From 2eea1afcd1ef9b386fe9893456fe9b67999183e7 Mon Sep 17 00:00:00 2001
From: Hajime Hoshi <hajimehoshi@gmail.com>
Date: Sat, 3 Jan 2015 18:35:44 +0900
Subject: [PATCH] Optimize ColorM and GeoM

---
 colorm.go                     | 20 ++++++++++++++++++++
 example/blocks/blocks/font.go | 28 +++++++++++++++-------------
 geom.go                       | 16 ++++++++++++++++
 3 files changed, 51 insertions(+), 13 deletions(-)

diff --git a/colorm.go b/colorm.go
index f76ba5946..a2bfd6ccd 100644
--- a/colorm.go
+++ b/colorm.go
@@ -79,6 +79,26 @@ func (c *ColorM) Add(other ColorM) {
 	*c = result
 }
 
+func (c *ColorM) Scale(r, g, b, a float64) {
+	if !c.initialized {
+		*c = colorMI
+	}
+	c.es[0][0] *= r
+	c.es[1][1] *= g
+	c.es[2][2] *= b
+	c.es[3][3] *= a
+}
+
+func (c *ColorM) Translate(r, g, b, a float64) {
+	if !c.initialized {
+		*c = colorMI
+	}
+	c.es[0][4] += r
+	c.es[1][4] += g
+	c.es[2][4] += b
+	c.es[3][4] += a
+}
+
 // SetElement sets an element at (i, j).
 func (c *ColorM) SetElement(i, j int, element float64) {
 	if !c.initialized {
diff --git a/example/blocks/blocks/font.go b/example/blocks/blocks/font.go
index 2095bb4bb..531b6acdb 100644
--- a/example/blocks/blocks/font.go
+++ b/example/blocks/blocks/font.go
@@ -20,6 +20,7 @@ import (
 	"image"
 	"image/color"
 	"math"
+	"strings"
 )
 
 var imageFont *ebiten.Image
@@ -41,9 +42,10 @@ func textWidth(str string) int {
 }
 
 func drawText(rt *ebiten.Image, str string, ox, oy, scale int, c color.Color) error {
-	parts := make([]ebiten.ImagePart, 0, len(str))
+	parts := make([]ebiten.ImagePart, len(strings.Replace(str, "\n", "", -1)))
 
 	locationX, locationY := 0, 0
+	i := 0
 	for _, c := range str {
 		if c == '\n' {
 			locationX = 0
@@ -53,27 +55,27 @@ func drawText(rt *ebiten.Image, str string, ox, oy, scale int, c color.Color) er
 		code := int(c)
 		x := (code % 16) * charWidth
 		y := ((code - 32) / 16) * charHeight
-		parts = append(parts, ebiten.ImagePart{
-			Dst: image.Rect(locationX, locationY, locationX+charWidth, locationY+charHeight),
-			Src: image.Rect(x, y, x+charWidth, y+charHeight),
-		})
+		parts[i].Dst = image.Rect(locationX, locationY, locationX+charWidth, locationY+charHeight)
+		parts[i].Src = image.Rect(x, y, x+charWidth, y+charHeight)
+		i++
 		locationX += charWidth
 	}
 
-	geo := ebiten.ScaleGeo(float64(scale), float64(scale))
-	geo.Concat(ebiten.TranslateGeo(float64(ox), float64(oy)))
+	options := &ebiten.DrawImageOptions{
+		Parts: parts,
+	}
+	options.GeoM.Scale(float64(scale), float64(scale))
+	options.GeoM.Translate(float64(ox), float64(oy))
+
 	c2 := color.NRGBA64Model.Convert(c).(color.NRGBA64)
 	const max = math.MaxUint16
 	r := float64(c2.R) / max
 	g := float64(c2.G) / max
 	b := float64(c2.B) / max
 	a := float64(c2.A) / max
-	clr := ebiten.ScaleColor(r, g, b, a)
-	return rt.DrawImage(imageFont, &ebiten.DrawImageOptions{
-		Parts:  parts,
-		GeoM:   geo,
-		ColorM: clr,
-	})
+	options.ColorM.Scale(r, g, b, a)
+
+	return rt.DrawImage(imageFont, options)
 }
 
 func drawTextWithShadow(rt *ebiten.Image, str string, x, y, scale int, clr color.Color) error {
diff --git a/geom.go b/geom.go
index f97fa3415..2ec8d2294 100644
--- a/geom.go
+++ b/geom.go
@@ -72,6 +72,22 @@ func (g *GeoM) Add(other GeoM) {
 	*g = result
 }
 
+func (g *GeoM) Scale(x, y float64) {
+	if !g.initialized {
+		*g = geoMI
+	}
+	g.es[0][0] *= x
+	g.es[1][1] *= y
+}
+
+func (g *GeoM) Translate(tx, ty float64) {
+	if !g.initialized {
+		*g = geoMI
+	}
+	g.es[0][2] += tx
+	g.es[1][2] += ty
+}
+
 // SetElement sets an element at (i, j).
 func (g *GeoM) SetElement(i, j int, element float64) {
 	if !g.initialized {