Handle tabs

glyphs/glyphs.go

@@ -14,7 +14,7 @@ import (
 )
 
 const floatsPerGlyph = 11
-const maxGlyphsPerBatch = 16384
+const MaxGlyphsPerBatch = 16384
 
 type GlyphRend struct {
 	Atlas    *FontAtlas
@@ -24,7 +24,7 @@ type GlyphRend struct {
 	InstancedBuf buffers.Buffer
 	GlyphMat     *materials.Material
 
-	GlyphCount int32
+	GlyphCount uint32
 	//NOTE: Because of the sad realities (bugs?) of CGO, passing an array in a struct
 	//to C explodes (Go pointer to Go pointer error) even though passing the same array
 	//allocated inside the function is fine (Go potentially can't detect what's happening properly).
@@ -35,6 +35,8 @@ type GlyphRend struct {
 
 	ScreenWidth  int32
 	ScreenHeight int32
+
+	SpacesPerTab uint
 }
 
 //DrawTextOpenGLAbs prepares text that will be drawn on the next GlyphRend.Draw call.
@@ -57,20 +59,25 @@ func (gr *GlyphRend) DrawTextOpenGLAbs(text string, screenPos *gglm.Vec3, color
 	pos := screenPos.Clone()
 	advanceF32 := float32(gr.Atlas.Advance)
 	lineHeightF32 := float32(gr.Atlas.LineHeight)
+	scale := gglm.NewVec2(advanceF32, lineHeightF32)
+
+	buffIndex := gr.GlyphCount * floatsPerGlyph
 	for i := 0; i < len(rs); i++ {
 
 		r := rs[i]
-		g := gr.Atlas.Glyphs[r]
 		if r == '\n' {
 			screenPos.SetY(screenPos.Y() - lineHeightF32)
 			pos = screenPos.Clone()
 			continue
 		} else if r == ' ' {
-			pos.SetX(pos.X() + advanceF32)
+			pos.AddX(advanceF32)
+			continue
+		} else if r == '\t' {
+			pos.AddX(advanceF32 * float32(gr.SpacesPerTab))
 			continue
 		}
 
-		scale := gglm.NewVec2(advanceF32, lineHeightF32)
+		g := gr.Atlas.Glyphs[r]
 
 		//See: https://developer.apple.com/library/archive/documentation/TextFonts/Conceptual/CocoaTextArchitecture/Art/glyph_metrics_2x.png
 		//The uvs coming in make it so that glyphs are sitting on top of the baseline (no descent) and with horizontal bearing applied.
@@ -80,33 +87,34 @@ func (gr *GlyphRend) DrawTextOpenGLAbs(text string, screenPos *gglm.Vec3, color
 		drawPos.SetY(drawPos.Y() - g.Descent)
 
 		//Add the glyph information to the vbo
-		startIndex := gr.GlyphCount * floatsPerGlyph
-
 		//UV
-		gr.GlyphVBO[startIndex+0] = g.U
+		gr.GlyphVBO[buffIndex+0] = g.U
-		gr.GlyphVBO[startIndex+1] = g.V
+		gr.GlyphVBO[buffIndex+1] = g.V
 
 		//Color
-		gr.GlyphVBO[startIndex+2] = color.R()
+		gr.GlyphVBO[buffIndex+2] = color.R()
-		gr.GlyphVBO[startIndex+3] = color.G()
+		gr.GlyphVBO[buffIndex+3] = color.G()
-		gr.GlyphVBO[startIndex+4] = color.B()
+		gr.GlyphVBO[buffIndex+4] = color.B()
-		gr.GlyphVBO[startIndex+5] = color.A()
+		gr.GlyphVBO[buffIndex+5] = color.A()
 
 		//Model Pos
-		gr.GlyphVBO[startIndex+6] = roundF32(drawPos.X())
+		gr.GlyphVBO[buffIndex+6] = roundF32(drawPos.X())
-		gr.GlyphVBO[startIndex+7] = roundF32(drawPos.Y())
+		gr.GlyphVBO[buffIndex+7] = roundF32(drawPos.Y())
-		gr.GlyphVBO[startIndex+8] = drawPos.Z()
+		gr.GlyphVBO[buffIndex+8] = drawPos.Z()
 
 		//Model Scale
-		gr.GlyphVBO[startIndex+9] = scale.X()
+		gr.GlyphVBO[buffIndex+9] = scale.X()
-		gr.GlyphVBO[startIndex+10] = scale.Y()
+		gr.GlyphVBO[buffIndex+10] = scale.Y()
 
 		gr.GlyphCount++
-		pos.SetX(pos.X() + advanceF32)
+		pos.AddX(advanceF32)
 
