diff --git a/camera.go b/camera.go
index a3ea7b6..b9227ba 100644
--- a/camera.go
+++ b/camera.go
@@ -27,7 +27,7 @@ type Camera struct {
 	on_ interface{}
 }
 
-func (c *Camera) init(g *Game, winW, winH float64, worldW, worldH float64) {
+func (c *Camera) init(g *Game) {
 	c.g = g
 }
 
diff --git a/game.go b/game.go
index 5a436af..b7ad893 100644
--- a/game.go
+++ b/game.go
@@ -443,7 +443,7 @@ func (p *Game) loadIndex(g reflect.Value, proj *projConfig) (err error) {
 	}
 	engine.SyncPlatformSetWindowSize(int64(p.windowWidth_), int64(p.windowHeight_))
 
-	p.Camera.init(p, float64(p.windowWidth_), float64(p.windowHeight_), float64(p.worldWidth_), float64(p.worldHeight_))
+	p.Camera.init(p)
 
 	// setup proxy's property
 	p.proxy = engine.SyncNewBackdropProxy(p, p.getCostumePath(), p.getCostumeRenderScale())
diff --git a/go.mod b/go.mod
index e5910a2..fe1f45f 100644
--- a/go.mod
+++ b/go.mod
@@ -5,11 +5,12 @@ go 1.21.3
 require (
 	github.com/pkg/errors v0.9.1
 	github.com/realdream-ai/gdspx v0.0.0-20241204130734-35c372f84f57
-	github.com/realdream-ai/mathf v0.0.0-20241204125103-284ee6a3722d
-	golang.org/x/image v0.18.0
+	github.com/realdream-ai/mathf v0.0.0-20241205091834-a85cb2402a16
 	golang.org/x/mobile v0.0.0-20220518205345-8578da9835fd
 )
 
