(',')
-	canvas.script.WriteString(strconv.FormatFloat(srcY, 'g', -1, 64))
-	canvas.script.WriteRune(',')
-	canvas.script.WriteString(strconv.FormatFloat(srcWidth, 'g', -1, 64))
-	canvas.script.WriteRune(',')
-	canvas.script.WriteString(strconv.FormatFloat(srcHeight, 'g', -1, 64))
-	canvas.script.WriteRune(',')
-	canvas.script.WriteString(strconv.FormatFloat(dstX, 'g', -1, 64))
-	canvas.script.WriteRune(',')
-	canvas.script.WriteString(strconv.FormatFloat(dstY, 'g', -1, 64))
-	canvas.script.WriteRune(',')
-	canvas.script.WriteString(strconv.FormatFloat(dstWidth, 'g', -1, 64))
-	canvas.script.WriteRune(',')
-	canvas.script.WriteString(strconv.FormatFloat(dstHeight, 'g', -1, 64))
-	canvas.script.WriteString(");\n}")
 }

canvasView.go

@@ -107,7 +107,7 @@ func (canvasView *canvasViewData) Redraw() {
 		if canvasView.drawer != nil {
 			canvasView.drawer(canvas)
 		}
-		canvasView.session.runScript(canvas.finishDraw())
+		canvas.finishDraw()
 	}
 }
 

imageView.go

@@ -1,7 +1,10 @@
 package rui
 
 import (
+	"encoding/base64"
 	"fmt"
+	"path/filepath"
+	"runtime"
 	"strings"
 )
 
@@ -129,12 +132,10 @@ func (imageView *imageViewData) set(tag string, value any) bool {
 		if text, ok := value.(string); ok {
 			imageView.properties[Source] = text
 			if imageView.created {
-				src := text
+				src, srcset := imageView.src(text)
-				if src != "" && src[0] == '@' {
-					src, _ = imageProperty(imageView, Source, imageView.session)
-				}
 				imageView.session.updateProperty(imageView.htmlID(), "src", src)
-				if srcset := imageView.srcSet(src); srcset != "" {
+
+				if srcset != "" {
 					imageView.session.updateProperty(imageView.htmlID(), "srcset", srcset)
 				} else {
 					imageView.session.removeProperty(imageView.htmlID(), "srcset")
@@ -214,29 +215,51 @@ func (imageView *imageViewData) htmlTag() string {
 	return "img"
 }
 
-/*
+func (imageView *imageViewData) src(src string) (string, string) {
-func (imageView *imageViewData) closeHTMLTag() bool {
+	if src != "" && src[0] == '@' {
-	return false
+		if image, ok := imageView.Session().ImageConstant(src[1:]); ok {
+			src = image
+		} else {
+			src = ""
+		}
+	}
+
+	if src != "" {
+		srcset := imageView.srcSet(src)
+		if runtime.GOOS == "js" {
+			if image, ok := resources.images[src]; ok && image.fs != nil {
+				dataType := map[string]string{
+					".svg":  "data:image/svg+xml",
+					".png":  "data:image/png",
+					".jpg":  "data:image/jpg",
+					".jpeg": "data:image/jpg",
+					".gif":  "data:image/gif",
+				}
+				ext := strings.ToLower(filepath.Ext(src))
+				if prefix, ok := dataType[ext]; ok {
+					if data, err := image.fs.ReadFile(image.path); err == nil {
+						return prefix + ";base64," + base64.StdEncoding.EncodeToString(data), ""
+					} else {
+						DebugLog(err.Error())
+					}
+				}
+			}
+		}
+		return src, srcset
+	}
+	return "", ""
 }
-*/
 
 func (imageView *imageViewData) htmlProperties(self View, buffer *strings.Builder) {
+
 	imageView.viewData.htmlProperties(self, buffer)
 
 	if imageResource, ok := imageProperty(imageView, Source, imageView.Session()); ok && imageResource != "" {
-		if imageResource[0] == '@' {
+		if src, srcset := imageView.src(imageResource); src != "" {
-			if image, ok := imageView.Session().ImageConstant(imageResource[1:]); ok {
-				imageResource = image
-			} else {
-				imageResource = ""
-			}
-		}
-
-		if imageResource != "" {
 			buffer.WriteString(` src="`)
-			buffer.WriteString(imageResource)
+			buffer.WriteString(src)
 			buffer.WriteString(`"`)
-			if srcset := imageView.srcSet(imageResource); srcset != "" {
+			if srcset != "" {
 				buffer.WriteString(` srcset="`)
 				buffer.WriteString(srcset)
 				buffer.WriteString(`"`)

path.go

@@ -1,10 +1,5 @@
 package rui
 
-import (
-	"strconv"
-	"strings"
-)
-
 // Path is a path interface
 type Path interface {
 	// Reset erases the Path
@@ -63,134 +58,79 @@ type Path interface {
 	// If the shape has already been closed or has only one point, this function does nothing.
 	Close()
 
