From 9388bc0c9247513709c157cfccce456f6481f790 Mon Sep 17 00:00:00 2001
From: bloeys <bloeys@outlook.com>
Date: Fri, 8 Jul 2022 07:58:08 +0400
Subject: [PATCH] Advance by char width+better debug tools

---
 glyphs/font_atlas.go   |  4 +++-
 glyphs/glyphs.go       |  4 +---
 imgui.ini              |  2 +-
 main.go                | 28 ++++++++++++++++++++--------
 res/shaders/glyph.glsl | 11 ++++++-----
 5 files changed, 31 insertions(+), 18 deletions(-)

diff --git a/glyphs/font_atlas.go b/glyphs/font_atlas.go
index 5871840..bdfaad9 100755
--- a/glyphs/font_atlas.go
+++ b/glyphs/font_atlas.go
@@ -35,6 +35,7 @@ type FontAtlasGlyph struct {
 	Ascent   float32
 	Descent  float32
 	BearingX float32
+	Advance  float32
 }
 
 //NewFontAtlasFromFile reads a TTF or TTC file and produces a font texture atlas containing
@@ -149,7 +150,7 @@ func NewFontAtlasFromFont(f *truetype.Font, face font.Face, pointSize uint) (*Fo
 
 	for currGlyphCount, g := range glyphs {
 
-		gBounds, _, _ := face.GlyphBounds(g)
+		gBounds, gAdvance, _ := face.GlyphBounds(g)
 		bearingX := gBounds.Min.X
 		ascentAbsFixed := absFixedI26_6(gBounds.Min.Y)
 		descentAbsFixed := absFixedI26_6(gBounds.Max.Y)
@@ -174,6 +175,7 @@ func NewFontAtlasFromFont(f *truetype.Font, face font.Face, pointSize uint) (*Fo
 			Ascent:   float32(ascentAbsFixed.Ceil()),
 			Descent:  float32(descentAbsFixed.Ceil()),
 			BearingX: float32(bearingX.Ceil()),
+			Advance:  float32(gAdvance.Ceil()),
 		}
 
 		imgRect, mask, maskp, _, _ := face.Glyph(drawer.Dot, g)
diff --git a/glyphs/glyphs.go b/glyphs/glyphs.go
index 98b3d1c..87a78e0 100755
--- a/glyphs/glyphs.go
+++ b/glyphs/glyphs.go
@@ -178,15 +178,13 @@ func (gr *GlyphRend) drawRune(rs []rune, i int, prevRune rune, screenPos, pos *g
 	*bufIndex += 2
 
 	gr.GlyphCount++
-	pos.AddX(advanceF32)
+	pos.AddX(g.Advance)
 
 	//If we fill the buffer we issue a draw call
 	if gr.GlyphCount == MaxGlyphsPerBatch {
 		gr.Draw()
 		*bufIndex = 0
 	}
-
-	// prevRune = r
 }
 
 func (gr *GlyphRend) GetTextRuns(t string) [][]rune {
diff --git a/imgui.ini b/imgui.ini
index 02e2318..fb172a6 100755
--- a/imgui.ini
+++ b/imgui.ini
@@ -1,5 +1,5 @@
 [Window][Debug##Default]
 Pos=814,53
-Size=405,63
+Size=396,114
 Collapsed=0
 
diff --git a/main.go b/main.go
index be69335..99340e9 100755
--- a/main.go
+++ b/main.go
@@ -106,13 +106,6 @@ func (p *program) Init() {
 
 	p.gridMat = materials.NewMaterial("grid", "./res/shaders/grid.glsl")
 	p.handleWindowResize()
-
-	// runs := p.GlyphRend.GetTextRuns("hello there يا friend. أسمي عمر wow")
-	// runs := p.GlyphRend.GetTextRuns("hello there my friend!")
-	// fmt.Printf("%+v\n", runs)
-	// for _, r := range runs {
-	// 	fmt.Printf("%s;\n", string(r))
-	// }
 }
 
 func (p *program) Update() {
@@ -167,10 +160,29 @@ func (p *program) Update() {
 		p.shouldDrawGrid = !p.shouldDrawGrid
 	}
 
+	//UI
 	imgui.InputText("", &textToShow)
+
+	if imgui.Button("Print Runs") {
+		runs := p.GlyphRend.GetTextRuns(textToShow)
+		for _, r := range runs {
+			fmt.Printf("%s; runes: %#x\n\n", string(r), r)
+		}
+		fmt.Printf("----------------\n")
+	}
+
+	if imgui.Checkbox("Draw Bounds", &isDrawingBounds) {
+
+		if isDrawingBounds {
+			p.GlyphRend.GlyphMat.SetUnifInt32("drawBounds", 1)
+		} else {
+			p.GlyphRend.GlyphMat.SetUnifInt32("drawBounds", 0)
+		}
+	}
 }
 
-var textToShow = " Hello there يا friend. أسمي عمر wow!"
+var isDrawingBounds = false
+var textToShow = " Hello there يا friend. اسمي عمر wow!"
 
 var xOff float32 = 0
 var yOff float32 = 0
diff --git a/res/shaders/glyph.glsl b/res/shaders/glyph.glsl
index b44d33a..cb050c0 100755
--- a/res/shaders/glyph.glsl
+++ b/res/shaders/glyph.glsl
@@ -42,16 +42,17 @@ in vec4 v2fColor;
 out vec4 fragColor;
 
 uniform sampler2D diffTex;
+uniform int drawBounds;
 
 void main()
 {
     vec4 texColor = texelFetch(diffTex, ivec2(v2fUV0), 0);
     // This commented out part highlights the full region of the char
-    // if (texColor.r == 0)
-    // {
-    //     fragColor = vec4(0,1,0,0.25);
-    // }
-    // else
+    if (texColor.r == 0 && drawBounds != 0)
+    {
+        fragColor = vec4(0,1,0,0.25);
+    }
+    else
     {
         fragColor = vec4(v2fColor.rgb, texColor.r*v2fColor.a);
     }