From 87c86256928ce8f6964f10d49eb161d27c5534c4 Mon Sep 17 00:00:00 2001
From: Hajime Hoshi <hajimehoshi@gmail.com>
Date: Thu, 28 Jan 2021 03:28:29 +0900
Subject: [PATCH] Remove internal/colormcache

---
 ebitenutil/shapes.go          | 17 ++++---
 internal/colormcache/cache.go | 96 -----------------------------------
 2 files changed, 10 insertions(+), 103 deletions(-)
 delete mode 100644 internal/colormcache/cache.go

diff --git a/ebitenutil/shapes.go b/ebitenutil/shapes.go
index a0284dab3..6a249f30d 100644
--- a/ebitenutil/shapes.go
+++ b/ebitenutil/shapes.go
@@ -20,7 +20,6 @@ import (
 	"math"
 
 	"github.com/hajimehoshi/ebiten/v2"
-	"github.com/hajimehoshi/ebiten/v2/internal/colormcache"
 )
 
 var (
@@ -32,11 +31,17 @@ func init() {
 	emptyImage.Fill(color.White)
 }
 
+func colorToScale(clr color.Color) (float64, float64, float64, float64) {
+	cr, cg, cb, ca := clr.RGBA()
+	if ca == 0 {
+		return 0, 0, 0, 0
+	}
+	return float64(cr) / float64(ca), float64(cg) / float64(ca), float64(cb) / float64(ca), float64(ca) / 0xffff
+}
+
 // DrawLine draws a line segment on the given destination dst.
 //
 // DrawLine is intended to be used mainly for debugging or prototyping purpose.
-//
-// DrawLine is not concurrent-safe.
 func DrawLine(dst *ebiten.Image, x1, y1, x2, y2 float64, clr color.Color) {
 	length := math.Hypot(x2-x1, y2-y1)
 
@@ -44,7 +49,7 @@ func DrawLine(dst *ebiten.Image, x1, y1, x2, y2 float64, clr color.Color) {
 	op.GeoM.Scale(length, 1)
 	op.GeoM.Rotate(math.Atan2(y2-y1, x2-x1))
 	op.GeoM.Translate(x1, y1)
-	op.ColorM = colormcache.ColorToColorM(clr)
+	op.ColorM.Scale(colorToScale(clr))
 	// Filter must be 'nearest' filter (default).
 	// Linear filtering would make edges blurred.
 	dst.DrawImage(emptySubImage, op)
@@ -53,13 +58,11 @@ func DrawLine(dst *ebiten.Image, x1, y1, x2, y2 float64, clr color.Color) {
 // DrawRect draws a rectangle on the given destination dst.
 //
 // DrawRect is intended to be used mainly for debugging or prototyping purpose.
-//
-// DrawRect is not concurrent-safe.
 func DrawRect(dst *ebiten.Image, x, y, width, height float64, clr color.Color) {
 	op := &ebiten.DrawImageOptions{}
 	op.GeoM.Scale(width, height)
 	op.GeoM.Translate(x, y)
-	op.ColorM = colormcache.ColorToColorM(clr)
+	op.ColorM.Scale(colorToScale(clr))
 	// Filter must be 'nearest' filter (default).
 	// Linear filtering would make edges blurred.
 	dst.DrawImage(emptyImage.SubImage(image.Rect(1, 1, 2, 2)).(*ebiten.Image), op)
diff --git a/internal/colormcache/cache.go b/internal/colormcache/cache.go
deleted file mode 100644
index 6cc5d7862..000000000
--- a/internal/colormcache/cache.go
+++ /dev/null
@@ -1,96 +0,0 @@
-// Copyright 2020 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.
-
-package colormcache
-
-import (
-	"image/color"
-	"math"
-
-	"github.com/hajimehoshi/ebiten/v2"
-)
-
-var (
-	monotonicClock int64
-)
-
-func now() int64 {
-	monotonicClock++
-	return monotonicClock
-}
-
-const (
-	cacheLimit = 512 // This is an arbitrary number.
-)
-
-type colorMCacheKey uint32
-
-type colorMCacheEntry struct {
-	m     ebiten.ColorM
-	atime int64
-}
-
-var (
-	colorMCache = map[colorMCacheKey]*colorMCacheEntry{}
-	emptyColorM ebiten.ColorM
-)
-
-func init() {
-	emptyColorM.Scale(0, 0, 0, 0)
-}
-
-func ColorToColorM(clr color.Color) ebiten.ColorM {
-	// RGBA() is in [0 - 0xffff]. Adjust them in [0 - 0xff].
-	cr, cg, cb, ca := clr.RGBA()
-	cr /= 0x101
-	cg /= 0x101
-	cb /= 0x101
-	ca /= 0x101
-	if ca == 0 {
-		return emptyColorM
-	}
-
-	key := colorMCacheKey(uint32(cr) | (uint32(cg) << 8) | (uint32(cb) << 16) | (uint32(ca) << 24))
-	e, ok := colorMCache[key]
-	if ok {
-		e.atime = now()
-		return e.m
-	}
-
-	if len(colorMCache) > cacheLimit {
-		oldest := int64(math.MaxInt64)
-		oldestKey := colorMCacheKey(0)
-		for key, c := range colorMCache {
-			if c.atime < oldest {
-				oldestKey = key
-				oldest = c.atime
-			}
-		}
-		delete(colorMCache, oldestKey)
-	}
-
-	cm := ebiten.ColorM{}
-	rf := float64(cr) / float64(ca)
-	gf := float64(cg) / float64(ca)
-	bf := float64(cb) / float64(ca)
-	af := float64(ca) / 0xff
-	cm.Scale(rf, gf, bf, af)
-	e = &colorMCacheEntry{
-		m:     cm,
-		atime: now(),
-	}
-	colorMCache[key] = e
-
-	return e.m
-}