-	scriptText() string
+	create(session Session)
+}
+
+type pathElement struct {
+	funcName string
+	args     []any
 }
 
 type pathData struct {
-	script strings.Builder
+	elements []pathElement
 }
 
 // NewPath creates a new empty Path
 func NewPath() Path {
 	path := new(pathData)
-	path.script.Grow(4096)
+	path.Reset()
-	path.script.WriteString("\nctx.beginPath();")
 	return path
 }
 
 func (path *pathData) Reset() {
-	path.script.Reset()
+	path.elements = []pathElement{
-	path.script.WriteString("\nctx.beginPath();")
+		pathElement{funcName: "beginPath", args: []any{}},
+	}
 }
 
 func (path *pathData) MoveTo(x, y float64) {
-	path.script.WriteString("\nctx.moveTo(")
+	path.elements = append(path.elements, pathElement{funcName: "moveTo", args: []any{x, y}})
-	path.script.WriteString(strconv.FormatFloat(x, 'g', -1, 64))
-	path.script.WriteRune(',')
-	path.script.WriteString(strconv.FormatFloat(y, 'g', -1, 64))
-	path.script.WriteString(");")
 }
 
 func (path *pathData) LineTo(x, y float64) {
-	path.script.WriteString("\nctx.lineTo(")
+	path.elements = append(path.elements, pathElement{funcName: "lineTo", args: []any{x, y}})
-	path.script.WriteString(strconv.FormatFloat(x, 'g', -1, 64))
-	path.script.WriteRune(',')
-	path.script.WriteString(strconv.FormatFloat(y, 'g', -1, 64))
-	path.script.WriteString(");")
 }
 
 func (path *pathData) ArcTo(x0, y0, x1, y1, radius float64) {
 	if radius > 0 {
-		path.script.WriteString("\nctx.arcTo(")
+		path.elements = append(path.elements, pathElement{funcName: "arcTo", args: []any{x0, y0, x1, y1, radius}})
-		path.script.WriteString(strconv.FormatFloat(x0, 'g', -1, 64))
-		path.script.WriteRune(',')
-		path.script.WriteString(strconv.FormatFloat(y0, 'g', -1, 64))
-		path.script.WriteRune(',')
-		path.script.WriteString(strconv.FormatFloat(x1, 'g', -1, 64))
-		path.script.WriteRune(',')
-		path.script.WriteString(strconv.FormatFloat(y1, 'g', -1, 64))
-		path.script.WriteRune(',')
-		path.script.WriteString(strconv.FormatFloat(radius, 'g', -1, 64))
-		path.script.WriteString(");")
 	}
 }
 
 func (path *pathData) Arc(x, y, radius, startAngle, endAngle float64, clockwise bool) {
 	if radius > 0 {
-		path.script.WriteString("\nctx.arc(")
-		path.script.WriteString(strconv.FormatFloat(x, 'g', -1, 64))
-		path.script.WriteRune(',')
-		path.script.WriteString(strconv.FormatFloat(y, 'g', -1, 64))
-		path.script.WriteRune(',')
-		path.script.WriteString(strconv.FormatFloat(radius, 'g', -1, 64))
-		path.script.WriteRune(',')
-		path.script.WriteString(strconv.FormatFloat(startAngle, 'g', -1, 64))
-		path.script.WriteRune(',')
-		path.script.WriteString(strconv.FormatFloat(endAngle, 'g', -1, 64))
 		if !clockwise {
-			path.script.WriteString(",true);")
+			path.elements = append(path.elements, pathElement{funcName: "arc", args: []any{x, y, radius, startAngle, endAngle, true}})
 		} else {
-			path.script.WriteString(");")
+			path.elements = append(path.elements, pathElement{funcName: "arc", args: []any{x, y, radius, startAngle, endAngle}})
 		}
 	}
 }
 