 		//If we fill the buffer we issue a draw call
-		if gr.GlyphCount == maxGlyphsPerBatch {
+		if gr.GlyphCount == MaxGlyphsPerBatch {
 			gr.Draw()
+			buffIndex = 0
+		} else {
+			buffIndex += floatsPerGlyph
 		}
 	}
 }
@@ -121,7 +129,7 @@ func (gr *GlyphRend) Draw() {
 	gr.InstancedBuf.Bind()
 	gr.GlyphMat.Bind()
 
-	gl.DrawElementsInstanced(gl.TRIANGLES, gr.GlyphMesh.Buf.IndexBufCount, gl.UNSIGNED_INT, gl.PtrOffset(0), gr.GlyphCount)
+	gl.DrawElementsInstanced(gl.TRIANGLES, gr.GlyphMesh.Buf.IndexBufCount, gl.UNSIGNED_INT, gl.PtrOffset(0), int32(gr.GlyphCount))
 	gr.GlyphCount = 0
 }
 
@@ -201,7 +209,8 @@ func NewGlyphRend(fontFile string, fontOptions *truetype.Options, screenWidth, s
 
 	gr := &GlyphRend{
 		GlyphCount:   0,
-		GlyphVBO:   make([]float32, floatsPerGlyph*maxGlyphsPerBatch),
+		GlyphVBO:     make([]float32, floatsPerGlyph*MaxGlyphsPerBatch),
+		SpacesPerTab: 4,
 	}
 
 	//Create glyph mesh

main.go

@@ -2,6 +2,7 @@ package main
 
 import (
 	"fmt"
+	"math"
 	"math/rand"
 
 	"github.com/bloeys/gglm/gglm"
@@ -10,6 +11,7 @@ import (
 	"github.com/bloeys/nmage/materials"
 	"github.com/bloeys/nmage/meshes"
 	"github.com/bloeys/nmage/renderer/rend3dgl"
+	"github.com/bloeys/nmage/timing"
 	nmageimgui "github.com/bloeys/nmage/ui/imgui"
 	"github.com/bloeys/nterm/glyphs"
 	"github.com/golang/freetype/truetype"
@@ -164,14 +166,13 @@ var b = rand.Float32()
 
 func (p *program) Render() {
 
-	const colorSpd = 0.005
-	// const charsPerFrame = 100_000
 	defer p.GlyphRend.Draw()
 
 	if p.shouldDrawGrid {
 		p.drawGrid()
 	}
 
+	const colorSpd = 0.005
 	r += colorSpd
 	if r > 1 {
 		r = 0
@@ -188,16 +189,16 @@ func (p *program) Render() {
 	}
 
 	textColor := gglm.NewVec4(r, g, b, 1)
-	str := " ijojo\n\n Hello there, friend|. pq?\n ABCDEFGHIJKLMNOPQRSTUVWXYZ"
+	str := " ijojo\n\n Hello there, friend|. pq?\n ABCDEFG\tHIJKLMNOPQRSTUVWXYZ"
 
-	p.GlyphRend.DrawTextOpenGLAbs(str, gglm.NewVec3(xOff, float32(p.GlyphRend.Atlas.LineHeight)*5+yOff, 0), textColor)
-
-	// strLen := len(str)
-	// for i := 0; i < charsPerFrame/strLen; i++ {
 	// p.GlyphRend.DrawTextOpenGLAbs(str, gglm.NewVec3(xOff, float32(p.GlyphRend.Atlas.LineHeight)*5+yOff, 0), textColor)
-	// }
 
-	// fmt.Println("FPS:", int(timing.GetAvgFPS()), "; Draws per frame:", charsPerFrame/16384)
+	strLen := len(str)
+	const charsPerFrame = 10_000
+	for i := 0; i < charsPerFrame/strLen; i++ {
+		p.GlyphRend.DrawTextOpenGLAbs(str, gglm.NewVec3(xOff, float32(p.GlyphRend.Atlas.LineHeight)*5+yOff, 0), textColor)
+	}
+	p.win.SDLWin.SetTitle(fmt.Sprint("FPS:", int(timing.GetAvgFPS()), "; Draws per frame:", math.Ceil(charsPerFrame/glyphs.MaxGlyphsPerBatch)))
 }
 
 func (p *program) drawGrid() {