+require golang.org/x/image v0.23.0 // indirect
+
 replace (
 	golang.org/x/image => golang.org/x/image v0.0.0-20210628002857-a66eb6448b8d
 	golang.org/x/mobile => golang.org/x/mobile v0.0.0-20210902104108-5d9a33257ab5
diff --git a/go.sum b/go.sum
index 3ebb0db..1cc4cf3 100644
--- a/go.sum
+++ b/go.sum
@@ -3,8 +3,8 @@ github.com/pkg/errors v0.9.1 h1:FEBLx1zS214owpjy7qsBeixbURkuhQAwrK5UwLGTwt4=
 github.com/pkg/errors v0.9.1/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
 github.com/realdream-ai/gdspx v0.0.0-20241204130734-35c372f84f57 h1:iF9BObP4FNyjdyxJD8ng0mCf+dJTaVExco+QWChoukc=
 github.com/realdream-ai/gdspx v0.0.0-20241204130734-35c372f84f57/go.mod h1:UCzetvoQdU+yfesI6xAL33acsuEbYICGQUcYpGiAW00=
-github.com/realdream-ai/mathf v0.0.0-20241204125103-284ee6a3722d h1:hEIUl272UkUUd2F77nONdEDR1tHLpe1MAgaYAGoVnEk=
-github.com/realdream-ai/mathf v0.0.0-20241204125103-284ee6a3722d/go.mod h1:oAFczOO99bG05kC9tKp5deLqrvZSjtBDIpNH36ZWwnY=
+github.com/realdream-ai/mathf v0.0.0-20241205091834-a85cb2402a16 h1:V/zAuyQF0v6ng+UVwJi+qF0s+P/nEHb/lha3Uf86TQM=
+github.com/realdream-ai/mathf v0.0.0-20241205091834-a85cb2402a16/go.mod h1:zCbLmeT7a+pH1sknxgdFLiha6xA3gezTtwbTuuNRJWE=
 github.com/yuin/goldmark v1.4.1/go.mod h1:mwnBkeHKe2W/ZEtQ+71ViKU8L12m81fl3OWwC1Zlc8k=
 golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
 golang.org/x/crypto v0.0.0-20191011191535-87dc89f01550/go.mod h1:yigFU9vqHzYiE8UmvKecakEJjdnWj3jj499lnFckfCI=
diff --git a/internal/gdi/color_utils.go b/internal/gdi/color_utils.go
deleted file mode 100644
index 0ce8634..0000000
--- a/internal/gdi/color_utils.go
+++ /dev/null
@@ -1,105 +0,0 @@
-package gdi
-
-import (
-	"math"
-	"math/rand"
-)
-
-// HSV2RGB converts hue (0-360), saturation (0-1), and brightness (0-1) to RGB.
-func HSV2RGB(h, s, v float64) (uint8, uint8, uint8) {
-	var r, g, b float64
-	h = math.Mod(h, 360)
-	if h < 0 {
-		h += 360
-	}
-	s = math.Max(0, math.Min(s, 1))
-	v = math.Max(0, math.Min(v, 1))
-
-	i := math.Floor(h / 60)
-	f := (h / 60) - i
-	p := v * (1 - s)
-	q := v * (1 - (s * f))
-	t := v * (1 - (s * (1 - f)))
-	switch int(i) {
-	case 0:
-		r = v
-		g = t
-		b = p
-	case 1:
-		r = q
-		g = v
-		b = p
-	case 2:
-		r = p
-		g = v
-		b = t
-	case 3:
-		r = p
-		g = q
-		b = v
-	case 4:
-		r = t
-		g = p
-		b = v
-	case 5:
-		r = v
-		g = p
-		b = q
-	}
-	return uint8(math.Floor(r * 255)), uint8(math.Floor(g * 255)), uint8(math.Floor(b * 255))
-}
-
-// RGB2HSV converts RGB to an array containing the hue, saturation, and brightness.
-func RGB2HSV(R, G, B uint8) (h, s, v float64) {
-	var f, i float64
-	r := float64(R) / 255
-	g := float64(G) / 255
-	b := float64(B) / 255
-	x := math.Min(math.Min(r, g), b)
-	v = math.Max(math.Max(r, g), b)
-	if x == v {
-		return // gray; hue arbitrarily reported as zero
-	}
-	if r == x {
-		f = g - b
-		i = 3
-	} else if g == x {
-		f = b - r
-		i = 5
-	} else {
-		f = r - g
-		i = 1
-	}
-	h = math.Mod((i-(f/(v-x)))*60, 360)
-	s = (v - x) / v
-	return
-}
-
-// ScaleBrightness changes color brightness.
-func ScaleBrightness(r, g, b uint8, scale float64) (uint8, uint8, uint8) {
-	h, s, v := RGB2HSV(r, g, b)
-	val := math.Max(0, math.Min(scale*v, 1))
-	return HSV2RGB(h, s, val)
-}
-
-// MixRGB mixs rgb1 with rgb2. 0 gives all rgb1, 1 gives rbg2, .5 mixes them 50/50.
-func MixRGB(r1, g1, b1 uint8, r2, g2, b2 uint8, fraction float64) (r, g, b uint8) {
-	if fraction <= 0 {
-		return r1, g1, b1
-	}
-	if fraction >= 1 {
-		return r2, g2, b2
-	}
-	r = uint8(fraction*float64(r2) + (1.0-fraction)*float64(r1))
-	g = uint8(fraction*float64(g2) + (1.0-fraction)*float64(g1))
-	b = uint8(fraction*float64(b2) + (1.0-fraction)*float64(b1))
-	return
-}
-
-// Random returns a random color.
-func Random() (uint8, uint8, uint8) {
-	h := 360 * rand.Float64()
-	s := 0.7 + (0.3 * rand.Float64())
-	v := 0.6 + (0.4 * rand.Float64())
-	return HSV2RGB(h, s, v)
-}
diff --git a/internal/gdi/text.go b/internal/text/text.go
similarity index 96%
rename from internal/gdi/text.go
rename to internal/text/text.go
index b489fd2..e5e3b7f 100644
--- a/internal/gdi/text.go
+++ b/internal/text/text.go
@@ -1,4 +1,4 @@
-package gdi
+package text
 
 import (
 	"strings"
@@ -29,7 +29,7 @@ func calculateWordLength(word string) int {
 }
 
 // splitString splits the input string into lines with a maximum placeholder width n
-func SplitString(input string, n int) string {
+func SplitLines(input string, n int) string {
 	words := strings.Fields(input)
 	var result strings.Builder
 	lineLength := 0
diff --git a/internal/ui/ui_say.go b/internal/ui/ui_say.go
index 38ae19c..231d30e 100644
--- a/internal/ui/ui_say.go
+++ b/internal/ui/ui_say.go
@@ -7,13 +7,13 @@ import (
 	. "github.com/realdream-ai/gdspx/pkg/engine"
 
