From 38dafbfd653ff1618115ab4d1350013cb2fc309a Mon Sep 17 00:00:00 2001
From: bloeys <bloeys@outlook.com>
Date: Mon, 11 Jul 2022 11:29:12 +0400
Subject: [PATCH] Fast path shaping non-joining chars

---
 glyphs/glyphs.go | 20 +++++---------------
 main.go          |  6 +++---
 2 files changed, 8 insertions(+), 18 deletions(-)

diff --git a/glyphs/glyphs.go b/glyphs/glyphs.go
index 3b575c1..2d81930 100755
--- a/glyphs/glyphs.go
+++ b/glyphs/glyphs.go
@@ -270,6 +270,7 @@ func (gr *GlyphRend) GetTextRuns(t string, textRunsBuf *[]TextRun) {
 	}
 }
 
+//GlyphFromRunes does shaping where it selects the proper rune based (e.g. end Alef) on the surrounding runes
 func GlyphFromRunes(glyphTable map[rune]FontAtlasGlyph, curr, prev, next rune) FontAtlasGlyph {
 
 	//PERF: Map access times are absolute garbage to the point that ~85%+ of the runtime of this func
@@ -287,11 +288,13 @@ func GlyphFromRunes(glyphTable map[rune]FontAtlasGlyph, curr, prev, next rune) F
 
 	//Isolated case
 	if !prevIsValid && !nextIsValid {
-		g := glyphTable[curr]
-		return g
+		return glyphTable[curr]
 	}
 
 	ri := RuneInfos[curr]
+	if ri.JoinType == JoiningType_None || ri.JoinType == JoiningType_Transparent {
+		return glyphTable[curr]
+	}
 
 	prevJoinType := RuneInfos[prev].JoinType
 	joinWithRight := prevIsValid &&
@@ -351,19 +354,6 @@ func GlyphFromRunes(glyphTable map[rune]FontAtlasGlyph, curr, prev, next rune) F
 				break
 			}
 		}
-
-	case PosCtx_isolated:
-
-		// equivRunes := RuneInfos[curr].EquivalentRunes
-		// for i := 0; i < len(equivRunes); i++ {
-
-		// 	otherRune := equivRunes[i]
-		// 	otherRuneInfo := RuneInfos[otherRune]
-		// 	if otherRuneInfo.DecompTag == DecompTag_isolated {
-		// 		curr = otherRune
-		// 		break
-		// 	}
-		// }
 	}
 
 	return glyphTable[curr]
diff --git a/main.go b/main.go
index d1883a6..409b453 100755
--- a/main.go
+++ b/main.go
@@ -95,8 +95,8 @@ func (p *program) Init() {
 	fmt.Printf("DPI: %f, font size: %d\n", dpi, p.FontSize)
 
 	w, h := p.win.SDLWin.GetSize()
-	p.GlyphRend, err = glyphs.NewGlyphRend("./res/fonts/tajawal-regular-var.ttf", &truetype.Options{Size: float64(p.FontSize), DPI: p.Dpi, SubPixelsX: subPixelX, SubPixelsY: subPixelY, Hinting: hinting}, w, h)
-	// p.GlyphRend, err = glyphs.NewGlyphRend("./res/fonts/alm-fixed.ttf", &truetype.Options{Size: float64(p.FontSize), DPI: p.Dpi, SubPixelsX: subPixelX, SubPixelsY: subPixelY, Hinting: hinting}, w, h)
+	// p.GlyphRend, err = glyphs.NewGlyphRend("./res/fonts/tajawal-regular-var.ttf", &truetype.Options{Size: float64(p.FontSize), DPI: p.Dpi, SubPixelsX: subPixelX, SubPixelsY: subPixelY, Hinting: hinting}, w, h)
+	p.GlyphRend, err = glyphs.NewGlyphRend("./res/fonts/alm-fixed.ttf", &truetype.Options{Size: float64(p.FontSize), DPI: p.Dpi, SubPixelsX: subPixelX, SubPixelsY: subPixelY, Hinting: hinting}, w, h)
 	if err != nil {
 		panic("Failed to create atlas from font file. Err: " + err.Error())
 	}
@@ -194,7 +194,7 @@ func (p *program) Update() {
 
 var isDrawingBounds = false
 var drawManyLines = false
-var textToShow = "Hello there يا friend. اسميعمر wow!"
+var textToShow = "Hello there, friend!"
 
 var xOff float32 = 0
 var yOff float32 = 0