 func (path *pathData) BezierCurveTo(cp0x, cp0y, cp1x, cp1y, x, y float64) {
-	path.script.WriteString("\nctx.bezierCurveTo(")
+	path.elements = append(path.elements, pathElement{funcName: "bezierCurveTo", args: []any{cp0x, cp0y, cp1x, cp1y, x, y}})
-	path.script.WriteString(strconv.FormatFloat(cp0x, 'g', -1, 64))
-	path.script.WriteRune(',')
-	path.script.WriteString(strconv.FormatFloat(cp0y, 'g', -1, 64))
-	path.script.WriteRune(',')
-	path.script.WriteString(strconv.FormatFloat(cp1x, 'g', -1, 64))
-	path.script.WriteRune(',')
-	path.script.WriteString(strconv.FormatFloat(cp1y, 'g', -1, 64))
-	path.script.WriteRune(',')
-	path.script.WriteString(strconv.FormatFloat(x, 'g', -1, 64))
-	path.script.WriteRune(',')
-	path.script.WriteString(strconv.FormatFloat(y, 'g', -1, 64))
-	path.script.WriteString(");")
 }
 
 func (path *pathData) QuadraticCurveTo(cpx, cpy, x, y float64) {
-	path.script.WriteString("\nctx.quadraticCurveTo(")
+	path.elements = append(path.elements, pathElement{funcName: "quadraticCurveTo", args: []any{cpx, cpy, x, y}})
-	path.script.WriteString(strconv.FormatFloat(cpx, 'g', -1, 64))
-	path.script.WriteRune(',')
-	path.script.WriteString(strconv.FormatFloat(cpy, 'g', -1, 64))
-	path.script.WriteRune(',')
-	path.script.WriteString(strconv.FormatFloat(x, 'g', -1, 64))
-	path.script.WriteRune(',')
-	path.script.WriteString(strconv.FormatFloat(y, 'g', -1, 64))
-	path.script.WriteString(");")
 }
 
 func (path *pathData) Ellipse(x, y, radiusX, radiusY, rotation, startAngle, endAngle float64, clockwise bool) {
 	if radiusX > 0 && radiusY > 0 {
-		path.script.WriteString("\nctx.ellipse(")
-		path.script.WriteString(strconv.FormatFloat(x, 'g', -1, 64))
-		path.script.WriteRune(',')
-		path.script.WriteString(strconv.FormatFloat(y, 'g', -1, 64))
-		path.script.WriteRune(',')
-		path.script.WriteString(strconv.FormatFloat(radiusX, 'g', -1, 64))
-		path.script.WriteRune(',')
-		path.script.WriteString(strconv.FormatFloat(radiusY, 'g', -1, 64))
-		path.script.WriteRune(',')
-		path.script.WriteString(strconv.FormatFloat(rotation, 'g', -1, 64))
-		path.script.WriteRune(',')
-		path.script.WriteString(strconv.FormatFloat(startAngle, 'g', -1, 64))
-		path.script.WriteRune(',')
-		path.script.WriteString(strconv.FormatFloat(endAngle, 'g', -1, 64))
 		if !clockwise {
-			path.script.WriteString(",true);")
+			path.elements = append(path.elements, pathElement{funcName: "ellipse", args: []any{x, y, radiusX, radiusY, rotation, startAngle, endAngle, true}})
 		} else {
-			path.script.WriteString(");")
+			path.elements = append(path.elements, pathElement{funcName: "ellipse", args: []any{x, y, radiusX, radiusY, rotation, startAngle, endAngle}})
 		}
 	}
 }
 
 func (path *pathData) Close() {
-	path.script.WriteString("\nctx.close();")
+	path.elements = append(path.elements, pathElement{funcName: "close", args: []any{}})
 }
 
-func (path *pathData) scriptText() string {
+func (path *pathData) create(session Session) {
-	return path.script.String()
+	for _, element := range path.elements {
+		session.callCanvasFunc(element.funcName, element.args...)
+	}
 }

resources.go

@@ -123,7 +123,7 @@ func scanEmbedImagesDir(fs *embed.FS, dir, prefix string) {
 			} else {
 				ext := strings.ToLower(filepath.Ext(name))
 				switch ext {
-				case ".png", ".jpg", ".jpeg", ".svg":
+				case ".png", ".jpg", ".jpeg", ".svg", ".gif", ".bmp":
 					registerImage(fs, path, prefix+name)
 				}
 			}