 	"github.com/goplus/spx/internal/engine"
-	"github.com/goplus/spx/internal/gdi"
+	"github.com/goplus/spx/internal/text"
 )
 
 const (
-	SayMsgSpliteWidth   = 25
-	SayMsgLineHeight    = 26
-	SayMsgDefaultHeight = 77
+	sayMsgSpliteWidth   = 25
+	sayMsgLineHeight    = 26
+	sayMsgDefaultHeight = 77
 )
 
 type UiSay struct {
@@ -50,10 +50,10 @@ func (pself *UiSay) SetText(winX, winY float64, x, y float64, w, h float64, msg
 	hasNextLine := strings.ContainsRune(msg, '\n')
 	finalMsg := msg
 	if !hasNextLine {
-		finalMsg = gdi.SplitString(msg, SayMsgSpliteWidth)
+		finalMsg = text.SplitLines(msg, sayMsgSpliteWidth)
 	}
 	lineCount := strings.Count(finalMsg, "\n")
-	uiHeight := SayMsgDefaultHeight + float64(lineCount)*SayMsgLineHeight
+	uiHeight := sayMsgDefaultHeight + float64(lineCount)*sayMsgLineHeight
 	maxYPos := winY/2 - uiHeight
 	yPos = math.Max(-winY/2, math.Min(yPos, maxYPos))
 	xPos = math.Max(-winX/2, math.Min(x, winX/2))
diff --git a/measure.go b/measure.go
index 44c79f7..02243bc 100644
--- a/measure.go
+++ b/measure.go
@@ -22,6 +22,7 @@ import (
 	"strings"
 
 	"github.com/goplus/spx/internal/ui"
+	"github.com/realdream-ai/mathf"
 )
 
 const (
@@ -38,7 +39,7 @@ type measure struct {
 
 	// computed properties
 	text         string
-	color        Color
+	color        mathf.Color
 	svgLineStyle string
 	svgRotate    string
 	svgSize      int // size*scale + 0.5 + measureLineWidth
@@ -52,7 +53,7 @@ func newMeasure(v specsp) *measure {
 	text = strings.TrimSuffix(text, ".0")
 	heading := getSpcspVal(v, "heading", 0.0).(float64)
 	svgSize := int(size*scale + 0.5 + measureLineWidth)
-	c, err := parseColor(getSpcspVal(v, "color", 0.0))
+	c, err := mathf.NewColorAny(getSpcspVal(v, "color", 0.0))
 	if err != nil {
 		panic(err)
 	}
@@ -69,7 +70,7 @@ func newMeasure(v specsp) *measure {
 		svgSize:      svgSize,
 		panel:        panel,
 	}
-	panel.UpdateInfo(meansureObj.x, meansureObj.y, size*scale, heading, text, toEngineColor(c))
+	panel.UpdateInfo(meansureObj.x, meansureObj.y, size*scale, heading, text, c)
 	return meansureObj
 }
 
diff --git a/monitor.go b/monitor.go
index af1412b..1fd90f0 100644
--- a/monitor.go
+++ b/monitor.go
@@ -25,6 +25,7 @@ import (
 
 	"github.com/goplus/spx/internal/tools"
 	"github.com/goplus/spx/internal/ui"
+	"github.com/realdream-ai/mathf"
 )
 
 // -------------------------------------------------------------------------------------
@@ -38,7 +39,7 @@ type Monitor struct {
 	val     string
 	eval    func() string
 	mode    int
-	color   Color
+	color   mathf.Color
 	x, y    float64
 	label   string
 	visible bool
@@ -72,9 +73,9 @@ func newMonitor(g reflect.Value, v specsp) (*Monitor, error) {
 		return nil, syscall.ENOENT
 	}
 	mode := int(v["mode"].(float64))
-	color, err := parseColor(getSpcspVal(v, "color"))
+	color, err := mathf.NewColorAny(getSpcspVal(v, "color"))
 	if err != nil {
-		color = Color{R: 0x28, G: 0x9c, B: 0xfc, A: 0xff}
+		color = RGBA(0x28, 0x9c, 0xfc, 0xff)
 	}
 	label := v["label"].(string)
 	x := v["x"].(float64)
@@ -100,7 +101,7 @@ func (pself *Monitor) onUpdate(delta float64) {
 	pself.panel.UpdateScale(pself.size)
 	pself.panel.UpdatePos(pself.x, pself.y)
 	pself.panel.UpdateText(pself.label, val)
-	pself.panel.UpdateColor(toEngineColor(pself.color))
+	pself.panel.UpdateColor(pself.color)
 }
 
 func getTarget(g reflect.Value, target string) (reflect.Value, int) {
@@ -151,26 +152,6 @@ func (p *Monitor) setVisible(visible bool) {
 	p.visible = visible
 }
 
