affine: Revert ColorM implementation to use float64 array

internal/affine/colorm.go

@@ -16,48 +16,11 @@ 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
@@ -67,22 +30,48 @@ var (
 //
 // The initial value is identity.
 type ColorM struct {
-	// when values is empty, this matrix is identity.
+	initialized bool
-	values string
+	es          [(ColorMDim - 1) * (ColorMDim)]float64
 }
 
 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.values == "" {
+	if !c.initialized {
-		c.values = colorMIdentityValue
+		c.initialize()
 	}
-	if other.values == "" {
+	if !other.initialized {
-		other.values = colorMIdentityValue
+		other.initialize()
 	}
-	return c.values == other.values
+	return c.es == other.es
 }
 
 // Concat multiplies a color matrix with the other color matrix.
@@ -130,20 +119,22 @@ var (
 	//   Cr: [-0.5 - 0.5]
 
 	rgbToYCbCr = ColorM{
-		values: colorMValueString([ColorMDim - 1][ColorMDim]float64{
+		initialized: true,
-			{0.2990, 0.5870, 0.1140, 0, 0},
+		es: [...]float64{
-			{-0.1687, -0.3313, 0.5000, 0, 0},
+			0.2990, 0.5870, 0.1140, 0, 0,
-			{0.5000, -0.4187, -0.0813, 0, 0},
+			-0.1687, -0.3313, 0.5000, 0, 0,
-			{0, 0, 0, 1, 0},
+			0.5000, -0.4187, -0.0813, 0, 0,
-		}),
+			0, 0, 0, 1, 0,
+		},
 	}
 	yCbCrToRgb = ColorM{
-		values: colorMValueString([ColorMDim - 1][ColorMDim]float64{
+		initialized: true,
-			{1, 0, 1.40200, 0, 0},
+		es: [...]float64{
-			{1, -0.34414, -0.71414, 0, 0},
+			1, 0, 1.40200, 0, 0,
-			{1, 1.77200, 0, 0, 0},
+			1, -0.34414, -0.71414, 0, 0,
-			{0, 0, 0, 1, 0},
+			1, 1.77200, 0, 0, 0,
-		}),
+			0, 0, 0, 1, 0,
+		},
 	}
 )
 
@@ -157,12 +148,13 @@ func (c *ColorM) ChangeHSV(hueTheta float64, saturationScale float64, valueScale
 	sin, cos := math.Sincos(hueTheta)
 	c.Concat(rgbToYCbCr)
 	c.Concat(ColorM{
-		values: colorMValueString([ColorMDim - 1][ColorMDim]float64{
+		initialized: true,
-			{1, 0, 0, 0, 0},
+		es: [...]float64{
-			{0, cos, -sin, 0, 0},
+			1, 0, 0, 0, 0,
-			{0, sin, cos, 0, 0},
+			0, cos, -sin, 0, 0,
-			{0, 0, 0, 1, 0},
+			0, sin, cos, 0, 0,
-		}),
+			0, 0, 0, 1, 0,
+		},
 	})
 	s := saturationScale
 	v := valueScale
@@ -184,24 +176,26 @@ 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{
-		values: colorMValueString([ColorMDim - 1][ColorMDim]float64{
+		initialized: true,
-			{r, 0, 0, 0, 0},
+		es: [...]float64{
-			{0, g, 0, 0, 0},
+			r, 0, 0, 0, 0,
-			{0, 0, b, 0, 0},
+			0, g, 0, 0, 0,
-			{0, 0, 0, a, 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{
-		values: colorMValueString([ColorMDim - 1][ColorMDim]float64{
+		initialized: true,
-			{1, 0, 0, 0, r},
+		es: [...]float64{
-			{0, 1, 0, 0, g},
+			1, 0, 0, 0, r,
-			{0, 0, 1, 0, b},
+			0, 1, 0, 0, g,
-			{0, 0, 0, 1, a},
+			0, 0, 1, 0, b,
-		}),
+			0, 0, 0, 1, a,
+		},
 	}
 }
 

internal/affine/colorm_js.go

@@ -1,46 +0,0 @@
-// Copyright 2016 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_nojs.go

@@ -1,57 +0,0 @@
-// Copyright 2016 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:]
-}