session.go

@@ -18,6 +18,13 @@ type webBrige interface {
 	removeProperty(htmlID, property string)
 	readMessage() (string, bool)
 	writeMessage(text string) bool
+	cavnasStart(htmlID string)
+	callCanvasFunc(funcName string, args ...any)
+	callCanvasVarFunc(v any, funcName string, args ...any)
+	callCanvasImageFunc(url string, property string, funcName string, args ...any)
+	createCanvasVar(funcName string, args ...any) any
+	updateCanvasProperty(property string, value any)
+	cavnasFinish()
 	canvasTextMetrics(htmlID, font, text string) TextMetrics
 	htmlPropertyValue(htmlID, name string) string
 	answerReceived(answer DataObject)
@@ -115,6 +122,13 @@ type Session interface {
 	runScript(script string)
 	startUpdateScript(htmlID string) bool
 	finishUpdateScript(htmlID string)
+	cavnasStart(htmlID string)
+	callCanvasFunc(funcName string, args ...any)
+	createCanvasVar(funcName string, args ...any) any
+	callCanvasVarFunc(v any, funcName string, args ...any)
+	callCanvasImageFunc(url string, property string, funcName string, args ...any)
+	updateCanvasProperty(property string, value any)
+	cavnasFinish()
 	canvasTextMetrics(htmlID, font, text string) TextMetrics
 	htmlPropertyValue(htmlID, name string) string
 	handleAnswer(data DataObject)
@@ -395,6 +409,49 @@ func (session *sessionData) finishUpdateScript(htmlID string) {
 	}
 }
 
+func (session *sessionData) cavnasStart(htmlID string) {
+	if session.brige != nil {
+		session.brige.cavnasStart(htmlID)
+	}
+}
+
+func (session *sessionData) callCanvasFunc(funcName string, args ...any) {
+	if session.brige != nil {
+		session.brige.callCanvasFunc(funcName, args...)
+	}
+}
+
+func (session *sessionData) updateCanvasProperty(property string, value any) {
+	if session.brige != nil {
+		session.brige.updateCanvasProperty(property, value)
+	}
+}
+
+func (session *sessionData) createCanvasVar(funcName string, args ...any) any {
+	if session.brige != nil {
+		return session.brige.createCanvasVar(funcName, args...)
+	}
+	return nil
+}
+
+func (session *sessionData) callCanvasVarFunc(v any, funcName string, args ...any) {
+	if session.brige != nil && v != nil {
+		session.brige.callCanvasVarFunc(v, funcName, args...)
+	}
+}
+
+func (session *sessionData) callCanvasImageFunc(url string, property string, funcName string, args ...any) {
+	if session.brige != nil {
+		session.brige.callCanvasImageFunc(url, property, funcName, args...)
+	}
+}
+
+func (session *sessionData) cavnasFinish() {
+	if session.brige != nil {
+		session.brige.cavnasFinish()
+	}
+}
+
 func (session *sessionData) runScript(script string) {
 	if session.brige != nil {
 		session.brige.writeMessage(script)

webBrige.go

@@ -13,13 +13,19 @@ import (
 )
 
 type wsBrige struct {
-	conn          *websocket.Conn
+	conn            *websocket.Conn
-	answer        map[int]chan DataObject
+	answer          map[int]chan DataObject
-	answerID      int
+	answerID        int
-	answerMutex   sync.Mutex
+	answerMutex     sync.Mutex
-	closed        bool
+	closed          bool
-	buffer        strings.Builder
+	buffer          strings.Builder
-	updateScripts map[string]*strings.Builder
+	canvasBuffer    strings.Builder
+	canvasVarNumber int
+	updateScripts   map[string]*strings.Builder
+}
+
+type canvasVar struct {
+	name string
 }
 
 var upgrader = websocket.Upgrader{
@@ -119,6 +125,21 @@ func (brige *wsBrige) argToString(arg any) (string, bool) {
 	case float64:
 		return fmt.Sprintf("%g", arg), true
 
+	case []float64:
+		buffer := allocStringBuilder()
+		defer freeStringBuilder(buffer)
+		lead := '['
+		for _, val := range arg {
+			buffer.WriteRune(lead)
+			lead = ','
+			buffer.WriteString(fmt.Sprintf("%g", val))
+		}
+		buffer.WriteRune(']')
+		return buffer.String(), true
+
+	case canvasVar:
+		return arg.name, true
+
 	default:
 		if n, ok := isInt(arg); ok {
 			return fmt.Sprintf("%d", n), true
@@ -203,6 +224,110 @@ func (brige *wsBrige) removeProperty(htmlID, property string) {
 	}
 }
 