-const (
-	stmDefaultW   = 47
-	stmDefaultSmW = 41
-	stmCornerSize = 2
-	stmVertGapSm  = 4
-	stmHoriGapSm  = 5
-)
-
-var (
-	stmBackground    = Color{R: 0xf6, G: 0xf8, B: 0xfa, A: 0xff}
-	stmBackgroundPen = Color{R: 0xf6, G: 0xf8, B: 0xfa, A: 0xff}
-	stmValueground   = Color{R: 0x21, G: 0x9f, B: 0xfc, A: 0xff}
-	stmValueRectPen  = Color{R: 0xf6, G: 0xf8, B: 0xfa, A: 0xff}
-)
-
-type rectKey struct {
-	x, y, w, h  float64
-	clr, clrPen Color
-}
-
 // -------------------------------------------------------------------------------------
 // IWidget
 func (pself *Monitor) GetName() WidgetName {
diff --git a/pen.go b/pen.go
index 3c4c815..14f1ecb 100644
--- a/pen.go
+++ b/pen.go
@@ -16,16 +16,14 @@
 
 package spx
 
-import (
-	"image/color"
-)
+import "github.com/realdream-ai/mathf"
 
 // -------------------------------------------------------------------------------------
 
 type penLine struct {
 	x1, y1 int
 	x2, y2 int
-	clr    color.RGBA
+	clr    mathf.Color
 	width  int
 }
 
diff --git a/sprite.go b/sprite.go
index 9a573de..b9e790a 100644
--- a/sprite.go
+++ b/sprite.go
@@ -17,13 +17,11 @@
 package spx
 
 import (
-	"image/color"
 	"log"
 	"math"
 	"reflect"
 
 	"github.com/goplus/spx/internal/engine"
-	"github.com/goplus/spx/internal/gdi"
 	"github.com/goplus/spx/internal/time"
 	"github.com/goplus/spx/internal/tools"
 	"github.com/realdream-ai/mathf"
@@ -199,7 +197,7 @@ type SpriteImpl struct {
 	animBindings     map[string]string
 	defaultAnimation SpriteAnimationName
 
-	penColor color.RGBA
+	penColor mathf.Color
 	penShade float64
 	penHue   float64
 	penWidth float64
@@ -1394,8 +1392,6 @@ func (p *SpriteImpl) ClearGraphEffects() {
 
 // -----------------------------------------------------------------------------
 
-type Color = color.RGBA
-
 func (p *SpriteImpl) TouchingColor(color Color) bool {
 	panic("todo gdspx")
 }
@@ -1544,7 +1540,7 @@ func (p *SpriteImpl) PenDown() {
 }
 
 func (p *SpriteImpl) SetPenColor(color Color) {
-	h, _, v := gdi.RGB2HSV(color.R, color.G, color.B)
+	h, _, v := color.ToHSV()
 	p.penHue = (200 * h) / 360
 	p.penShade = 50 * v
 	p.penColor = color
@@ -1595,17 +1591,18 @@ func (p *SpriteImpl) setPenShade(v float64, change bool) {
 }
 
 func (p *SpriteImpl) doUpdatePenColor() {
-	r, g, b := gdi.HSV2RGB((p.penHue*180)/100, 1, 1)
+	color := mathf.NewColorHSV((p.penHue*180)/100, 1, 1)
 	shade := p.penShade
 	if shade > 100 { // range 0..100
 		shade = 200 - shade
 	}
+	a := p.penColor.A
 	if shade < 50 {
-		r, g, b = gdi.MixRGB(0, 0, 0, r, g, b, (10+shade)/60)
+		p.penColor = mathf.LerpColor(mathf.ColorBlack(), color, (10+shade)/60)
 	} else {
-		r, g, b = gdi.MixRGB(r, g, b, 255, 255, 255, (shade-50)/60)
+		p.penColor = mathf.LerpColor(color, mathf.ColorWhite(), (shade-50)/60)
 	}
-	p.penColor = color.RGBA{R: r, G: g, B: b, A: p.penColor.A}
+	p.penColor.A = a
 }
 
