graphics: Make copying ColorM faster

internal/affine/colorm.go

@@ -16,11 +16,48 @@ package affine
 
 import (
 	"math"
+
+	"github.com/hajimehoshi/ebiten/internal/endian"
 )
 
 // ColorMDim is a dimension of a ColorM.
 const ColorMDim = 5
 
+func uint64ToBytes(value uint64) []uint8 {
+	result := make([]uint8, 8)
+	if endian.IsLittle() {
+		for i := 0; i < 8; i++ {
+			result[i] = uint8(value)
+			value >>= 8
+		}
+	} else {
+		for i := 7; 0 <= i; i-- {
+			result[i] = uint8(value)
+			value >>= 8
+		}
+	}
+	return result
+}
+
+func colorMValueString(values [ColorMDim - 1][ColorMDim]float64) string {
+	b := make([]uint8, 0, (ColorMDim-1)*(ColorMDim)*8)
+	for i := 0; i < ColorMDim-1; i++ {
+		for j := 0; j < ColorMDim; j++ {
+			b = append(b, uint64ToBytes(math.Float64bits(values[i][j]))...)
+		}
+	}
+	return string(b)
+}
+
+var (
+	colorMIdentityValue = colorMValueString([ColorMDim - 1][ColorMDim]float64{
+		{1, 0, 0, 0, 0},
+		{0, 1, 0, 0, 0},
+		{0, 0, 1, 0, 0},
+		{0, 0, 0, 1, 0},
+	})
+)
+
 // A ColorM represents a matrix to transform coloring when rendering an image.
 //
 // A ColorM is applied to the source alpha color
@@ -30,48 +67,22 @@ const ColorMDim = 5
 //
 // The initial value is identity.
 type ColorM struct {
-	initialized bool
-	es          [(ColorMDim - 1) * (ColorMDim)]float64
+	// When values is empty, this matrix is identity.
+	values string
 }
 
 func (c *ColorM) dim() int {
 	return ColorMDim
 }
 
-func (c *ColorM) initialize() {
-	c.initialized = true
-	for i := 0; i < ColorMDim-1; i++ {
-		c.es[i*ColorMDim+i] = 1
-	}
-}
-
-// Element returns a value of a matrix at (i, j).
-func (c *ColorM) Element(i, j int) float64 {
-	if !c.initialized {
-		if i == j {
-			return 1
-		}
-		return 0
-	}
-	return c.es[i*ColorMDim+j]
-}
-
-// SetElement sets an element at (i, j).
-func (c *ColorM) SetElement(i, j int, element float64) {
-	if !c.initialized {
-		c.initialize()
-	}
-	c.es[i*ColorMDim+j] = element
-}
-
 func (c *ColorM) Equals(other *ColorM) bool {
-	if !c.initialized {
-		c.initialize()
+	if c.values == "" {
+		c.values = colorMIdentityValue
 	}
-	if !other.initialized {
-		other.initialize()
+	if other.values == "" {
+		other.values = colorMIdentityValue
 	}
-	return c.es == other.es
+	return c.values == other.values
 }
 
 // Concat multiplies a color matrix with the other color matrix.
@@ -119,22 +130,20 @@ var (
 	//   Cr: [-0.5 - 0.5]
 
 	rgbToYCbCr = ColorM{
-		initialized: true,
-		es: [...]float64{
-			0.2990, 0.5870, 0.1140, 0, 0,
-			-0.1687, -0.3313, 0.5000, 0, 0,
-			0.5000, -0.4187, -0.0813, 0, 0,
-			0, 0, 0, 1, 0,
-		},
+		values: colorMValueString([ColorMDim - 1][ColorMDim]float64{
+			{0.2990, 0.5870, 0.1140, 0, 0},
+			{-0.1687, -0.3313, 0.5000, 0, 0},
+			{0.5000, -0.4187, -0.0813, 0, 0},
+			{0, 0, 0, 1, 0},
+		}),
 	}
 	yCbCrToRgb = ColorM{
-		initialized: true,
-		es: [...]float64{
-			1, 0, 1.40200, 0, 0,
-			1, -0.34414, -0.71414, 0, 0,
-			1, 1.77200, 0, 0, 0,
-			0, 0, 0, 1, 0,
-		},
+		values: colorMValueString([ColorMDim - 1][ColorMDim]float64{
+			{1, 0, 1.40200, 0, 0},
+			{1, -0.34414, -0.71414, 0, 0},
+			{1, 1.77200, 0, 0, 0},
+			{0, 0, 0, 1, 0},
+		}),
 	}
 )
 