+func (brige *wsBrige) cavnasStart(htmlID string) {
+	brige.canvasBuffer.Reset()
+	brige.canvasBuffer.WriteString(`const ctx = getCanvasContext('`)
+	brige.canvasBuffer.WriteString(htmlID)
+	brige.canvasBuffer.WriteString(`');`)
+}
+
+func (brige *wsBrige) callCanvasFunc(funcName string, args ...any) {
+	brige.canvasBuffer.WriteString("\nctx.")
+	brige.canvasBuffer.WriteString(funcName)
+	brige.canvasBuffer.WriteRune('(')
+	for i, arg := range args {
+		if i > 0 {
+			brige.canvasBuffer.WriteString(", ")
+		}
+		argText, _ := brige.argToString(arg)
+		brige.canvasBuffer.WriteString(argText)
+	}
+	brige.canvasBuffer.WriteString(");")
+}
+
+func (brige *wsBrige) updateCanvasProperty(property string, value any) {
+	brige.canvasBuffer.WriteString("\nctx.")
+	brige.canvasBuffer.WriteString(property)
+	brige.canvasBuffer.WriteString(" = ")
+	argText, _ := brige.argToString(value)
+	brige.canvasBuffer.WriteString(argText)
+	brige.canvasBuffer.WriteString(";")
+}
+
+func (brige *wsBrige) createCanvasVar(funcName string, args ...any) any {
+	brige.canvasVarNumber++
+	result := canvasVar{name: fmt.Sprintf("v%d", brige.canvasVarNumber)}
+	brige.canvasBuffer.WriteString("\nvar ")
+	brige.canvasBuffer.WriteString(result.name)
+	brige.canvasBuffer.WriteString(" = ctx.")
+	brige.canvasBuffer.WriteString(funcName)
+	brige.canvasBuffer.WriteRune('(')
+	for i, arg := range args {
+		if i > 0 {
+			brige.canvasBuffer.WriteString(", ")
+		}
+		argText, _ := brige.argToString(arg)
+		brige.canvasBuffer.WriteString(argText)
+	}
+	brige.canvasBuffer.WriteString(");")
+	return result
+}
+
+func (brige *wsBrige) callCanvasVarFunc(v any, funcName string, args ...any) {
+	varName, ok := v.(canvasVar)
+	if !ok {
+		return
+	}
+	brige.canvasBuffer.WriteString("\n")
+	brige.canvasBuffer.WriteString(varName.name)
+	brige.canvasBuffer.WriteRune('.')
+	brige.canvasBuffer.WriteString(funcName)
+	brige.canvasBuffer.WriteRune('(')
+	for i, arg := range args {
+		if i > 0 {
+			brige.canvasBuffer.WriteString(", ")
+		}
+		argText, _ := brige.argToString(arg)
+		brige.canvasBuffer.WriteString(argText)
+	}
+	brige.canvasBuffer.WriteString(");")
+}
+
+func (brige *wsBrige) callCanvasImageFunc(url string, property string, funcName string, args ...any) {
+
+	brige.canvasBuffer.WriteString("\nimg = images.get('")
+	brige.canvasBuffer.WriteString(url)
+	brige.canvasBuffer.WriteString("');\nif (img) {\n")
+	if property != "" {
+		brige.canvasBuffer.WriteString("ctx.")
+		brige.canvasBuffer.WriteString(property)
+		brige.canvasBuffer.WriteString(" = ")
+	}
+	brige.canvasBuffer.WriteString("ctx.")
+	brige.canvasBuffer.WriteString(funcName)
+	brige.canvasBuffer.WriteString("(img")
+	for _, arg := range args {
+		brige.canvasBuffer.WriteString(", ")
+		argText, _ := brige.argToString(arg)
+		brige.canvasBuffer.WriteString(argText)
+	}
+	brige.canvasBuffer.WriteString(");\n}")
+}
+
+func (brige *wsBrige) cavnasFinish() {
+	brige.canvasBuffer.WriteString("\n")
+	script := brige.canvasBuffer.String()
+	if ProtocolInDebugLog {
+		DebugLog("Run script:")
+		DebugLog(script)
+	}
+	if brige.conn == nil {
+		ErrorLog("No connection")
+	} else if err := brige.conn.WriteMessage(websocket.TextMessage, []byte(script)); err != nil {
+		ErrorLog(err.Error())
+	}
+}
+
 func (brige *wsBrige) readMessage() (string, bool) {
 	_, p, err := brige.conn.ReadMessage()
 	if err != nil {