 func (p *SpriteImpl) SetPenSize(size float64) {
diff --git a/uinode.go b/uinode.go
deleted file mode 100644
index 453513e..0000000
--- a/uinode.go
+++ /dev/null
@@ -1,19 +0,0 @@
-package spx
-
-import (
-	gdspx "github.com/realdream-ai/gdspx/pkg/engine"
-
-	"github.com/goplus/spx/internal/engine"
-)
-
-type ProxyUi struct {
-	gdspx.UiNode
-}
-
-func NewUiNode(path string) *ProxyUi {
-	node := engine.SyncCreateUiNode[ProxyUi](path)
-	return node
-}
-func (pthis *ProxyUi) SetText(text string) {
-	engine.SyncUiSetText(pthis.UiNode.Id, text)
-}
diff --git a/utils.go b/utils.go
index d8fd31b..a6825b2 100644
--- a/utils.go
+++ b/utils.go
@@ -17,22 +17,15 @@
 package spx
 
 import (
-	"errors"
 	"math/rand"
 	"os"
 	"time"
 
 	"github.com/realdream-ai/mathf"
-	"golang.org/x/image/colornames"
 )
 
 // -----------------------------------------------------------------------------
 
-var (
-	errInvalidColorFormat     = errors.New("invalid color format")
-	errUnsupportedColorFormat = errors.New("unsupported color format")
-)
-
 func init() {
 	rand.Seed(time.Now().UnixNano())
 }
@@ -59,74 +52,23 @@ func Iround(v float64) int {
 	return int(v - 0.5)
 }
 
+type Color = mathf.Color
+
 // -----------------------------------------------------------------------------
 func RGB(r, g, b uint8) Color {
-	return Color{R: r, G: g, B: b, A: 0xff}
+	return mathf.NewColorRGBi(r, g, b)
 }
 
 func RGBA(r, g, b, a uint8) Color {
-	return Color{R: r, G: g, B: b, A: a}
+	return mathf.NewColorRGBAi(r, g, b, a)
 }
 
-func toEngineColor(c Color) mathf.Color {
-	return mathf.NewColor(float64(c.R)/255, float64(c.G)/255, float64(c.B)/255, float64(c.A)/255)
+func RGBf(r, g, b float64) Color {
+	return mathf.NewColorRGB(r, g, b)
 }
 
-// parseColor, s can be int, float64 or string
-func parseColor(s interface{}) (Color, error) {
-	if s == nil {
-		return Color{}, errors.New("color is nil")
-	}
-	if c, ok := s.(int); ok {
-		return Color{uint8(c >> 16), uint8((c >> 8) & 0xff), uint8(c & 0xff), 0xff}, nil
-	}
-	if f, ok := s.(float64); ok {
-		c := int(f)
-		return Color{uint8(c >> 16), uint8((c >> 8) & 0xff), uint8(c & 0xff), 0xff}, nil
-	}
-	ss, ok := s.(string)
-	if !ok {
-		return Color{}, errUnsupportedColorFormat
-	}
-	c, ok := colornames.Map[ss]
-	if ok {
-		return c, nil
-	}
-	return parseHexColor(ss)
-}
-
-func parseHexColor(s string) (Color, error) {
-	if s == "" || s[0] != '#' {
-		return Color{}, errInvalidColorFormat
-	}
-	var err error
-	hexToByte := func(b byte) byte {
-		switch {
-		case b >= '0' && b <= '9':
-			return b - '0'
-		case b >= 'a' && b <= 'f':
-			return b - 'a' + 10
-		case b >= 'A' && b <= 'F':
-			return b - 'A' + 10
-		default:
-			err = errInvalidColorFormat
-			return 0
-		}
-	}
-	c := Color{A: 0xff}
-	switch len(s) {
-	case 7:
-		c.R = hexToByte(s[1])<<4 + hexToByte(s[2])
-		c.G = hexToByte(s[3])<<4 + hexToByte(s[4])
-		c.B = hexToByte(s[5])<<4 + hexToByte(s[6])
-	case 4:
-		c.R = hexToByte(s[1]) * 17
-		c.G = hexToByte(s[2]) * 17
-		c.B = hexToByte(s[3]) * 17
-	default:
-		err = errInvalidColorFormat
-	}
-	return c, err
+func RGBAf(r, g, b, a float64) Color {
+	return mathf.NewColorRGBA(r, g, b, a)
 }
 
 // -----------------------------------------------------------------------------