@@ -148,13 +157,12 @@ func (c *ColorM) ChangeHSV(hueTheta float64, saturationScale float64, valueScale
 	sin, cos := math.Sincos(hueTheta)
 	c.Concat(rgbToYCbCr)
 	c.Concat(ColorM{
-		initialized: true,
-		es: [...]float64{
-			1, 0, 0, 0, 0,
-			0, cos, -sin, 0, 0,
-			0, sin, cos, 0, 0,
-			0, 0, 0, 1, 0,
-		},
+		values: colorMValueString([ColorMDim - 1][ColorMDim]float64{
+			{1, 0, 0, 0, 0},
+			{0, cos, -sin, 0, 0},
+			{0, sin, cos, 0, 0},
+			{0, 0, 0, 1, 0},
+		}),
 	})
 	s := saturationScale
 	v := valueScale
@@ -176,26 +184,24 @@ func Monochrome() ColorM {
 // ScaleColor is deprecated as of 1.2.0-alpha. Use Scale instead.
 func ScaleColor(r, g, b, a float64) ColorM {
 	return ColorM{
-		initialized: true,
-		es: [...]float64{
-			r, 0, 0, 0, 0,
-			0, g, 0, 0, 0,
-			0, 0, b, 0, 0,
-			0, 0, 0, a, 0,
-		},
+		values: colorMValueString([ColorMDim - 1][ColorMDim]float64{
+			{r, 0, 0, 0, 0},
+			{0, g, 0, 0, 0},
+			{0, 0, b, 0, 0},
+			{0, 0, 0, a, 0},
+		}),
 	}
 }
 
 // TranslateColor is deprecated as of 1.2.0-alpha. Use Translate instead.
 func TranslateColor(r, g, b, a float64) ColorM {
 	return ColorM{
-		initialized: true,
-		es: [...]float64{
-			1, 0, 0, 0, r,
-			0, 1, 0, 0, g,
-			0, 0, 1, 0, b,
-			0, 0, 0, 1, a,
-		},
+		values: colorMValueString([ColorMDim - 1][ColorMDim]float64{
+			{1, 0, 0, 0, r},
+			{0, 1, 0, 0, g},
+			{0, 0, 1, 0, b},
+			{0, 0, 0, 1, a},
+		}),
 	}
 }
 

internal/affine/colorm_js.go

@@ -0,0 +1,46 @@
+// Copyright 2017 The Ebiten Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// +build js
+
+package affine
+
+import (
+	"github.com/gopherjs/gopherjs/js"
+)
+
+// Element returns a value of a matrix at (i, j).
+func (c *ColorM) Element(i, j int) float64 {
+	if c.values == "" {
+		if i == j {
+			return 1
+		}
+		return 0
+	}
+	a := js.NewArrayBuffer([]uint8(c.values))
+	af64 := js.Global.Get("Float64Array").New(a)
+	return af64.Index(i*ColorMDim + j).Float()
+}
+
+// SetElement sets an element at (i, j).
+func (c *ColorM) SetElement(i, j int, value float64) {
+	if c.values == "" {
+		c.values = colorMIdentityValue
+	}
+	a := js.NewArrayBuffer([]uint8(c.values))
+	a8 := js.Global.Get("Uint8Array").New(a)
+	af64 := js.Global.Get("Float64Array").New(a)
+	af64.SetIndex(i*ColorMDim+j, value)
+	c.values = string(a8.Interface().([]uint8))
+}

internal/affine/colorm_notjs.go

@@ -0,0 +1,57 @@
+// Copyright 2017 The Ebiten Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// +build !js
+
+package affine
+
+import (
+	"math"
+
+	"github.com/hajimehoshi/ebiten/internal/endian"
+)
+
+// Element returns a value of a matrix at (i, j).
+func (c *ColorM) Element(i, j int) float64 {
+	if c.values == "" {
+		if i == j {
+			return 1
+		}
+		return 0
+	}
+	offset := 8 * (i*ColorMDim + j)
+	v := uint64(0)
+	if endian.IsLittle() {
+		for k := 7; 0 <= k; k-- {
+			v <<= 8
+			v += uint64(c.values[offset+k])
+		}
+	} else {
+		for k := 0; k < 8; k++ {
+			v <<= 8
+			v += uint64(c.values[offset+k])
+		}
+	}
+	return math.Float64frombits(v)
+}
+
+// SetElement sets an element at (i, j).
+func (c *ColorM) SetElement(i, j int, value float64) {
+	if c.values == "" {
+		c.values = colorMIdentityValue
+	}
+	b := uint64ToBytes(math.Float64bits(value))
+	offset := 8 * (i*ColorMDim + j)
+	c.values = c.values[:offset] + string(b) + c.values[offset+8:]
+}